Supercritical hydrolysis is a

chemical engineering Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials int ...

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 Continuity or continuous may refer to: Mathematics * Continuity (mathematics), the opposing concept to discreteness; common examples include ** Continuous probability distribution or random variable in probability and statistics ** 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 , 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 A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

components of the biomass, usually exemplified by

lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity ...

s, are converted into a water-insoluble liquid mixture of low molecular

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are c ...

(

monomer In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Mo ...

ization). A private company, Renmatix, based in

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, 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 Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the design of products and processes that minimize or eliminate the use and generation of hazardous substances. While environmental che ...

process that utilizes water simultaneously as a heat transfer agent, a solvent, a reactant, a source of hydrogen and as a char-reduction component.

References

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 {{Reflist Environmental chemistry Green chemistry