S Awasthi and A Goyal
Isgec, A-4,Sector -24, Noida 201301, India; sanjayawasthi@isgec.co.in
A modern sugar complex with a crushing capacity of 7500 t cane/d with a steam demand of 26% on cane and steam consumption (260 kg of steam/t of cane) to save bagasse. The purpose of bagasse saving was to utilize it for paper production. Several modern technologies, such as high- efficiency mills with AC VFD drives, de-pither machines for separation of pith and fibre, a septuple-effect evaporator configuration with all falling film evaporators, vertical continuous pans for B and C massecuite boiling, and a specially designed travelling grate type pith fired high-pressure boiler having captive power production were considered for this plant. This plant successfully crushed its first crop of 560,000 t of sugarcane in 2023-24 with steam consumption of approx. 26% on cane, achieving approx. 13% bagasse saving. Conventionally, the steam consumption in sugar plants in India is in the range of 32-38% with about 7-10% bagasse saving. This plant consists of a distillery of 120 kL/d capacity which was originally designed to operate on B molasses. Due to change in government policies, now it is operating on C molasses with a 90 kL/d capacity of ethanol (fuel grade) production with zero liquid discharge concept and burning all vinasse in an incineration boiler with 20% bagasse as support fuel. Steam consumption of ethanol plant on B heavy molasses was 3.3 kg/L total spirit and on C heavy molasses it is 3.8 kg/L total spirit. This paper elaborates the new technologies and provides a new path to the sugar industry in steam saving and zero liquid discharge.