Biomass can be converted to energy via direct combustion or thermochemical conversion to liquid or gas fuels. This study focuses on burning producer gases derived from gasifying biomass wastes to produce power. Since the producer gases are usually of low calorific values (LCV), power plant performance under various operating conditions has not yet been proven. In this study, system performance calculations are conducted for $5MWe$ power plants. The power plants considered include simple gas turbine systems, steam turbine systems, combined cycle systems, and steam injection gas turbine systems using the producer gas with low calorific values at approximately 30% and 15% of the natural gas heating value (on a mass basis). The LCV fuels are shown to impose high compressor back pressure and produce increased power output due to increased fuel flow. Turbine nozzle throat area is adjusted to accommodate additional fuel flows to allow the compressor to operate within safety margin. The best performance occurs when the designed pressure ratio is maintained by widening nozzle openings, even though the turbine inlet pressure is reduced under this adjustment. Power augmentations under four different ambient conditions are calculated by employing gas turbine inlet fog cooling. Comparison between inlet fog cooling and steam injection using the same amount of water mass flow indicates that steam injection is less effective than inlet fog cooling in augmenting power output. Maximizing steam injection, at the expense of supplying the steam to the steam turbine, significantly reduces both the efficiency and the output power of the combined cycle. This study indicates that the performance of gas turbine and combined cycle systems fueled by the LCV fuels could be very different from the familiar behavior of natural gas fired systems. Care must be taken if on-shelf gas turbines are modified to burn LCV fuels.

2.
Swanikemp
,
R.
, 2001, “
Project Developers Consider New Solid Fuels, New Technologies
,”
Power
0032-5929,
145
(
2
), pp.
35
42
.
3.
Layne
,
A. W.
, 2001, “
,” National Energy Technology Laboratory, http://www.netl.doe.gov/publications/factsheets/program/prog002.pdfhttp://www.netl.doe.gov/publications/factsheets/program/prog002.pdf
4.
Yap
,
M. R.
, and
Wang
,
T.
, 2004, “
Simulation of Producer Gas Fueled Power Plants
,” ECCC Report No. 2004-07, Energy Conversion and Conservation Center, University of New Orleans.
5.
THERMOFLOW Inc., 2004, THERMOFLOW manual, release 13.
6.
Ishimura
,
D. M.
,
Kinoshita
,
C. M.
,
Masutani
,
S. M.
, and
Turn
,
S. Q.
, 1999, “
Cycle Analyses of 5 and 20MWe Biomass Gasifier-Based Electric Power Stations in Hawaii
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
121
, pp.
25
30
.
7.
Nicholson
,
A.
, 2004, “
Cooling Potential Across The US
,” MEE Industries Inc., http://www.meefog.com/turbine/gtps-cp.htmlhttp://www.meefog.com/turbine/gtps-cp.html
8.
Cohen
,
C.
,
Rogers
,
G. F. C.
, and
Saravanamauttoo
,
H. I. H.
, 1999,
Gas Turbine Theory
, 4th ed.,
Longman Group Limited
, Essex, UK.
9.
Petrotech
, July 1999, “
Gas Turbine Steam Injection System for NOx Reduction
,” ⟨www.petrotechinc.com/pdf/94023.pdfwww.petrotechinc.com/pdf/94023.pdf⟩, Product Bulletin No. 94023.
10.
Brun
,
K.
,
Kurz
,
R.
, and
Simmons
,
H. R.
, 2005, “
Aerodynamic Instability and Life Limiting Effects of Inlet And Interstage Water Injection Into Gas Turbines
,”
Proceedings of ASME Turbo Expo 2005
, Reno, NV, ASME Paper No. GT2005-68007.
11.
Khan
,
J.
, and
Wang
,
T.
, 2006, “
Fog and Overspray Cooling for Gas Turbine Systems Using Low Calorific Value Fuels
,” ASME Paper No. GT2006-90396, presented at the ASME Turbo Expo 2006, Barcelona, Spain, May 8–11.