Biomass is a clean, renewable energy source with a large potential to contribute significantly to power generation, promising a more environmentally friendly production of electricity in future, with lower greenhouse gas emissions.
A large variety of biomass feedstock exists, including agricultural and biomass residues and by-products, with wood, sludge, and waste among them. Biomass can be used directly to generate electricity if converted to more user-friendly sources of energy, e.g. by fermentation producing mainly methane (biogas) and by gasification leading mostly to hydrogen and carbon monoxide (syngas), allowing a more efficient use of the product gases compared to direct combustion, besides further advantages, with less amounts of ash and corrosive species.
The resulting product gases can be burned in small to large scale gas turbines, stand alone, process integrated or in combined cycles. In a hybrid power plant, an increase of the electrical efficiency of small gas turbines to more than 50 % can be reached, by coupling a gasifier or biogas reactor with a fuel cell (FC) and a micro gas turbine.
To widen the acceptable range in the variation of fuel composition and conditions and to ensure a reliable and more efficient operation, it is of outmost importance to expand our knowledge on biogenic gas mixtures with respect to modeling capabilities e.g. of major combustion properties, thus enabling predictive calculations.
The present work is dealing with the use of representative biogenic gas mixtures for decentralized power production. The concept of coupling a gasifier or biogas reactor with a fuel cell and a micro gas turbine (hybrid power plant) is followed.
The product gases are stemming from the fermentation of sludge and algae as well as from the gasification of their residues and wood, in addition. Their combustion behavior — lower heating value (LHV), Wobbe index, adiabatic flame temperature, laminar flame speed, and ignition delay time — is calculated for the relevant parameters — fuel-air ratio, pressure — and discussed with respect to the intended use.
A Test Rig for the Experimental Investigation of a MGT/SOFC Hybrid Power Plant Based on a 3kWel Micro Gas Turbine
