Calysta, Inc. reported that it has achieved 8-fold improved performance over traditional fermentation technologies in a high mass transfer bioreactor. The bioreactor technology is under development for efficient methane-to-liquids fermentation processes, enabling rapid, cost-effective methane conversion into protein, industrial chemicals and fuels. (Earlier post.)
The improved performance was achieved in the research phase of a program funded in part by the Department of Energy’s ARPA-E program under the REMOTE program (Reducing Emissions using Methanotrophic Organisms for Transportation Energy), awarded in September 2013. (Earlier post.) Calysta develops sustainable industrial products using novel natural gas conversion technology using methane.
Stirred tanks, which are traditionally used for fermentation processes, are extremely inefficient for gas-fed fermentation, achieving only a small percentage of the potential productivity at high cost. Calysta’s technology is the only validated, commercial scale process available to directly convert natural gas into biological products. Using Calysta’s proprietary reactor design—from our recent acquisition of BioProtein (earlier post)—we have now demonstrated the ability to substantially improve the rate and efficiency of methane usage in a bioreactor. The improved technology platform we are developing can be applied to a wide range of gaseous feedstocks and biological products, addressing the key bottlenecks in developing low cost, sustainable fermentation processes.—Josh Silverman, Ph.D., Calysta Chief Technology Officer
Calysta’s Biological Gas-to-Liquids (BioGTL) platform is based on biological conversion of methane. The design of the company’s loop reactor technology allows for maximal transfer of multiple gaseous feedstocks into solution to allow rapid and efficient conversion by the microorganisms.
The unique feature of Calysta’s loop reactor design is the use of rapid liquid flow to drive the gas mixtures downwards against gravity faster than the normal rise rate of the bubbles. This leads to pressurization of the gas in situ, improving the rate of dissolution of the gas into the liquid. The liquid flow is achieved using pumps which operate at significantly lower energy costs relative to traditional stirred tanks while achieving orders of magnitude increases in mass transfer rates.
Calysta is developing integrated biocatalyst-reactor solutions based on its proprietary biocatalytic coating technology. Biocatalytic coatings are biocomposite materials, in which living microorganisms are immobilized in thin, nano-structured polymeric matrices. These coating-enabled reactor designs overcome key hurdles in traditional biocatalysis and are particularly well suited for multi-phase processes, such as gas-liquid processes (e.g. methane fermentation, CO2 sequestration, partial oxidations), the company says.
Gaseous feedstocks such as methane represent the next generation of biological feedstocks due to their abundance, sustainability, low cost, and the beneficial climate impact of their capture. However, due to limited solubility, optimizing and improving reactor technology is a key bottleneck in the successful deployment of gas-fed biological systems. It is important to note that Calysta’s new developments in this area can be applied to a wide range of both feedstocks and products.—Josh Silverman