Sustainable utilisation of rice husk for cleaner energy: A circular economy between agricultural, energy and construction sectors

Global research focuses on cleaner and sustainable energy alternatives like biomass due to the limited availability of coal and high CO2 emissions associated with coal combustion. Rice husk-based electricity generation is hindered by the absence of cogeneration facilities in rice mills. Rice (Oryza sativa) cultivation is wide-spread and constructing several biomass plants at various locations is uneconomical. Hence, instead of using as biomass, rice husk is field burnt as a method of disposal. Construction of only few rice cogenerations facilitates and using already existing sugar mills and coal based thermal plants cogeneration facilities in a combined way is cost-effective and sustainable solution. Therefore, the present study examines the synergistic utilisation of sugar mills, coal-based power plants and only few newly proposed biomass power plants for effective combustion of rice husk. Maharashtra, one of the largest states in India is considered as the study area. Already existing 181 sugar mills, 18 thermal power plants are considered in 36 districts of Maharashtra state. Site suitability analysis was performed using a multi-criteria decision-making technique and ArcGIS. Furthermore, sensitivity analysis was conducted to assess the robustness of the suitability index values. From the analysis, it is found that nine districts require new biomass power plants. In remaining 27 districts use of already existing cogeneration facilities at sugar mills and coal-based power plants are found to be economical than new plants. In addition, 98.7 % of carbon emission was reduced when rice husk is used instead of coal for generating the equivalent quantity of power.