Optimization of methane yield by using straw briquettes- influence of additives and mold size.

A combination of briquetting wheat straw (BWS) and additives is presented in this work. Two experiments were designed: firstly the mold size of the briquetting equipment and the additive addition were evaluated as an integrated pre-treatment promoting methane (CH 4 ) yield and hydrolysis rate ( k ). Secondly, two combinations from the first experiment were used in continuous stirred tank reactors (CSTR) in co-digestion with cattle manure (CM). In this second experiment, CH 4 yield, reactor performance and residual CH 4 production were measured. The addition of alkali to BWS had a more significant effect on k than on the CH 4 promotion. The CSTR results showed that the addition of 3% KOH to BWS had a positive effect on VS degradation, CH 4 production and energy and economic balances. In addition, the potential for CH 4 emissions during the subsequent storage was reduced. [ABSTRACT FROM AUTHOR]