Assessment of Rice Residues as Potential Energy Source in Pakistan

Abstract

Pakistan produces enormous quantity of biomass wastes for example rice straw (RS) and rice husk (RH), wheat straw, and other biomass wastes that are being burned in the field after crop harvest to prepare the land for next crop. Biomass is known as potential energy source which can be effectively utilized as an alternative to fossil fuels. This study aims to assess the energy potential and gaseous pollutant emissions from rice residues such as RS and RH. The Energy potential of crop residues in Pakistan was obtained by considering the residual characteristics like residue to crop product ratio, moisture level and lower heating value of dry biomass was obtained from the South Asian countries. The mathematical models were defined for the assessment of amount of residues, available energy potential and emissions of gaseous pollutants. The estimated amount of rice residues is 10147.65 thousand tons dry biomass. The theoretical and available energy potential of the rice residues were estimated as 159219TJ, and 100,431TJ respectively. Based on dry matter fraction and proportion of crop residue burnt, the total amount of crop residue burnt for RS and RH were 1356.38 thousand tons and 307.7 thousand tons respectively. Total emissions from burning of rice residues were 1749.59, 27.639, 2.432, 1.265, 4.997, and 0.549 Gg for CO₂, CO, NO, NO₂, NOx, and SO₂ respectively. It was concluded that the crop residues generated in Pakistan can be effectively utilized as an alternative energy source, to reduce demand supply gap, reliance on fossils fuels and lower contribution in global warming.