British Gas/Lurgi (BGL) Slagging Gasifier
The BGL slagging gasifier is an extension of the Lurgi pressure gasification technology developed by British Gas and Lurgi with the ash discharge designed for slagging conditions. Initial work took place in the 1950s and 1960s but ceased with the discoveries of natural gas in the North Sea. Work resumed in 1974 after the “oil crisis.” An existing Lurgi gasifier in Westfield, Scotland was modified for slagging operation and operated for several years, proving itself with a wide range of coals and other solid feedstocks, such as petroleum coke. The motivation for the development of a slagging version of the existing Lurgi gasifier included a desire to:
• Increase CO and H2 yields (at the expense of C02 and CH4).
• Increase specific reactor throughput.
• Have a reactor suitable for coals with a low ash-melting point.
• Have a reactor suitable for accepting fines.
• Reduce the steam consumption and consequent gas condensate production.
The decline in interest for coal gasification generally in the 1980s prevented commercialization of the technology. In the mid-1990s the first commercial project was realized at Schwarze Pumpe in Germany, where a mixture of lignite and
municipal solid waste (MSW) is gasified within a large complex and the syngas is used for methanol and power production (Hirschfelder, Buttker, and Steiner 1997). A number of other projects also for MSW gasification are currently under consideration.