Sustainable Energy Generation from Agricultural Crop Residues

Abstract

Sustainable energy generation from renewable energy resources is need of the day considering depleting conventional energy supplies and environmental impact due to fossil fuel utilization. Energy generation from biomass is one of the focus areas of renewable energy programs in India. Considerable amount of crop residues are generated in Indian agricultural sector. These crop residues can be subjected to gasification to generate energy enriched producer gas. This product gas is a versatile energy carrier which can be used as a feedstock for generating hydrogen or for combined heat and power (CHP) applications. An assessment of three locally available crop residues is carried out to determine their gasification feasibility. The viability is evaluated by analyzing the thermochemical behavior of the crop residues. The assessment is made through biomass characterization and experimental investigation. Biomass characterization revealed that the biomasses are capable of undergoing thermochemical conversion at high temperature. An experimental investigation of air gasification of biomasses using a bubbling fluidized bed gasifier at different operating conditions is carried out to assess producer gas yield (PGY) especially hydrogen yield from each biomass. Hydrogen yield is influenced by reactor temperature (T) and equivalence ratio (ER). At specified operating conditions of T = 800 °C and ER = 0.24, hydrogen concentration in producer gas was 16.4% by volume from coffee husk compared to 13.7% from groundnut shell and 10.2% from sugarcane bagasse.