Numerical and Experimental Study of the Emissions During Methanol Combustion

Abstract

The study focuses on the emission of pollutants generated during combustion of methanol, including the formation of formaldehyde and acrolein, the two main additional hazardous pollutants formed during the combustion of methanol. The study is based on chemical kinetic analysis using the CHEMKIN code (1D-reactor model) and ANSYS code for numerical computation. A parallel experimental combustion study was performed using a laboratory scaled swirl stabilized combustor model using methanol fuel. The combustor model was built in order to calibrate and test the developed theoretical models. The chemical kinetic analysis, using the CHEMKIN code, showed that under the investigated conditions, the maximum acrolein concentration at the exhaust was 0.12ppmv. Currently, there is no emission standard that we know of that refers to acrolein. However, it may very well be that due to the high toxify of acrolein, even such a low value may be too high. The results from the CFD simulations about the acrolein concentration at the exhaust revealed very low values, less than 0.01ppm, and consequently were not presented. Formaldehyde emission was evaluated by chemical kinetics studies, CFD analyses, and measured experimentally using two different analyzers. It is shown that the current common standard for the allowable limit of formaldehyde, which is based on the absolute amount exhausted, is too low and will limit the use of methanol only to small power units.