M/s. BMMIL has installed 5Nos & 7Nos of “Extended Shaft 100% Top Offtake EXTENDED SHAFT GAS PRODUCERS” to supply adequate energy with the help of production of 19,000Nm3/hr & 26,600Nm3/hr of recent generation high CV producer gas generated from C grade coal having UHV 4940 to 5600 Kcal/Kg&SARB-3 grade coal having GCV of about 4940 Kcal/Kg. The Plant has subsequently been installed as per IIEPL design involving latest generation technology for producing auto-enriched higher CV producer gas a suitable replacement for Petro-Fuels.
BASIC DESIGN PHILISOPHY
The object of the new technology is to produce a clean consistent quality Producer Gas of high calorific value from majority of grades of Indian coal from ‘A’ to ‘F/G’ grade and with faster rate of gasification or more coal through-put per unit grate area. With this objective in view, a deep coal bed has been introduced with extension of shaft over the conventional generator proper of the single stage design and the product gas has been fully diverted to the top to come out from the top of Gasifier. The Extended shaft is so precisely calculated that the fuel coal while moving downwards get stripper off its volatile matter to a great extent and the coal itself gets converted to Near-Coke state with an acquired advantage of greater reactivity for a faster gasification almost similar to coke gasification. The product gas on the other hand, while moving upwards, counter-current to the incoming feed coal gets auto enriched with the stripped and distilled volatile matter of coal to a higher calorific value. This novel feature had greatly improved the kinetics of Gasification, specific mass flow of gas per unit empty cross section of the Gasifier, gas make per MT of coal, calorific value, and consistency of gas quality and more stream days of operation without interruption.
At the same time, coal bed of extended shaft helps to adsorb dusts soot’s etc. of the product gas and no extensive cleaning facilities are required for better and consistent quality of gas.