India is a country whose population largely depends on agriculture, with 50% of its population being employed in agriculture, and revenue from agriculture and other allied fields contributing 13.7% of our country’s GDP. Most farmers in India face various challenges on a day-to-day basis and disposing off the agricultural residue that remain after a crop is successfully harvested, is one such major issue faced by millions of farmers.
Agricultural residues include various parts of the crop that cannot be used as food, like the stalk, stubbles, leaves, husks and seed pods. Conventional ways of disposing these residues have generally relied on using these residues as fodder, as fertilizers after being ploughed into the ground, or burning them completely. Additionally, newer methods of utilizing and disposing these crop residues, like converting them into biofuels, are all promising, but have not yet been fully developed. Thus, there is a genuine need for further study and research in this area to come up with more functional, practical and efficient ways of disposing or recycling the crop residues. One such study by the scientists from CSIR- Indian Institute of Petroleum and AS College, looks at enhancing and optimising the burning efficiencies of four agricultural residues: corn cob, wheat straw, rice straw and rice husk, in order to produce the maximum amount of bio-oils as a by-product.
The scientists carefully studied the pyrolysis of crop residues. Pyrolysis refers to the thermal degradation of organic matter in the absence of oxygen under high temperatures, and is known to release liquid and gaseous by-products, while leaving a carbon- enriched char behind. The process of pyrolysis is frequently used to get rid of vegetation and agricultural residues as it is quick, easy and convenient. The scientists studied the effect of pyrolysis temperatures and biomass type on the yield of bio-oils as a by-product. While wheat and rice straw yielded maximum bio-oils at 400 ℃, corn cob and rice husk yielded maximum bio-oils when burnt at 450℃. Corn cob was also shown to yield the maximum amount of bio-oils, while rice husk yielded the least. Such studies could help our farmers dispose off these agricultural residues in more efficient ways in the future.