Completely Stirred Tank Reactor Research Articles

Biohydrogen Production from Waste Black Cumin (Nigella Sativa) Extract Liquid.

Hydrogen creates water during combustion. Therefore, it is expected to be the most promising environmentally friendly energy alternative in the coming years. This study used extract liquid obtained from the waste nigella sativa generated by the black cumin oil industry. The performance of biological hydrogen manufacturing via dark fermentation was investigated in the fluidized bed reactor (FBR) and completely stirred tank reactor (CSTR) under the operation conditions of pH 5.0, 4.0, and 6.0 and a hydraulic retention time (HRT) of 36 and 24 h. The performance of hydrogen manufacturing was determined to be good under an organic loading ratio (OLR) of 6.66 g.nigella sativa extract/L and pH 4.0. According to these conditions, the maximum amount of hydrogen in CSTR and FBR was found to be 20.8 and 7.6 mL H2/day, respectively. The operating process of the reactors displayed that a reduction in HRT augmented biohydrogen manufacturing. The work that used mixed culture found that the dominant microbial population at pH 4.0 involved Hydrogenimonas thermophila, Sulfurospirillum carboxydovorans, Sulfurospirillum cavolei, Sulfurospirillum alkalitolerans, and Thiofractor thiocaminus. No research on waste black cumin extract was found in biohydrogen studies, and it was determined that this substrate source is applicable for biological hydrogen manufacturing.

Determination residence time distribution of the solid phase in a dry anaerobic semi-continuous horizontal reactor of 0.5 m3 using innovative 3D printed tracers

Solid residence time distribution (SRTD) analysis is important in the design, modeling, and operation of solid biomass in continuous dry anaerobic digestion (D-AD) reactors. SRTD analysis could allow the appropriately adjust of the applicable organic charge and the study of unusable volume due to solid accumulation and preferential pathways. The lack of sustainable, environmentally friendly, and cost-effective solid tracers limits the study of solid flow patterns in D-AD digesters. In this study, 3D printing enabled the fabrication of customized Poly Lactic Acid (PLA) tracers with a specific shape to perform SRTD analysis of the semi-continuous digestion of straw-cattle manure (SCM) in a horizontal reactor of 0.5 m3. The recovery of tracers at the reactor outlet allowed the determination of the average SRTD at 29.43 days. Solid convection was predominant over diffusion, indicating that the reactor behaves closer to a plug flow reactor (PFR) rather than a complete stirred tank reactor.

Kinetic Study of Anaerobic Digestion of Compost Leachate from Organic Fraction of Municipal Solid Waste

The anaerobic digestion (AD) of compost leachate has been scarcely investigated and, to the best of our knowledge, no previous work has analyzed the kinetics of the process in completely stirred tank reactors (CSTR). To overcome this lack of knowledge, the present work aimed to deepen the study of the AD of compost leachate in CSTR and to identify the kinetics that can represent the process evolution under different operating conditions. In this regard, an experimental investigation was carried out on a laboratory anaerobic pilot plant that worked in semi-continuous mode under mesophilic conditions. After the start-up phase, the digester was fed with organic loading rates (OLR) between 4 and 30 gCOD/Ld. The chemical oxygen demand (COD) removal ranged between 80 and 85% for OLR values up to 20 gCOD/Ld and, then, it was observed as 54% at 30 gCOD/Ld. The deterioration of process performance was caused by an excessive generation of volatile fatty acids leading to a decrease of methane production yield from 0.32–0.36 LCH4/gCODremoved at 20 gCOD/Ld, to 0.23–0.26 LCH4/gCODremoved at 30 gCOD/Ld. Using kinetic analysis, the Monod model was shown to be quite accurate in modelling the trends of COD degradation rates for OLR values up to 20 gCOD/Ld. On the other hand, a better fit was achieved with the Haldane model at 30 gCOD/Ld. The conducted modelling allowed to identify the kinetic parameters for each model. The detected results could help in the management and design of the digesters for the treatment of compost leachate.

Effects of organic loading rate and pretreatments on digestion performance of corn stover and chicken manure in completely stirred tank reactor (CSTR)

The performance, system stability, and microbial community response in anaerobic co-digestion (AcoD) of corn stover (CS) and chicken manure (CM) were investigated by running completely stirred tank reactor (CSTR) under controlled organic loading rate (OLR). Prior to anaerobic digestion (AD), potassium hydroxide (KOH) or liquid fraction of digestate (LFD) was applied to pretreat CS, respectively. The results showed that the daily biogas production (DBP) in co-digestion showed a gradual increasing trend with an increase in the OLR from 65 g TS·L−1 to 100 g TS·L−1. The daily methane production per g volatile solids (DMP-VS) in co-digestion increased by 23.0%–27.1%, 18.7%–18.8%, and 17.5%–18.0% at the OLRs of 65, 80, and 100 g TS·L−1, respectively, upon pretreatment with KOH or LFD, as compared to that in co-digestion CSTR without any pretreatment. In addition, all co-digestion CSTRs were operated in stable state. Approximately half of the total carbon in the substrates was recovered in the form of a biogas product, with the carbon mass balance being impacted by the OLR as well as pretreatment. The diversity as well as function of the microbial community varied in response to different OLRs and pretreatment methods. The majority of bacterial genera were strongly correlated with operational parameters. The study indicates that management of OLR and selection of proper pretreatment method could enhance the efficiency and productivity of CS and CM co-digestion in CSTR.

Wet Torrefaction of Poultry Litter in a Pilot Unit: A Numerical Assessment of the Process Parameters

A numerical model for the wet torrefaction of poultry litter in a pilot unit was developed in this study. The model accounted for the following process steps: preheating biomass in a feed hopper, feeding biomass into the reactor, fluidized-bed generation using superheated steam, and the supply of additional heat by the electric heating of the reactor walls. Following a “black box” approach, a major assumption of the model is that the behavior of the fluidized-bed reactor is similar to a completely stirred tank reactor (CSTR). Under this assumption, the properties of the particles and gases do not depend on their location inside the reactor. During wet torrefaction, poultry-litter biomass was heated to a predetermined temperature and decomposed, generating biochar along with a gas phase (torgas), whose amounts depended on the content of inert ash in the biomass particles. Variable optimization in the model was performed using MATLAB software. The model successfully estimated the optimal duration required for the completion of wet torrefaction under various conditions: temperature, batch weight, reactor dimensions, etc. The model was validated using experimental data obtained from a series of wet torrefaction experiments performed in a fluidized bed, and provided reliable estimations of the duration of the process depending on material properties, reactor size and feedstock characteristics.

Effect of turbulence, dispersion, and stratification on Escherichia coli disinfection in a subtropical maturation pond

Sunlight disinfection is important for treatment of wastewater within maturation ponds. This study analyses the movement of Escherichi coli within a slice of a maturation pond, being affected by stratification, sunlight attenuation and mixing driven by wind shear and natural convection using computational fluid dynamics (CFD). Since the exposure to ultraviolet light is most effective in the near-surface region of the pond, natural convective mixing mechanisms to transport the pathogens from the lower parts of the pond are critical for disinfection efficacy. Different turbulence models are considered for closure of the momentum conservation equations and compared with a laminar flow simulation and a completely stirred tank reactor (CSTR) model. The effect of turbulence and stratification is shown to be significant for thermal and velocity distributions, and predictions of E. coli die-off. Greater volume-averaged E. coli die-off was predicted by the computationally convenient CSTR model than the CFD turbulence and laminar models. The simulation results are compared with experimental data and show that complete vertical mixing occurs in a diurnal pattern aiding die-off in sunlight-attenuating water. Practical applications of the model can assist in management strategies for maturation ponds such as off-take locations/times and evaluating seasonal variations in sunlight disinfection.

Impact of organic loading rate and reactor design on thermophilic anaerobic digestion of mixed supermarket waste

A mixture of supermarket food waste from bakery, butchery, cooked meats and cheese, fishmonger, fruit, and vegetable sections was subjected to anaerobic digestion under thermophilic conditions (55 °C). Lab-scale induced bed reactors (IBR) and completely stirred tank reactors (CSTR) were operated at different organic loading rates (OLR), i.e., 3.0, 3.6 and 4.6 kg volatile solids (VS) per m3 of reactor and day.Regardless of the type of reactor, an OLR of 3.6 kg VS/m3·day was found to be the optimum, achieving up to 48.1% more methane production per kg of treated waste than for the other OLRs tested. In general, there were no statistically significant differences (p-value < 0.05) between IBR and CSTR performance at the same OLR tested. However, for the optimum OLR, the IBR achieved a mean methane production of 1.5 L CH4/Lreactor·day (426.7 L CH4/kg VS) and the highest VS removal (89.0%, on average). This reactor obtained 22.1% more CH4 yield than the analogous CSTR and the highest methane content in the biogas (66.9% CH4).Finally, the process was successfully tested under large-scale conditions (1.25 m3 IBR pilot-plant). The CH4 production and the biodegradation yield were in line with those obtained in the lab-scale IBR.

Dynamic response of aerobic granular sludge to feast and famine conditions in plug flow reactors fed with real domestic wastewater

Plug flow reactors (PFRs) approximated by the connection of multiple completely stirred tank reactors (CSTRs) in series were used to achieve continuous flow aerobic granulation in real domestic wastewater. This study revealed, possibly for the first time, that the morphology and characteristics of aerobic granular sludge transformed in the course of a mixed liquor flow through a PFR. The feast zone, located at the front end of the PFR, can quickly develop filamentous structure on the surface of aerobic granular sludge which later disappeared in the famine zone at the back end of the PFR. Detention time from the front to the back end of the PFR was only 6.5 h. During this period the observed sludge morphological change led to sludge settleability fluctuation as much as 66% in zone settling velocity, 16% in specific gravity, and 40% in settled sludge volume. Further analysis revealed these types of sludge morphologies and characteristics were closely related to the specific substrate removal rate profiles of the PFR, i.e., the feast zone might have encouraged filamentous bacteria to extend outward into the bulk solution for soluble substrate, and the famine zone appeared to play an essential role in solidifying the structure of granular sludge structure prior to subjecting it to the gravity selection pressure. It can be inferred from this study that the lack of a famine zone in aerobic granulation reactors can loosen the granule structure and in turn deteriorate granule settleability. For a PFR, a famine zone following the feast zone is essential for maintaining the structural integrity of aerobic granular sludge in a continuous flow wastewater treatment system.

Kinetics study of methane production from anaerobic digestion of sludge and wastewater recycled pulp and paper

Methane yield is one of the important factors that indicate the anaerobic digestion (AD) process efficiency. The AD is an available treatment of recycled pulp and paper sludge (RPPS) and recycled pulp and paper wastewater (RPPW). This process protects the environment and produces methane, which is considered as renewable energy. In this study, the anaerobic treatment of the RPPW and RPPS were studied using 1L completely stirred tank reactor (CSTR) at laboratory scale with mesophilic conditions. However, a kinetic study was carried out using four models in order to compare and adjust the experimental results. The experimental results show that the RPPW and RPPS methane productions were between 691 and 945 mL/g based on volatile solid (VS), and the corresponding digestion time was about 26 days for the both experiment. The corresponding digestion time could be understood through the methane production kinetic models by digestion experiments within a short time. Different kinetics models were tested including Richards, Logistic, modified Gompertz and Cone models. The obtained results show the modified Gompertz model as the suitable model since it gives the lowest deviation from experimental results. Therefore, the proposed model could be used to accurately predict behavior of AD processes.

Feast/famine ratio determined continuous flow aerobic granulation

Plug flow reactors (PFRs) made of multiple completely stirred tank reactors (CSTRs) in series were used to cultivate aerobic granules in real domestic wastewater. Theoretically, changing the number of CSTR chambers in series will change the nature of plug flow, and thus alter the pattern of the feast/famine condition and impact the aerobic granulation progress. Therefore, PFRs were operated in 4-, 6-, and 8-chamber mode under the same gravity selection pressure (a critical settling velocity of 9.75 m h−1) and hydraulic retention time (6.5 h) until steady states were reached to evaluate the effect of the feast/famine condition on continuous flow aerobic granulation. The sludge particle size, circularity, settleability, specific gravity, zone settling velocity, and extracellular polymeric substance contents were analyzed to evaluate the role that a feast/famine regime plays in aerobic granulation. It was found that aerobic granulation failed whenever the feast/famine ratio was greater than 0.5. The results support a conclusion that the feast/famine condition is likely a prerequisite for continuous flow aerobic granulation.

Biological treatment of a brominated micropollutant α-hexabromocyclododecane (α-HBCDD) from a raw hospital wastewater

The brominated micropollutants were not removed with conventional biological treatment processes. In this study it was aimed to treat the α-HBCDD which is a hydrophobic organic substance using a sequential treatment process consisting from an upflow anaerobic batch reactor (UASB) and a completely stirred tank reactor (CSTR) since α-HBCDD is a hydrophobic brominated micropollutant and its removals was very low under long retention times in anaerobic sediments (in monitored natural attenuation environments) and under aerobic stimulated environments (in conditions adding limiting nutrient and electron acceptors for support the microorganisms growth), separately, a sequential anaerobic/aerobic reactor system proses was choosen. The anaerobic and aerobic removals of α-HBCDD were 7% and 12%, respectively, at a SRT of 55 days. The effects of SRTs on α-HBCDD and its metabolite removals was investigated. The yields increased as the SRT was increased from 5 days up to 55 days. The total α-HBCDD yields in the whole sequential biological system was recorded as 18,3%. The metabolite of α-HBCDD is α2-Bromocyclododecan-1-ol (2-BCD). This metabolite was produced under anaerobic conditions and it was removed in aerobic reactor with a yield of 17% at 55 days SRT. The maximum 2-BCD removal efficiency was 63,6% in the sequential reactor process.

Biogas Generation through Anaerobic Digestion of Compost Leachate in Semi-Continuous Completely Stirred Tank Reactors

The composting process of organic fraction of municipal solid waste, besides to the residual compost, generates a wastewater that is characterized by a high organic load. The application of anaerobic processes represents an advantageous solution for the treatment and valorization of this type of wastewater. Nevertheless, few works have been focused on the anaerobic digestion of compost leachate. To overcome this dearth, in the present paper an extensive experimental investigation was carried out to develop and analyse the anaerobic treatment of young leachate in completely stirred tank reactors (CSTR). Initially, it was defined a suitable leachate pretreatment to correct its acidic characteristics that is potentially able to inhibit methanogenic biomass activity. The pretreated leachate was fed to the digester over the start-up phase that was completed in about 40 days. During the operational period, the organic load rate (OLR) changed between 4.25 kgCOD/m3d and 38.5 kgCOD/m3d. The chemical oxygen demand (COD) abatement was higher than 90% for OLR values up to 14.5 kgCOD/m3d and around to 80% for applied loads equal to 24.5 kgCOD/m3d. At this OLR, it was reached the maximum daily biogas production of about 9.3 Lbiogas/(Lreactord). The CH4 fraction was between 70%–78% and the methane production yield in the range 0.34–0.38 LCH4/gCODremoved. The deterioration of biogas production started for OLR values that were over the threshold of 24.5 kgCOD/m3d when a volatile fatty acids (VFA) accumulation occurred and the pH dropped below 6.5. The maximum ratio between VFA and alkalinity (ALK) tolerable in the CSTR was identified to be 0.5 gCH3COOH/gCaCO3. Through an economic analysis, it was proven that the digestion of compost leachate could ensure significant economic profits. Furthermore, the produced digestate had characteristics that were compatible for agricultural applications.

Influence of reactor’s hydrodynamics on the performance of microbial fuel cells

Microbial fuel cells (MFCs) were the first bioelectrochemical systems to have been intensively studied and applied. In this study, two double-chamber MFCs (MFC1 and MFC2), identically designed and built as completely-mixed systems, were run for 69 days using dairy wastewater as anode substrate. To characterize the hydrodynamic behavior of the MFCs, a comprehensive specific study was performed, to identify any reactors’ dead spaces, and the hydrodynamic model closer to their real performance. Both anodic chambers showed to behave as completely stirred tank reactors (CSTRs) without perceivable dead spaces, while cathodic chambers showed a radically different hydrodynamic behavior. While MFC1’s cathode system performed as two CSTR reactors in series, with 9–13% dead space, MFC2′s cathode system was best described by a single CSTR model with dead space varied in the wider range 11–30%. Electric production and organic matter removal were also monitored, and correlated to the MFCs’ hydrodynamics, showing the latter’s influence on the entire process. Interesting considerations can be drawn from this study on MFC constructive methods: the absence of hydrodynamics’ invariance in MFCs equipped with granular graphite electrodes suggests the unfeasibility of their scaling up.

Effects of liquid fraction of digestate recirculation on system performance and microbial community structure during serial anaerobic digestion of completely stirred tank reactors for corn stover

Several completely stirred tank reactors (CSTRs) connected in series for corn stover anaerobic digestion was devised to obtain more methane yield and increase conversion rates. Liquid fraction of the digestate (LFD) was recirculated from the second-stage reactor to first-stage reactors to reuse LFD and improve system performance. LFD recirculation didn’t inhibit methane production of serial digestion, and methane and biogas production were increased by 2.3% and 10.8%, respectively. Moreover, LFD recirculation increased pH and alkalinity concentration (AC) and decreased volatile fatty acids (VFAs) concentrations and the ratio of VFAs to AC, which means a significant increase in system stability of anaerobic digestion (AD). Ammonia concentrations gradually increased with LFD recirculation, but was far lower than the inhibition concentration. Microbial analysis indicated that the recirculation increased the richness, but decreased the diversity of both bacterial and archaeal community in the first and second stage of serial system. More specifically, LFD recirculation enriched the dominant bacterial phyla (Bacteroidetes and Firmicutes), but had little influence on the dominated archaeal genus (Methanobacterium). The results showed that the recirculation of LFD during serial AD was technically suitable by minimizing both discharge of LFD and possible pollution related with discharging LFD.

Biogas and Volatile Fatty Acids Production: Temperature as a Determining Factor in the Anaerobic Digestion of Spirulina platensis

This investigation compared the digestion in completely stirred tank reactor (CSTR) of Spirulina platensis at two digestion temperatures (25 and 35 °C). This comparison was conducted in terms methane production, organic matter (COD) removal, volatile fatty acids (VFAs) production and nitrogen mineralization. In mesophilic range, 42%tCOD removal and methane yield of 107 mL CH4 g VSin−1 was attained. Due to the high digestate ammonium concentration, methane yield diminished along digestion time and VFAs accumulated. At 25 °C, methane production was negligible while 23%tCOD was removed. Ammonium concentration and nitrogen mineralization (± 70%) remained as high as in mesophilic range and thus, VFAs accumulation was also observed at 25 °C. Low temperature digestion shifted, however, the VFAs profile. This study shows that S. platensis might not be an optimum substrate for biogas production due to their high protein content. Nevertheless, VFAs can be used as building blocks for the production of fuels or chemicals.

Sugar beet silage as highly flexible feedstock for on demand biogas production

On demand biogas production is a great option to complement solar and wind power for the energy revolution. Alternatives like feedstock management are important in order to avoid expensive and complex adjustments for gas storage systems. The use of sugar beet silage (S) is a good option because it mainly contains carbohydrates that are easily degradable. Anaerobic digestion was performed for 63 days in four completely stirred tank reactors (CSTR) with different ratios of maize silage (M) and S. M given every hour was used as a base load for the fermentation and S was given two times a day every 12h. Biogas and methane production rates were measured every 5min in order to achieve data with high resolution. Also, pH value, VFA/TIC values and volatile fatty acids were measured during the experiment. The process remained stable in CSTR1 (M:S1:0), CSTR2 (M:S6:1) and CSTR3 (M:S3:1). Instabilities occurred in CSTR4 (M:S1:3) after an operation time of 33 days. Nevertheless, methane yields more than doubled for CSTR3 within 5min after the input of S. Use of sugar beet as a feedstock for biogas production is a further application for this agricultural commodity.

Nitrification in a completely stirred tank reactor treating the liquid phase of digestate: The way towards rational use of nitrogen

The nitrification of the liquid phase of digestate (LPD) was conducted using a 5L completely stirred tank reactor (CSTR) in two independent periods (P1 – without pH control; P2 – with pH control). The possibility of minimizing nitrogen losses during the application of LPD to the soil as well as during long-term storage or thermal thickening of LPD using nitrification was discussed. Moreover, the feasibility of applying the nitrification of LPD to the production of electron acceptors for biological desulfurization of biogas was assessed. Despite an extremely high average concentration of ammonia and COD in LPD reaching 2470 and 9080mg/L, respectively, nitrification was confirmed immediately after the start-up of the CSTR. N-NO3− concentration reached 250mg/L only two days after the start of P1. On the other hand, P1 demonstrated that working without pH control is a risk because of the free nitrous acid (FNA) inhibition towards nitrite oxidizing bacteria (NOB) resulting in massive nitrite accumulation. Up to 30.9mg/L of FNA was present in the reactor during P1, where the NOB started to be inhibited even at 0.15mg/L of FNA. During P2, the control of pH at 7.0 resulted in nitrogen oxidation efficiency reaching 98.3±1.5% and the presence of N-NO3− among oxidized nitrogen 99.6±0.4%. The representation of volatile free ammonia within total nitrogen was reduced more than 1000 times comparing with raw LPD under these conditions. Thus, optimum characteristics of the tested system from the point of view of minimizing the nitrogen losses as well as production of electron acceptors for the desulfurization of biogas were gained in this phase of reactor operation. Based on the results of the experiments, potential improvements and modifications of the tested system were suggested.

Kinetic and Enhancement of Biogas Production For The Purpose of Renewable Fuel Generation by Co-digestion of Cow Manure and Corn Straw in A Pilot Scale CSTR System

Biogas production from anaerobic co-digestion of cow manure (CM) and corn straw residue (CSR) were experimentally investigated using a completely stirred tank reactor (CSTR) under semi- continuously feeding circumstance at mesophilic (35°C±2) temperature. The pilot-scale digester with 180 L in volume was employed under experimental protocol to examine the effect of the change in organic loading rate on efficiency of biogas production and to report on its steady-state performance. An average organic loading rates of 2 and 3 kg VS. (m-3.d-1) and a hydraulic retention time (HRT) of 25 days was examined with respect to two different CM to CSR mixing ratios of 100:0 , 75:25 and 50:50, respectively. The results showed both organic loading rates at co-digestion of CM+ CSR gave better methane yields than single digestion of cow manure. The biogas production efficiency was obtained 0.242, 0.204, 0.311 0.296, 259.5 and 235 m3.(kg VS input)-1 for 2 and 3 kg VS.(m-3.d-1) at CM to CSR mixing ratios of100:0 , 75:25 and 50:50, respectively. The reactor showed stable performance with VS reduction between 55-74% during different runs. With increment of loading rate, the VS degradation and biogas yield decreased. Modified Gompertz and logistic plot equation was employed to model the methane production at different organic loading rates and substrate concentrations. The equations gave a good approximation of the maximum methane production (rm) and the methane yield potential (P) with correlation coefficient (R2) over 0.99.Article History: Received Oct 25th 2016; Received in revised form Dec 19th 2016; Accepted 2nd January 2017; Available onlineHow to Cite This Article: Taghinazhad. J., Abdi, R. and Adl, M. (2017). Kinetic and Enhancement of Biogas Production for the purpose of renewable fuel generation by Co-digestion of Cow Manure and Corn Straw in a Pilot Scale CSTR System. Int Journal of Renewable Energy Development, 6(1),37-44http://dx.doi.org/10.14710/ ijred.6.1.37-44

Serial completely stirred tank reactors for improving biogas production and substance degradation during anaerobic digestion of corn stover

Several completely stirred tank reactors (CSTR) connected in series for anaerobic digestion of corn stover were investigated in laboratory scale. Serial anaerobic digestion systems operated at a total HRT of 40days, and distribution of HRT are 10+30days (HRT10+30d), 20+20days (HRT20+20d), and 30+10days (HRT30+10d) were compared to a conventional one-step CSTR at the same HRT of 40d. The results showed that in HRT10+30d serial system, the process became very unstable at organic load of 50gTS·L−1. The HRT20+20d and HRT30+10d serial systems improved methane production by 8.3–14.6% compared to the one-step system in all loads of 50, 70, 90gTS·L−1. The conversion rates of total solid, cellulose, and hemicellulose were increased in serial anaerobic digestion systems compared to single system. The serial systems showed more stable process performance in high organic load. HRT30+10d system showed the best biogas production and conversions among all systems.

Pathways of 3-biofules (hydrogen, ethanol and methane) production from petrochemical industry wastewater via anaerobic packed bed baffled reactor inoculated with mixed culture bacteria

Simultaneous production of 3-biofuels (hydrogen, ethanol and methane) as by-products of the biodegradation of petrochemical wastewater containing MEG via anaerobic packed bed baffled reactor (AnPBBR), was extensively investigated. A four-chambered reactor supported by polyurethane sheets, was operated at a constant hydraulic retention time (HRT) of 36h and different organic loading rates (OLRs) of 0.67, 1, 2 and 4gCOD/L/d. The maximum specific H2 and CH4 production rates of 438.07±43.02 and 237.80±21.67ml/L/d were respectively achieved at OLR of 4gCOD/L/d. The residual bio-ethanol significantly increased from 57.15±2.31 to 240.19±34.69mg/L at increasing the OLR from 0.67 to 4gCOD/L/d, respectively. The maximum MEG biodegradability of 98% was attained at the lowest OLR. Compartment-wise profiles revealed that the maximum H2 and ethanol production were achieved at HRT of 9h (1st compartment), while the CH4 production was peaked at HRTs of 27 and 36h (last two compartments). Kinetic studies using Stover–Kincannon and completely stirred tank reactor (CSTR) in series models were successfully applied to the AnPBBR overall and compartment-to-compartment performance, respectively. The economic evaluation strongly revealed the potentials of using AnPBBR for simultaneous treatment and bio-energy production from petrochemical wastewater as compared to the classical anaerobic baffled reactor (ABR). Microbial analysis using Illumina MiSeq sequencing showed a diversity of bacterial community in AnPBBR. Proteobacteria (36.62%), Firmicutes (20.85%) and Bacteroidetes (3.44%) were the most dominant phyla.