Pyrolysis of Cotton Stalk by Microwave Irradiation

A novel, pyrolysis method was employed for pyrolyzing cotton stalk powder samples and the corresponding sodium carbonate treated ones to obtaining acetol rich bib-nil. The powder sample was mixed with silicon carbide which acted as microwave absorber in a quartz reactor and the reactor was then put into a 2450MHz microwave oven for pyrolyzing at ca. 470 degrees C for 12min. The mass ratio of silicon carbide to sample was 5:3. In contrast, the same samples were pyrolyzed in a Curie-point pyrolyser coupled to GC-MS. Analysis of both volatile products indicates that microwave pyrolysis led to a novel distribution of the organic products in the condensed volatiles. Specifically, more light components appeared in the volatile from microwave pyrolysis, in which acetol was a dominant component. Sodium carbonate made acetol more abundant with a concentration up to 50% in terms of integration of the 25 main organic compounds in the condensed volatile. In contrast, the instant analysis of volatile from the Curie-point pyrolyser proved to be a composition of wider distribution and none was extraordinary abundant. Moreover, sodium carbonate inhibited the acetol formation in this case. A potential application of acetol was proposed and the critical problems related to realizing this application were discussed.