Energy and Economic Analyses of Integrated Biogas-Fed Energy Systems

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
R. Bettocchi ◽  
M. Cadorin ◽  
G. Cenci ◽  
M. Morini ◽  
M. Pinelli ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Thermal Energy ◽  
Internal Combustion Engines ◽  
Energy Systems ◽  
Internal Combustion ◽  
Solid Wastes ◽  
Combustion Engines ◽  
Organic Fraction ◽  
Municipal Solid Wastes ◽  
Economic Indices

The process, which includes production, collection, carriage, and transformation of biomass into renewable fuels and then into energy (both electrical and thermal), involves a large number of decisions to select the most efficient plant layout. In order to identify the optimal solutions, models, which simulate the whole process, represent a useful and practical tool. In this paper, the energy and economic analysis of the entire process from biomass to energy production is presented. Among the different transformation processes, the thermophilic batch anaerobic digestion is considered in this paper. The analyses performed allow the comparison of the results for different scenarios characterized by different types of biomass (ensiled corn and organic fraction of municipal solid wastes), yearly mass of biomass, anaerobic digestion process parameters (number of yearly batch cycles and number of batch digesters), and type of energy systems (micro gas turbine and internal combustion engine). The results are presented in terms of classical economic indices for the investment and of producible electric and thermal energy. With respect to the economic indices, micro gas turbines allow a higher profitability than internal combustion engines, mainly because internal combustion engines require a scrubbing system to remove hydrogen sulphide from biogas. The contrary occurs with the producible electric and thermal energy. With regard to the digested substance, even if the methane yield is lower for organic fraction of municipal solid wastes than for ensiled corn, the net present values for organic fraction of municipal solid wastes are always higher than those obtained by using ensiled corn, and they are always positive, since municipal waste digestion avoids their disposal costs. The efficiency of the cogeneration process, evaluated in terms of primary energy saving index, usually shows quite high values and confirm the good capability of these systems.

scholarly journals Impact of pH Management Interval on Biohydrogen Production from Organic Fraction of Municipal Solid Wastes by Mesophilic Thermophilic Anaerobic Codigestion

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chaudhry Arslan ◽  
Asma Sattar ◽  
Ji Changying ◽  
Abdul Nasir ◽  
Irshad Ali Mari ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Solid Wastes ◽  
Biohydrogen Production ◽  
Organic Fraction ◽  
Municipal Solid Wastes ◽  
Anaerobic Codigestion ◽  
Ph Management

The biohydrogen productions from the organic fraction of municipal solid wastes (OFMSW) were studied under pH management intervals of 12 h (PM12) and 24 h (PM24) for temperature of37±0.1°C and55±0.1°C. The OFMSW or food waste (FW) along with its two components, noodle waste (NW) and rice waste (RW), was codigested with sludge to estimate the potential of biohydrogen production. The biohydrogen production was higher in all reactors under PM12 as compared to PM24. The drop in pH from 7 to 5.3 was observed to be appropriate for biohydrogen production via mesophilic codigestion of noodle waste with the highest biohydrogen yield of 145.93 mL/gCODremovedunder PM12. When the temperature was increased from 37°C to 55°C and pH management interval was reduced from 24 h to 12 h, the biohydrogen yields were also changed from 39.21 mL/gCODremovedto 89.67 mL/gCODremoved, 91.77 mL/gCODremovedto 145.93 mL/gCODremoved, and 15.36 mL/gCODremovedto 117.62 mL/gCODremovedfor FW, NW, and RW, respectively. The drop in pH and VFA production was better controlled under PM12 as compared to PM24. Overall, PM12 was found to be an effective mean for biohydrogen production through anaerobic digestion of food waste.

Biological pretreatment applied to industrial organic fraction of municipal solid wastes (OFMSW): Effect on anaerobic digestion

2011 ◽  
Vol 172 (1) ◽  
pp. 321-325 ◽  
Author(s):  
L.A. Fdez.-Güelfo ◽  
C. Álvarez-Gallego ◽  
D. Sales Márquez ◽  
L.I. Romero García
Keyword(s):  
Anaerobic Digestion ◽  
Solid Wastes ◽  
Biological Pretreatment ◽  
Organic Fraction ◽  
Municipal Solid Wastes

Performance of thermophilic semi-dry anaerobic digestion process changing the feed biodegradability

2000 ◽  
Vol 41 (3) ◽  
pp. 75-81 ◽  
Author(s):  
P. Pavan ◽  
P. Battistoni ◽  
J. Mata-Alvarez ◽  
F. Cecchi
Keyword(s):  
Anaerobic Digestion ◽  
Pilot Scale ◽  
Progressive Increase ◽  
Solid Wastes ◽  
Organic Fraction ◽  
Municipal Solid Wastes ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Double Phase ◽  
Stable Conditions

The study concerns the application of the semi-dry single phase thermophilic anaerobic digestion process to the organic fraction of municipal solid waste. The xperiments were carried out using 3 m3 and 1 m3 CSTR pilot scale reactors. The process performance in terms of biogas yields, digester stability and kinetic spects was studied, considering a progressive increase in the feed biodegradability, in order to evaluate the process behaviour changing from an undifferentiated collection of waste to a separate collection. This was carried out using blends of two different kinds of substrates: mechanically sorted organic fraction of municipal solid wastes (MS-OFMSW) and source sorted organic fraction of municipal solid wastes (SS-OFMSW). The study shows that OLR up to 6 kgTVS/m3d can be applicable for the medium selected fraction (TVS/TS≤0.7), while for the MS-OFMSW alone this limit can be doubled. The results obtained with SS-OFMSW alone suggest the use of the double phase process to give more stable conditions.

scholarly journals Thermophilic Co-Digestion of the Organic Fraction of Municipal Solid Wastes—The Influence of Food Industry Wastes Addition on Biogas Production in Full-Scale Operation

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3146 ◽  
Author(s):  
Przemysław Seruga ◽  
Małgorzata Krzywonos ◽  
Marta Wilk
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Full Scale ◽  
Solid Wastes ◽  
Process Efficiency ◽  
Electricity Production ◽  
Organic Fraction ◽  
Municipal Solid Wastes ◽  
Biogas Yield ◽  
Yield Increase

Anaerobic digestion (AD) has been used widely as a form of energy recovery by biogas production from the organic fraction of municipal solid wastes (OFMSW). The aim of this study was to evaluate the effect of the introduction of co-substrates (restaurant wastes, corn whole stillage, effluents from the cleaning of chocolate transportation tanks) on the thermophilic anaerobic digestion process of the mechanically separated organic fraction of municipal solid wastes in a full-scale mechanical-biological treatment (MBT) plant. Based on the results, it can be seen that co-digestion might bring benefits and process efficiency improvement, compared to mono-substrate digestion. The 15% addition of effluents from the cleaning of chocolate transportation tanks resulted in an increase in biogas yield by 31.6%, followed by a 68.5 kWh electricity production possibility. The introduction of 10% corn stillage as the feedstock resulted in a biogas yield increase by 27.0%. The 5% addition of restaurant wastes contributed to a biogas yield increase by 21.8%. The introduction of additional raw materials, in fixed proportions in relation to the basic substrate, increases biogas yield compared to substrates with a lower content of organic matter. In regard to substrates with high organic loads, such as restaurant waste, it allows them to be digested. Therefore, determining the proportion of different feedstocks to achieve the highest efficiency with stability is necessary.

scholarly journals INCREASING THE EFFICIENCY OF INTERNAL COMBUSTION ENGINES: HEAT RECOVERY FROM EXHAUST GASES BY THERMOELECTRIC EFFECT

2018 ◽  
Author(s):  
Mauro Francesco Sgroi
Keyword(s):  
Particulate Matter ◽  
Internal Combustion Engine ◽  
Co2 Emissions ◽  
Thermal Energy ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Medium Size ◽  
Combustion Engines ◽  
Exhaust Gases

The concern related to global warming is generating a legislative pressure on reducing CO2 emissions that is forcing automotive industry to find alternative and more efficient solutions to internal combustion engines. In Europe, the current regulation for passenger vehicles limits the CO2 emissions calculated as fleet average to 130 g/km and fix a target value of 95 g/km to be achieved by 2021. Car manufacturers will have to pay heavy penalties for each registered vehicle exceeding the CO2 limits (€95 per exceeding gram by 2019). Concurrently, the regulations on toxic emissions (CO, NOx, unburned hydrocarbons, particulate matter) is also becoming more and more stringent and requires complex and costly abatement systems to respect the strict limitations imposed on NOx and particulate matter emissions. On the other hand, zero emission electric vehicles, based on batteries, are still not mature enough for a replacement of the internal combustion engine in extra-urban applications, since they are not able to guarantee the driving range required by customers. Hydrogen fuelled vehicles, could meet the same performance of conventional cars, but the cost of materials used in the fuel cell stack is preventing the penetration into the market. Therefore, even though characterized by low energy efficiency, the internal combustion engine will remain, in the short-medium term, the reference technology for the transport industry but the environmental regulations will impose its hybridization with electric systems. Hybrid architectures allow circulating in electric mode in urban areas, limiting the local pollution, and increase the efficiency of the car through energy recovery during breaking phases. An energetic analysis of conventional internal combustion engine reveals that about 70% percent of the chemical energy stored in the fuel is converted in to mechanical energy for traction: the remaining part is dissipated as heat in the exhaust gases (30%) and in the cooling circuit (40%). So a great amount of thermal energy (tens of kW) is available on a car and its effective recovery can dramatically increase the efficiency of the system. Hybrid systems facilitate this task, since the produced electric energy can be stored in the battery pack. Thermoelectric generators (TEGs) offer the possibility to directly convert thermal energy into electricity with a reduced complexity and potential low cost. Even though available semiconducting junctions are characterized by low efficiency and limited operating temperatures, coupling a TEG to the internal combustion engine would allow recovering about 1 kW of electric power on a medium size car, with a reduction of CO2 emissions of about 10 g/km.

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