Supercritical hydrolysis is a chemical engineering process in which water in the supercritical state can be employed to achieve a variety of reactions within seconds. To cope with the extremely short times of reaction on an industrial scale, the process should be continuous. This continuity enables the ratio of the amount of water to the other reactants to be less than unity which minimizes the energy needed to heat the water above 374 °C (705 °F), the critical temperature. Application of the process to biomass provides simple sugars in near quantitative yield by supercritical hydrolysis of the constituent polysaccharides. The phenolic polymer components of the biomass, usually exemplified by lignins, are converted into a water-insoluble liquid mixture of low molecular phenols (monomerization).
A private company, Renmatix, based in King of Prussia, PA, has developed a supercritical hydrolysis technology to convert a range of non-food biomass feedstocks into cellulosic sugars for application in biochemicals and biofuels. It has a demonstration facility in Georgia, currently capable of processing three dry tons of hardwood biomass into cellulosic sugar daily. In Australia, a government-sponsored entity called Licella, is similarly transforming sawdust. Both processes require high ratios of water to the amount of feedstock. This energy profligacy can be avoided by the use of a plastic-type extruder through which the solid, but wet, biomass is conveyed to a small inductively heated reaction zone as shown by Xtrudx Technologies Inc of Seattle.
Supercritical hydrolysis can be considered a broadly applicable green chemistry process that utilizes water simultaneously as a heat transfer agent, a solvent, a reactant, a source of hydrogen and as a char-reduction component.
The pyrolysis process is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements pyro "fire", "heat", "fever" and lysis "separating".
Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages, used as fuel. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. The first production car running entirely on ethanol was the Fiat 147, introduced in 1978 in Brazil by Fiat. Ethanol is commonly made from biomass such as corn or sugarcane. World ethanol production for transport fuel tripled between 2000 and 2007 from 17×109 liters (4.5×10 9 U.S. gal; 3.7×10 9 imp gal) to more than 52×109 liters (14×10 9 U.S. gal; 11×10 9 imp gal). From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. In 2011 worldwide ethanol fuel production reached 8.46×109 liters (2.23×10 9 U.S. gal; 1.86×10 9 imp gal) with the United States of America and Brazil being the top producers, accounting for 62.2% and 25% of global production, respectively. US ethanol production reached 57.54×109 liters (15.20×10 9 U.S. gal; 12.66×10 9 imp gal) in May 2017.
A supercritical fluid (SCF) is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist, but below the pressure required to compress it into a solid. It can effuse through porous solids like a gas, overcoming the mass transfer limitations that slow liquid transport through such materials. SCF are much superior to gases in their ability to dissolve materials like liquids or solids. In addition, close to the critical point, small changes in pressure or temperature result in large changes in density, allowing many properties of a supercritical fluid to be "fine-tuned".
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions of transesterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols. The alcohols used should be of low molecular weight. Ethanol is the most used because of its low cost, however, greater conversions into biodiesel can be reached using methanol. Although the transesterification reaction can be catalyzed by either acids or bases, the base-catalyzed reaction is more common. This path has lower reaction times and catalyst cost than those acid catalysis. However, alkaline catalysis has the disadvantage of high sensitivity to both water and free fatty acids present in the oils.
The Fischer–Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen or water gas into liquid hydrocarbons. These reactions occur in the presence of metal catalysts, typically at temperatures of 150–300 °C (302–572 °F) and pressures of one to several tens of atmospheres. The process was first developed by Franz Fischer and Hans Tropsch at the Kaiser-Wilhelm-Institut für Kohlenforschung in Mülheim an der Ruhr, Germany, in 1925.
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:
Glucose syrup, also known as confectioner's glucose, is a syrup made from the hydrolysis of starch. Glucose is a sugar. Maize (corn) is commonly used as the source of the starch in the US, in which case the syrup is called "corn syrup", but glucose syrup is also made from potatoes and wheat, and less often from barley, rice and cassava.p. 21
Iogen Corporation is a Canadian company based in Ottawa, Ontario, Canada, and was founded by Patrick Foody Sr. in 1975.
Biomass to liquid is a multi-step process of producing synthetic hydrocarbon fuels made from biomass via a thermochemical route.
Bioconversion, also known as biotransformation, is the conversion of organic materials, such as plant or animal waste, into usable products or energy sources by biological processes or agents, such as certain microorganisms. One example is the industrial production of cortisone, which one step is the bioconversion of progesterone to 11-alpha-Hydroxyprogesterone by Rhizopus nigricans. Another example is the bioconversion of glycerol to 1,3-propanediol, which is part of scientific research for many decades.
Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Each has distinct chemical behavior. Being a composite of three very different components makes the processing of lignocellulose challenging. The highly evolved resistance to degradation or even separation is referred to as recalcitrance. Overcoming this recalcitrance to produce useful, high value products requires a combination of heat, chemicals, enzymes, and microorganisms. These carbohydrate-containing polymers contain different sugar monomers and they are covalently bound to lignin. Lignocellulosic biomass can be broadly classified into virgin biomass, waste biomass, and energy crops. Virgin biomass includes all naturally occurring terrestrial plants such as trees, bushes and grass. Waste biomass is produced as a low value byproduct of various industrial sectors such as agriculture and forestry. Energy crops are crops with high yield of lignocellulosic biomass produced to serve as a raw material for production of second generation biofuel; examples include switchgrass and Elephant grass.
Abengoa, S.A. is 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 is 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.
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.
Superheated water is liquid water under pressure at temperatures between the usual boiling point, 100 °C (212 °F) and the critical temperature, 374 °C (705 °F). It is also known as "subcritical water" or "pressurized hot water". Superheated water is stable because of overpressure that raises the boiling point, or by heating it in a sealed vessel with a headspace, where the liquid water is in equilibrium with vapour at the saturated vapor pressure. This is distinct from the use of the term superheating to refer to water at atmospheric pressure above its normal boiling point, which has not boiled due to a lack of nucleation sites.
Reactive flash volatilization (RFV) is a chemical process that rapidly converts nonvolatile solids and liquids to volatile compounds by thermal decomposition for integration with catalytic chemistries.
Hydrothermal liquefaction (HTL) is a thermal depolymerization process used to convert wet biomass, and other macromolecules, into crude-like oil under moderate temperature and high pressure. The crude-like oil has high energy density with a lower heating value of 33.8-36.9 MJ/kg and 5-20 wt% oxygen and renewable chemicals.
Inbicon is a Danish company that produces cellulosic ethanol.
Cellulosic sugars are derived from non-food biomass (e.g. wood, agricultural residues, municipal solid waste). The biomass is primarily composed of carbohydrate polymers cellulose, hemicellulose, and an aromatic polymer (lignin). The hemicellulose is a polymer of mainly five-carbon sugars C5H10O5 (xylose). and the cellulose is a polymer of six-carbon sugar C6H12O6 (glucose). Cellulose fibers are considered to be a plant’s structural building blocks and are tightly bound to lignin, but the biomass can be deconstructed using Acid hydrolysis, enzymatic hydrolysis, organosolv dissolution, autohydrolysis or supercritical hydrolysis.
Ethanol Producers Magazine 2012, 18(3), 70-72 US Patent 7,955,508 June 11, 2011 US Patent 8,057,666 November 15, 2011 US Patent 8.890,143 March 17, 2015