The Combustion of Low Heating Value Gaseous Fuel Mixtures

Abstract

The presence of diluents such as carbon dioxide and nitrogen with methane lowers significantly the effective heating value of the fuel mixture and can bring about adverse changes to the combustion characteristics of the methane. It may undermine its effective utilization altogether depending on the composition and the type of device used and the associated operating conditions. Such fuel mixtures are often encountered with varying composition in numerous natural, industrial and biogases and represent a potential energy source that needs to be exploited effectively. This section will discuss primarily how the presence of such diluent gases with methane modifies significantly the thermodynamic, kinetic and combustion characteristics of the fuel in air. It is shown that the presence with methane of nitrogen is tolerated relatively much better in combustion systems than the corresponding similar presence of carbon dioxide. The bases for these trends are discussed with examples of some operational considerations.