Project Synopsis

Provide an evaluation and recommendations for improving an existing syngas cleaning system feeding an a large engine used for electric power generation.

Project Summary


The client, a major international producer of industrial machines and large engines, had purchased three biomass (wood) gasifiers.  The gasifiers were originally designed to provide a low BTU syngas that was used in a kiln for drying.  The client had developed a new use for the syngas, namely making electrical power by burning the syngas in an internal combustion engine designed to run off of natural gas (methane).  The engine required a clean, cool, and dry syngas stream.  The client had designed and was operating a syngas cleaning system to produce a gas conducive for use in the engine, however the system was not performing as required.  Process Engineering Associates, LLC (PROCESS) was contracted to execute an operational evaluation of the system based on its previous design and operating experience with similar systems.

The syngas cleaning system was designed to remove tars and water.  The tars included heavy tars (heavier than naphthalene), solids-forming tars (napthalenes), and light tars (benzene/toluene).

Project tasks included the following:

  • Developing a process simulation model, utilizing PROCESS‘ licensed commercial computer process simulation software (CHEMCAD), based on data provided by the client
  • Producing a mass and energy balance of the heat recovery and syngas processes
  • Performing an on-site visit to witness the process in operation
  • Interviewing operations personnel to gather pertinent operating facts, including determining how close to steady state the system currently operated.

Major findings were that the system had considerable problems removing the solids-forming tars from the oil and water streams.  These tars tended to accumulate and plug demisters, packing, suction pipes, and coolers.  It was recommended that the client avoid using a chiller to additionally cool the syngas stream because the tar carryover was a result of diffusion and it was determined that no amount of chilling alone would allow the syngas to meet the engine requirements.  PROCESS instead helped the client improve the existing cooling systems, recommended adding filtration to the liquid oil streams, and a demister to the system to remove the carryover tars.

Industry Type

  • Power Equipment Manufacturing

Utilized Skills

  • Process troubleshooting
  • Syngas cleaning systems design

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