|Schematic of GE gasifier in an IGCC application.|
DKRW will use GE’s coal gasification technology in its proposed Medicine Bow, Wyoming coal-to-liquids (CTL) plant. The first phase of the Medicine Bow project is designed to produce approximately 11,000 bpd of Fischer-Tropsch diesel and other fuels from Carbon Basin coal.
In January, DKRW announced it would use Rentech’s Fischer-Tropsch (FT) coal-to-liquids (CTL) technology in the plant. (Earlier post.) The GE gasifier will provide the syngas that feeds into Rentech’s F-T process.
We chose GE because of its leadership in the coal gasification technology industry. We believe that utilizing US-based technology, such as GE’s, is an important step in making the US less dependent on foreign energy sources while improving its technology for the future. This agreement completes a major set of feedstock and technology agreements needed to move forward with the Medicine Bow Project.—Robert Kelly, Executive Officer of DKRW and Medicine Bow Fuel & Power
GE Energy acquired the assets of Chevron’s (then Chevron Texaco) gasification technology business in June 2004. More than 65 commercial gasification facilities using the technology are in operation or advanced development stages, but this marks its first application in a CTL process.
The GE gasifier is an entrained flow gasifier, as are the systems from Shell and E-Gas (Conoco-Phillips). The GE system uses a coal in water slurry in a single-stage downflow reactor configuration.
The dry solids concentration in the slurry is typically around 65%. A pump delivers the slurry to the gasifier at a pressure of up to 80 bar. The gasifier is refractory lined and typically operates at around 1,400° C.
According to an analysis by MIT’s Laboratory for Energy and the Environment (LFEE), the Shell technology has the highest efficiency and the highest capital cost, while the GE technology has the lowest efficiency and the lowest cost.
DKRW entered into an agreement with Arch Coal, the second largest U.S. coal miner owner and operator, for the purchase of the high-BTU, low-sulfur Carbon Basin Coal Reserve. Arch will be the constructor and operator for the Medicine Bow coal mine which is sufficient to support the first phase of the CTL project and expansion up to 40,000 bpd.
The project will transport diesel and other fuels via pipeline to energy companies in the region. Power, carbon dioxide, and other products will be produced and sold from the Project. The power will be produced in steam turbines from steam generated from the GE licensed gasification process. The end result is that the project’s power is projected to be produced with very low carbon dioxide and SOx emissions.
LFEE: An Overview of Coal-Based Integrated Gasification Combined Cycle Technology (September 2005)