scholarly journals STUDI PENGOLAHAN AIR BUANGAN DOMESTIK MENGGUNAKAN DIGESTER ANAEROBIK SATU TAHAP DAN DUA TAHAP

2018 ◽  
Vol 7 (1) ◽  
pp. 21-27
Author(s):  
Tamaria Kesia Hutasoit ◽  
Halimatuddahliana ◽  
Amir Husin
Keyword(s):  
Biogas Production ◽  
Domestic Wastewater ◽  
Neutral Condition ◽  
Cow Dung ◽  
Acid Condition ◽  
Two Stage ◽  
Two Phase ◽  
Second Stage ◽  
Substrate Removal ◽  
Substrate Degradation

This research provides an analyzed performance of one and two-stage anaerobic digestion processes. One-stage and two-stage analyzed, individual, from substrate degradation, microbiological, metabolite and biogas production. First, the research initiated by acclimatization in a neutral condition and acid condition. Both one (R1) and two-stage (R2) digesters filled up with domestic wastewater. Into the digesters, it added cow dung as inoculums. pH in R1 maintained at pH 7 for 40 days and pH 5.5 in two-stage anaerobic: first stage (R2-1) for two days. After that, the mixture added with inoculums and then adjusted at pH 7 for the second stage (R2-2) for 38 days. The results showed that the substrate removal efficiency of two-phase is higher one-phase. The highest metabolite production obtained at R2-1: the 2nd day.

DIFFUSION ACTIVITY OF CARBON DURING POLYMORPHIC TRANSFORMATION OF STEEL AND TWO-STAGE LOW-TEMPERATURE CEMENTATION

2020 ◽  
pp. 3-10
Author(s):  
B. V. Fokin ◽  
A. A. Zhukov ◽  
A. P. Navoev ◽  
Yu. A. Kustov ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Polymorphic Transformation ◽  
Interatomic Interaction ◽  
Carbon Diffusion ◽  
Two Stage ◽  
Two Phase ◽  
Second Stage ◽  
Required Quality

It was studied diffusive mobility of carbon’s atoms in the process of decarbonation steel У8 and cementation steel Ст3 in the temperature’s interval of polymorphic transformation. It was set that low temperature cementation (LTC) is possible only after a preliminary austenitization steel. In the state of polymorphic transformation due to the weakening of interatomic interaction, the formation of a two-phase structure of complexes, there is a decrease in the activation energy of carbon diffusion and a corresponding increase in the diffusion coefficient, which indicates the possibility of conducting LTC. The diffusion ability of carbon in LTC in a two-phase state was estimated using the value of the effective activation energy of diffusion taking into account the relative content of austenite and ferrite according to the «lever» rule. As a result of the studies performed, the following two-stage LTC method is proposed: the first stage – austenization (carburization) of the surface layer at a temperature of 920 °С for 20 minutes; the second stage – cementation in the temperature range 700…740 °С for 2 hours. Subsequent hardening and low-temperature tempering provide the required quality of the cemented layer by analogy with the traditional cementation process.

Producing Biogas with Two-Stage Fermentation Process of High Total Solids Content Kitchen Wastes

2012 ◽  
Vol 608-609 ◽  
pp. 344-349
Author(s):  
Xiao Ju Zhang ◽  
Shi Jie Li
Keyword(s):  
Fermentation Process ◽  
Biogas Production ◽  
Methanogenic Bacteria ◽  
Cow Dung ◽  
Kitchen Waste ◽  
Two Stage ◽  
Total Solids ◽  
Fermentation Tank ◽  
Solids Content ◽  
Biogas Process

This paper inoculated kitchen waste with activated sludge and fresh cow dung to explore the acidification and fermentation separated two-stage fermentation biogas process, in order to get acclimation acidification bacteria and methanogenic bacteria, high total solids content (TS) fermentation process, reduce the hydraulic load and shorten the fermentation cycle. The physiochemical characteristics of kitchen waste were that TS is 22.9%,the volatile solids (VS) is 11.7%, initial pH value is 6. The biogas producing process was as follow: Adjusting the TS of kitchen waste to 11.5% ,with 10% inoculum quantity, fermented at 37 °C , monitoring and adjusting pH. There were two biogas producing peak , and biogas production cycle was 15 days. The two-stage fermentation biogas process was as follow: Acidized the material of 22.9%TS for 5 days, Feeding the acidized material at the ratio of 1/4 to the vigorous biogas reaction system, then pH reduced but the biogas production was normal. After 5 days, pH raised and the second batch of material could be added. Feeding materials to the acidification tank and fermentation tank continuously, which can gradually get good acclimation acidification bacteria and methanogenic bacteria. Refluxing the biogas to acidification tank and methane fermentation tank, which can mix the materials evenly, shorten the fermentation cycle, improve the efficiency of the acidification and biogas production.

scholarly journals Anaerobic two stage degradation pattern of fermentable components of municipal solid waste

2018 ◽  
Vol 19 (4) ◽  
pp. 706-715
Keyword(s):  
Solid Waste ◽  
Biogas Production ◽  
Degradation Kinetics ◽  
Gas Production ◽  
Second Phase ◽  
Two Stage ◽  
Second Stage ◽  
Degradation Pattern ◽  
Urban Solid Waste ◽  
Linear Fit

With increased contribution of household and kitchen wastes in overall MSW and its preferred conversion by biomethanation there is a need to study decomposition rates and kinetics, ‘leachate potential’ and related issues– especially to promote decentralized treatment. Anaerobic digestion characteristics of ten predominant types of the fermentable components (fruits, vegetables and their mixture) commonly found in urban solid waste in Bangalore were examined under lab conditions by monitoring biogas production in micro-digesters at room temperatures (25±3°C). The rate of decomposition, the pattern of fit and extent and rate of biogas production from these potential feedstocks are analyzed to understand the degradation kinetics. All feedstocks showed a two stage linear fit for gas production comprising of a rapid initial phase lasting 10-20days accounting for >70% gas production followed by a slower second phase. Degradation could be predicted using a two stage linear fit transiting from initial to a second stage at an appropriate unique transition point, yet similar amongst fruits or vegetables. The need for large aceticlastic capability (rapid initial degradation) thus becomes a criteria for biomethanation process of such feedstocks.

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 Inoculum Selection and Micro-Aeration for Biogas Production in Two-Stage Anaerobic Digestion of Palm Oil Mill Effluent (POME)

2019 ◽  
Vol 8 (1) ◽  
pp. 14-21
Author(s):  
Sri Ismiyati Damayanti ◽  
Dian Fitriani Astiti ◽  
Chandra Wahyu Purnomo ◽  
Sarto Sarto ◽  
Wiratni Budhijanto
Keyword(s):  
Anaerobic Digestion ◽  
Palm Oil ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Liquid Waste ◽  
Palm Oil Mill Effluent ◽  
Cow Manure ◽  
Two Stage ◽  
Second Stage ◽  
Palm Oil Mill

Two-stage anaerobic fluidized bed is an innovation in anaerobic digestion technology intended to handle liquid waste with high organic loading and complex substrate. The process is based on separation between acidogenic/acetogenic and methanogenic processes. The first stage is anaerobic process to convert substrate (represented as soluble chemical oxygen demand/sCOD) into volatile fatty acids (VFA). The second stage is methanogenic process to convert VFA into biogas. This study aimed to separate acidogenic/acetogenic and methanogenic processes by means of limited injection of air (micro-aeration) and inoculum selection. Micro-aeration was introduced in acidogenic/acetogenic stage because the relevant microbes were facultative so that the obligate anaerobic methanogens will be suppressed. On the other hand, the methanogenic reactor was kept completely anaerobic to ensure methanogenic dominance over acidogenic/acetogenic ones. Two sources of inoculums were used in this study, i.e. anaerobically digested biodiesel waste and anaerobically digested cow manure. Both inoculums were taken from active biogas reactor treating biodiesel waste and cow manure, respectively. Experiments were run in batch reactors treating palm oil mill effluent (POME) as the substrate for the acidogenic/acetogenic reactor. After the reaction in the first stage reached the minimum substrate concentration, the content of the reactor was used as the substrate for the methanogenic reactor as the second stage. Routine measurements were taken for sCOD and VFA concentrations, biogas production, and methane concentration in the biogas. Results confirmed that micro-aeration maintained good performance of acidogenic/acetogenic process, which was indicated by peaks in VFA accumulation, while suppressing methanogenic activities as no methane produced in this stage. Digested biodiesel waste was superior inoculum to be compared to digested cow manure with respect to sCOD removal. In the methanogenic stage, digested biodiesel waste also performed better as inoculum as it led to higher VFA conversion, higher biogas production rate, and higher methane content in the biogas. 

scholarly journals Two-stage method for the simulation of the comminution process in a high-speed beater mill

2017 ◽  
Vol 18 ◽  
pp. 01011
Author(s):  
Michał J. Marijnissen ◽  
Cezary Graczykowski ◽  
Jerzy Rojek
Keyword(s):  
High Speed ◽  
Normal Velocity ◽  
Two Stage ◽  
Two Phase ◽  
Copper Ore ◽  
Simulation Methodology ◽  
Second Stage ◽  
Discrete Element Method Simulation ◽  
Comminution Process ◽  
Embedded Particles

The paper presents a two-stage simplified method for the simulation of comminution process which takes place in a beater mill. The first stage of the proposed method is a simulation of the flow of gas and ore particles through a mill based on a two-phase continuous-discrete model. It allows to capture the interaction between the fluid flow and embedded particles, to determine trajectories of their motion and average velocities and frequencies of their collisions against the flywheel and the mill's walls. The second stage of the proposed method is a discrete element method simulation of the process of comminution of a single ore particle. It allows to determine the size distribution of created smaller particles in terms of normal velocity and angle of impact and to estimate the global efficiency of the comminution process. The proposed simulation methodology is applied for the verification of the innovative concept of the application of high–speed beater mill for the comminution of the copper ore.

scholarly journals The Study of Rice Husk as Co-Digestion Together with Cow Dung is Biogas Production of Anaerobic Digester

2018 ◽  
Vol 73 ◽  
pp. 01013 ◽  
Author(s):  
Sania Septiani Mulyawan ◽  
Dini Widyani Aghnia ◽  
Elisabeth Rianawati ◽  
Enri Damanhuri ◽  
Marisa Handjani ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Rice Husk ◽  
Positive Impact ◽  
Biogas Production ◽  
Waste To Energy ◽  
Cow Dung ◽  
Second Stage ◽  
Energy Technologies ◽  
Last Stage ◽  
Cellulose Concentration

One of alternative waste-to-energy technologies to treat organic waste is anaerobic digestion. This study conducted by three stage of experiments using the laboratory scale biogas production from cow dung and rice husk as co-digestion. Based on the first stage experiments, TS 10% gave the highest accumulation of biogas 458 ml and 506,95 ml. In the second stage of the experiments, 10 ml media in TS 20% gave the highest accumulation of biogas production (743.1 ml). The last stage of experiments showe d that Blank TS 30% with 5 ml media gave the highest accumulation of biogas production (922.2 ml). From the last stage we can conclude that the presented of rice husk as a co-digestion didn’t give the significant effect to increase biogas production in anaerobic digestion, at least at room temperature. This caused by the high lignin and cellulose concentration in the rice husk that might resist or inhibit the production of biogas production. This is contrast situation when TS 40% occured, the existing of rice husk in AD will give positive impact to biogas produce.

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