Improvement in the Calorific Value of Producer Gas from Rice Husk with Addition of Spent Tea Waste as Secondary Fuel

The need for effective utilization of primary sources of energy across the globe leads to intensive research on renewable energy-based technologies. Biomass gasification is one such technology, and the conversion of bio-waste to useful energy plays an important role to meet the future energy demand including decentralized power generation. Spent tea waste (STW), a waste generated after the preparation of tea, has a good potential for gasification; however, its size is a critical factor for using the same alone in an existing downdraft gasifier. The blending of STW with rice husk has been identified as the best strategy for the effective use of this waste. Therefore, in this study, STW has been added with rice husk at various proportions, and the basic characteristics of the producer gas generated from the blends in a 40 kW downdraft gasifier have been investigated. The issues in handling STW because of its size are also discussed. The performance has been studied for different flow rates of gasification medium (air). The results are compared with the performance of rice husk, and it was observed that adding 40% of STW can enhance the hydrogen composition and calorific value of the producer gas by 10.29-16.25% and 5.33-6.18 MJ/Nm(3) respectively, besides an increase of 12-14.5% in cold gas efficiency.