scholarly journals Techno-Economic Assessment of On-Farm Anaerobic Digestion System Using Attached-Biofilm Reactor in the Dairy Industry

2021 ◽  
Vol 13 (4) ◽  
pp. 2063
Author(s):  
Jia Boh Tan ◽  
Nur Syakina Jamali ◽  
Wei En Tan ◽  
Hasfalina Che Man ◽  
Zurina Zainal Abidin

In this study, a techno-economic assessment of an on-farm biogas system using an anaerobic biofilm reactor utilizing cow manure as a fermentation substrate was evaluated. A projection model was developed using Microsoft Excel software with three outputs, the size and dimension of a bioreactor, experimental microbial kinetic studies, and the economic studies based on the experimental results. Characterization analysis of cow manure wastewater showed the total solid (TS), total volatile solid (TVS), total carbohydrate (TC), chemical oxygen demand (COD), and pH values which were 10.95 g/L, 8.65 g/L, 6.65 g/L, 57.80 g/L, and 7, respectively. Using the modified Gompertz equation for the microbial studies, it was found that, at 37 °C and 20 days hydraulic retention time (HRT), the biogas yield was 934.54 mL/gVS, the volume of biogas produced was 11.28 m3/d, and 22.56 kWh of electricity was generated. The Gompertz prediction helps to determine the optimal HRT for the system so that the microorganisms are at their optimum stage to produce biogas. The economic analysis was done, and the results illustrated that, when the rate of cow manure produced was at 55 L/day.cow, the net present value (NPV) was RM 611,936.09, with a 13% internal rate of return (IRR), 0.14 return on investment (ROI), and 7.02 years of payback period (PP). By developing a techno-economic assessment that included all the necessary parameters such as sizing of the bioreactor, microbial kinetic studies, and economics of the plant, farmers could easily implement the system into their farms. This model showed that the anaerobic digestion system utilizing an attached biofilm with cow manure as a fermentation inoculum and substrate was applicable on an industrial scale to generate electricity and reutilize to the farm, at the same time generating additional income from the production of fertilizer.

2017 ◽  
Vol 18 (3) ◽  
pp. 799-807
Author(s):  
Dimitris Gotsis ◽  
Spyros Giakoumakis

Abstract The disposal of the excessive volume of degraded water coming from agricultural drainage systems is a serious environmental and economic issue, since a significant load of agrochemicals and salts contaminates water bodies downstream. An integrated on-farm drainage management (IFDM) system is an effective method of treatment by successively irrigating zones with drainage water. Each zone is cultivated with crops that have increasing tolerance to salinity, so that the drainage water effluents are minimized to an extent that the final drainage water volume is collected into an evaporation pond. The methodology of the system is proposed herein for a regional irrigation-drainage network (E1 in Agoulinitsa irrigation district in western Greece) as a method of reducing the disposal of agrochemicals in the coastal environment. Based on the design principles of an IFDM system, both the surface area of every irrigation zone and the costs of installing and operating the system are assessed. A scenario regarding the volume of drainage water that must be treated is examined as a sensitivity analysis. The results show that almost 15% of the cultivated area must be bounded for non-productive uses, resulting in a significant economic impact on the net present value of the investment.


2011 ◽  
Vol 697-698 ◽  
pp. 326-330 ◽  
Author(s):  
S.X. Zhou ◽  
Y.P. Dong ◽  
Y.L. Zhang

Microbial pretreatment was applied to enhance biogas production from corn stover through solid-state anaerobic digestion, but the price of microbial strains is high. The objective of this study was to find the effects on biogas production by the naturally microbial pretreatment method. The highest cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained in B group (the pretreated corn straws with cow dung), which was 19.6% higher than that of the untreated samples. The D group(the pretreated corn straws with the sludge)cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained, which was 18.87% higher than that of the untreted samples. The biogas of D group increased to the range of 55%~60% methane content, while B group with the range of 75%~80%.The results indicated that the pretreated corn straws mixing cow manure can improve both the biogas production yield and the content of methane in CH4。


2018 ◽  
Vol 31 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Mattia De Rosa

Biogas is a promising renewable energy resource produced by using anaerobic digestion of organic substrates and it is mainly used to generate electricity by means of biogas engines. Other potential utilisations are growing, e.g. grid injection and biofuels production but, generally, a treatment aimed to increase its quality is mandatory and greater investments are generally required to produce upgraded biogas (biomethane). Despite the increasing of interest on these applications, a lack of information is still present from an economic point of view. The present paper performs an extended economic assessment of upgrading and selling biogas starting from a typical farm-based anaerobic digestion plant in Northern Ireland assumed as reference. Several economic indexes have been considered to assess the economic performance of the upgraded anaerobic digestion plant, namely net present value, pay-back period, profitability index and internal rate of return. Moreover, different scenarios in terms of fossil fuel prices have been analysed. The results show that producing and selling biomethane can be economically feasible if an adequate market is fostered. Optimum anaerobic digestion sizes between 26.9 and 64.4 tonne/y have been found, with correspondent net present value and pay-back period values in the range of £6.7–64.4M and 2.8–7.5 years, respectively, depending on the price scenarios analysed and the economic index chosen. Generally, adopting the net present value as objective function of the optimisation leads to greater anaerobic digestion size than the other indexes for any price scenarios considered. Finally, tougher market conditions (i.e. higher fossil fuel prices) lead to better economic performances of the upgraded anaerobic digestion configuration.


2021 ◽  
Author(s):  
Omar Anaya-Reza ◽  
María Fe Altamirano-Corona ◽  
Gabriel Castelan-Rodríguez ◽  
Sergio Adrian García-González ◽  
Alfonso Durán-Moreno

Abstract Mexico City is one of the largest cities in the world and therefore there is a high generation of waste, of which 44% is equivalent to the Organic Fraction of Municipal Solid Waste (OFMSW). In this work, two case studies are evaluated for the application of biogas obtained in an anaerobic digestion process using OFMSW. CASE I considers obtaining biomethane, while CASE II considers energy cogeneration. The biogas yield was determined and was used to carry out an analysis of the process through an economic and environmental impact evaluation on different amounts of OFMSW (100-500 MT). The net present value of this project does not show the feasibility of the process, unless subsidy support is considered. The value of the smallest subsidy over the total investment to find NPV = 0, is 5.64 % for CASE I and 6.84% for CASE II at 200 MT of OFMSW. The WAste Reduction (WAR) methodology was used, which shows that the potential for environmental impact for the two cases is only 4%. The in-depth research of this work helps to maintain the anaerobic digestion process in a circular economy context, for the supply of energy and the protection of the environment.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2557
Author(s):  
Łukasz Bartela ◽  
Paweł Gładysz ◽  
Charalampos Andreades ◽  
Staffan Qvist ◽  
Janusz Zdeb

The near and mid-term future of the existing Polish coal-fired power fleet is uncertain. The longer-term operation of unabated coal power is incompatible with climate policy and is economically challenging because of the increasing price of CO2 emission allowances in the EU. The results of the techno-economic analysis presented in this paper indicate that the retrofit of existing coal-fired units, by means of replacing coal-fired boilers with small modular reactors, may be an interesting option for the Polish energy sector. It has been shown that the retrofit can reduce the costs in relation to greenfield investments by as much as 35%. This analysis focuses on the repowering of a 460 MW supercritical coal-fired unit based on the Łagisza power plant design with high temperature small modular nuclear reactors based on the 320 MWth unit design by Kairos Power. The technical analyses did not show any major difficulties in integrating. The economic analyses show that the proposed retrofits can be economically justified, and, in this respect, they are more advantageous than greenfield investments. For the base economic scenario, the difference in NPV (Net Present Value) is more favorable for the retrofit by 556.9 M€ and the discounted payback period for this pathway is 10 years.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2561
Author(s):  
Furqan Muhayodin ◽  
Albrecht Fritze ◽  
Oliver Christopher Larsen ◽  
Marcel Spahr ◽  
Vera Susanne Rotter

Rice straw is an agricultural residue produced in abundant quantities. Open burning and plowing back the straw to the fields are common practices for its disposal. In-situ incorporation and burning cause emissions of greenhouse gas and particulate matter. Additionally, the energy potential of rice straw is lost. Anaerobic digestion is a technology that can be potentially used to utilize the surplus rice straw, provide renewable energy, circulate nutrients available in the digestate, and reduce greenhouse gas emissions from rice paddies. An innovative temperature phased anaerobic digestion technology was developed and carried out in a continuous circulating mode of mesophilic and hyperthermophilic conditions in a loop digester (F1). The performance of the newly developed digester was compared with the reference digester (F2) working at mesophilic conditions. Co-digestion of rice straw was carried out with cow manure to optimize the carbon to nitrogen ratio and to provide the essential trace elements required by microorganisms in the biochemistry of methane formation. F1 produced a higher specific methane yield (189 ± 37 L/kg volatile solids) from rice straw compared to F2 (148 ± 36 L/kg volatile solids). Anaerobic digestion efficiency was about 90 ± 20% in F1 and 70 ± 20% in F2. Mass fractions of Fe, Ni, Co, Mo, Cu, and Zn were analyzed over time. The mass fractions of Co, Mo, Cu, and Zn were stable in both digesters. While mass fractions of Fe and Ni were reduced at the end of the digestion period. However, no direct relationship between specific methane yield and reduced mass fraction of Fe and Ni was found. Co-digestion of rice straw with cow manure seems to be a good approach to provide trace elements except for Se.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4175
Author(s):  
Lütfiye Dumlu ◽  
Asli Seyhan Ciggin ◽  
Stefan Ručman ◽  
N. Altınay Perendeci

Pretreatment and codigestion are proven to be effective strategies for the enhancement of the anaerobic digestion of lignocellulosic residues. The purpose of this study is to evaluate the effects of pretreatment and codigestion on methane production and the hydrolysis rate in the anaerobic digestion of agricultural wastes (AWs). Thermal and different thermochemical pretreatments were applied on AWs. Sewage sludge (SS) was selected as a cosubstrate. Biochemical methane potential tests were performed by mixing SS with raw and pretreated AWs at different mixing ratios. Hydrolysis rates were estimated by the best fit obtained with the first-order kinetic model. As a result of the experimental and kinetic studies, the best strategy was determined to be thermochemical pretreatment with sodium hydroxide (NaOH). This strategy resulted in a maximum enhancement in the anaerobic digestion of AWs, a 56% increase in methane production, an 81.90% increase in the hydrolysis rate and a 79.63% decrease in the technical digestion time compared to raw AWs. On the other hand, anaerobic codigestion (AcoD) with SS was determined to be ineffective when it came to the enhancement of methane production and the hydrolysis rate. The most suitable mixing ratio was determined to be 80:20 (Aws/SS) for the AcoD of the studied AWs with SS in order to obtain the highest possible methane production without any antagonistic effect.


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