GROUNDNUT SHELLS BRIQUETTING TO MEET FUEL ENERGY REQUIREMENTS

Abstract

India stands second in producing groundnut after China. Groundnut shell is the waste product of groundnut processing which is one-fifth of the dried product. Generally, these groundnut shells are either burnt or buried, or disposed of inefficiently. Apart from the problems of transportation, storage, and handling, the direct burning of loose groundnut shells in conventional grates is associated with very low thermal efficiency and widespread air pollution. Rich in lignin, groundnut shells undergo slow degradation in the natural environment. An alternate better use may be converting low bulk-density groundnut shells into high-density energy-concentrated solid fuels termed briquettes and pellets. These briquettes or pellets have higher thermal value, low ash content, and combustion is more uniform. Briquettes are ready substitutes for coal/wood in industrial boilers and brick kilns for thermal applications. There is no fly ash when burning bio-briquettes. The use of briquettes/pellets as a coal co-firing solution saw a boost in mid-2021 when India’s power ministry set up a national mission on the use of these solid biofuels in coal-based power plants. The residue compaction methods are the screw press, piston press, roller press, and palletizing machines. A review of groundnut shell briquetting and major constraints being faced by the industries have been presented in this paper.