Biogas is a gaseous renewable energy source produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester, biodigester or a bioreactor. The gas composition is primarily methane and carbon dioxide and may have small amounts of hydrogen sulfide, moisture and siloxanes. The gases methane and hydrogen 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 heating purpose, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.
Biofuel is a fuel that is produced over a short period from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. Biofuel can be produced from plants or agricultural, domestic, or industrial biowaste. Biofuels are mostly used for transportation but can also be used for heating and electricity. Biofuels are regarded as a renewable energy source. However, the use of biofuel has been controversial because of the several disadvantages associated with the use of it. These include for example : the "food vs fuel" debate, biofuel production methods being sustainable or not, leading to deforestation and loss of biodiversity or not.
Cellulosic ethanol is ethanol produced from cellulose rather than from the plant's seeds or fruit. It can be produced from grasses, wood, algae, or other plants. It is generally discussed for use as a biofuel. The carbon dioxide that plants absorb as they grow offsets some of the carbon dioxide emitted when ethanol made from them is burned, so cellulosic ethanol fuel has the potential to have a lower carbon footprint than fossil fuels.
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.
A biorefinery is a refinery that converts biomass to energy and other beneficial byproducts. The International Energy Agency Bioenergy Task 42 defined biorefining as "the sustainable processing of biomass into a spectrum of bio-based products and bioenergy ". As refineries, biorefineries can provide multiple chemicals by fractioning an initial raw material (biomass) into multiple intermediates that can be further converted into value-added products. Each refining phase is also referred to as a "cascading phase". The use of biomass as feedstock can provide a benefit by reducing the impacts on the environment, as lower pollutants emissions and reduction in the emissions of hazard products. In addition, biorefineries are intended to achieve the following goals:
- Supply the current fuels and chemical building blocks
- Supply new building blocks for the production of novel materials with disruptive characteristics
- Creation of new jobs, including rural areas
- Valorization of waste
- Achieve the ultimate goal of reducing GHG emissions
Bioenergy is energy made or generated from biomass, which consists of recently living organisms, mainly plants. Types of biomass commonly used for bioenergy include wood, food crops such as corn, energy crops and waste from forests, yards, or farms. The IPCC defines bioenergy as a renewable form of energy. Bioenergy can either mitigate or increase greenhouse gas emissions. There is also agreement that local environmental impacts can be problematic.
Algal mats are one of many types of microbial mat that forms on the surface of water or rocks. They are typically composed of blue-green cyanobacteria and sediments. Formation occurs when alternating layers of blue-green bacteria and sediments are deposited or grow in place, creating dark-laminated layers. Stromatolites are prime examples of algal mats. Algal mats played an important role in the Great Oxidation Event on Earth some 2.3 billion years ago. Algal mats can become a significant ecological problem, if the mats grow so expansive or thick as to disrupt the other underwater marine life by blocking the sunlight or producing toxic chemicals.
Pyrolysis oil, sometimes also known as bio-crude or bio-oil, is a synthetic fuel under investigation as substitute for petroleum. It is obtained by heating dried biomass without oxygen in a reactor at a temperature of about 500 °C (900 °F) with subsequent cooling. Pyrolysis oil is a kind of tar and normally contains levels of oxygen too high to be considered a pure hydrocarbon. This high oxygen content results in non-volatility, corrosiveness, immiscibility with fossil fuels, thermal instability, and a tendency to polymerize when exposed to air. As such, it is distinctly different from petroleum products. Removing oxygen from bio-oil or nitrogen from algal bio-oil is known as upgrading.
Energy crops are low-cost and low-maintenance crops grown solely for renewable bioenergy production. The crops are processed into solid, liquid or gaseous fuels, such as pellets, bioethanol or biogas. The fuels are burned to generate electrical power or heat.
The United States produces mainly biodiesel and ethanol fuel, which uses corn as the main feedstock. The US is the world's largest producer of ethanol, having produced nearly 16 billion gallons in 2017 alone. The United States, together with Brazil accounted for 85 percent of all ethanol production, with total world production of 27.05 billion gallons. Biodiesel is commercially available in most oilseed-producing states. As of 2005, it was somewhat more expensive than fossil diesel, though it is still commonly produced in relatively small quantities.
Biomass, in the context of energy production, is matter from recently living organisms which is used for bioenergy production. Examples include wood, wood residues, energy crops, agricultural residues including straw, and organic waste from industry and households. Wood and wood residues is the largest biomass energy source today. Wood can be used as a fuel directly or processed into pellet fuel or other forms of fuels. Other plants can also be used as fuel, for instance maize, switchgrass, miscanthus and bamboo. The main waste feedstocks are wood waste, agricultural waste, municipal solid waste, and manufacturing waste. Upgrading raw biomass to higher grade fuels can be achieved by different methods, broadly classified as thermal, chemical, or biochemical.
Abengoa, S.A. was a Spanish multinational company in the green infrastructure, energy and water sectors. The company was founded in 1941 by Javier Benjumea Puigcerver and José Manuel Abaurre Fernández-Pasalagua, and was based in Seville, Spain. Its current chairman is Gonzalo Urquijo Fernández de Araoz. After repeated bankruptcies and rescues, it declared insolvency in February 2021 amid various regulatory and financial charges against the board and management, the second-largest corporate collapse in Spanish history.
Acetone–butanol–ethanol (ABE) fermentation, also known as the Weizmann process, is a process that uses bacterial fermentation to produce acetone, n-butanol, and ethanol from carbohydrates such as starch and glucose. It was developed by chemist Chaim Weizmann and was the primary process used to produce acetone, which was needed to make cordite, a substance essential for the British war industry during World War I.
Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass in this context means plant materials and animal waste used especially as a source of fuel.
China has set the goal of attaining one percent of its renewable energy generation through bioenergy in 2020.
Algae fuel, algal biofuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane. When made from seaweed (macroalgae) it can be known as seaweed fuel or seaweed oil.
Algae fuel in the United States, as with other countries, is under study as a source of biofuel.
Biorefining is the process of "building" multiple products from biomass as a feedstock or raw material much like a petroleum refinery that is currently in use.
NNFCC is a consultancy company specialising in bioenergy, biofuels and bio-based products.
