PRE-CARBONATATION WITH PURE CO_2 IN A CANE SUGAR REFINERY

摘要

Cane sugar refineries sought to take advantage of the competitive price of natural gas, leading to its consumption in the boilers. This has raised a serious problem for the carbonatation process, dependent on carbon dioxide in flue gases. The lower CO_2 content in flue gases from boilers burning natural gas demanded a search for a solution to this problem. We describe the steps taken to implement a system able to supplement the needed carbon dioxide for carbonatation, based on the injection of pure CO_2 in limed liquor. A test installation was first operated, using CO_2 flows corresponding to 18% to 51% of stoichiometric. Pure CO_2 was injected in limed liquor before the first saturators. Given the excellent results obtained, a definitive installation was put in routine operation, with a pure CO_2 consumption corresponding to 30% of stoichiometric. This pre-carbonatation proved to be a simple, easy to operate and economical solution.