Production of hydrogen from brewery wastewater by aqueous phase reforming with Pt/C catalysts

This paper reports for the first time on the aqueous phase reforming (APR) of a brewery wastewater, which was synthetically prepared according to a real effluent composition. Home-made Pt (3 wt. %) catalysts supported on different carbon materials, have been tested for this purpose at temperatures of 473 and 498 K. The effects of the supports and the organic load of the wastewater on the results of APR have been evaluated. Well characterized commercial carbons with different pH slurry and porous texture have been used as catalyst supports. A wide range of wastewater organic load has been tested, varying the COD from about 1500 to more than 11,200 mg/L, which corresponded to TOC values around 500 and more than 4000 mg/L, respectively. The highest removal of TOC and COD was observed for catalyst supported on highly mesoporous carbon blacks with virtually no microporosity and high pH slurry. At the lowest wastewater organic load (1531 mg/L TOC and COD removal up 99% was achieved and 93% of the TOC was converted into gases, with H2 and alkanes representing more than 70% of the total gas volume generated. The removal of organic matter in the liquid phase decreased at increasing its concentration in the starting wastewater, although the resulting gas contained a higher percentage of H2. Increasing the temperature allowed a higher TOC and COD removal, gas production, carbon conversion to gas and H2 yield. Some deactivation of the catalysts was observed after five successive uses, which can be attributed to partial blockage of the active Pt sites by carbonaceous deposits. The results obtained allow considering APR as an environmentally promising solution for these biomass-derived wastewaters providing also an interesting way of valorisation to H2-rich gas.