In a coking plant in which coal tar is processed coke oven gas occurs as a waste product. Coke oven gas can be used as an alternative fuel for a gas turbine, instead of natural gas, if it meets the local environmental regulations.
As a result of higher flame temperature of coke oven gas caused by the hydrogen content, the NOx emission of a gas turbine burning coke oven gas is higher than in case of natural gas. In Germany a 10 MW gas fired gas turbine has to meet a NOx emission limit of 150 mg/Nm3 @ 15% O2 dry. To reach this goal in case of MS 3002, which is installed in the coking plant as reported in previous ASME paper, steam injection is necessary.
NOx- and CO-emissions of a gas turbine are difficult to be predicted by calculation, therefore measurements had to be done to see how good the predictions were, that were made in face of the local regulations.
This paper deals with the NOx- and CO-emissions of a coke oven gas fired gas turbine with and without steam injection in difference to natural gas fired gas turbine. It shows also significantly lower CO2-emissions, because coke oven gas contains less hydrocarbon which is a great benefit for the greenhouse problem. It illustrates the effect of power augmentation and discusses the different thermal efficiency with steam injection.
This paper gives a short glance to the effects which influence the emissions, so that the specific problems caused by burning coke oven gas can be understood.