Co-digestion Of Palm Oil Mill Effluent Research Articles

Co-digestion of domestic kitchen food waste and palm oil mill effluent for biohydrogen production

Biohydrogen production from organic waste not only provides a sustainable way to produce biofuel but it also resolves the growing environmental concerns associated with agro-industrial waste. This research study investigated the biological hydrogen production potential in batch mode through co-digestion of domestic kitchen food waste (DKFW) and palm oil mill effluent (POME) under mesophilic conditions by immobilized Bacillus anthracis bacterial strain. The results showed that hydrogen production from co-digestion of DKFW and POME with an equal proportion of the combination is pH and temperature-dependent. Where, the elevated pH from 4.0 to 5.0 increases hydrogen production significantly; however, increasing the pH > 5.0 reduces productivity. Similarly, by raising the operating temperature from 25 °C to 35 °C the hydrogen production rate (HPR) increases up to 67 mL/h. Apart from hydrogen production, a reduction in chemical oxygen demand (COD) was observed by up to 72 % in this study. The improvement observed for HPR and a significant reduction in COD, suggests that the co-digestion of POME and DKFW is an ideal substrate for hydrogen production at operational temperatures and initial pH of 35 °C and 5.0, respectively. The strategy for utilizing the different organic waste together as a substrate provides a new avenue for the complex substrate for bioenergy production.

Co-digestion of palm oil mill effluent with chicken manure and crude glycerol: biochemical methane potential by monod kinetics

In Thailand, the palm oil industry produces a huge amount of palm oil mill effluent (POME), mostly used for electricity generation through biogas production. Co-digestion with other waste can further improve biogas yield and solve waste management problems. Most previous studies relied on biochemical methane potential (BMP) assay or batch co-digestion to obtain the optimal mixing ratio, ignoring the kinetic part or treat it for sole discussion of the results. This work directly uses mechanistic models based on Monod kinetics to describe the experimental results obtained from the co-digestion of POME (40 ml, BMP = 281.2 mlCH4/gCODadded)) with chicken manure (CM) (0–50 g) and crude glycerol (Gly) (0–10 ml). The best mixing ratio between CM and POME was 5 gCM: 40 mlPOME (BMP = 276.9 mlCH4/gCODadded). The best ratio for Gly and POME was 2 mlGly: 40 mlPOME (BMP = 211.9 mlCH4/gCODadded). Adding Gly only 2 mlGly/40 mlPOME doubled the amount of biogas. Hence, crude glycerol is a good substrate for on-demand biogas output. The co-digestion increases the methane output but with a decreased yield. A multi-substrate Monod model was developed based on the levels of digestion difficulty. A partial-least squared fitting was used to estimate its main parameters. All parameters included in the model passed the significant tests at a 95% confidence level. The model can describe the experimental results very well, predict observable state variables of batch co-digestion, and allow a simple extension for continuous co-digestion dynamics. A limited continuous experiment was conducted to confirm the applicability of the model parameters of POME digestion obtained from BMP tests to predict a continuous AD. The results show good potential but must be carefully interpreted. It is generally possible and practical to directly obtain design and operational parameters from BMP assays based on only accumulated biogas curves and initial and final COD/VS.

Biochemical Methane Potential of Palm Oil Mill Effluent (POME) Co-Digested with Rubber Latex Effluent (LTE): Effect of POME/LTE Ratio and Temperature

Single anaerobic digestion of rubber latex effluent (LTE) is known to be difficult and low yield which produces biogas containing high sulfur dioxide and ammonia. This article investigates the potential of co-digestion of palm oil mill effluent (POME) and LTE both in terms of synergistic, inhibitory effects and process stability particularly in inferring what would happen in an industrial-scale biogas plant if this type of co-digestion is to be used. The article focuses on the biochemical methane potential (BMP) of POME-LTE at different mixing ratio within the temperature range of 30 - 45 °C, the range which is used in most commercial biogas power plants in Thailand. It was found that proper co-digestion between POME and LTE provided a good opportunity to optimize the bio-methane yield because of their synergistic effect. All mixing ratios provided stable biogas production up to at least 45 days. Co-digestion of POME and LTE had a synergistic effect that when mixing 80 - 90 % of POME with 10 - 20 % of LTE, it enhanced the BMP by 25 - 35 %. It is also recommended that, in mesophilic range, 45 °C would be the best for both methane yield and high methane content in the biogas. We also have illustrated that 2-substrate models (in this case the Gompertz 2 substrate (GTS) model) is very suitable for representing and describing co-digestion data because of their inherently multiple substrate tendency. In most cases, Gompertz-type equations for single substrate did not represent the accumulated biogas/methane data adequately.

Enhanced biogas production by mesophilic and thermophilic anaerobic co-digestion of palm oil mill effluent with empty fruit bunches in expanded granular sludge bed reactor

This study aimed to utilize Palm Oil Mill Effluent (POME) and preheated Empty Fruit Bunches (EFB) as a source for enhanced biogas production in Expanded Granular Sludge Bed (EGSB) Reactor. The reactor was operated continuously for 48 days with 2 days hydraulic retention time (HRT), POME: EFB mixing ratios of 1: 0; 0.10; 0.15; 0.20; temperature of 35 ± 2±C and 55 ± 2±C. The best improved was achieved from co-digestion of POME with EFB at a mesophilic temperature of 35 ± 2±C and mixing ratios of 1: 0.10, highest total biogas volume achieved was 7,400 ml (0.1359 – 0.1619 m3 CH4/kg COD removed), Volatile Fatty Acid (VFA)/Total Alkalinity (TA) ratios 0.1418 – 0.1582, and COD removal 61.97 – 78.87 %. The Methane content was 46.10 %. Under a Thermophilic temperature of 55 ± 2±C and mixing ratios of 1: 0, 10, the highest total biogas volume achieved was 1.350 ml (0.0859 – 0.1358 m3 CH4/kg COD removed) VFA/TA ratios increased to 0.4498 – 0.6685 with COD removal 61.97 – 74.65 %.

Biohythane Production from Co-Digestion of Palm Oil Mill Effluent with Solid Residues by Two-Stage Solid State Anaerobic Digestion Process

Biohythane production from co-digestion of palm oil mill effluent (POME) with empty fruit bunches (EFB) and decanter cake (DC) by two-stage solid state anaerobic digestion process was investigated. The first stage, thermophilic hydrogen fermentation of co-digestion of POME with DC at 10, 30, 50 and 70% of DC in POME has hydrogen yield of 16, 14, 3 and 1ml H2/gVS, respectively. Co-digestion of POME with 10% DC gave the best hydrogen yield of 16ml H2/gVS with hydrogen production of 1.4 m3/ton mixed waste. Co-digestion of POME with 10% EFB gave the best hydrogen yield of 16ml H2/gVS with hydrogen production of 1.4 m3/ton mixed waste. The effluent from the hydrogen production was further converted to methane in the second stage. The methane yield from POME mixed withn10% DC was 391 mlCH4/gVS and from POME mixed with 10% EFB was 240 mlCH4/gVS. The hydrogen and methane content in biogas was 25.33% and 65.21% respectively. The two-stage solid stage anaerobic digestion process can be removal efficiently of cellulose 57-59%, hemicelluloses 35-40% and lignin 16-27%. Result obtained make practical use for the development of two-stage anaerobic digestion process providing hydrogen and methane co-production from palm oil waste residues.

Effect of C/N ratio in methane productivity and biodegradability during facultative co-digestion of palm oil mill effluent and empty fruit bunch

The effect of carbon to nitrogen (C/N) ratios towards facultative co-digestion of palm oil mill effluent (POME) and empty fruit bunches (EFB) in terms of methane production and biodegradability of the substrates was experimentally evaluated. The experiment was performed with different EFB and POME loadings which are adjusted to specific C/N ratios. Based on the methane production, gross electricity production from the co-digestion was also calculated and presented. The results showed that cumulative methane production increased from 0.17L CH4 (without EFB admixture) to 2.03L CH4 in response for the treatment with C/N ratio of 45. After the digestion process, BOD and hemicellulose shows the highest biodegradability rate in POME and EFB, respectively. The maximum estimated gross electricity production of 196kWh was observed with C/N ratio of 45 (10L of POME, 3.1kg of EFB). Conclusively, co-digestion of POME with EFB generates higher methane production, and this relates with the higher degradation of organic substrates.