The carboxylate platform capitalizes on fermentations that are thermodynamically driven, and hence does not require sterile operating conditions or genetic engineering. Without the need for externally added enzymes, these fermentations depolymerize biomass components (e.g., cellulose) into monomers (e.g., glucose), which are fermented to carboxylate salts (e.g., acetate).
Industrially, a methane-inhibited anaerobic digester can convert nearly all biomass components into carboxylate salts, which can be chemically transformed into a wide variety of chemicals and hydrocarbon fuels. Some key intermediate steps require hydrogen, which can be derived from gasified biomass residues.
Alternatively, hydrogen can be derived from reformed natural gas, thus creating opportunities for a hybrid system that uses both biomass and abundant natural gas.
This article explores the biochemistry behind the carboxylate platform, and details the advantages of this upcoming platform over the more-established sugar and thermochemical platforms.