Thermodynamic Approach to Design and Optimization of Biomass Gasifier Utilizing Agro-Residues

Abstract

In recent years, biomass gasification has emerged as a viable option for decentralized power generation, especially in developing countries like India. In this chapter, we have given an overview of the energy scenario in India with statistics of electricity generation through various sources along with data on coal deposits and agro-residues, which are potential feedstock for electricity production through thermal route. Moreover, using the non-stoichiometric equilibrium and semi-equilibrium models, we have assessed the outcome of gasification process for different combinations of operating conditions and various biomass as feedstock, either single biomass or their mixtures. Four key parameters have been used for optimization, viz. biomass type, air or equivalence ratio, temperature of gasification, and gasification medium. The gasification medium has been taken to be either pure air or air–steam mixture. It is revealed that the biomass mixtures also form potential feedstock for gasifiers, and the performance of gasifier is very similar to that with single biomass as feedstock. On the basis of simulations results, we have also attempted to optimize the operating conditions for biomass gasifier operation. The optimum sets of operating conditions for gasifier for application of decentralized power generation are: Air Ratio = 0.3–0.4, Temperature = 700–800°C with gasification medium being air.