Experimental and numerical study on laminar combustion characteristics of by-product hydrogen coke oven gas

Abstract

The coke oven gas (COG) which mainly consists of H2, CH4 and CO is a kind of feasible by-product hydrogen that could be applied by combustion plants. This paper conducted experiments and numerical calculations to explore the combustion properties of COG. The laminar burning velocity (LBV) and flame stability of COG with different CO/CH4/H2 fractions were firstly tested. Then, based on the LBV results, a new chemical kinetic model was proposed and a mixing rule for quick estimating the LBV of COG was acquired. The influences of different COG components on LBV were obtained. The peak LBV of COG could achieve 100.2 cm/s when the highest tested hydrogen portion in COG was adopted at an equivalence ratio of 1.2. Concerning its application in real combustion plants, the exhaust emissions of CO and NO from the COG final combustion products were also detected by an emissions analyzer. The results showed that raising the hydrogen fraction in COG availed reducing CO at rich conditions through lowering the carbon fraction. The NO emission gained the peak value around the equivalence ratio of 0.9, which was found to be generally raised with the hydrogen fraction due to the increased combustion temperature.