Description:
The United States currently produces about 10 million tons of hydrogen per year, primarily for use at petroleum refineries and for the production of ammonia and methanol. Today, nearly all of hydrogen produced in the US is derived from natural gas via steam methane reforming, a process which converts natural gas and water into hydrogen and carbon dioxide. Steam methane reforming, which is done almost exclusively in centralized facilities, offers the lowest factory gate cost of hydrogen (~$1.0‐$1.2/kg), but also produces large quantities of carbon dioxide (9‐14 kgCO2/kgH2). While the market demand for hydrogen from steam methane reforming has remained relative steady over the last few years, there is a significant growth potential for hydrogen with a small CO2 footprint in electricity production, transportation, and novel chemical processes. Already, hydrogen use in the transportation sector has seen rapid growth with 500 megawatts of fuel cells shipped worldwide in 2016. Current options for producing hydrogen with little or no release of carbon dioxide include electrolysis of water to hydrogen and oxygen and steam methane reforming with CO2 capture and sequestration. A third option is to split methane directly into hydrogen and elemental carbon at high temperatures. The hydrogen produced in this process, which is also known as methane pyrolysis or methane cracking, would contain roughly half the embodied energy of the natural gas feedstock, while the carbon could be used as a product. Carbon products that have been produced via methane pyrolysis include metallurgical coke, carbon black, graphite, carbon nanotubes, and carbon fiber.
While ARPA‐E has already selected for award negotiations a small number of methane pyrolysis projects as part of the OPEN 2018 funding opportunity, ARPA‐E has identified an ongoing need to better understand the formation and control the production of specific carbon structures in a process environment that is simultaneously suitable for the economical production of hydrogen at scale (> 10,000 tons/yr.) with a low CO2 footprint.
ARPA‐E is specifically interested in integrated and scalable catalytic approaches that can economically convert natural gas to both fuel cell‐grade hydrogen and higher value carbon materials such as carbon fiber or other structural materials with a low CO2 footprint.
While scalable hydrogen production is the ultimate goal, the emphasis is to advance the identification, understanding, and control of new reaction conditions and processes necessary to direct carbon formation towards desirable product targets. Critical consideration should also
be given to both (i) the separation techniques required to economically recover the targeted grades of carbon, and (ii) advanced monitoring tools (in‐situ and ex‐situ) to enable fundamental understanding of carbon‐carbon bond formation, rearrangement, and intermolecular
aggregation into valuable carbon products under current methane pyrolysis conditions (20 bar; 800–1100 oC), in ways that are applicable for real‐time process monitoring and control (i.e. low latency).
