Effect of volatile retention on the products from low temperature pyrolysis in a fixed bed batch reactor

Abstract

This study looks at the effect of volatile retention, within a batch reactor, on the products from fixed bed coal pyrolysis. It has been found that increased retention of volatiles within the reactor can increase the specific calorific value of the solid product. Increased confinement can also increase the specific calorific value of the gas, by increasing the production of methane and ethane from the reactor. The oxygen content of the coal is also shown to be an important parameter in determining the degree of upgrading that can be achieved. The reactivity of the chars from the fixed bed has also been tested in a drop tube furnace. Increasing treatment temperature and increased confinement have been shown to decrease the reactivity of the solid, as measured by combustibles remaining from the drop tube. It is concluded that increased confinement during pyrolysis in a fixed bed batch reactor may improve both the gas and solid products in terms of heat content, although problems may be encountered in burning the solid, in conventional pulverised fuel boilers.