Spent tea waste as a biomass for co-gasification enhances the performance of semi-industrial gasifier working on groundnut shell

Abstract

An effective utilization of agricultural waste as an energy source for decentralised power generation and thermal applications can meet the increasing energy demand in rural areas. A substantial number of thermo-chemical conversion systems are used for this purpose; nevertheless, it is significant to improve their efficiency to widen the implementation of this technology for various applications. Groundnut shell is one of the popular agricultural wastes available in many countries like India. Due to its low bulk density and physical nature co-gasification of this feedstock with another biomass is not popular. However, a high carbonaceous powdery biomass like Spent Tea Waste (STW), a waste after brew tea can be suitably mixed with groundnut shell along with some moisture to accomplish this task. To prove this strategy an experimental study has been conducted at various combinations of these two types of biomass as feedstock in a 115 kWth semi-industrial type gasifier, and its performance parameters are studied for possible operating conditions of the gasifier. The observations show that the wet STW can maintain a uniform consistency, when mixing both the biomasses until its composition is 40% of the blend. The results show that the increase in hydrogen composition, calorific value and cold gas efficiency is in the ranges of 9.9–21.5%, 4.1–10.4% and 3.9–9.9% respectively as compared to groundnut shell. Besides, the maximum calorific value of producer gas is 6.68 MJ m−3.