International Journal of Hydrogen Energy, Vol.44, No.11, 5189-5202, 2019
Psychrophilic hydrogen production from petrochemical wastewater via anaerobic sequencing batch reactor: techno-economic assessment and kinetic modelling
Independent hydrogen production from petrochemical wastewater containing mono ethylene glycol (MEG) via anaerobic sequencing batch reactor (ASBR) was extensively assessed under psychrophilic conditions (15-25 degrees C). A lab-scale ASBR was operated at pH of 5.50, and different organic loading rates (OLR) of 1.00, 1.67, 2.67, and 4.00 gCOD/L/d. The hydrogen yield (HY) progressed from 134.32 +/- 10.79 to 189.09 +/- 22.35 mL/gMEG(initial) at increasing OLR from 1.00 to 4.00 gCOD/L/d. The maximum hydrogen content of 47.44 +/- 3.60% was achieved at OLR of 4.0 gCOD/L/d, while methane content remained low (17.76 +/- 1.27% at OLR of 1.0 gCOD/L/d). Kinetic studies using four different mathematical models were conducted to describe the ASBR performance. Furthermore, two batch-mode experiments were performed to optimize the nitrogen supplementation as a nutrient (C/N ratio), and assess the impact of salinity (as gNaCl/L) on hydrogen production. HY substantially dropped from 62.77 +/- 4.09 to 6.02 +/- 0.39 mL/gMEG(initial) when C/N ratio was increased from 28.5 to 114.0. Besides, the results revealed that salinity up to 10.0 gNaCl/L has a relatively low inhibitory impact on hydrogen production. Eventually, the cost/benefit analysis showed that environmental and energy recovery revenues from ASBR were optimized at OLR of 4.0 gCOD/L/d (payback period of 7.13 yrs). (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Mono-ethylene glycol;Psychrophilic conditions;Hydrogen yield;Kinetic modelling;Nitrogen demand;Economic analysis