Hydrogen production in a novel configuration of UASB reactor under different hydraulic retention time

Abstract

The aim of this work was to evaluate the production of hydrogen in a conventional and hybrid Upflow Anaerobic Sludge Blanket (UASB) reactors by modifying the hydraulic retention time (HRT). Both reactors operated continuously close to 135 days, with organic loading rate (OLR) of 11.26 kgCOD.m-3.d-1 at 12, 8 and 4 h. In the hybrid reactor, Biopack® rings with polyurethane foam at its center were used. The results showed that the UASB hybrid reactor achieved a stable and continuous production of over 60% of hydrogen gas at each HRT, related to carbon dioxide reduction until the end of the operation. The ANOVA and TUKEY tests, with a 95% reliability level, showed that there was a significant difference between the HRT evaluated, observing that the highest hydrogen production was obtained with 4 h of HRT. In the conventional UASB reactor, there was no stability during the operation time.