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Biogas

From Wikipedia, in a visual modern way
Pipes carrying biogas (foreground) and condensate
Pipes carrying biogas (foreground) and condensate

Biogas is a mixture of gases, primarily consisting of methane, carbon dioxide and hydrogen sulphide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. It is a renewable energy source.[1]

Biogas is produced by anaerobic digestion with anaerobic organisms or methanogen inside an anaerobic digester, biodigester or a bioreactor.[2]

Biogas is primarily methane (CH
4
) and carbon dioxide (CO
2
) and may have small amounts of hydrogen sulfide (H
2
S
), moisture and siloxanes. The gases methane, hydrogen, and carbon monoxide (CO) can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.[3]

Biogas can be compressed after removal of carbon dioxide and hydrogen sulphide, the same way as natural gas is compressed to CNG, and used to power motor vehicles. In the United Kingdom, for example, biogas is estimated to have the potential to replace around 17% of vehicle fuel.[4] It qualifies for renewable energy subsidies in some parts of the world. Biogas can be cleaned and upgraded to natural gas standards, when it becomes bio-methane. Biogas is considered to be a renewable resource because its production-and-use cycle is continuous, and it generates no net carbon dioxide. As the organic material grows, it is converted and used. It then regrows in a continually repeating cycle. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy.

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Gas

Gas

Gas is one of the four fundamental states of matter. The others are solid, liquid, and plasma.

Carbon dioxide

Carbon dioxide

Carbon dioxide (chemical formula CO2) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (HCO−3), which causes ocean acidification as atmospheric CO2 levels increase.

Agricultural waste

Agricultural waste

Agricultural waste are plant residues from agriculture. These waste streams originate from arable land and horticulture. Agricultural waste are all parts of crops that are not used for human or animal food. Crop residues consist mainly of stems and leaves. It is estimated that, on average, 80% of the plant of such crops consists of agricultural waste.

Green waste

Green waste

Green waste, also known as "biological waste", is any organic waste that can be composted. It is most usually composed of refuse from gardens such as grass clippings or leaves, and domestic or industrial kitchen wastes. Green waste does not include things such as dried leaves, pine straw, or hay. Such materials are rich in carbon and considered "brown wastes," while green wastes contain high in concentrations of nitrogen. Green waste can be used to increase the efficiency of many composting operations and can be added to soil to sustain local nutrient cycling.

Anaerobic digestion

Anaerobic digestion

Anaerobic digestion is a sequence of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.

Anaerobic organism

Anaerobic organism

An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. Deep waters of the ocean are a common anoxic environment.

Bioreactor

Bioreactor

A bioreactor refers to any manufactured device or system that supports a biologically active environment. In one case, a bioreactor is a vessel in which a chemical process is carried out which involves organisms or biochemically active substances derived from such organisms. This process can either be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a device or system designed to grow cells or tissues in the context of cell culture. These devices are being developed for use in tissue engineering or biochemical/bioprocess engineering.

Carbon monoxide

Carbon monoxide

Carbon monoxide is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest carbon oxide. In coordination complexes the carbon monoxide ligand is called carbonyl. It is a key ingredient in many processes in industrial chemistry.

Fuel

Fuel

A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy.

Fuel cell

Fuel cell

A fuel cell is an electrochemical cell that converts the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requiring a continuous source of fuel and oxygen to sustain the chemical reaction, whereas in a battery the chemical energy usually comes from substances that are already present in the battery. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied.

Compressed natural gas

Compressed natural gas

Compressed natural gas (CNG) is a fuel gas mainly composed of methane (CH4), compressed to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 megapascals (2,900–3,600 psi), usually in cylindrical or spherical shapes.

Alternative fuel vehicle

Alternative fuel vehicle

An alternative fuel vehicle is a motor vehicle that runs on alternative fuel rather than traditional petroleum fuels. The term also refers to any technology powering an engine that does not solely involve petroleum. Because of a combination of factors, such as environmental concerns, high oil-prices and the potential for peak oil, development of cleaner alternative fuels and advanced power systems for vehicles has become a high priority for many governments and vehicle manufacturers around the world.

Production

Biogas is produced by microorganisms, such as methanogens and sulfate-reducing bacteria, performing anaerobic respiration. Biogas can refer to gas produced naturally and industrially.

Natural

In soil, methane is produced in anaerobic environments by methanogens, but is mostly consumed in aerobic zones by methanotrophs. Methane emissions result when the balance favors methanogens. Wetland soils are the main natural source of methane. Other sources include oceans, forest soils, termites, and wild ruminants.[5]

Industrial

The purpose of industrial biogas production is the collection of biomethane, usually for fuel. Industrial biogas is produced either;

Biogas production in rural Germany
Biogas production in rural Germany

Bio-gas Plants

A biogas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops. It can be produced using anaerobic digesters (air-tight tanks with different configurations). These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During the process, the micro-organisms transform biomass waste into biogas (mainly methane and carbon dioxide) and digestate. Higher quantities of biogas can be produced when the wastewater is co-digested with other residuals from the dairy industry, sugar industry, or brewery industry. For example, while mixing 90% of wastewater from beer factory with 10% cow whey, the production of biogas was increased by 2.5 times compared to the biogas produced by wastewater from the brewery only.[6]

Manufacturing of biogas from intentionally planted maize has been described as being unsustainable and harmful due to very concentrated, intense and soil eroding character of these plantations.[7]

Key processes

There are two key processes: mesophilic and thermophilic digestion which is dependent on temperature. In experimental work at University of Alaska Fairbanks, a 1000-litre digester using psychrophiles harvested from "mud from a frozen lake in Alaska" has produced 200–300 liters of methane per day, about 20–30% of the output from digesters in warmer climates.[8]

Dangers

The air pollution produced by biogas is similar to that of natural gas as when methane (a major constituent of biogas) is ignited for its usage as an energy source, Carbon dioxide is made as a product which is a greenhouse gas ( as described by this equation: CH4 + 2O2CO2 + 2H2O ). The content of toxic hydrogen sulfide presents additional risks and has been responsible for serious accidents.[9] Leaks of unburned methane are an additional risk, because methane is a potent greenhouse gas. A facility may leak 2% of the methane.[10][11]

Biogas can be explosive when mixed in the ratio of one part biogas to 8–20 parts air. Special safety precautions have to be taken for entering an empty biogas digester for maintenance work. It is important that a biogas system never has negative pressure as this could cause an explosion. Negative gas pressure can occur if too much gas is removed or leaked; Because of this biogas should not be used at pressures below one column inch of water, measured by a pressure gauge.

Frequent smell checks must be performed on a biogas system. If biogas is smelled anywhere windows and doors should be opened immediately. If there is a fire the gas should be shut off at the gate valve of the biogas system.[12]

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Marsh gas

Marsh gas

Marsh gas, also known as swamp gas or bog gas, is a mixture primarily of methane and smaller amounts of hydrogen sulfide, carbon dioxide, and trace phosphine that is produced naturally within some geographical marshes, swamps, and bogs.

Methanotroph

Methanotroph

Methanotrophs are prokaryotes that metabolize methane as their source of carbon and to unlock the energy of oxygen, nitrate, sulfate, or other oxidized species. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to survive.

Methane emissions

Methane emissions

Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.

Anaerobic digestion

Anaerobic digestion

Anaerobic digestion is a sequence of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.

Landfill gas

Landfill gas

Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.

Biodegradable waste

Biodegradable waste

Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. It mainly includes kitchen waste, ash, soil, dung and other plant matter. In waste management, it also includes some inorganic materials which can be decomposed by bacteria. Such materials include gypsum and its products such as plasterboard and other simple sulfates which can be decomposed by sulfate reducing bacteria to yield hydrogen sulfide in anaerobic land-fill conditions.

Silage

Silage

Silage is a type of fodder made from green foliage crops which have been preserved by fermentation to the point of acidification. It can be fed to cattle, sheep and other such ruminants. The fermentation and storage process is called ensilage, ensiling or silaging. Silage is usually made from grass crops, including maize, sorghum or other cereals, using the entire green plant. Silage can be made from many field crops, and special terms may be used depending on type: oatlage for oats, haylage for alfalfa.

Digestate

Digestate

Digestate is the material remaining after the anaerobic digestion of a biodegradable feedstock. Anaerobic digestion produces two main products: digestate and biogas. Digestate is produced both by acidogenesis and methanogenesis and each has different characteristics. These characteristics stem from the original feedstock source as well as the processes themselves.

University of Alaska Fairbanks

University of Alaska Fairbanks

The University of Alaska Fairbanks is a public land-grant research university in College, Alaska, a suburb of Fairbanks. It is the flagship campus of the University of Alaska system. UAF was established in 1917 and opened for classes in 1922. Originally named the Alaska Agricultural College and School of Mines, it became the University of Alaska in 1935. Fairbanks-based programs became the University of Alaska Fairbanks in 1975.

Air pollution

Air pollution

Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. It is also the contamination of indoor or outdoor surrounding either by chemical activities, physical or biological agents that alters the natural features of the atmosphere. There are many different types of air pollutants, such as gases, particulates, and biological molecules. Air pollution can cause diseases, allergies, and even death to humans; it can also cause harm to other living organisms such as animals and food crops, and may damage the natural environment or built environment. Air pollution can be caused by both human activities and natural phenomena.

Natural gas

Natural gas

Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Natural gas is colorless and odorless, so odorizers such as mercaptan are commonly added to natural gas supplies for safety so that leaks can be readily detected.

Methane

Methane

Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure.

Landfill gas

Landfill gas is produced by wet organic waste decomposing under anaerobic conditions in a similar way to biogas.[13][14]

The waste is covered and mechanically compressed by the weight of the material that is deposited above. This material prevents oxygen exposure thus allowing anaerobic microbes to thrive. Biogas builds up and is slowly released into the atmosphere if the site has not been engineered to capture the gas. Landfill gas released in an uncontrolled way can be hazardous since it can become explosive when it escapes from the landfill and mixes with oxygen. The lower explosive limit is 5% methane and the upper is 15% methane.[15]

The methane in biogas is 28[16] times more potent a greenhouse gas than carbon dioxide. Therefore, uncontained landfill gas, which escapes into the atmosphere may significantly contribute to the effects of global warming. In addition, volatile organic compounds (VOCs) in landfill gas contribute to the formation of photochemical smog.

Technical

Biochemical oxygen demand (BOD) is a measure of the amount of oxygen required by aerobic micro-organisms to decompose the organic matter in a sample of material being used in the biodigester as well as the BOD for the liquid discharge allows for the calculation of the daily energy output from a biodigester.

Another term related to biodigesters is effluent dirtiness, which tells how much organic material there is per unit of biogas source. Typical units for this measure are in mg BOD/litre. As an example, effluent dirtiness can range between 800 and 1200 mg BOD/litre in Panama.

From 1 kg of decommissioned kitchen bio-waste, 0.45 m3 of biogas can be obtained. The price for collecting biological waste from households is approximately €70 per ton.[17]

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Composition

Typical composition of biogas
Compound Formula Percentage by volume
Methane CH
4
50–80
Carbon dioxide CO
2
15–50
Nitrogen N
2
0–10
Hydrogen H
2
0–1
Hydrogen sulfide H
2
S
0–0.5
Oxygen O
2
0–2.5
Source: www.kolumbus.fi, 2007[18]

The composition of biogas varies depending upon the substrate composition, as well as the conditions within the anaerobic reactor (temperature, pH, and substrate concentration).[19] Landfill gas typically has methane concentrations around 50%. Advanced waste treatment technologies can produce biogas with 55–75% methane,[20] which for reactors with free liquids can be increased to 80–90% methane using in-situ gas purification techniques.[21] As produced, biogas contains water vapor. The fractional volume of water vapor is a function of biogas temperature; correction of measured gas volume for water vapour content and thermal expansion is easily done via simple mathematics[22] which yields the standardized volume of dry biogas.

For 1000 kg (wet weight) of input to a typical biodigester, total solids may be 30% of the wet weight while volatile suspended solids may be 90% of the total solids. Protein would be 20% of the volatile solids, carbohydrates would be 70% of the volatile solids, and finally fats would be 10% of the volatile solids.

Contaminants

Sulfur compounds

Toxic and foul smelling Hydrogen sulfide (H
2
S
) is the most common contaminant in biogas, but other sulfur-containing compounds, such as thiols may be present. Left in the biogas stream, hydrogen sulfide is corrosive and when combusted yields sulfur dioxide (SO
2
) and sulfuric acid (H
2
SO
4
), also corrosive and environmentally hazardous compounds.[23]

Ammonia

Ammonia (NH
3
) is produced from organic compounds containing nitrogen, such as the amino acids in proteins. If not separated from the biogas, combustion results in NO
x
emissions.[23]

Siloxanes

In some cases, biogas contains siloxanes. They are formed from the anaerobic decomposition of materials commonly found in soaps and detergents. During combustion of biogas containing siloxanes, silicon is released and can combine with free oxygen or other elements in the combustion gas. Deposits are formed containing mostly silica (SiO
2
) or silicates (Si
x
O
y
) and can contain calcium, sulfur, zinc, phosphorus. Such white mineral deposits accumulate to a surface thickness of several millimeters and must be removed by chemical or mechanical means.

Practical and cost-effective technologies to remove siloxanes and other biogas contaminants are available.[24]

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Chemical compound

Chemical compound

A chemical compound is a chemical substance composed of many identical molecules containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed.

Methane

Methane

Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure.

Carbon dioxide

Carbon dioxide

Carbon dioxide (chemical formula CO2) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (HCO−3), which causes ocean acidification as atmospheric CO2 levels increase.

Nitrogen

Nitrogen

Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere.

Hydrogen

Hydrogen

Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula H2. It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen each atom has one proton, one electron, and no neutrons.

Hydrogen sulfide

Hydrogen sulfide

Hydrogen sulfide is a chemical compound with the formula H2S. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is stinkdamp. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry.

Oxygen

Oxygen

Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.

Landfill gas

Landfill gas

Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.

Sulfur dioxide

Sulfur dioxide

Sulfur dioxide or sulphur dioxide is the chemical compound with the formula SO2. It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of sulfur-bearing fossil fuels.

Sulfuric acid

Sulfuric acid

Sulfuric acid or sulphuric acid, known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is miscible with water.

Ammonia

Ammonia

Ammonia is an inorganic compound of nitrogen and hydrogen with the formula NH3. A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil.

NOx

NOx

In atmospheric chemistry, NOx is shorthand for nitric oxide and nitrogen dioxide, the nitrogen oxides that are most relevant for air pollution. These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone.

Benefits of manure derived biogas

High levels of methane are produced when manure is stored under anaerobic conditions. During storage and when manure has been applied to the land, nitrous oxide is also produced as a byproduct of the denitrification process. Nitrous oxide (N
2
O
) is 320 times more aggressive as a greenhouse gas than carbon dioxide[25] and methane 25 times more than carbon dioxide[26] By converting cow manure into methane biogas via anaerobic digestion, the millions of cattle in the United States would be able to produce 100 billion kilowatt hours of electricity, enough to power millions of homes across the United States. In fact, one cow can produce enough manure in one day to generate 3 kilowatt hours of electricity; only 2.4 kilowatt hours of electricity are needed to power a single 100-watt light bulb for one day.[27] Furthermore, by converting cattle manure into methane biogas instead of letting it decompose, global warming gases could be reduced by 99 million metric tons or 4%.[28]

Applications

A biogas bus in Linköping, Sweden
A biogas bus in Linköping, Sweden

Biogas can be used for electricity production on sewage works,[29] in a CHP gas engine, where the waste heat from the engine is conveniently used for heating the digester; cooking; space heating; water heating; and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells and is a much more effective displacer of carbon dioxide than the normal use in on-site CHP plants.[29]

Biogas upgrading

Raw biogas produced from digestion is roughly 60% methane and 39% CO
2
with trace elements of H
2
S
: inadequate for use in machinery. The corrosive nature of H
2
S
alone is enough to destroy the mechanisms.[23]

Methane in biogas can be concentrated via a biogas upgrader to the same standards as fossil natural gas, which itself has to go through a cleaning process, and becomes biomethane. If the local gas network allows, the producer of the biogas may use their distribution networks. Gas must be very clean to reach pipeline quality and must be of the correct composition for the distribution network to accept. Carbon dioxide, water, hydrogen sulfide, and particulates must be removed if present.[23]

There are four main methods of upgrading: water washing, pressure swing absorption, selexol absorption, and amine gas treating.[30] In addition to these, the use of membrane separation technology for biogas upgrading is increasing, and there are already several plants operating in Europe and USA.[23][31]

The most prevalent method is water washing where high pressure gas flows into a column where the carbon dioxide and other trace elements are scrubbed by cascading water running counter-flow to the gas. This arrangement could deliver 98% methane with manufacturers guaranteeing maximum 2% methane loss in the system. It takes roughly between 3% and 6% of the total energy output in gas to run a biogas upgrading system.

Biogas gas-grid injection

Gas-grid injection is the injection of biogas into the methane grid (natural gas grid). Until the breakthrough of micro combined heat and power two-thirds of all the energy produced by biogas power plants was lost (as heat). Using the grid to transport the gas to consumers, the energy can be used for on-site generation,[32] resulting in a reduction of losses in the transportation of energy. Typical energy losses in natural gas transmission systems range from 1% to 2%; in electricity transmission they range from 5% to 8%.[33]

Before being injected in the gas grid, biogas passes a cleaning process, during which it is upgraded to natural gas quality. During the cleaning process trace components harmful to the gas grid and the final users are removed.[34]

Biogas in transport

"Biogaståget Amanda" ("Amanda the Biogas Train") train near Linköping station, Sweden
"Biogaståget Amanda" ("Amanda the Biogas Train") train near Linköping station, Sweden

If concentrated and compressed, it can be used in vehicle transportation. Compressed biogas is becoming widely used in Sweden, Switzerland, and Germany. A biogas-powered train, named Biogaståget Amanda (The Biogas Train Amanda), has been in service in Sweden since 2005.[35][36] Biogas powers automobiles. In 1974, a British documentary film titled Sweet as a Nut detailed the biogas production process from pig manure and showed how it fueled a custom-adapted combustion engine.[37][38] In 2007, an estimated 12,000 vehicles were being fueled with upgraded biogas worldwide, mostly in Europe.[39]

Biogas is part of the wet gas and condensing gas (or air) category that includes mist or fog in the gas stream. The mist or fog is predominately water vapor that condenses on the sides of pipes or stacks throughout the gas flow. Biogas environments include wastewater digesters, landfills, and animal feeding operations (covered livestock lagoons).

Ultrasonic flow meters are one of the few devices capable of measuring in a biogas atmosphere. Most of thermal flow meters are unable to provide reliable data because the moisture causes steady high flow readings and continuous flow spiking, although there are single-point insertion thermal mass flow meters capable of accurately monitoring biogas flows with minimal pressure drop. They can handle moisture variations that occur in the flow stream because of daily and seasonal temperature fluctuations, and account for the moisture in the flow stream to produce a dry gas value.

Biogas generated heat/electricity

Biogas can be used in different types of internal combustion engines, such as the Jenbacher or Caterpillar gas engines.[40] Other internal combustion engines such as gas turbines are suitable for the conversion of biogas into both electricity and heat. The digestate is the remaining inorganic matter that was not transformed into biogas. It can be used as an agricultural fertiliser.

Biogas can be used as the fuel in the system of producing biogas from agricultural wastes and co-generating heat and electricity in a combined heat and power (CHP) plant. Unlike the other green energy such as wind and solar, the biogas can be quickly accessed on demand. The global warming potential can also be greatly reduced when using biogas as the fuel instead of fossil fuel.[41]

However, the acidification and eutrophication potentials produced by biogas are 25 and 12 times higher respectively than fossil fuel alternatives. This impact can be reduced by using correct combination of feedstocks, covered storage for digesters and improved techniques for retrieving escaped material. Overall, the results still suggest that using biogas can lead to significant reduction in most impacts compared to fossil fuel alternative. The balance between environmental damage and green house gas emission should still be considered while implicating the system.[42]

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Linköping

Linköping

Linköping is a city in southern Sweden, with around 105,000 inhabitants as of 2021. It is the seat of Linköping Municipality and the capital of Östergötland County. Linköping is also the episcopal see of the Diocese of Linköping and is well known for its cathedral. Linköping is the center of an old cultural region and celebrated its 700th anniversary in 1987. Dominating the city's skyline from afar is the steeple of the cathedral, Domkyrka.

Cogeneration

Cogeneration

Cogeneration or combined heat and power (CHP) is the use of a heat engine or power station to generate electricity and useful heat at the same time.

Gas engine

Gas engine

A gas engine is an internal combustion engine that runs on a gaseous fuel, such as coal gas, producer gas, biogas, landfill gas or natural gas. In the United Kingdom and British English-speaking countries, the term is unambiguous. In the United States, due to the widespread use of "gas" as an abbreviation for gasoline (petrol), such an engine might also be called a gaseous-fueled engine or natural gas engine or spark ignited.

Compressed natural gas

Compressed natural gas

Compressed natural gas (CNG) is a fuel gas mainly composed of methane (CH4), compressed to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 megapascals (2,900–3,600 psi), usually in cylindrical or spherical shapes.

Internal combustion engine

Internal combustion engine

An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to. This replaced the external combustion engine for applications where the weight or size of an engine were more important.

Fuel cell

Fuel cell

A fuel cell is an electrochemical cell that converts the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requiring a continuous source of fuel and oxygen to sustain the chemical reaction, whereas in a battery the chemical energy usually comes from substances that are already present in the battery. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied.

Biogas upgrader

Biogas upgrader

A biogas upgrader is a facility that is used to concentrate the methane in biogas to natural gas standards. The system removes carbon dioxide, hydrogen sulphide, water and contaminants from the biogas. One technique for doing this uses amine gas treating. This purified biogas is also called biomethane. It can be used interchangeably with natural gas.

Carbon dioxide

Carbon dioxide

Carbon dioxide (chemical formula CO2) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature, and as the source of available carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (HCO−3), which causes ocean acidification as atmospheric CO2 levels increase.

Hydrogen sulfide

Hydrogen sulfide

Hydrogen sulfide is a chemical compound with the formula H2S. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is stinkdamp. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry.

Amine gas treating

Amine gas treating

Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines (commonly referred to simply as amines) to remove hydrogen sulfide (H2S) and carbon dioxide (CO2) from gases. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing plants and other industries.

Anaerobic digestion

Anaerobic digestion

Anaerobic digestion is a sequence of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.

Distributed generation

Distributed generation

Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to as distributed energy resources (DER).

Technological advancements

Projects such as NANOCLEAN are nowadays developing new ways to produce biogas more efficiently, using iron oxide nanoparticles in the processes of organic waste treatment. This process can triple the production of biogas.[43]

Biogas and Sanitation

Faecal Sludge is a product of onsite sanitation systems. Post collection and transportation, Faecal sludge can be treated with sewage in a conventional treatment plant, or otherwise it can be treated independently in a faecal sludge treatment plant. Faecal sludge can also be co-treated with organic solid waste in composting or in an anaerobic digestion system.[44] Biogas can be generated through anaerobic digestion in the treatment of faecal sludge.

The appropriate management of excreta and its valorisation through the production of biogas from faecal sludge helps mitigate the effects of poorly managed excreta such as waterborne diseases and water and environmental pollution.[45]

Legislation

European Union

The European Union has legislation regarding waste management and landfill sites called the Landfill Directive.

Countries such as the United Kingdom and Germany now have legislation in force that provides farmers with long-term revenue and energy security.[46]

The EU mandates that internal combustion engines with biogas have ample gas pressure to optimize combustion, and within the European Union ATEX centrifugal fan units built in accordance with the European directive 2014–34/EU (previously 94/9/EG) are obligatory. These centrifugal fan units, for example Combimac, Meidinger AG or Witt & Sohn AG are suitable for use in Zone 1 and 2 .

United States

The United States legislates against landfill gas as it contains VOCs. The United States Clean Air Act and Title 40 of the Code of Federal Regulations (CFR) requires landfill owners to estimate the quantity of non-methane organic compounds (NMOCs) emitted. If the estimated NMOC emissions exceeds 50 tonnes per year, the landfill owner is required to collect the gas and treat it to remove the entrained NMOCs. That usually means burning it. Because of the remoteness of landfill sites, it is sometimes not economically feasible to produce electricity from the gas.[47]

There are a variety of grants and loans the support the development of anaerobic digestor systems. The Rural Energy for American Program provides loan financing and grant funding for biogas systems, as does the Environmental Quality Incentives Program, Conservation Stewardship Program, and Conservation Loan Program.[48]

Discover more about Legislation related topics

Landfill Directive

Landfill Directive

The Landfill Directive, more formally Council Directive 1999/31/EC of 26 April 1999 is a European Union directive that regulates waste management of landfills in the European Union. It was implemented by its Member States by 16 July 2001.

ATEX directive

ATEX directive

The 'ATEX directives are two EU directives describing the minimum safety requirements for workplaces and equipment used in explosive atmospheres. The name is an initialization of the French term Appareils destinés à être utilisés en ATmosphères EXplosibles.

Fan (machine)

Fan (machine)

A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.

Combimac

Combimac

COMBIMAC is a manufacturer of special electric motors and centrifugal fans located in the town Emmen, the Netherlands.

Volatile organic compound

Volatile organic compound

Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility.

Clean Air Act (United States)

Clean Air Act (United States)

The Clean Air Act (CAA) is the United States' primary federal air quality law, intended to reduce and control air pollution nationwide. Initially enacted in 1963 and amended many times since, it is one of the United States' first and most influential modern environmental laws.

Title 40 of the Code of Federal Regulations

Title 40 of the Code of Federal Regulations

Title 40 is a part of the United States Code of Federal Regulations. Title 40 arranges mainly environmental regulations that were promulgated by the US Environmental Protection Agency (EPA), based on the provisions of United States laws. Parts of the regulation may be updated annually on July 1.

Environmental Quality Incentives Program

Environmental Quality Incentives Program

The Environmental Quality Incentives Program (EQIP) is a United States government program designed to assist farmers in improving environmental quality, particularly water quality and soil conservation. Congress established the program in the 1996 farm bill to provide primarily cost-sharing assistance, but also technical and educational assistance, aimed at promoting production and environmental quality, and optimizing environmental benefits.

Global developments

United States

With the many benefits of biogas, it is starting to become a popular source of energy and is starting to be used in the United States more.[49] In 2003, the United States consumed 43 TWh (147 trillion BTU) of energy from "landfill gas", about 0.6% of the total U.S. natural gas consumption.[39] Methane biogas derived from cow manure is being tested in the U.S. According to a 2008 study, collected by the Science and Children magazine, methane biogas from cow manure would be sufficient to produce 100 billion kilowatt hours enough to power millions of homes across America. Furthermore, methane biogas has been tested to prove that it can reduce 99 million metric tons of greenhouse gas emissions or about 4% of the greenhouse gases produced by the United States.[50]

The number of farm-based digesters increased by 21% in 2021 according to the American Biogas Council.[51] In Vermont biogas generated on dairy farms was included in the CVPS Cow Power program. The program was originally offered by Central Vermont Public Service Corporation as a voluntary tariff and now with a recent merger with Green Mountain Power is now the GMP Cow Power Program. Customers can elect to pay a premium on their electric bill, and that premium is passed directly to the farms in the program. In Sheldon, Vermont, Green Mountain Dairy has provided renewable energy as part of the Cow Power program. It started when the brothers who own the farm, Bill and Brian Rowell, wanted to address some of the manure management challenges faced by dairy farms, including manure odor, and nutrient availability for the crops they need to grow to feed the animals. They installed an anaerobic digester to process the cow and milking center waste from their 950 cows to produce renewable energy, a bedding to replace sawdust, and a plant-friendly fertilizer. The energy and environmental attributes are sold to the GMP Cow Power program. On average, the system run by the Rowells produces enough electricity to power 300 to 350 other homes. The generator capacity is about 300 kilowatts.[52]

In Hereford, Texas, cow manure is being used to power an ethanol power plant. By switching to methane biogas, the ethanol power plant has saved 1000 barrels of oil a day. Over all, the power plant has reduced transportation costs and will be opening many more jobs for future power plants that will rely on biogas.[53]

In Oakley, Kansas, an ethanol plant considered to be one of the largest biogas facilities in North America is using integrated manure utilization system (IMUS) to produce heat for its boilers by utilizing feedlot manure, municipal organics and ethanol plant waste. At full capacity the plant is expected to replace 90% of the fossil fuel used in the manufacturing process of ethanol and methanol.[54][55]

In California, the Southern California Gas Company has advocated for mixing biogas into existing natural gas pipelines. However, California state officials have taken the position that biogas is "better used in hard-to-electrify sectors of the economy-- like aviation, heavy industry and long-haul trucking."[56]

Europe

Biogas fueling station in Mikkeli, Finland
Biogas fueling station in Mikkeli, Finland

The level of development varies greatly in Europe. While countries such as Germany, Austria and Sweden are fairly advanced in their use of biogas, there is a vast potential for this renewable energy source in the rest of the continent, especially in Eastern Europe. MT-Energie is a German biogas technology company operating in the field of renewable energies.[57] Different legal frameworks, education schemes and the availability of technology are among the prime reasons behind this untapped potential.[58] Another challenge for the further progression of biogas has been negative public perception.[59]

In February 2009, the European Biogas Association (EBA) was founded in Brussels as a non-profit organisation to promote the deployment of sustainable biogas production and use in Europe. EBA's strategy defines three priorities: establish biogas as an important part of Europe's energy mix, promote source separation of household waste to increase the gas potential, and support the production of biomethane as vehicle fuel. In July 2013, it had 60 members from 24 countries across Europe.[60]

UK

As of September 2013, there are about 130 non-sewage biogas plants in the UK. Most are on-farm, and some larger facilities exist off-farm, which are taking food and consumer wastes.[61]

On 5 October 2010, biogas was injected into the UK gas grid for the first time. Sewage from over 30,000 Oxfordshire homes is sent to Didcot sewage treatment works, where it is treated in an anaerobic digestor to produce biogas, which is then cleaned to provide gas for approximately 200 homes.[62]

In 2015 the Green-Energy company Ecotricity announced their plans to build three grid-injecting digesters.

Italy

In Italy the biogas industry first started in 2008, thanks to the introduction of advantageous feed tariffs. They were later replaced by feed-in premiums and the preference was given to by products and farming waste and leading to stagnation in biogas production and derived heat and electricity since 2012.[63]As of September 2018, in Italy there are more than 200 biogas plants with a production of about 1.2 GW[64][65][66]

Germany

Germany is Europe's biggest biogas producer[67] and the market leader in biogas technology.[68] In 2010 there were 5,905 biogas plants operating throughout the country: Lower Saxony, Bavaria, and the eastern federal states are the main regions.[69] Most of these plants are employed as power plants. Usually the biogas plants are directly connected with a CHP which produces electric power by burning the bio methane. The electrical power is then fed into the public power grid.[70] In 2010, the total installed electrical capacity of these power plants was 2,291 MW.[69] The electricity supply was approximately 12.8 TWh, which is 12.6% of the total generated renewable electricity.[71]

Biogas in Germany is primarily extracted by the co-fermentation of energy crops (called 'NawaRo', an abbreviation of nachwachsende Rohstoffe, German for renewable resources) mixed with manure. The main crop used is corn. Organic waste and industrial and agricultural residues such as waste from the food industry are also used for biogas generation.[72] In this respect, biogas production in Germany differs significantly from the UK, where biogas generated from landfill sites is most common.[67]

Biogas production in Germany has developed rapidly over the last 20 years. The main reason is the legally created frameworks. Government support of renewable energy started in 1991 with the Electricity Feed-in Act (StrEG). This law guaranteed the producers of energy from renewable sources the feed into the public power grid, thus the power companies were forced to take all produced energy from independent private producers of green energy.[73] In 2000 the Electricity Feed-in Act was replaced by the Renewable Energy Sources Act (EEG). This law even guaranteed a fixed compensation for the produced electric power over 20 years. The amount of around 8 ¢/kWh gave farmers the opportunity to become energy suppliers and gain a further source of income.[72]

The German agricultural biogas production was given a further push in 2004 by implementing the so-called NawaRo-Bonus. This is a special payment given for the use of renewable resources, that is, energy crops.[74] In 2007 the German government stressed its intention to invest further effort and support in improving the renewable energy supply to provide an answer on growing climate challenges and increasing oil prices by the 'Integrated Climate and Energy Programme'.

This continual trend of renewable energy promotion induces a number of challenges facing the management and organisation of renewable energy supply that has also several impacts on the biogas production.[75] The first challenge to be noticed is the high area-consuming of the biogas electric power supply. In 2011 energy crops for biogas production consumed an area of circa 800,000 ha in Germany.[76] This high demand of agricultural areas generates new competitions with the food industries that did not exist hitherto. Moreover, new industries and markets were created in predominately rural regions entailing different new players with an economic, political and civil background. Their influence and acting has to be governed to gain all advantages this new source of energy is offering. Finally biogas will furthermore play an important role in the German renewable energy supply if good governance is focused.[75]

Developing countries

Domestic biogas plants convert livestock manure and night soil into biogas and slurry, the fermented manure. This technology is feasible for small-holders with livestock producing 50 kg manure per day, an equivalent of about 6 pigs or 3 cows. This manure has to be collectable to mix it with water and feed it into the plant. Toilets can be connected. Another precondition is the temperature that affects the fermentation process. With an optimum at 36 C° the technology especially applies for those living in a (sub) tropical climate. This makes the technology for small holders in developing countries often suitable.[77]

Simple sketch of household biogas plant
Simple sketch of household biogas plant

Depending on size and location, a typical brick made fixed dome biogas plant can be installed at the yard of a rural household with the investment between US$300 to $500 in Asian countries and up to $1400 in the African context.[78] A high quality biogas plant needs minimum maintenance costs and can produce gas for at least 15–20 years without major problems and re-investments. For the user, biogas provides clean cooking energy, reduces indoor air pollution, and reduces the time needed for traditional biomass collection, especially for women and children. The slurry is a clean organic fertilizer that potentially increases agricultural productivity.[77]

Energy is an important part of modern society and can serve as one of the most important indicators of socio-economic development. As much as there have been advancements in technology, even so, some three billion people, primarily in the rural areas of developing countries, continue to access their energy needs for cooking through traditional means by burning biomass resources like firewood, crop residues and animal dung in crude traditional stoves.[79]

Domestic biogas technology is a proven and established technology in many parts of the world, especially Asia.[80] Several countries in this region have embarked on large-scale programmes on domestic biogas, such as China[81] and India.

The Netherlands Development Organisation, SNV,[82] supports national programmes on domestic biogas that aim to establish commercial-viable domestic biogas sectors in which local companies market, install and service biogas plants for households. In Asia, SNV is working in Nepal,[83] Vietnam,[84] Bangladesh,[85] Bhutan, Cambodia,[85] Lao PDR,[86] Pakistan[87] and Indonesia,[88] and in Africa; Rwanda,[89] Senegal, Burkina Faso, Ethiopia,[90] Tanzania,[91] Uganda, Kenya,[92] Benin and Cameroon.

In South Africa a prebuilt Biogas system is manufactured and sold. One key feature is that installation requires less skill and is quicker to install as the digester tank is premade plastic.[93]

India

Biogas in India[94] has been traditionally based on dairy manure as feed stock and these "gobar" gas plants have been in operation for a long period of time, especially in rural India. In the last 2–3 decades, research organisations with a focus on rural energy security have enhanced the design of the systems resulting in newer efficient low cost designs such as the Deenabandhu model.

The Deenabandhu Model is a new biogas-production model popular in India. (Deenabandhu means "friend of the helpless".) The unit usually has a capacity of 2 to 3 cubic metres. It is constructed using bricks or by a ferrocement mixture. In India, the brick model costs slightly more than the ferrocement model; however, India's Ministry of New and Renewable Energy offers some subsidy per model constructed.

Biogas which is mainly methane/natural gas can also be used for generating protein rich cattle, poultry and fish feed in villages economically by cultivating Methylococcus capsulatus bacteria culture with tiny land and water foot print.[95][96][97] The carbon dioxide gas produced as by product from these plants can be put to use in cheaper production of algae oil or spirulina from algaculture particularly in tropical countries like India which can displace the prime position of crude oil in near future.[98][99] Union government of India is implementing many schemes to utilise productively the agro waste or biomass in rural areas to uplift rural economy and job potential.[100][101] With these plants, the non-edible biomass or waste of edible biomass is converted in to high value products without any water pollution or green house gas (GHG) emissions.[102]

LPG (Liquefied Petroleum Gas) is a key source of cooking fuel in urban India and its prices have been increasing along with the global fuel prices. Also the heavy subsidies provided by the successive governments in promoting LPG as a domestic cooking fuel has become a financial burden renewing the focus on biogas as a cooking fuel alternative in urban establishments. This has led to the development of prefabricated digester for modular deployments as compared to RCC and cement structures which take a longer duration to construct. Renewed focus on process technology like the Biourja process model[103] has enhanced the stature of medium and large scale anaerobic digester in India as a potential alternative to LPG as primary cooking fuel.

In India, Nepal, Pakistan and Bangladesh biogas produced from the anaerobic digestion of manure in small-scale digestion facilities is called gobar gas; it is estimated that such facilities exist in over 2 million households in India, 50,000 in Bangladesh and thousands in Pakistan, particularly North Punjab, due to the thriving population of livestock. The digester is an airtight circular pit made of concrete with a pipe connection. The manure is directed to the pit, usually straight from the cattle shed. The pit is filled with a required quantity of wastewater. The gas pipe is connected to the kitchen fireplace through control valves. The combustion of this biogas has very little odour or smoke. Owing to simplicity in implementation and use of cheap raw materials in villages, it is one of the most environmentally sound energy sources for rural needs. One type of these system is the Sintex Digester. Some designs use vermiculture to further enhance the slurry produced by the biogas plant for use as compost.[104]

In Pakistan, the Rural Support Programmes Network is running the Pakistan Domestic Biogas Programme[105] which has installed 5,360 biogas plants[106] and has trained in excess of 200 masons on the technology and aims to develop the Biogas Sector in Pakistan.

In Nepal, the government provides subsidies to build biogas plant at home.

China

The Chinese have experimented with the applications of biogas since 1958. Around 1970, China had installed 6,000,000 digesters in an effort to make agriculture more efficient. During the last few years, technology has met high growth rates. This seems to be the earliest developments in generating biogas from agricultural waste.[107]

The rural biogas construction in China has shown an increased development trend. The exponential growth of energy supply caused by rapid economic development and severe haze condition in China have led biogas to become the better eco-friendly energy for the rural areas. In Qing county, Hebei Province, the technology of using crop straw as a main material to generate biogas is currently developing.[108]

China had 26.5 million biogas plants, with an output of 10.5 billion cubic meter biogas until 2007. The annual biogas output has increased to 248 billion cubic meter in 2010.[109] The Chinese government had supported and funded rural biogas projects, but only about 60% were operating normally.[110] During the winter, the biogas production in northern regions of China is lower. This is caused by the lack of heat control technology for digesters thus the co-digestion of different feedstock failed to complete in the cold environment.[111]

Zambia

Lusaka, the capital city of Zambia, has two million inhabitants with over half of the population residing in peri-urban areas. The majority of this population use pit latrines as toilets generating approximately 22,680 tons of fecal sludge per annum. This sludge is inadequately managed: Over 60% of the generated faecal sludge remains within the residential environment thereby compromising both the environment and public health.[112]

In the face of research work and implementation of biogas having started as early as in the 1980s, Zambia is lagging behind in the adoption and use of biogas in the sub-Saharan Africa. Animal manure and crop residues are required for the provision of energy for cooking and lighting. Inadequate funding, absence of policy, regulatory framework and strategies on biogas, unfavorable investor monetary policy, inadequate expertise, lack of awareness of the benefits of biogas technology among leaders, financial institutions and locals, resistance to change due cultural and traditions of the locals, high installation and maintenance costs of biogas digesters, inadequate research and development, improper management and lack of monitoring of installed digesters, complexity of the carbon market, lack of incentives and social equity are among the challenges that have impeded the acquiring and sustainable implementation of domestic biogas production in Zambia.[113]

Discover more about Global developments related topics

Hereford, Texas

Hereford, Texas

Hereford is a city in and county seat of Deaf Smith County, Texas, United States. It is 48 miles southwest of Amarillo. Its population was 15,370 at the 2010 census. It is the only incorporated locality named "Hereford" in the country.

Ethanol fuel

Ethanol fuel

Ethanol fuel is fuel containing ethyl alcohol, the same type of alcohol as found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline.

Oakley, Kansas

Oakley, Kansas

Oakley is a city in Gove, Logan, and Thomas counties in the U.S. state of Kansas. It is the county seat of Logan County. As of the 2020 census, the population of the city was 2,046.

Integrated manure utilization system

Integrated manure utilization system

IMUS is an anaerobic digestion technology that converts organic material into biogas that is used to produce electricity, heat and nutrients. The technology uses waste such as municipal waste, cow manure, sand laden feed lot waste, and food processing waste. The technology can be integrated with other industrial process, such as municipal facilities, open pen feedlots, food processing, and ethanol plants. The technology was developed in 1999 by Himark BioGas.

Mikkeli

Mikkeli

Mikkeli is a town and municipality in Finland. It is located in what used to be the province of Eastern Finland and is part of the Etelä-Savo region. The municipality has a population of 52,121 and covers an area of 3,229.57 square kilometres (1,246.94 sq mi) of which 424.7 km2 (164.0 sq mi) is water. The population density is 30.66 inhabitants per square kilometre (79.4/sq mi) The town is located on lake Saimaa. Together with Savonlinna, it is one of the largest towns in the South Savonia region and one of the concentrations in the region's hospital districts.

MT-Energie

MT-Energie

MT-Energie GmbH is a biogas technology company operating in the field of renewable energies. The company's headquarters are in Zeven (Germany) The UK branch office is located in Bridgnorth, Shropshire. MT-Energie develops and distributes both turnkey biogas powerplants and special bioprocess engineering components. Furthermore, it offers technical and biological services for biogas plants. The company’s subsidiary MT-Biomethan GmbH, which was founded as part of the MT Group in 2008, offers technologies for biogas upgrading based on the process of pressureless amine scrubbing and a membrane-based gas permeation.

Renewable energy

Renewable energy

Renewable energy is energy from renewable resources that are naturally replenished on a human timescale. Renewable resources include sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation. Renewable energy is often used for electricity generation, heating and cooling. Renewable energy projects are typically large-scale, but they are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Renewable energy is often deployed together with further electrification, which has several benefits: electricity can move heat or objects efficiently, and is clean at the point of consumption. In addition, electrification with renewable energy is more efficient and therefore leads to significant reductions in primary energy requirements.

Ecotricity

Ecotricity

Ecotricity is a British energy company based in Stroud, Gloucestershire, England, specialising in selling green energy to consumers that it primarily generates from its 87.2 megawatt wind power portfolio – the company prefers the term windmill rather than wind turbine. It is built on the principle of heavily reinvesting its profit in building more of its own green energy generation.

German Renewable Energy Sources Act

German Renewable Energy Sources Act

The Renewable Energy Sources Act  or EEG is a series of German laws that originally provided a feed-in tariff (FIT) scheme to encourage the generation of renewable electricity. The EEG 2014 specified the transition to an auction system for most technologies which has been finished with the current version EEG 2017.

Indoor air quality

Indoor air quality

Indoor air quality (IAQ) is the air quality within and around buildings and structures. IAQ is known to affect the health, comfort, and well-being of building occupants. Poor indoor air quality has been linked to sick building syndrome, reduced productivity, and impaired learning in schools. Common pollutants of indoor air include: Secondhand tobacco smoke, air pollutants from indoor combustion, radon, molds and other allergens, carbon monoxide, volatile organic compounds, legionella and other bacteria, asbestos fibers, carbon dioxide, ozone and particulates. Source control, filtration, and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality in most buildings.

Ferrocement

Ferrocement

Ferrocement or ferro-cement is a system of construction using reinforced mortar or plaster applied over an "armature" of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel, and the mesh is made with wire with a diameter between 0.5 mm and 1 mm. The cement is typically a very rich mix of sand and cement in a 3:1 ratio; when used for making boards, no gravel is used, so that the material is not concrete.

Methylococcus capsulatus

Methylococcus capsulatus

Methylococcus capsulatus is an obligately methanotrophic gram-negative, non-motile coccoid bacterium. M. capsulatus are thermotolerant; their cells are encapsulated and tend to have a diplococcoid shape. In addition to methane, M. capsulatus is able to oxidize some organic hydrogen containing compounds such as methanol. It has been used commercially to produce animal feed from natural gas.

Associations

Society and culture

In the 1985 Australian film Mad Max Beyond Thunderdome the post-apocalyptic settlement Barter town is powered by a central biogas system based upon a piggery. As well as providing electricity, methane is used to power Barter's vehicles.

"Cow Town", written in the early 1940s, discusses the travails of a city vastly built on cow manure and the hardships brought upon by the resulting methane biogas. Carter McCormick, an engineer from a town outside the city, is sent in to figure out a way to utilize this gas to help power, rather than suffocate, the city.

Contemporary biogas production provides new opportunities for skilled employment, drawing on the development of new technologies.[117]

Source: "Biogas", Wikipedia, Wikimedia Foundation, (2023, March 18th), https://en.wikipedia.org/wiki/Biogas.

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See also
References
  1. ^ National Non-Food Crops Centre. "NNFCC Renewable Fuels and Energy Factsheet: Anaerobic Digestion", Retrieved on 2011-02-16
  2. ^ Webdesign, Insyde. "How does biogas work?". www.simgas.com. Archived from the original on 10 May 2018. Retrieved 16 May 2018.
  3. ^ "Biogas & Engines". clarke-energy.com. Retrieved 21 November 2011.
  4. ^ "Biomethane fueled vehicles the carbon neutral option". Claverton Energy Conference Bath, UK. 24 October 2009.
  5. ^ Le Mer, Jean; Roger, Pierre (January 2001). "Production, oxidation, emission and consumption of methane by soils: A review". European Journal of Soil Biology. 37 (1): 25–50. doi:10.1016/S1164-5563(01)01067-6. S2CID 62815957.
  6. ^ Appels, Lise; Baeyens, Jan; Degrève, Jan; Dewil, Raf (2008). "Principles and potential of the anaerobic digestion of waste-activated sludge". Progress in Energy and Combustion Science. 34 (6): 755–781. doi:10.1016/j.pecs.2008.06.002. ISSN 0360-1285. S2CID 95588169.
  7. ^ "How a false solution to climate change is damaging the natural world | George Monbiot". the Guardian. 14 March 2014. Retrieved 5 October 2021.
  8. ^ "Cold climates no bar to biogas production". New Scientist. London: Sunita Harrington. 6 November 2010. p. 14. Retrieved 4 February 2011.
  9. ^ Hedlund, FH; Madsen, M (2018). "Incomplete understanding of biogas chemical hazards – Serious gas poisoning accident while unloading food waste at biogas plant" (PDF). Journal of Chemical Health & Safety. 25 (6): 13–21. doi:10.1016/j.jchas.2018.05.004. S2CID 67849856.
  10. ^ Reinelt, Torsten; Liebetrau, Jan (January 2020). "Monitoring and Mitigation of Methane Emissions from Pressure Relief Valves of a Biogas Plant". Chemical Engineering & Technology. 43 (1): 7–18. doi:10.1002/ceat.201900180.
  11. ^ Michael Fredenslund, Anders; Gudmundsson, Einar; Maria Falk, Julie; Scheutz, Charlotte (February 2023). "The Danish national effort to minimise methane emissions from biogas plants". Waste Management. 157: 321–329. doi:10.1016/j.wasman.2022.12.035.
  12. ^ "Biogas Problems". Retrieved 15 May 2015.
  13. ^ "Biogas – Bioenergy Association of New Zealand (BANZ)". Bioenergy.org.nz. Archived from the original on 25 January 2010. Retrieved 21 February 2010.
  14. ^ LFG energy projects Archived 3 January 2009 at the Wayback Machine
  15. ^ Safety Page, Beginners Guide to Biogas Archived 17 February 2015 at the Wayback Machine, www.adelaide.edu.au/biogas. Retrieved 22.10.07.
  16. ^ "Archived copy" (PDF). Archived from the original (PDF) on 12 November 2018. Retrieved 22 December 2018.{{cite web}}: CS1 maint: archived copy as title (link)
  17. ^ Obrecht, Matevz; Denac, Matjaz (2011). "Biogas – a sustainable energy source: new measures and possibilities for SLovenia" (PDF). Journal of Energy Technology (5): 11–24.
  18. ^ Basic Information on Biogas Archived 6 January 2010 at the Wayback Machine, www.kolumbus.fi. Retrieved 2.11.07.
  19. ^ Hafner, Sasha (2017). "Predicting methane and biogas production with the biogas package" (PDF). CRAN.
  20. ^ "Juniper". Archived from the original on 30 April 2015. Retrieved 15 May 2015.
  21. ^ Richards, B.; Herndon, F. G.; Jewell, W. J.; Cummings, R. J.; White, T. E. (1994). "In situ methane enrichment in methanogenic energy crop digesters". Biomass and Bioenergy. 6 (4): 275–282. doi:10.1016/0961-9534(94)90067-1. hdl:1813/60790.
  22. ^ Richards, B.; Cummings, R.; White, T.; Jewell, W. (1991). "Methods for kinetic analysis of methane fermentation in high solids biomass digesters". Biomass and Bioenergy. 1 (2): 65–73. doi:10.1016/0961-9534(91)90028-B. hdl:1813/60787.
  23. ^ a b c d e Abatzoglou, Nicolas; Boivin, Steve (2009). "A review of biogas purification processes". Biofuels, Bioproducts and Biorefining. 3 (1): 42–71. doi:10.1002/bbb.117. ISSN 1932-104X. S2CID 84907789.
  24. ^ Tower, P.; Wetzel, J.; Lombard, X. (March 2006). "New Landfill Gas Treatment Technology Dramatically Lowers Energy Production Costs". Applied Filter Technology. Archived from the original on 2 January 2016. Retrieved 30 April 2009.(broken link)
  25. ^ "Increased Greenhouse Gas Emissions" Archived 17 January 2016 at the Wayback Machine, Food and Agricultural Organization of the United Nations
  26. ^ Overview of Greenhouse Gases, Methane Emissions. Climate Change, United States Environmental Protection Agency, 11 December 2015.
  27. ^ State Energy Conservation Office (Texas). "Biomass Energy: Manure for Fuel." State Energy Conservation Office (Texas). State of Texas, 23 April 2009. Web. 3 October 2009.
  28. ^ Webber, Michael E and Amanda D Cuellar. "Cow Power. In the News: Short News Items of Interest to the Scientific Community." Science and Children os 46.1 (2008): 13. Gale. Web. 1 October 2009 in United States.
  29. ^ a b Administrator. "Biogas CHP – Alfagy – Profitable Greener Energy via CHP, Cogen and Biomass Boiler using Wood, Biogas, Natural Gas, Biodiesel, Vegetable Oil, Syngas and Straw". Archived from the original on 30 April 2015. Retrieved 15 May 2015.
  30. ^ "Nyheter – SGC". Archived from the original (PDF) on 4 December 2014. Retrieved 15 May 2015.
  31. ^ Petersson A., Wellinger A. (2009). Biogas upgrading technologies – developments and innovations. IEA Bioenergy Task 37 Archived 29 November 2014 at the Wayback Machine
  32. ^ "Biogas Flows Through Germany's Grid Big Time – Renewable Energy News Article". 14 March 2012. Archived from the original on 14 March 2012. Retrieved 17 June 2016.
  33. ^ "energy loss, transmission loss". Archived from the original on 22 September 2018. Retrieved 15 May 2015.
  34. ^ "Adding gas from biomass to the gas grid" (PDF). Swedish Gas Center. Swedish Gas Center. Retrieved 20 October 2017.
  35. ^ Biogas train in Sweden Archived 29 September 2011 at the Wayback Machine
  36. ^ Friendly fuel trains (30 October 2005) New Straits Times, p. F17.
  37. ^ "Bates Car – Sweet As a Nut (1975)". BFI. Archived from the original on 23 July 2013. Retrieved 15 May 2015.
  38. ^ National Film Board of Canada. "Bate's Car: Sweet as a Nut". NFB.ca. Retrieved 15 May 2015.
  39. ^ a b What is biogas?, U.S. Department of Energy, 13 April 2010
  40. ^ State Energy Conservation Office (Texas). "Biomass Energy: Manure for Fuel." Archived 23 October 2012 at the Wayback Machine, 23 April 2009. Web. 3 October 2009.
  41. ^ Comparison of energy systems using life cycle assessment. World Energy Council. 2004. ISBN 0946121168. OCLC 59190792.
  42. ^ Whiting, Andrew; Azapagic, Adisa (2014). "Life cycle environmental impacts of generating electricity and heat from biogas produced by anaerobic digestion". Energy. 70: 181–193. doi:10.1016/j.energy.2014.03.103. ISSN 0360-5442.
  43. ^ "Creating BIOGAS+: a new technology to improve the efficiency and profitability in the treatment of biowaste". SIOR. Social Impact Open Repository. Archived from the original on 5 September 2017. Retrieved 5 September 2017.
  44. ^ Semiyaga, Swaib; Okure, Mackay A. E.; Niwagaba, Charles B.; Katukiza, Alex Y.; Kansiime, Frank (1 November 2015). "Decentralized options for faecal sludge management in urban slum areas of Sub-Saharan Africa: A review of technologies, practices and end-uses". Resources, Conservation and Recycling. 104: 109–119. doi:10.1016/j.resconrec.2015.09.001. ISSN 0921-3449.
  45. ^ Hidenori Harada, Linda Strande, Shigeo Fujii (2016). "Challenges and Opportunities of Faecal Sludge Management for Global Sanitation". Kaisei Publishing, Tokyo.: 81–100.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  46. ^ "CHP | Combined Heat and Power | Cogeneration | Wood Biomass Gasified Co-generation | Energy Efficiency | Electricity Generation". Alfagy.com. Archived from the original on 7 July 2011. Retrieved 21 February 2010.
  47. ^ US EPA, OAR (15 April 2016). "Basic Information about Landfill Gas". www.epa.gov. Retrieved 17 June 2022.
  48. ^ Lazenby, Ruthie (15 August 2022). "Rethinking Manure Biogas: Policy Considerations to Promote Equity and Protect the Climate and Environment" (PDF). Retrieved 19 October 2022.
  49. ^ "Inflation Reduction Act Gives a Boost to the Biogas Sector". The National Law Review. Retrieved 19 October 2022.
  50. ^ Cuellar, Amanda D and Michael E Webber (2008). "Cow power: the energy and emissions benefits of converting manure to biogas". Environ. Res. Lett. 3 (3): 034002. Bibcode:2008ERL.....3c4002C. doi:10.1088/1748-9326/3/3/034002.
  51. ^ Moran, Barbara (9 November 2022). "Massachusetts companies are turning to 'anaerobic digesters' to dispose of food waste". NPR News. Retrieved 11 November 2022.
  52. ^ Zezima, Katie. "Electricity From What Cows Leave Behind." The New York Times, 23 September 2008, natl. ed.: SPG9. Web. 1 October 2009.
  53. ^ State Energy Conservation Office (Texas). "Biomass Energy: Manure for Fuel Archived 23 October 2012 at the Wayback Machine." State Energy Conservation Office (Texas). State of Texas, 23 April 2009. Web. 3 October 2009.
  54. ^ Trash-to-energy trend boosts anaerobic digesters [1]."
  55. ^ Western Plains Energy finishing up North America’s largest biogas digester [2]."
  56. ^ McKenna, Phil (13 November 2019). "Fearing for Its Future, a Big Utility Pushes 'Renewable Gas,' Urges Cities to Reject Electrification". InsideClimate News. Archived from the original on 16 November 2019. Retrieved 16 November 2019.
  57. ^ "Renewables - Made in Germany". German Energy Agency. Archived from the original on 6 July 2011. Retrieved 13 April 2011.
  58. ^ "About SEBE". Archived from the original on 28 November 2014. Retrieved 15 May 2015.
  59. ^ "FNR: Fachagentur Nachwachsende Rohstoffe e. V." (PDF). Retrieved 17 June 2016.
  60. ^ "European Biogas Association". Retrieved 15 May 2015.
  61. ^ The Official Information Portal on AD 'Biogas Plant Map'
  62. ^ Sewage project sends first ever renewable gas to grid Thames Water Archived 9 December 2010 at the Wayback Machine
  63. ^ Eyl-Mazzega, Mark Antione; Mathieu, Carole (27 October 2020). "Biogas and Biomethane in Europe: Lessons from Denmark, Italy and Germany" (PDF). Études de l'Ifri.
  64. ^ ANSA Ambiente & Energia Installed biogas power in Italy
  65. ^ AuCo Solutions biogas software Biogas software solution Archived 25 September 2018 at the Wayback Machine
  66. ^ Snam IES Biogas Biogas Plant in Italy Archived 25 September 2018 at the Wayback Machine
  67. ^ a b "European Biogas Barometer" (PDF). EurObserv'ER. Archived from the original (PDF) on 25 April 2012. Retrieved 7 November 2011.
  68. ^ "Biogas". BMU. Archived from the original on 29 January 2015. Retrieved 7 November 2011.
  69. ^ a b "Biogas Segments Statistics 2010" (PDF). Fachverband Biogas e.V. Retrieved 5 November 2011.
  70. ^ "Biomass for Power Generation and CHP" (PDF). IEA. Archived from the original (PDF) on 3 November 2011. Retrieved 7 November 2011.
  71. ^ "Renewable Energy Sources". 6 September 2014. Retrieved 6 June 2018.
  72. ^ a b Wieland, P. (2003). "Production and Energetic Use of Biogas from Energy Crops and Wastes in Germany". Applied Biochemistry and Biotechnology. 109 (1–3): 263–274. doi:10.1385/abab:109:1-3:263. PMID 12794299. S2CID 9468552.
  73. ^ "Erneuerbare Energien in Deutschland. Rückblick und Stand des Innovationsgeschehens" (PDF). IfnE et al. Archived from the original (PDF) on 6 April 2012. Retrieved 5 November 2011.
  74. ^ Wieland, P. (2006). "Biomass Digestion in Agriculture: A Successful Pathway for the Energy Production and Waste Treatment in Germany". Engineering in Life Sciences. Engineering in Life Science. 6 (3): 302–309. doi:10.1002/elsc.200620128. S2CID 54685767.
  75. ^ a b Kanning, H.; et al. (2009). "Erneuerbare Energien – Räumliche Dimensionen, neue Akteurslandschaften und planerische (Mit)Gestaltungspotenziale am Beispiel des Biogaspfades". Raumforschung und Raumordnung. 67 (2): 142–156. doi:10.1007/BF03185702.
  76. ^ "Cultivation of renewable Resources in Germany". FNR. Retrieved 5 November 2011.
  77. ^ a b Roubík, Hynek; Mazancová, Jana; Banout, Jan; Verner, Vladimír (20 January 2016). "Addressing problems at small-scale biogas plants: a case study from central Vietnam". Journal of Cleaner Production. 112, Part 4: 2784–2792. doi:10.1016/j.jclepro.2015.09.114.
  78. ^ Ghimire, Prakash C. (1 January 2013). "SNV supported domestic biogas programmes in Asia and Africa". Renewable Energy. Selected papers from World Renewable Energy Congress – XI. 49: 90–94. doi:10.1016/j.renene.2012.01.058.
  79. ^ Surendra, K. C.; Takara, Devin; Hashimoto, Andrew G.; Khanal, Samir Kumar (1 March 2014). "Biogas as a sustainable energy source for developing countries: Opportunities and challenges". Renewable and Sustainable Energy Reviews. 31: 846–859. doi:10.1016/j.rser.2013.12.015. ISSN 1364-0321.
  80. ^ "SNV World". Archived from the original (PDF) on 5 October 2018. Retrieved 15 May 2015.
  81. ^ "China – Biogas". Retrieved 15 May 2015.
  82. ^ "Renewable energy". Archived from the original on 27 February 2012. Retrieved 15 May 2015.
  83. ^ "[Biogas Sector Partnership-Nepal]". Bspnepal.org.np. Retrieved 21 February 2010.
  84. ^ "Dự án chương trình khí sinh học cho ngành chăn nuôi Việt Nam". Biogas.org.vn. Archived from the original on 25 October 2004. Retrieved 21 February 2010.
  85. ^ a b http://www.idcol.org (click 'Projects')
  86. ^ "Home". Biogaslao.org. Archived from the original on 10 November 2010. Retrieved 21 February 2010.
  87. ^ "SNV World". Archived from the original (PDF) on 6 October 2018. Retrieved 15 May 2015.
  88. ^ Indonesia Domestic Biogas Programme Archived 28 July 2011 at the Wayback Machine
  89. ^ "Renewable Energy". Snvworld.org. Archived from the original on 3 January 2015. Retrieved 3 January 2015.
  90. ^ "Renewable energy". Snvworld.org. Archived from the original on 3 January 2015. Retrieved 3 January 2015.
  91. ^ SNV Tanzania Domestic Biogas Programme Archived 28 July 2011 at the Wayback Machine
  92. ^ Biogas First in Kenya for Clarke Energy and Tropical Power Accessed 11 September 2013
  93. ^ "Renewable Energy Solutions – Living Lightly". Renewable Energy Solutions. Archived from the original on 2 May 2015. Retrieved 15 May 2015.
  94. ^ "GPS Renewables – Waste management through biogas". GPS Renewables. Archived from the original on 18 May 2015. Retrieved 15 May 2015.
  95. ^ "BioProtein Production" (PDF). Archived from the original (PDF) on 10 May 2017. Retrieved 31 January 2018.
  96. ^ Le Page, Michael. "Food made from natural gas will soon feed farm animals – and us". New Scientist. Retrieved 31 January 2018.
  97. ^ "New venture selects Cargill's Tennessee site to produce Calysta FeedKind® Protein". Retrieved 31 January 2018.
  98. ^ "Algenol and Reliance launch algae fuels demonstration project in India". Retrieved 29 May 2017.
  99. ^ "ExxonMobil Announces Breakthrough in Renewable Energy". Retrieved 20 June 2017.
  100. ^ "Indrapratha Gas, Mahindra & Mahindra join hands to stop stubble burning". Retrieved 20 February 2018.
  101. ^ "Modi govt plans Gobar-Dhan scheme to convert cattle dung into energy". Retrieved 22 February 2018.
  102. ^ "Assessment of environmental impact of FeedKind protein" (PDF). Archived from the original (PDF) on 2 August 2019. Retrieved 20 June 2017.
  103. ^ "GPS Renewables – Monitoring Methodology". GPS Renewables. Archived from the original on 10 May 2015. Retrieved 15 May 2015.
  104. ^ "Biogas plants provide cooking and fertiliser". Ashden Awards, sustainable and renewable energy in the UK and developing world. Archived from the original on 27 September 2011. Retrieved 15 May 2015.
  105. ^ "PAK-ENERGY SOLUTION". Archived from the original on 24 May 2015. Retrieved 15 May 2015.
  106. ^ "5,360 bio-gas plants installed in 12 districts". Business Recorder. 27 December 2014. Archived from the original on 2 April 2015. Retrieved 15 May 2015.
  107. ^ Biogas in China. Retrieved 27 October 2016
  108. ^ Hu, Die (2015). "Hebei Province Qing County Straw Partnerships Biogas Application and Promotion Research". Proceedings of the 2015 International Conference on Mechatronics, Electronic, Industrial and Control Engineering. Paris, France: Atlantis Press. doi:10.2991/meic-15.2015.260. ISBN 9789462520622.
  109. ^ Deng, Yanfei; Xu, Jiuping; Liu, Ying; Mancl, Karen (2014). "Biogas as a sustainable energy source in China: Regional development strategy application and decision making". Renewable and Sustainable Energy Reviews. 35: 294–303. doi:10.1016/j.rser.2014.04.031. ISSN 1364-0321.
  110. ^ Chen, Yu; Yang, Gaihe; Sweeney, Sandra; Feng, Yongzhong (2010). "Household biogas use in rural China: A study of opportunities and constraints". Renewable and Sustainable Energy Reviews. 14 (1): 545–549. doi:10.1016/j.rser.2009.07.019. ISSN 1364-0321. S2CID 154461345.
  111. ^ He, Pin Jing (2010). "Anaerobic digestion: An intriguing long history in China". Waste Management. 30 (4): 549–550. doi:10.1016/j.wasman.2010.01.002. ISSN 0956-053X. PMID 20089392.
  112. ^ Tembo, J.M.; Nyirenda, E.; Nyambe, I. (2017). "Enhancing faecal sludge management in peri-urban areas of Lusaka through faecal sludge valorisation: challenges and opportunities". IOP Conference Series: Earth and Environmental Science. 60 (1): 012025. Bibcode:2017E&ES...60a2025T. doi:10.1088/1755-1315/60/1/012025.
  113. ^ Shane, Agabu; Gheewala, Shabbir H (2020). "Potential, Barriers and Prospects of Biogas Production in Zambia" (PDF). Journal of Sustainable Energy & Environment. 6 (2015) 21-27.
  114. ^ "European Biogas Association". Retrieved 15 May 2017.
  115. ^ "German Biogas Association". Retrieved 15 May 2017.
  116. ^ "Biogas-india – Home". Retrieved 15 May 2015.
  117. ^ "Generating new employment opportunities [Social Impact]". SIOR. Social Impact Open Repository. Archived from the original on 5 September 2017.
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