Transportation

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.

The University of Minnesota will design a cell-free biocatalytic system that will reduce CO2 efficiently into formate, an important feedstock for chemicals and fuels, with energy supplied from electricity. Renewable electricity is now competitive with and in many instances less expensive than fossil fuel-derived electricity, but its storage remains challenging. Energy storage in chemical bonds through electricity-driven carbon reduction offers higher energy densities and greater safety and transportability than batteries.

To make the power density of electric aircraft closer to conventional aircraft, an electric power system (EPS) with high power delivery and low system mass is necessary. As an essential component of aircraft EPS, cables are necessary to transmit power from one node to another. Virginia Tech will develop a high-power density, cost-effective ±5 kV cable for twin-aisle all-electric aircraft.

GE Research will develop a safe, lightweight, and altitude-capable megawatt power cable system with electromagnetic interference shielding capability for large aircraft. The proposed 10 MW cable system is expected to achieve ten times greater power density than conventional technology without degradation by partial discharge and is fire safe and oil resistant.

There are two key engineering challenges in the development of 10 kV, 10 MW electric power distribution cables for double-aisle passenger aircraft. One is providing sufficient electrical insulation at high voltages and the second is transferring heat away from the conductors.

The Zero-carbon Ammonia-Powered Turboelectric (ZAPTurbo) Propulsion System is a very high efficiency and lightweight turboelectric system that uses green ammonia as a fuel and coolant via regenerative cooling. Coke-free heating of this carbon-free ammonia fuel enables a high level of waste-heat recovery that will be used for the endothermic cracking of ammonia prior to its combustion, significantly increasing the cycle efficiency. The proposed propulsion system includes an efficient AC electric powertrain for turboelectric cruise, with battery boost for takeoff and climb flight phases.