STTR Phase I: Novel Bioprocess for Natural Gas Conversion

The broader impact/commercialization potential of this Small Business Technology Transfer (STTR) Phase I project is to produce an important platform chemical, hexanoic acid. Currently, the 6-carbon compounds are difficult to attain since crude petroleum contains just a small fraction in this carbon range as part of light naphtha. Most of the 6-carbon compounds are produced via multiple steps that constitute conversion of olefins derived from light naphtha. The various 6-carbon compounds include hexanol, hexene, caprolactam and hexa-easters. All of these compounds are direct derivatives of hexanoic acid. The proposed technology will manufacture hexanoic acid using a novel bioprocess, which will provide an alternative source for this chemical at a reduced cost. Current direct market uses of hexanoic acid include artificial flavors, rubber chemicals, varnish driers, resins and pharmaceuticals. It can be converted to hexene, caprolactam (nylon feedstock). These value addedá-olefins, polymers and premium lubricant industry feedstocks, become excellent candidates for early commercialization. In addition, hexanoic acid can be converted to decane, a jet fuel component via decarboxylation and radical coupling chemistry. Thus, longer-term prospects exist for using the proposed innovation to penetrate a>$300 Billion jet fuel market. This STTR Phase I project proposes to develop a novel microbial strain to convert methanol to hexanoic acid. The primary objective of this project is to demonstrate techno-economic feasibility of methanol conversion to hexanoic acid. The overall estimated carbon yield and energy efficiency are significantly higher compared to state of the art. The biological pathway consists of two elements added to an acetogenic host: (1) Addition of methanol oxidation reactions to provide reductant; and (2) Extension of the chain length of the acid formed. Methanol oxidation will use well-known pathways from known organisms and reactions capable of operation without oxygen in the utilization of methanol and H2/CO2. The chain length will be extended by using the basic pathway of Clostridium and known enzymes to form hexanoic acid. At the end of the project, a novel strain will be developed that can convert methanol to hexanoic acid in a single step. A preliminary assessment of the overall process will be performed and compared to the current commercial manufacturing process.