scholarly journals Fermentasi Anaerobik Biogas Dua Tahap Dengan Aklimatisasi dan Pengkondisian pH Fermentasi

2017 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Purwinda Iriani ◽  
Yanti Suprianti ◽  
Fitria Yulistiani
Keyword(s):  
Anaerobic Digestion ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Organic Load ◽  
Cow Dung ◽  
Activation Process ◽  
Two Stage ◽  
One Stage ◽  
Load Rate ◽  
Initial Ph

Produksi biogas pada skala rumah tangga umumnya menggunakan teknologi fermentasi anaerobik di dalam satu biodigester (satu tahap), yang mengakomodasi dua tahap utama prinsip pembentukan biogas, yakni tahap asetogenesis dan tahap metanogenesis. Permasalahan yang muncul dari penggunaan digester biogas satu tahap adalah ketidakseimbangan proses fermentasi (peningkatan laju beban organik, waktu retensi senyawa organik yang lebih cepat, dan produktivitas biogas yang menjadi tidak maksimal). Untuk mengatasi hal tersebut, dilakukan penelitian yang bertujuan melakukan produksi biogas melalui sistem fermentasi anaerobik dua-tahap (two-stage anaerobic digestion), yang didukung dengan pengaturan pH pada proses metanogenik. Pada penelitian ini telah dilakukan proses aklimatisasi (aktivasi) bakteri yang menunjang proses asetogenik dan metanogenik pada skala laboratorium (19 L), dan selanjutnya menjadi inokulum untuk proses fermentasi skala pilot dengan kapasitas biodigester asetogenik 125 L dan metanogenik 500 L. Hasil proses aklimatisasi bakteri asetogenik pada media kotoran sapi menunjukkan adanya kestabilan pH yang dibutuhkan untuk reaksi asetogenik, yaitu pada kisaran pH 5-6, sedangkan kontrol menunjukkan perubahan pH yang masih ada di rentang pH netral yaitu 6-7. Kotoran sapi yang telah melalui proses asetogenik selama 2 minggu (pH awal 5,5), menjadi bahan baku pembuatan biogas pada digester metanogenik. Hasil dari proses metanogenik menunjukkan terjadinya peningkatan volume biogas dan komposisi gas metana (CH4) di dalam biogas. Komposisi CH4 tertinggi diperoleh pada hari ke-20 yakni 74,82% dengan volume produksi biogas tertinggi ada pada hari ke-22, dengan laju 8,87 L/hari. Potensi energi tertinggi yang diperoleh mencapai 217,66 kJ/hari.Generally, biogas production on the household scale is using one-stage anaerobic fermentation technology, which accommodates two main processes of biogas production, namely acetogenesis and methanogenesis. An obstacle of using one-stage biogas digester is the imbalance of the fermentation process that indicated by the increase of organic load rate and shorter retention time that lead to un-optimal biogas productivity. This research undertook the application of two-stage anaerobic digestion, supported by adjusting the initial pH for both acetogenic and methanogenic processes. Firstly, the research initiated by acclimatization (activation) process of acetogenic and methanogenic bacteria via fermentation in laboratory scale (19 L) digesters, separately. The results of acetogenic bacteria acclimatization process on cow dung media showed the pH stability needed for the reaction acetogenic, in the range of 5-6, while the control showed the pH changes still in the neutral pH range (6-7). The substrate from lab-scale acetogenic and methanogenic digester, then used as a starter for pilot-scale digester (125 L and 500 L, respectively). The mixture of water and cow dung were adjusted at initial pH 5.5 on acetogenic digester for 2 weeks. Those material were used for biogas production in the methanogenic digester. The result of the methanogenic process showed an increasing volume of biogas and the composition of methane (CH4) in the biogas. The highest CH4 composition was obtained on the 20th day, which reached 74.82%, and the highest volume of biogas production was at day 22, with the rate of 8.87 L/day. The highest energy potential obtained was 217.66 kJ/day.

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

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 635 ◽  
Author(s):  
Siciliano ◽  
Limonti ◽  
Curcio ◽  
Calabrò
Keyword(s):  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Stirred Tank ◽  
Organic Load ◽  
Stirred Tank Reactors ◽  
Load Rate ◽  
Compost Leachate

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.

scholarly journals PENGOLAHAN LIMBAH CAIR TAHU MENGGUNAKAN BIOREAKTOR ANAEROB SATU TAHAP DAN DUA TAHAP SECARA BATCH

2018 ◽  
Vol 7 (1) ◽  
pp. 34-40
Author(s):  
Florence T.N. Silalahi ◽  
Halimatuddahliana ◽  
Amir Husin
Keyword(s):  
Waste Treatment ◽  
Anaerobic Fermentation ◽  
Liquid Waste ◽  
Cow Dung ◽  
Two Stage ◽  
Biogas Yield ◽  
Second Stage ◽  
One Stage ◽  
Batch Bioreactor ◽  
The One

This research aimed to study the effect of one stage and two stage anaerobic fermentation on the performance of bioreactors in tofu liquid waste treatment. This research started with acclimatization that is adaptation process of microorganism derived from cow dung with tofu liquid waste. Acclimatization is carried out in acid condition (pH 5.5) and in neutral condition (pH 7). This is followed by a batch bioreactor operation for 40 days for one stage anaerobic fermentation (pH 7), while for the first stage of the two stage anaerobic fermentation (pH 5.5) lasted two days and proceeds with the second stage of the two stage anaerobic fermentation (pH 7) lasts 38 days The results obtained were COD removal efficiency of 76.6% for one stage anaerobic and 83.05% for two stage anaerobic. While the VFA concentration in the first stage of the two stage anaerobic increased by 33% of the one-stage anaerobic VFA concentration. One-stage anaerobic biogas yield of 0.24 L/g CODconvertedand 0.27 L/g CODconverted for to two stage anaerobic.

scholarly journals Psychrophilic Full Scale Tubular Digester Operating over Eight Years: Complete Performance Evaluation and Microbiological Population

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 151
Author(s):  
Jaime Jaimes-Estévez ◽  
German Zafra ◽  
Jaime Martí-Herrero ◽  
Guillermo Pelaz ◽  
Antonio Morán ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Low Cost ◽  
Oxygen Demand ◽  
Mean Value ◽  
Organic Load ◽  
Microbiological Analysis ◽  
Complete Evaluation ◽  
Load Rate ◽  
Biogas Plants

Most biogas plants in the world run under psychrophilic conditions and are operated by small and medium farmers. There is a gap of knowledge on the performance of these systems after several years of operation. The aim of this research is to provide a complete evaluation of a psychrophilic, low-cost, tubular digester operated for eight years. The thermal performance was monitored for 50 days, and parameters such as pH, total volatile fatty acid (tVFA), chemical oxygen demand (COD) and volatile solids (VS) were measured every week for the influent and effluent. The digester operated at a stabilized slurry temperature of around 17.7 °C, with a mean organic load rate (OLR) equal to 0.52 kg VS/m3digester *d and an estimated hydraulic retention time (HRT) of 25 days. The VS reduction in the digester was around 77.58% and the COD reduction was 67 ± 3%, with a mean value for the effluent of 3.31 ± 1.20 g COD/Lt, while the tVFA decreased by 83.6 ± 15.5% and the presence of coliforms decreased 10.5%. A BioMethane potential test (BMP) for the influent and effluent showed that the digester reached a specific methane production of 0.40 Nm3CH4/kg VS and a 0.21 Nm3CH4/m3digester d with 63.1% CH4 in the biogas. These results, together with a microbiological analysis, show stabilized anaerobic digestion and a biogas production that was higher than expected for the psychrophilic range and the short HRT; this may have been due to the presence of an anaerobic digestion microorganism consortium which was extremely well-adapted to psychrophilic conditions over the eight-year study period.

scholarly journals Influence of the Heating Method on the Efficiency of Biomethane Production from Expired Food Products

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Joanna Kazimierowicz ◽  
Marcin Zieliński ◽  
Marcin Dębowski
Keyword(s):  
Biogas Production ◽  
Food Products ◽  
Organic Load ◽  
Organic Substrates ◽  
Methane Fermentation ◽  
Anaerobic Reactors ◽  
Convection Heating ◽  
Load Rate ◽  
Biomethane Production ◽  
Positive Effect

The aim of the study was to determine the effect of heating with microwave electromagnetic radiation (EMR) on the efficiency of the methane fermentation (MF) of expired food products (EFP). The research was inspired by the positive effect of EMR on the production of biogas and methane from different organic substrates. The experiment was carried out on a laboratory scale in fully mixed, semi-continuous anaerobic reactors. The technological conditions were as follows: temperature, 35 ± 1 °C; organic load rate (OLR), 2.0 kgVS·m−3∙d−1; and hydraulic retention time (HRT), 40 days. The source of the EMR was a magnetron (electric power, 300 W). There was no statistically significant influence of the use of EMR on the achieved technological effects of MF. The efficiency of biogas production was 710 ± 35 dm3·kgVS−1 in the variant with EMR and 679 ± 26 dm3·kgVS−1 in the variant with convection heating (CH). The methane contents were 63.5 ± 2.4% (EMR) and 62.4 ± 4.0% (CH), and the cumulative methane production after 40 days was 271.2 and 288.6 dm3CH4, respectively.

scholarly journals Biogas Production from Combined Irish Potato and Poultry Wastes: Optimization and Kinetic Studies

2018 ◽  
Vol 7 (3.36) ◽  
pp. 170
Author(s):  
Umar M. Ibrahim ◽  
Saeed I. Ahmed ◽  
Babagana Gutti ◽  
Idris M. Muhammad ◽  
Usman D. Hamza ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Parameters ◽  
Ph Value ◽  
Biogas Production ◽  
Irish Potato ◽  
Coefficient Of Determination ◽  
Optimum Conditions ◽  
Biogas Yield ◽  
Potato Waste ◽  
Initial Ph

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.  

Study on the biogas potential of anaerobic digestion of coffee husks wastes in Ethiopia

2020 ◽  
pp. 0734242X2093961 ◽  
Author(s):  
Ning Du ◽  
Meng Li ◽  
Qian Zhang ◽  
Mihret Dananto Ulsido ◽  
Ruyi Xu ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Dual Purpose ◽  
Effective Utilization ◽  
Leading Role ◽  
Initial Ph ◽  
Waste Reclamation

The poorly controlled discharge of coffee husks in Ethiopia causes severe environmental pollution and is a waste of resources. The volatile solid and carbon content in coffee husks waste indicates that it is rich in organic matter and has huge potential to produce biogas. This study investigated the feasibility of coffee husks to produce biomass through anaerobic digestion, based on temperature, initial pH, inoculum/substrate (I/S) ratio and carbon/nitrogen (C/N) ratio. The study demonstrated that the maximum production of biogas and methane reached 3359.6 ml and 2127.30 ml, respectively, under the conditions of mesophilic temperature (35±1°C), an initial pH of 7, an I/S ratio of 0.75 and a C/N ratio of 30. Based on this result, the effects of trace elements (Fe2+, Ni2+, Co2+) on biogas production and methane content were also explored. Compared with the group with no addition of trace elements, the experiment adding trace elements had significant enhancement effects on the production of biogas and methane, in which Fe2+ played a leading role ( p<0.05). Fe2+ promoted the hydrolysis and acidification of coffee husks, resulting in the production of a series of intermediates such as volatile fatty acids and the other kinds of dissolved organic matter. Furthermore, the cooperation of Ni2+, Co2+ and Fe2+ enhanced the activity of the enzyme system in methanogens, promoting methane production. The results in this paper show that coffee husks have clear biogas potential through anaerobic digestion, and its effective utilization could fulfill the dual purpose of solid waste reclamation and local environmental protection in Ethiopia.

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