(12c) Doe Thermal Conversion with Carbon Capture and Storage R&D

This is an unprecedented time in history for hydrogen with interest being amplified worldwide due to its potential to address the climate crisis as well as energy security and resiliency. Though there are major challenges, zero and low-carbon hydrogen can be a key part of a comprehensive portfolio of solutions to achieve a sustainable and equitable clean energy future. The US Department of Energy’s Fossil Energy and Carbon Management Office is investing significant R&D in low-carbon hydrogen derived from fossil, waste and biomass feedstocks, primarily through gasification, coupled with carbon capture and storage, and clean hydrogen from solid oxide electrolyzers. The Office’s efforts are an integral part of the Department of Energy's (DOE) recently launched Hydrogen Shot, with a goal of reducing clean hydrogen costs by 80% to $1 per 1 kilogram (kg) within 1 decade (1-1-1). For gasification systems, DOE is investing in: Using novel microwaves for enhanced gasification robustness and quality: This activity area aims to advance waste cleanup/gasification technology by developing microwave enhancements that produce valuable hydrogen from organic impurities in syngas that might survive the primary gasification process. Addressing the concerns of condensable organic species in raw syngas increases the likelihood of commercial sector adoption of flexible and variable waste-feedstocks to clean hydrogen production. Incorporating microwave technology at a gasifier’s exit offers the promise of converting any remaining complex molecules into simple molecules like hydrogen, which will improve the systems reliability, availability, and maintainability, all of which allows greater impact on generating clean electricity with net-zero carbon emissions.

Enhanced biomass pretreatment processes: This activity area aims to develop, investigate, and advance the TRL of various novel biomass pretreatment techniques. Biomass-based systems are severely limited in scope due to two key issues: feeding materials into the gasification process, and accessing, transporting, and storing the material in a low- or zero-carbon method, from a lifecycle perspective. Development of these technologies focuses on addressing these two key issues.

Clean hydrogen production systems integration & optimization: This activity area focuses on integration of components within systems, hybridization of processes, and improving process reliability, to optimize hydrogen production efficiency and cost reductions given scale of the system, feedstock availability, and market factors.

Scale-up of moderate-TRL advanced oxygen production technologies: The activity area aims to advance the Technology Readiness Level (TRL) of emerging oxygen production technologies from air separation. Scale-up will allow for maturation of novel, highly efficient, and lower cost oxygen production technologies from DOE’s national labs into commercially-relevant prominence, thus facilitating interest from the commercial sector and attracting technology transfer partner(s). Lower cost oxygen is crucial to enable gasification to leverage pre-combustion carbon capture and produce clean hydrogen at a low enough cost to meet the Hydrogen Shot initiative’s goal. This technological maturation activity will improve the viability and economics of net-zero carbon gasification systems.

An additional important aspect of low-carbon hydrogen production from these sources is the carbon capture component. Key RDD&D challenges in this space include: Improving Scalability – providing economic viability at all relevant process scales; Optimizing Thermodynamics – reducing energetic requirements through better regeneration energy, lower pressure drops, lower required temperatures, and process optimization; Improving Kinetics – improving equipment through faster, more selective chemical/physical separation pathways; Reducing Capital Cost – reducing equipment size and costs through advanced manufacturing, process intensification, integration, and optimization; Improving Durability – providing rugged long-term performance with slow degradation rates; Improving Flexibility – improving process dynamics by improving turn down and operation at variable capture rates; Minimizing Environmental Impact – providing technologies that minimize air pollution release and minimizing waste generation. DOE’s Office of FECM will be funding many Front End Engineering Design projects and pilot scale CCS projects. R&D for CO2 capture technologies such as non-aqueous solvents, membranes, advanced sorbents, and cryogenic processes continues and may lead to significantly decreased energy needs. DOE will rely on advanced computational tools for rational material discovery, design of advanced capture systems components, use of advanced manufacturing, and synthesis of these materials with characterization of their physical properties.

Besides the work being funded by FECM on clean hydrogen production, FECM is also funding CO2 conversion to fuel technologies. Each conversion technology comes with challenges and opportunities. A critical challenge across conversion technology pathways (catalytic conversion and bio-mediated) is the cost-effective, energy-efficient, and selective upgrading of CO2. CO2 is a stable, non-reactive molecule that typically requires heat or electricity, and other reactants to be converted into products. This program works to address the need for enabling technologies, including using carbon-neutral hydrogen as a reactant in the synthesis of fuels and chemicals. The efficiency of reaction conversion and energy use of these utilization processes also represent critical challenges. The Carbon Conversion program supports lab- and bench-scale carbon conversion technologies that have the potential to develop carbon-based products that promise GHG and environmental benefits over incumbent products. Areas of research include, but are not limited to, new projects focused on the catalytic conversion to higher value products such as fuels, chemicals, and polymers; generation of synthetic aggregates; and algal systems with high CO2 utilization efficiency of conversion to various bioproducts. The program aims to continue investment activities from the past, such as reactive capture and conversion, and progress first generation conversion technologies to field-scale testing. Additional efforts will include guidance on benchmarking prototypical catalytical conversion, such as electrochemical reduction for carbon conversion, as well as developing techno-economic analysis (TEA) guidance for screening various technology pathways or product markets.

DOE FECM’s is also investing in Reversible Solid Oxide Fuel Cells (R-SOFCs) which can use 100% hydrogen or hydrocarbon fuels to produce electricity, water and CO₂ when operating in a fuel cell mode. R-SOFCs can be configured to operate in reverse as an electrolyzer using power and water as inputs to produce hydrogen, with oxygen as a byproduct. This electrolyzer mode turns the R-SOFC into a Solid Oxide Electrolyzer Cell (SOEC). SOECs essentially function as an SOFC in reverse and optimize the use of these system to reduce overall costs. The carbon dioxide produced from the process with natural gas as a fuel in a fuel cell mode can then be sequestered for storage or use in other applications.

R-SOFCs can both store and produce energy with a single system and can contribute to clean energy generation/storage when paired with a renewable fuel such as hydrogen (in fuel cell mode) or renewable electricity (in electrolysis mode). Hydrogen created from R-SOFCs is a promising fuel source and can be stored for future use when renewable energy sources are not available. When the grid demands power, the R-SOFC consumes the stored hydrogen to produce electricity. R-SOFCs allow for a continuous stream of clean energy into the grid.

The focus areas for Reversible Solid Oxide Fuel Cells Program include:

• Developing and validating the materials proposed for improving the cost, performance, and reliability of R-SOFC systems; and
• RDD&D for degradation at start-up of SOEC operation and enabling technologies for dynamic operation of SOEC/SOFC Systems.