Influence of post-reformer temperature on the yields and qualities of the products from the TCR® process

Abstract

Abstract This work investigates the influence of the post-reformer temperature on the yield and quality of the products from the thermo-catalytic reforming (TCR®) process. It seeks to establish an optimisation methodology for achieving desired product yields and qualities by means of adjusting the post-reformer temperature. Five different feedstock materials are studied: straw, bio-stabilised compost, and three feedstock materials, which are mixtures of horse manure, straw, saw dust, and miscanthus in varying proportions. Two sets of experiments, one at a post-reformer temperature of 500°C and the other at 700°C, are carried out on all the feedstock materials. The results show that a greater biogas yield is achieved at the higher post-reformer temperature, but at the expense of the other products: biochar, process water, and biooil. As the post-reformer temperature increases, the carbon and energy yields generally increase for the biogas, but generally decrease for the other products. Moreover, the hydrogen fraction of the biogas is larger in the higher post-reformer temperature trials. In addition, the biooils and process waters produced at the higher post-reformer temperature of 700°C have less impurities, and the biooils are less acidic because of better reforming. However, there is no clear indication of any change in the calorific value of the biooil with increased post-reformer temperature. Conversely, the biochar produced from the lower post-reformer temperature trials have higher calorific values due to less thermal decomposition.