Editorial: DOE Clean-Coal Technology Project Pays Off
The technology to produce methanol from coal, which could be a very important source of liquid fuel, has been known for some time but was cost prohibitive. Now, in what is claimed to be one of the Department of Energy's most successful Clean Coal Technology projects, Air Products Liquid Phase Conversion Co. LP, a partnership between Air Products and Chemicals Inc. and Eastman Chemical Co., successfully completed a nearly 11-year project to demonstrate an advanced method to make methanol from coal. The project was one of 38 joint government-industry clean coal technology demonstration ventures funded by the Energy Department in a program originally started during the Reagan Administration.
Prior to the project, Eastman made methanol using coal or synthesis gas from its Coal Gasification Facility. The synthesis gas was reacted to methanol in a fixed catalyst bed reactor. The Clean Coal Technology project demonstrated a new, more effective way to carry out the coal gas-to-methanol synthesis step with enhanced feedstock flexibility. In the 1980s, a joint Air Products-DOE research project improved the process by suspending the catalyst in an inert mineral oil, and bubbling the coal gases through the slurry. In 1989, the Energy Department co-funded a proposal by Air Products to scale up the Liquid Phase Methanol (LPMEOHTM) process to full commercial size. Project plans were outlined in 1992 and plant construction began in 1995. The first production of methanol occurred in April 1997, and operation reliability was 97.5% percent during a demonstration phase from 1998 through 2000-the best of any of the original Clean Coal Technology projects co-funded by the Energy Department in the late 1980s and early 1990s.
The methanol not only provided a chemical feedstock for Eastman, but also, some methanol was used in tests to determine whether coal-derived methanol (free of sulfur and other impurities) could replace petroleum in transportation, be used as a peaking fuel in combustion turbines, or supply a source of hydrogen for fuel cells. The result: Stabilized as-produced methanol can be used directly in fuel flexible vehicles, gas turbines, and diesel generators with little affect on performance and fuel economy. The methanol needs to be purified to use it as a source of hydrogen for a phosphoric acid fuel cell.
According to DOE, LPMEOHTM technology and the application of methanol to transportation and power generation systems offers benefits to integrated gasification combined cycle electric power plants, which traditionally have been viewed as strictly baseload power generation technology. Now, central clean coal technology processing plants that make coproducts of electricity and methanol could simultaneously meet the needs of local communities for dispersed power, transportation fuels and manufactured chemical products.
One of DOE's top priorities is to develop a multiproduct coal plant; that is, a plant that would co-produce hydrogen and other chemical compounds simultaneously with the generation of electricity.
With an estimated known and undiscovered U.S. coal reserves of about four-trillion tons, the aim of developing of cost-effective methanol-from-coal technology looks like it hit the bull's-eye.