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Fluid-Bed Gasifier (high-pressure, 20 lb/hr)

Fluid Bed Gasifier
The Fluid-Bed Gasifier (FBG) converts solid fuels into a syngas consisting mainly of hydrogen and carbon monoxide, which can be further processed to produce a synthetic natural gas or to produce liquid fuels via the Fischer–Tropsch (FT) process. The gasifier is gravity-fed and includes gas cleaning to remove moisture and organics.

Operating Conditions

  • Nominal feed rate: 15–20 lb/hr
  • Syngas production: 30–40 scfm
  • System pressure: 600–1000 psi
  • Nominal temperature: 1600°–1800°F (870°–980°C)
  • Warm-gas cleanup capability: full stream

Feedstocks Tested

  • Lignite coal
  • Torrefied and leached olive pits
  • Torrefied dry distillers' grains
  • Switchgrass
  • Untreated dry distillers' grains


The FBG operates in a pure O2- or air-blown mode, depending on the desired syngas composition. The system was designed according to American Society of Mechanical Engineers B31.3 Process Piping Code specifications for operation at maximum operating pressures. The system can be externally electrically heated. The 2500-lb 316H stainless steel flanged connections at the top and bottom of the reactor are limited to maximum operating temperatures. The system is fully instrumented with thermocouples in all key locations to monitor operating temperatures.

The feed system uses a K-Tron loss-in-weight feeder installed inside of the pressure vessel, operating at pressures up to 6.9 MPa (1000 psig). The feed system provides instantaneous measurement of the fuel feed rate, and system electronic controls are interfaced to a data acquisition system for local or remote computer control.

A syngas cleanup train was installed for removal of particulates, S, Hg, trace metals, Cl, and tars. Two sets of three (six total) water-cooled quench pots condense moisture and organics from the product gas stream. These quench pots have been designed for operation at 1000 psig: a design that has proven effective in the removal of organics and moisture without plugging. Water or a cooled glycol and water mixture is circulated through the outer jacket of each quench pot to cool the product gas.