Performance of an innovative two-stage process converting food waste to hydrogen and methane

Abstract

This study was conducted to evaluate the performance of an innovative two-stage process, BIOCELL, that was developed to produce hydrogen (H-2) and methane (CH4) from food waste on the basis of phase separation, reactor rotation mode, and sequential batch technique. The BIOCELL process consisted of four leaching-bed reactors for H-2 recovery and post-treatment and a UASB reactor for CH4 recovery. the leaching-bed reactors were operated in a rotation mode with a 2-day interval between degradation stages. The sequential batch technique was useful to optimize environmental conditions during H-2 fermentation. The BIOCELL process demonstrated that, at the high volatile solids (VS) loading rate of 11. 9 kg/m(3).day, it could remove 72.5% of VS and convert VSremoved to H-2(28.2%) and CH4 (69.9%) on a chemical oxygen demand (COD) basis in 8 days. H-2 gas production rate was 3.63 m(3)/m.day, while CH4 gas production rate Was 1.75 m(3)/m(3) .day. The yield values of H-2 and CH4 were 0.31 and 0.21 m(3)/kg VSadded respectively. Moreover, the output from the post-treatment could be used as a soil amendment. The BIOCELL process proved to be stable, reliable, and effective in resource recovery as well as waste stabilization.