Chromatin will engineer sweet sorghum--a plant that naturally produces large quantities of sugar and requires little water--to accumulate the fuel precursor farnesene, a molecule that can be blended into diesel fuel. Chromatin's proprietary technology enables the introduction of a completely novel biosynthetic process into the plant to produce farnesene, enabling sorghum to accumulate up to 20% of its weight as fuel. Chromatin will also introduce a trait to improve biomass yields in sorghum. The farnesene will accumulate in the sorghum plants--similar to the way in which it currently stores sugar--and can be extracted and converted into a type of diesel fuel using low-cost, conventional methods. Sorghum can be easily grown and harvested in many climates with low input of water or fertilizer, and is already planted on an agricultural scale. The technology will be demonstrated in a model plant, guayule, before being used in sorghum.

CSU is developing technology to rapidly introduce novel traits into crops that currently cannot be readily engineered. Presently, a limited number of crops can be engineered, and the processes are not standardized - restricting the agricultural sources for engineered biofuel production. More--and more diverse--biofuel crops could substantially improve the efficiency, time scale, and geographic range of biofuel production. CSU's approach would enable simple and efficient engineering of a broad range of bioenergy crops using synthetic biology tools to standardize their genetic modification.

The innovation lies in the exploitation of novel natural energy source: reduced metal deposits. The energy released during oxidation of these metals could be used to reduce CO₂ into fuels and chemicals reducing petroleum usage.This proposed project fits within the Chemical-Chemical Area of Interest, as it involves the coupling of the oxidation of reduced minerals in the Earth's crust to the production of reduced carbon chemicals for fuel utilization. This addresses both of Mission Areas of ARPA-E as the co-generation of fuels during copper bioleaching will potentially reduce the import of energy from foreign sources, reduce greenhouse gas emissions, improve energy efficiency in the mining industry, and ensure that the U.S. maintains a lead in the development of this disruptive new technology.

Cornell University will develop a new type of rechargeable lithium metal battery that provides superior performance over existing lithium-ion batteries. The anode, or negative side of a lithium-ion battery, is usually composed of a carbon-based material. In lithium metal batteries, the anode is made of metallic lithium. While using metallic lithium could result in double the storage capacity, lithium metal batteries have unreliable performance, safety issues, and premature cell failure. There are two major causes for this performance degradation. First, side reactions can occur between the lithium metal and the liquid or solid electrolyte placed between the positive and negative electrodes. Second, when recharged, branchlike metal fibers called dendrites can grow on the negative electrode. These dendrites can grow to span the space between the negative and positive electrodes, causing short-circuiting. To overcome these challenges, Cornell proposes research to pair a variety of cathodes with a lithium metal anode. The work builds upon recent theoretical and experimental discoveries by the team, which show that a class of structured electrolytes can provide multiple mechanisms for stabilizing lithium metal anodes and suppress dendrite growth. The team will also develop structured electrolyte coatings that provide barriers to oxygen and moisture, but do not impede lithium-ion transport across the electrolyte/electrode interface. Such coatings will suppress the unwelcome lithium metal/electrolyte reactions and will also enable manufacturing of lithium metal batteries under standard dry room conditions. The structures developed could also be used in batteries based on other metals, such as sodium and aluminum that are more abundant and less expensive than lithium, but also affected by dendrite formation.

The Donald Danforth Plant Science Center, in collaboration with partners from seven institutions, proposes an integrated open-sourced phenotyping system for energy sorghum. Phenotyping is the assessment of observable plant traits, and is critical for breeding improvements. The team will develop a central repository for high quality phenotyping datasets, and make this resource available to other TERRA project groups and the wider community to stimulate further innovations. The team will collect data with their complete system that will include a number of components. First, the team will install, operate, and maintain a reference phenotyping field system that employs a bridge-like overhead structure with a moveable platform supporting sensing equipment, called the Scanalyzer, at the Maricopa Agricultural Center (MAC) at the University of Arizona. The Scanalyzer's advanced sensors will be used for automated high-throughput phenotyping to gather data from the energy sorghum in the field. Second, the project will combine field- and controlled-environment phenotyping. The controlled-environment facilities allow the team to more precisely manipulate environmental conditions and resolve complex dynamic interactions observed in the field. Third, plant and environment data gathered will be used to create computational solutions and predictive algorithms to improve the ability to predict phenotypes; increasing the ability to identify traits for improved biomass yield earlier in a plant's development. Collected data will also be used in the fourth component of the project, advancing our understanding of phenotype-to-genotype trait associations, determining which genes control observable traits in the sorghum. Some traits are largely determined by genes and others are largely determined by environmental factors; work in this project will help elucidate the differences. All of these components generate an incredible amount of data. An "Open Data" policy is central to the philosophy of the Danforth project. To ensure that this data is useful, the team will convene a standards committee selected in collaboration with the TERRA program to standardize phenotyping efforts between institutions. This sharing of standards, data, and open-source code will reduce redundancy, lower costs for researchers, allow for long-term curation, and unlock potential new innovations from entrepreneurs outside the TERRA community.

Eaton is developing an at-home natural gas refueling system that relies on a liquid piston to compress natural gas. A traditional compressor uses an electric motor to rotate a crankshaft, which is tied to several metal pistons that pump to compress gas. Traditional compressor systems can be inefficient and their complex components make them expensive to manufacture, difficult to maintain, and short-lived. Eaton's system replaces traditional pistons with a liquid that comes into direct contact with the natural gas without the need for the costly high-pressure piston seals that are used in conventional gas compression.

Exelus is developing a method to convert olefins from oil refinery exhaust gas into alkylate, a clean-burning, high-octane component of gasoline. Traditionally, olefins must be separated from exhaust before they can be converted into another source of useful fuel. Exelus' process uses catalysts that convert the olefin to alkylate without first separating it from the exhaust. The ability to turn up to 50% of exhaust directly into gasoline blends could result in an additional 46 million gallons of gasoline in the U.S. each year.

GTI is developing a natural gas tank for light-duty vehicles that features a thin, tailored shell containing microscopic valves which open and close on demand to manage pressure within the tank. Traditional natural gas storage tanks are thick and heavy, which makes them expensive to manufacture. GTI's tank design uses unique adsorbent pellets with nano-scale pores surrounded by a coating that functions as valves to help manage the pressure of the gas and facilitate more efficient storage and transportation. GTI's low-pressure tanks would have thinner walls than today's best alternatives, resulting in a lighter, more affordable product with increased storage capacity.

GTI will partner with Northwestern University, NuMat Technologies, a Northwestern start-up company, and Westport Fuel Systems to identify materials with the best characteristics for low-pressure natural gas storage. The gas-storing materials, known as metal organic framework (MOF) adsorbents, hold natural gas the way a sponge holds liquids. The project team will further develop their computer modeling and screening technique to support the creation of a low-pressure adsorbent material specifically designed for natural gas vehicles. The team will also validate the materials properties in real-world conditions. Low-pressure gas tanks represent significant potential for lowering not only the cost of NGVs, but also the cost of fueling by reducing the need to compress the gas.