Estimation of Surplus Crop Residue in India for Biofuel Production

Abstract

The study quantified the generation of surplus crop biomass at district level in three crop growing seasons (kharif, rabi and summer) for all the 662 districts of the country. A total of eleven crops, namely rice, wheat, maize, sugarcane, cotton, pulses (Gram & Tur) and oilseed (groundnut, mustard, soybean and castor) were selected for the study. The crops were selected based on their acreage and total production across the country. The total gross cultivated area of the country is about 195 million hectare. The area under cultivation for the selected eleven selected crops is 137 M ha i.e about 70% of gross cultivated area. The assessment methodology involved four major steps: (1) compilation of area and production statistics of selected crops, (2) estimation of dry biomass generation, (3) development of surplus factors and quantification of surplus biomass generation, and (4) estimation of bioethanol production potential of surplus crop biomass. The crop biomass usage pattern by farmers for their own self as well as the biomass sold to others for industrial or any other usage was compiled to estimate the factors for surplus crop biomass generation. A novelty of this study is that it has developed crop specific season wise and district wise surplus factors and these factors were used to estimate the surplus crop biomass generated by the selected crops in the country. The study also estimated the district wise theoretical bio-ethanol production potential of surplus crop biomass generated by each crop in each season. Of the total gross area under cultivation for the eleven selected crops, 72% area is accounted by rice, wheat, cotton and soybean crops only. These eleven crops generate about 683 million tons (MT) of total dry biomass in the three crop growing seasons. Out of this total annual crop biomass, 59% is generated during kharif season and 39% during rabi season. The remaining about 2% is generated during summer season. After different usages of this crop biomass by farmers, there is still some surplus left which can be utilized in a useful manner. The total annual surplus crop biomass is estimated to be approximately 178 MT which is about 26% of the total dry biomass generated. The season wise surplus biomass is highest in kharif season (72%) and the major crops contributing to surplus biomass are rice sugarcane cotton and soybean. In rabi season wheat, gram, rice and mustard are the crops contributing to the surplus crop biomass. The surplus biomass generated during summer is negligible. In kharif season the States of Punjab, Uttar Pradesh (U.P.), Maharashtra, Tamil Nadu (T.N.), Andhra Pradesh (A.P.), Karnataka, Telangana, Gujarat, Madhya Pradesh (M.P.), and Rajasthan generated high surplus crop biomass. Whereas in rabi season the States of Punjab, U.P., M.P., Maharashtra, Karnataka, Rajasthan, and Haryana generated high surplus crop biomass. The total annual bio-ethanol production potential from this surplus crop biomass generated in the country is 51.35 billion litres from eleven selected crops. The study provides district scale seasons wise crop area, crop dry biomass, surplus biomass and bioethanol maps for each of the eleven crops for use by different stakeholders. It is expected that the outcome of this study shall help in developing an improved policy for 2nd generation biofuel by utilizing surplus crop residues. This will also help India in achieving the goal of bio-ethanol blending with gasoline.