MixAlco > The Technology behind MixAlco
MixAlco™ economically converts biomass to biofuel using carboxylic acid fermentation followed by conventional chemistry that processes the resulting carboxylate salts into valuable chemicals that can be further refined through a separate, well-established process to produce renewable biofuels.
This technology has been developed over the past 15 years by Dr. Mark Holtzapple, Professor of Chemical Engineering at Texas A&M University. Terrabon has funded development of the technology and its intellectual property since 1995. Currently, this includes 12 U.S. patents and more than 17 U.S. patent applications as well as numerous others in international markets. Terrabon holds the only world-wide licensing rights from Texas A&M for this unique acid fermentation technology.
MixAlco™ can use such feedstocks as municipal solid waste, sewage sludge, forest product residues including wood chips, wood molasses and other wood waste and non-edible energy crops such as sweet sorghum. The technology uses conventional non-sterile anaerobic digestion and well-established chemistry, resulting in capital and operating costs that are lower than other biochemical or thermochemical technologies.
Here is how:
- The biomass is treated with lime to enhance its digestibility.
- The lime-treated biomass is fermented using a mixed-culture of microorganisms that produces a mixture of carboxylic acids (e.g., acetic, propionic, butyric acids).
- Calcium carbonate is added to the fermentation to neutralize the acids to form their corresponding carboxylate salts (e.g., calcium acetate, propionate, and butyrate).
- These salts are then dewatered, concentrated, dried and thermally converted to ketones, which are hydrogenated to alcohols (e.g., isopropanol, propanol, and butanol).
- Alternatively, after dewatering the fermentation broth, carboxylic acids are "sprung" from the concentrated carboxylate salt solution. In this step, the carboxylate salts react with tertiary amines, forming tertiary amine carboxylates and calcium carbonate. The tertiary amine carboxylates are then thermally cracked, which regenerates the tertiary amine and produces the carboxylic acids as product. The tertiary amine and calcium carbonate are recycled within the process, so no chemicals are consumed. If desired, the final mixed carboxylic acid product can be separated into constituent acids via distillation.
- The carboxylic acids (e.g., acetic acid) can then be hydrogenated to form primary alcohols (e.g., ethanol) or the ketones (e.g., acetone) may also be hydrogenated to make secondary alcohols (e.g., isopropanol).
- The carboxylic acids, ketones, primary alcohols, and secondary alcohols can be refined through a separate, well-established process to produce renewable gasoline, diesel and jet fuel.
MixAlco™
AdVE™
SoluPro™