Tom, Don't get Kevin started on definitions of gasification. :-)
Try http://en.wikipedia.org/wiki/Gasification The plants that received fines do not have gasifiers. The only similarity is that they convert wet wood to steam. They use fluidized bed combustors. They use excess air directly in the fluidized bed of sand. They also burn fuels such as urban wood waste that require acid gas control. An FB combustor allows you to control acid gas directly by adding limestone to the bed to form calcium sulfate or calcium chloride that is removed as a particulate. In a combustor the heat transfer - boiler and convective sections - are integral to the furnace-boiler design. In the Nexterra and other gasifier application the gas is transported from the gasifier to a burner that is in a separate boiler enclosure. (From 1985-1998 Interpretations of the tax code allowed the grate portion of a furnace to be called a gasifier when operated with limited air such that staged combustion within a boiler qualified for a producer gas tax credit. That credit has now expired.) It's important to look at the whole system. Nexterra uses a unique proprietary bed design, a low velocity above the bed that reduces particulate, a partial oxidation step to clean up tars between the gasifier and the burner in the boiler. Tar reduction is similar in concept to what other fixed bed suppliers, like PRM and PrimEnergy, have done for years. Combustible gas is transported from the gasifier to a burner in the boiler. The gas fired in the boiler is clean enough to use the ESP for particulate control. The combination of the low NOx precursors from the gasifier and their burner design allows them good CO and NOx control. Comparative data are in the Levelton report. Tom Miles -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Monday, February 21, 2011 4:05 PM To: [email protected] Subject: Re: [Gasification] Emissions fines Dear Tom, In comparing the Kruger Products installation to the ones which received fines, one might be tempted to say that a fixed bed is better than a fluidized bed, but one would have to compare emission standards between the two jurisdictions to firmly make this claim. The Nexterra design has a relatively high tar yield. The word gasification in my opinion is still misapplied unless the gas can be cleaned and transported across a jurisdictional boundary for use, otherwise, it is still a dual stage combustor. Sincerely, Leland T. "Tom" Taylor President Thermogenics Inc. www.thermogenics.com 505-463-8422 -----Original Message----- From: Tom Miles <[email protected]> To: 'Discussion of biomass pyrolysis and gasification' <[email protected]> Sent: Sun, Feb 20, 2011 8:24 pm Subject: Re: [Gasification] Emissions fines Pulp and Paper Canada (Feb 2011) reporting on a gasifier-boiler application: http://www.pulpandpapercanada.com/issues/story.aspx?aid=1000402062 Kruger's Biomass Gasifier Fuels Customers' Need for GreenBiomass gasification has quantifiable environmental benefits to show customers: fewer GHG emissions, less fossil fuel, better air quality.By: By Tony Kryzanowski _______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
