Calcination-desulfurization of green coke with concurrent sulfur production

摘要

In a staged calcination process a sulfur-containing green coke is converted to a low-sulfur-content coke and two off-gas streams, one which contains sulfur dioxide and another which contains hydrogen sulfide. In one stage the green coke is calcined and partially desulfurized under oxidative conditions at a temperature in the range 1000° to 3000. degree.F. In a second stage, the calcination and desulfurization is continued by heating the coke from 2000° to 4000°F under substantially reducing conditions. Preferably the reaction times and conditions in the stages are adjusted to result in the production of two mols of hydrogen sulfide per mol of sulfur dioxide. Portions of the two off-gas streams are mixed and reacted to form elemental sulfur.