Performance evaluation of atmospheric biomass integrated gasifier combined cycle systems under different strategies for the use of low calorific gases

Abstract

This work aims at a performance evaluation of atmospheric BIGCC (biomass integrated gasifier combined cycle) systems operating under different strategies for the use of low calorific fuel in gas turbines. The fuel is a synthetic gas derived from gasification of sugar cane residues. Two analysed strategies for surge control on gas turbines originally designed for operation on natural gas are de-rating and air extraction from the compressor. Another strategy for use of biomass derived gas is the retrofit of a gas turbine through modification of the expander geometry. Three generic gas turbines, whose main parameters have been taken from off the shelf machines, are proposed as representative of certain classes of gas turbines. Results are compared to the hypothetical situation in which it is possible to accept any increase in gas turbine pressure ratio. According to the results, de-rating is the worst surge control strategy, both from the point of view of power production and thermal efficiency. Conversely, results showed considerable gains that can be obtained on cycle power production when the gas turbine expander is modified. Additionally, an overview of issues concerning the suitability of sugar cane residues (bagasse and trash) for the production of gasified gas and its use in BIGCC plants is presented.

Comparative techno-economic analysis of ORC and gasification for bioenergy applications

“…This heat is coming from the cooling water of the engine and the turbocharger, but also from the heat content of the exhaust gas of the engine. Other possible uses of the produced gas from biomass gasification are its combustion in a gas turbine of a biomass integrated gasification combined cycle, as presented by Rodrigues et al [29], or the use of the gas in microturbines [30] or fuel cell systems [30,31] for CHP production.…”

Bioelectricity Versus Bioethanol From Sugarcane Bagasse: Is It Worth Being Flexible?

“…The heat of exhaust gasses of the turbine is captured in a HRSG to generate steam at 60 bar for the 'combined' steam cycle [58,60,61]. The superheated steam is generated with water that had been preheated with waste heats from the BIGCC system, as determined by PPA.…”

“…The combined bagasse and trash would be initially dried to a moisture content of 10 to 15% with exhaust flue gasses [59,60]. The moisture content within the biomass would serve as the gasification control agent [59] since steam injection is generally not considered for gasifier applications in the BIGCC systems.…”

“…The syngas is further cooled to 97°C before it is scrubbed with water to remove the nitrogenous and sulfurous compounds for the protection of downstream equipment, and to prevent nitrous and sulfurous oxide emissions [46,60]. The scrubbing also humidifies the syngas, which assists in the control of the temperature in the gas turbine [62].…”

“…The general flow sheet of the BIGCC system ( Figure 7) for biomass conversion to electricity was adapted from models developed by the NREL [46,58] and previous reports [59][60][61]. The combined bagasse and trash would be initially dried to a moisture content of 10 to 15% with exhaust flue gasses [59,60].…”