Evolutionary Prediction of Biohydrogen Production by Dark Fermentation

Abstract

The present work is a study of the performance and effect of operational parameters on biohydrogen production from palm oil mill effluent by dark fermentation in batch mode. The process parameters examined are pH (5, 5.5, and 6), temperature (30, 35, and 40 °C), substrate concentration (5000, 12 500, and 20 000 mg L−1) and inoculum volume (20, 25, and 30 mL). The inoculum concentration prepared was 10 000 mg L−1 volatile suspended solids. The experiments were designed by response surface methodology (RSM). The highest chemical oxygen demand (COD) removal, hydrogen percentage (H2%) and hydrogen yield (HY) obtained were 58.3%, 80%, and 4.83 mol H2/mole of COD consumed, respectively. Based on the experimental data obtained with the RSM design, gene expression programming (GEP) was developed to predict the COD removal, hydrogen production, and hydrogen yield as process responses. The projected models were assessed based on the correlation coefficient (R2), root mean square error, mean absolute relative error, scatter index, and BIAS. The results demonstrate that the GEP model outperformed the RSM model and was superior in predicting the response variables. Partial derivative sensitivity analysis was also employed to assess the effect of each variable on COD%, H2%, and HY prediction. The prediction uncertainty for COD%, H2%, and HY was quantified, and the results were ±0.11, ±0.17, and 0.015, respectively. According to the results, the GEP model is more efficient than the RSM model in predicting the experimental data for biological hydrogen production in the dark fermentation process.

Start‐Up Study on Biohydrogen from Palm Oil Mill Effluent in a Pilot‐Scale Reactor

“…[ 27 ] Prior to usage, the sludge was sieved with a 1 mm mesh to remove sand and coarse particles, and then heated at 80 °C for 50 min to inactivate the hydrogenotrophic methanogens and to enrich for H 2 ‐producing bacteria. [ 19 ] Before transferring the heated sludge into the reactor, its temperature was reduced to room temperature. The characteristics of anaerobic sludge used after the pre‐treatment were: pH 7.8 ± 0.1; total suspended solids (TSS) = 35 g L −1 , and volatile suspended solids (VSS) = 10 g L −1 .…”

“…[ 17 ] Although POME does not contain toxic constituents, its high organic content comprising very complex lignocellulosic components renders it to be an extremely polluting effluent. POME characteristics may differ based on raw material consumption, and production process, [ 18,19 ] and researchers have looked at POME remediation using different reactor configurations. [ 20–23 ] In this study, the feasibility of an up‐flow anaerobic sludge blanket fixed‐film reactor (UASFF) as a hybrid bioreactor at pilot‐scale was investigated for treatment efficiency and production of biohydrogen.…”

Clean hydrogen generation and storage strategies via CO 2 utilization into chemicals and fuels: A review

“…Bio‐H 2 production from cellulose is a prospective alternative and an important source of environmentally friendly sustainable energy. This production also attracts considerable attention as a neutral method to produce H 2 from renewable resources and wastes . Direct biophotolysis is the transformation of H 2 O to O 2 and H 2 by using green algae, and it may be represented by the following overall reaction .…”

Modelling of dark fermentation of glucose and sour cabbage

“…Glucose is a too expensive material for use as a substrate for dark fermentation at the industrial scale. Another model used trigonometric function for palm oil effluent DF (only tested more complex substrate [ 19 ]). Anaerobic Digestion Models 1 (ADM-1) is the most commonly used model in anaerobic digestion [ 20 ].…”