A laboratory study of cotton gin waste pyrolysis

The disposal of wastes associated with the processing of cotton is posing great problems in some ginning sites in Greece. Traditional disposal methods, such as open-air incineration and landfilling are no longer adequate due to increasing environmental concerns. This paper evaluates cotton gin wastes as an energy resource by studying the effect of temperature on the product yields in their pyrolysis. Experiments were carried out in a captive sample batch reactor at 1 bar in a helium atmosphere. The heating rate was 80-100 degrees C s(-1) and the temperature range studied was 350-850 degrees C. The pyrolysis yielded char and gaseous products. Liquids and tar were produced in very small. quantities. The gaseous products yield increased with temperature in contrast to the yield of char. The peak temperature at which the percentage of gaseous products was equal to the percentage of char was 550 degrees C; above this temperature the percentage of gaseous products was higher than that of the char. Gases contained a high percentage of CO and H-2 increased with temperature. Experimental data combined with a first-order kinetic model was used to estimate the kinetic parameters of total weight loss and the yield of CO, CH4 and H-2. (C) 2000 Elsevier Science B.V. All rights reserved.