Utilising fluctuating off-gases more efficiently in a power co-generation environment through less flaring

Abstract

Common engineering practice is to generate steam from burnable off-gases, in boiler houses, where excess steam is allocated for power generation after plant requirements are met. If the quantities or chemical composition of raw material feeds are not constant, off-gases and therefore steam productions may fluctuate over time. Fluctuating steam flows may cause turbines to trip due to insufficient availability at times. All off-gases not utilised are flared to atmosphere, nullifying its energy potential.This paper investigates the effect for when the volume quantity of off-gas flaring is regulated and the improved potential that this could have on power co-generation, taking into account the maximum combined boiler houses' capacities. Although flaring must always take place for line pressure control; for the engineering works under consideration 46.9 % of all the off-gas productions were flared. A mathematical model is used that distributes steam between turbines for optimal power generation to assist with the investigation in determining the power generation capabilities of the available and potential steam flow. Significant increases in potential power generation were observed when regulated flare percentages were decreased