Transportation Fuels

The University of Washington will develop cell-free (in vitro) platforms that produce functional multi-enzyme systems and perform the cost-effective bioconversion of CO2 into industrial chemicals. Cell-free transcription-translation (TXTL) is a popular, robust approach for producing cell-free biocatalytic systems capable of complex, multi-enzyme reactions.

The University of California, Irvine, proposes a cell-free enzymatic process as the first biological platform to convert carboxylic acids into a broad range of fuels and commodities with greater than 100% carbon efficiency. This is achieved using stabler bioenergy-storage and transmission molecules and specially engineered enzymes. Natural biological pathways for carboxylic acid conversion suffer from a low carbon yield, however.

ZymoChem has created fermentation processes that convert sugars into polymer precursors using microorganisms with novel enzyme-based pathways that avoid the loss of the sugar’s carbon as CO2. ZymoChem will develop two transformational innovations that combine (1) inexpensive metal catalysts from abundant metals for converting electricity and CO2 into formate and (2) electricity-compatible fermentation systems that enable microbes to co-utilize formate and sugars for the production of a high-volume platform fuel and chemical intermediate.

The University of Delaware aims to develop a platform technology based on synthetic syntrophic consortia of Clostridium microbes to enable fast and efficient use of renewable carbohydrates to produce targeted metabolites as biofuels or chemicals. In this syntrophic microbial consortium, two microbial species are co-cultured, allowing the different species to divide individual bioconversion steps and reduce their individual metabolic burden.

The Soil Health Institute aims to develop an integrated, affordable, and user-friendly soil carbon measurement and monitoring system—the DeepC System. The system will be designed to meet current and future needs for farmers, landowners, and agricultural carbon markets nationwide. The system’s three main components are in-field measurement hardware, an optimized spatial sampling algorithm to select measurement sites, and machine learning calibrations that leverage the current infrastructure of national soil spectroscopy libraries.

The agricultural production of crops, the primary source of nitrous oxide (N2O), contributes approximately 4% of all greenhouse gases from the U.S. annually. Quantifying these emissions, which are non-uniform in space and time, is a significant challenge at the field and farm scales. Princeton University’s NitroNet is an autonomous sensing system designed to monitor N2O emissions over an entire growing season at high spatial and temporal resolutions.

Nitricity is developing a non-thermal plasma reactor that uses air, water, and renewable electricity to produce nitrogen fertilizer. If successful, this technology has the potential to economically decarbonize fertilizer production from the Haber-Bosch process, which produces more CO2 than any other chemical-making reaction.

The rate of photosynthetic assimilation and decay of lignocellulosic biomass currently limits carbon drawdown and retention in terrestrial biomass. Living Carbon is developing innovative methods to reduce the susceptibility of vegetative biomass to decay by lignin-eating fungi, thereby reducing the rate of release of carbon dioxide back to the atmosphere through fungal respiration.

OCOchem proposes to build a tall (1800 cm2 ) electrochemical cell, addressing a critical scale-up issue for many processes seeking to convert carbon dioxide into useful products. The cell will be used to convert carbon dioxide, water, and renewable electricity into formic acid. The project will integrate multiple innovative electrolyzer components and materials into a first-of-its-kind single design. If successful, the new process will reduce the cost of formic acid 33%, be based exclusively on renewable energy and feeds, and avoid the use fossil-based inputs.

Green hydrogen, which is produced with renewable energy and electrolysis, can reduce emissions for the ammonia fertilizer, refineries, chemicals, and steel industries that use hydrogen as a feedstock. Existing water electrolysis technologies are expensive due to high materials cost or complex balance-of-plant systems required when using conventional alkaline electrolysis. The ARPA-E IONICS program developed highly conductive, chemically stable anion exchange membranes that are now commercially produced.