Process description

First, the feed dust is prepared in the feed preparation unit. Approximately 80% of the dust is smaller than 0.1 mm and has a water content of approx. 1-2 wt.% in the case of hard coals and approx. 8-10 wt.% in the case of lignite. This feed dust is then gasified in the PRENFLO® gasifier using oxygen and steam as gasification agents. The gasification temperature is higher than the ash melting temperature, which allows the coal ash to be removed as slag. The cooled-type gasifier is equipped with multiple, horizontally arranged burners.

In the PRENFLO® Process with Steam Generation (PSG), the raw gas produced, which contains mainly carbon monoxide and hydrogen, is cooled in the waste heat boiler, generating steam. The gas is then dedusted in a candle filter and further treated in a Venturi scrubber.

The slag from the gasifier can be used as a construction material and the fly ash from the candle filter as a base product in the cement industry.

PRENFLO® technology is used at the world’s largest solid-feedstock-based IGCC power plant in Puertollano, Spain.

This plant operates with a mixture of petroleum coke and coal. The following tables show the feedstock composition and an analysis of the raw gas produced.

Main features of the PSG process:

  • Entrained-flow
  • Dry dust feed for high efficiency
  • Multiple burners with high availability and long lifetime
  • Horizontally arranged burners for high carbon conversion
  • Membrane wall with long lifetime
  • Waste heat boiler for efficient heat recovery
  • Operates above ash melting point