Experimental study of the reaction of methanol at low oxygen concentrations in the presence of NO{sub}x

摘要

While there have been a number of studies of the oxidation of methanol, there is still no chemical kinetic model capable of describing the observed experimental results satisfactorily. The current study focuses on the reaction of methanol (450 ppm CH{sub}3OH/N{sub}2) in a laminar flow reactor with the addition of small concentration of O2 (0 - 1500 ppm), thus providing a range of mostly fuel rich conditions. The reaction was studied in the temperature range of 573 - 1023 K (with residence times of 2 - 3.5 s) and at atmospheric pressure. The reaction was also perturbed by the addition of NO{sub}x (0 - 200 ppm). The main products of the reaction are formaldehyde (CH{sub}2O), hydrogen (H{sub}2), carbon monoxide (CO), water (H{sub}2O) and carbon dioxide (CO{sub}2) and in the presence of NO{sub}x, nitrogen oxide (NO) and nitrogen dioxide (NO{sub}2). In the absence of NO{sub}x, methanol reacts with O2 only at temperatures above 923 K. With the addition of NO{sub}x the reaction temperature is lowered to 773 K. The present experimental results cover a range of reaction conditions not studied before and will be used in the development of a more robust comprehensive kinetic model. The reaction is suspected to follow different pathways at low O{sub}2 concentration to the reaction performed at higher O{sub}2 concentrations studied in previous works.