Analysis of a wood-fueled trimburner system for use in a combined-cycle, wood-fired power plant Public Deposited


Attribute NameValues
Abstract or Summary
  • This report investigates the use of wood to fuel a trimburner incorporated in a combined-cycle, biomass-fired power plant. The term "trimburner" applies to a ductburner which is designed to boost the temperature of the air stream entering the gas turbine. The work presented here is part of a larger biomass energy project at Oregon State University. Wood conversion processes capable of producing a clean synthetic fuel were investigated since direct wood combustion products are too "dirty" to be allowed to pass through the turbine blading. Of the three wood conversion processes considered (pyrolysis, gasification, methanol production), gasification was selected as the most applicable process for the trimburner concept. Three wood-fueled trimburner systems were then developed employing an up-draft gasifier design. These sub-systems, designated A, B, and C, differ in the way the producer gas formed in the gasifier was compressed to the trimburner operating pressure. Sub-system A compresses the producer gas after the gasifier, thus simulating the operation of an atmospheric gasifier. Sub-systems B and C compress the inlet air entering the gasifier and, therefore, simulate a pressurized gasifer system. Subsystem B accomplishes the inlet air compression via a separate compressor whereas sub-system C bleeds some compressed air from the power plant's main compressor. The simulation of the sub-systems allowed for comparision of the designs in terms of parameters such as efficiency and gas composition. In addition, the effects of changing system variables such as wood moisture content and gasifier air/fuel equivalence ratio on the performance of the sub-systems and the overall system were evaluated. It was determined that the most efficient operation of all the trimburner sub-systems occurred at the lowest allowable operating gasifier equivalence ratio. Also, increasing the wood moisture content decreased the efficiency of the sub-systems. In general, sub-system C exhibited superior subsystem efficiency values by about 2 percentage points over the entire range of equivalence ratios and moisture contents. Also, results for the entire plant indicate that sub-system C again maintains superiority in efficiency by about .5 percentage points. However, results from the simulation of the sub-systems indicate a basic difference in the producer gas formed from pressurized and non-pressurized gasifiers. The atmospheric gasifier of sub-system A produces a gas higher in combustible gases but lower in temperature as compared to that from the pressurized gasifiers of sub-systems B and C. This indicates that sub-system C (and B) will be much more sensitive to the heat exchanger process used to recover the sensible energy in the dirty producer gas stream than sub-system A. Based on the apparent superiority of sub-system C, a simple economic analysis between this sub-system and a conventional oil-fired trimburner was conducted. Results of this analysis indicated that the oil-fired trimburner would yield a more attractive payback period than the wood-fueled sub-system C trimburner. The payback periods for the oil-fired and wood-fired trimburner systems were estimated at approximately one year and four years respectively.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Academic Affiliation
Non-Academic Affiliation
Rights Statement
Peer Reviewed
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Additional Information
  • description.provenance : Made available in DSpace on 2013-07-02T15:05:24Z (GMT). No. of bitstreams: 1 StephensonJerryD1986.pdf: 1735053 bytes, checksum: b1aa40918215c7fd21df78fb0f25715f (MD5) Previous issue date: 1985-09-16
  • description.provenance : Approved for entry into archive by Deborah Campbell( on 2013-07-02T15:05:24Z (GMT) No. of bitstreams: 1 StephensonJerryD1986.pdf: 1735053 bytes, checksum: b1aa40918215c7fd21df78fb0f25715f (MD5)
  • description.provenance : Submitted by Kirsten Clark ( on 2013-06-25T17:08:20Z No. of bitstreams: 1 StephensonJerryD1986.pdf: 1735053 bytes, checksum: b1aa40918215c7fd21df78fb0f25715f (MD5)
  • 1986
  • description.provenance : Approved for entry into archive by Patricia Black( on 2013-06-26T14:42:05Z (GMT) No. of bitstreams: 1 StephensonJerryD1986.pdf: 1735053 bytes, checksum: b1aa40918215c7fd21df78fb0f25715f (MD5)


In Administrative Set:
Last modified: 10/19/2017

Downloadable Content

Download PDF

EndNote | Zotero | Mendeley