Projects to address the technological challenges of large-scale hydrogen production from coal

The US Department of Energy has selected six research and development projects that will promote the production of hydrogen from coal at large-scale facilities. This central approach aims to combat climate change by allowing for the capture – and subsequent sequestration – of carbon dioxide generated during hydrogen production. The selections support President Bush’s Hydrogen Fuel Initiative, which provides funding for research and technology development to realize a future hydrogen economy that minimizes America’s dependence on foreign oil and reduces greenhouse gas emissions.

Pure hydrogen is a potential energy carrier for the future, and it may be produced from hydrogen-containing materials such as water and fossil fuels. Until other resources are available to produce hydrogen at lower costs, production from coal is the most economical source. However, the large-scale production of hydrogen from coal faces several technological challenges that must be overcome before its widespread use becomes a reality. To address these challenges, the new cost-shared projects will focus on two areas of interest:

  • Ultra-Pure Hydrogen – Hydrogen has the potential to be used in a number of end-use applications, each having its own purity standard. Some of these end uses include hydrogen turbines, fuel cells, and modified internal combustion engines. Three projects will focus on the development and scale-up of advanced materials and devices for producing ultra-pure hydrogen from coal-derived synthesis gas.
  • Process Consolidation – Strategies are needed for selectively removing pure hydrogen, carbon dioxide, and synthesis gas impurities in a single-reactor configuration that can operate simultaneously at high temperature and high conversion. Three projects will perform a combination of theoretical and experimental research to provide a scientific basis for consolidating multiple processes – synthesis gas cleanup, water-gas shift reaction, hydrogen separation, and carbon dioxide separation – into a single module.

The six projects total nearly $9.4 million in value, with DOE providing $7.4 million and industry partners contributing more than $1.8 million. Praxair (Tonawanda, NewYork state) will develop a device to purify hydrogen before it is fed to a proton exchange membrane (PEM) fuel cell. At the heart of the device will be a palladium alloy-based hydrogen transport membrane that only allows hydrogen atoms to pass through its structure. The device will be integrated with a PEM fuel cell and designed such that, when it is produced in mass quantities, it is potentially the lowest-cost, most effective method to ‘polish’ crude hydrogen, independent of the source. Praxair will be joined by Praxair Surface Technologies (Indianapolis), the Colorado School of Mines (Golden), and Boothroyd Dewhurst (Wakefield, Rhode Island).

Southwest Research Institute (San Antonio, Texas) will develop and demonstrate a durable, ultra-thin (less than 5 micron) hydrogen-separation membrane with excellent resistance to sulphur and halides. The palladium alloy-based membrane is expected to meet or exceed DOE’s cost and performance targets for 2010. Partners with Southwest Research Institute in this effort are the Colorado School of Mines, Carnegie Mellon University (Pittsburgh) and TDA Research (San Antonio, Texas).

United Technologies Research Center (East Hartford, Connecticut) will undertake research, technology development, and economic analysis to further develop a sulphur-, halide-, and ammonia-resistant hydrogen-separation membrane. Based on alloys of palladium, copper, and transition metals, the membrane will potentially have commercially relevant hydrogen production flux and be capable of operating at high temperature and pressure. The United Technologies Research Center will collaborate with Power+Energy (Ivyland, Pennsylvania) and Metal Hydride Technologies (Burlington, Vermont) for this research.

Media and Process Technology (Pittsburgh) will explore a membrane-based ‘one box’ process to generate low-cost hydrogen from coal. Cooled and particulate-free synthesis gas will be passed through a single reactor that converts the synthesis gas to hydrogen and carbon dioxide and separates the two using a carbon molecular sieve membrane. Bench-top testing will be conducted during year 1 of the three-year project, slip-stream testing will be conducted in year 2, and pilot-scale testing and cost analysis will be performed in year 3. Partnering with Media and Process Technology will be the University of Southern California (Los Angeles), Pall Corp (Port Washington, New York), and Southern Co (Wilsonville, Alabama).

Ohio State University (Columbus, Ohio) will develop a process to produce high-purity hydrogen from synthesis gas in a single-stage reactor. The process will employ a calcium looping scheme in which a patented calcium oxide sorbent removes carbon dioxide from synthesis gas by forming calcium carbonate; the calcium carbonate is calcined to produce a pure stream of carbon dioxide and calcium oxide, which is recycled back into the process. The continuous removal of carbon dioxide enhances the ‘water-gas shift’ reaction – the conversion of synthesis gas into hydrogen and carbon dioxide – and enhances the purity and yield of hydrogen. Researchers at Ohio State will partner with Clear Skies Consulting (Cornelius, North Carolina) and CONSOL Energy (Pittsburgh).

Worcester Polytechnic Institute (Worcester, Massachusetts) will investigate the use of composite palladium and palladium-alloy porous stainless steel membranes to reduce the number of unit operations needed to produce hydrogen from synthesis gas at an advanced integrated gasification combined cycle power plant. The research will include developing processes to remove sulphur compounds from synthesis gas, synthesizing composite palladium and palladium-alloy porous stainless steel membranes, testing the membranes to demonstrate their effectiveness and long-term stability, developing comprehensive process intensification and control and monitoring strategies, and performing economic analysis. Worcester Polytechnic Institute will collaborate with Adsorption Research (Dublin, Ohio) on this project.