Design of the Solar Energy-Heated Biogas Digester

2014 ◽  
Vol 953-954 ◽  
pp. 103-106
Author(s):  
Jin Yang Li ◽  
Jian Li ◽  
Qing Yu Liu ◽  
Hao Zheng
Keyword(s):  
Anaerobic Digestion ◽  
Solar Energy ◽  
Production Rate ◽  
Northern China ◽  
Gas Production ◽  
Raw Material ◽  
Solar Thermal ◽  
Biogas Slurry ◽  
Optimum Temperature ◽  
Working Principle

Heating biogas digester is essential in northern China, especially during the winter. Solar energy-heated biogas digester is a facility that radiates heat by the solar thermal, which maintains the temperature of the biogas digester. The working principle behind this facility is the division of the traditional biogas digester into three parts, namely, raw material storage section, biogas slurry storage section, and anaerobic digestion section. We only heat the anaerobic digestion section to decrease the heating volume and reduce the heat dissipating surface, thereby saving energy. Solar energy is unstable, and the anaerobic digestion section needs to be maintained at its best temperature, thus, we control the raw material inlet at its optimum temperature. This biogas digester improves the anaerobic digestion condition and enhances gas production rate, which enables the efficient function of the digester during winter.

Study of Methane Production by High Temperature Anaerobic Fermentation of Chicken Manure and Stalks

2020 ◽  
Vol 14 (4) ◽  
pp. 551-557
Author(s):  
Yongku Li ◽  
Xiaomin Hu ◽  
Lei Feng
Keyword(s):  
High Temperature ◽  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Gas Production ◽  
Chicken Manure ◽  
Biogas Slurry ◽  
Production Rates

The changing parameters, as the biogas production rate, the methane production rate, the cumulative biogas amount, the cumulative methane amount, the biogas composition, pH etc. in high temperature anaerobic fermentation of chicken manure and stalks were analyzed by experiments with different mass ratios of chicken manure or livestock manure and stalks with a high C/N ratio. The methane production mechanism of high temperature anaerobic digestion of chicken manure and stalks was discussed in detail. It showed that not only the biogas production rates but also the methane production rates of R1–R7 demonstrated the trend of initial increase and then decrease after 50 d of high temperature anaerobic digestion. Besides, the gas production of R1 with pure chicken manure stopped on the 30th d of the reaction. The gas production of other groups R2–R7 also stopped on the corresponding 34th, 36th, 36th, 37th, 37th, and 37th day, respectively. At the end of the reaction, the cumulative biogas amounts and the cumulative methane amounts of R1–R7 were 411.58 and 269.54, 459.91 and 314.41, 425.32 and 294.11, 401.85 and 272.54, 382.63 and 257.07, 363.04 and 218.16, and 257.15 and 160.10 N ml/(g VS). The biogas slurry pH of R1–R7 all demonstrated a trend of initial decrease and then increase, e. g., pH of R2 reached the minimum of 5.94 on the 5th day. pH values of other groups were between 6.01 and 6.39. After the addition of 4 g of sodium bicarbonate on the 7th day, biogas slurry pH of R1–R7 all increased. pH was maintained between 7.16 and 7.44 until the end of the reaction.

A Potential Treatment Alternative for Swine Wastewater in the Tropics

1985 ◽  
Vol 17 (4-5) ◽  
pp. 819-831 ◽  
Author(s):  
P. Y. Yang ◽  
S. Y. Nagano
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Algal Biomass ◽  
Energy Production ◽  
Loading Rate ◽  
Gas Production ◽  
Energy Utilization ◽  
Swine Wastewater ◽  
N Removal ◽  
The Tropics

Development of a low-cost and effective swine waste management system in the tropics is the main objective of this study. Because of the apppropriate temperature environment and abundance of sunlight, an integration of an anaerobic digestion and an algal biomass process was selected and investigated. A pilot, plant integrating a 20 m3 anaerobic digester with sludge recycling and a 120 m3 algal-biomass raceway were installed and evaluated. Maximum gas production rate of 1.527 liter/liter/day (69% methane content) can be achieved by a TVS loading rate of 4.23 gram/liter/day. A sludge production rate of 0.82-2.62 g TS/liter is obtained from a TVS loading rate of 0.76-4.23 g TVS/liter/day. Critical SRT for maximum gas production rate is 2.67. For the algal biomass raceway, a loading rate of 0.097 g SCOD/liter/day or 0.017 g NH4-N/liter/day would achieve SCOD and NH4-N removal efficiencies of 94.44% and 98.42%, respectively. Combining the previous analysis of energy input and land requirement for an algal biomass raceway and mass balance of energy production and utilization, integrating the energy production (anaerobic digestion) and energy utilization (dehydration of digested sludge and power requirement of raceway) provides a great potential for a swine wastewater treatment in the tropics.

Modelling of anaerobic digestion using self-organizing maps and artificial neural networks

2000 ◽  
Vol 41 (12) ◽  
pp. 149-156 ◽  
Author(s):  
P. Holubar ◽  
L. Zani ◽  
M. Hagar ◽  
W. Fröschl ◽  
Z. Radak ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Regression Coefficient ◽  
Gas Production ◽  
Neural Nets ◽  
Organic Loading Rate ◽  
Self Organizing Map ◽  
Gas Composition ◽  
Volatile Fatty Acid Concentration ◽  
Self Organizing

In this work the training of a self-organizing map and a feed-forward back-propagation neural network was made. The aim was to model the anaerobic digestion process. To produce data for the training of the neural nets an anaerobic digester was operated at steady state and disturbed by pulsing the organic loading rate. Measured parameters were: gas composition, gas production rate, volatile fatty acid concentration, pH, redox potential, volatile suspended solids and chemical oxygen demand of feed and effluent. It could be shown that both types of self-learning networks in principle could be used to model the process of anaerobic digestion. Using the unsupervised Kohonen self-organizing map, the model's predictions could not follow the measurements in all details. This resulted in an unsatisfactory regression coefficient of R2= 0.69 for the gas composition and R2= 0.76 for the gas production rate. When the supervised FFBP neural net was used the training resulted in more precise predictions. The regression coefficient was found to be R2= 0.74 for the gas composition and R2== 0.92 for the gas production rate.

scholarly journals Application of Modified Gompertz Model to Study on Biogas production from middle temperature co-digestion of pig manure and dead pigs

2019 ◽  
Vol 118 ◽  
pp. 03022
Author(s):  
Hongguang Zhu ◽  
Jing Yang ◽  
Cheng Xiaowei
Keyword(s):  
Anaerobic Digestion ◽  
Degradation Rate ◽  
Biogas Production ◽  
Raw Materials ◽  
Gompertz Model ◽  
Gas Production ◽  
Raw Material ◽  
Pig Manure ◽  
Middle Temperature ◽  
Modified Gompertz Model

The dead pig is an organic waste rich in oil and protein, and is an ideal anaerobic digestion raw material. This study based on single factor ANOVA and Modified Gompertz model. It investigated the effects of the ratio of dead pigs on biogas production by middle temperature co-digestion of pig manure and dead pigs. And the biogas production potential was determined. The results showed that there was no significant correlation between the ratio of dead pigs and the biogas production. The ratio would significantly affect the average methane content and degradation rate. When the addition ratio was in the range of 3 to 15%, the biogas production was between 191.39 and 202.44 (L/kg VS). The average contents of methane were 50.67%, 50.35%, 41.83%, 45.53% and 44.57%, respectively. The time required to reach 80% of the biogas production was 28, 34, 36, 65 and 63 days, respectively. The degradation rate of the raw materials was generally decreased with the increase of the addition ratio. The results of Modified Gompertz model fitting showed that the mixed raw materials had a fully anaerobic digestion with high utilization rate and short hysteresis in the range of 0 ~ 9%. Therefore, a hydraulic retention time (HRT) of 30 days and the addition ratio was in the range of 0 to 6% could be recommended for a continuous digester. It could get a better gas production and higher raw material utilization.

Experimental Study on Potential of Biogas Fermentation with Lily Straw

2012 ◽  
Vol 608-609 ◽  
pp. 396-401
Author(s):  
Hong Yang ◽  
Wu Di Zhang ◽  
Xing Ling Zhao ◽  
Jing Liu ◽  
Yu Bao Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Anaerobic Digestion ◽  
Ph Value ◽  
Biogas Production ◽  
Gas Production ◽  
The Other ◽  
Raw Material ◽  
Production Potential ◽  
Biogas Yield ◽  
The Third

This paper studies on the biogas production yield of which use the lily straw as raw material and the fermentation is batch by batch at 30°C. In the third day of fermentation, fermented liquid became acidic. But it can be back to normal with the action of the anaerobic microbe. Its biogas yield is higher than the other group to adjust pH value. So gas production potential of the lily straw is 475ml/gTS and 573ml/gVS with 31 days of anaerobic digestion. The volumetric biogas production rate reaches 0.19ml/ml/d.

scholarly journals Effect Of Co-Digestion Of Source Separated Organics And Manure On Methane Production

2021 ◽  
Author(s):  
Devarshi Sevak ◽  
Elsayed Elbeshbishy
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Gas Production ◽  
Mixture Ratio ◽  
Biomethane Potential ◽  
Methane Production Rate ◽  
Biomethane Production ◽  
Mesophilic Condition

Anaerobic co-digestion (AcoD) is more advantageous than conventional mono-digestion, because of higher gas production rate. This study was aimed to study the effect of mixture ratio in codigestion of manure and source separated organics (SSO) in mesophilic condition. Manure and SSO at different mixture ratios of 9:1, 7:3, 5:5, 3:7, and 1:9 on a volumetric basis were used to determine the effect of the mixture ratios on methane production in biomethane potential assay (BMP). Results showed that co-digestion of SSO and manure at the ratio of 1:9 (V/V) resulted in the highest biomethane production rate of 46 mL CH4 /day. In comparison, the maximum methane production rate for anaerobic digestion of manure alone was 43 mL CH4 /day. When manure is mixed with SSO at a ratio of 5:5, about 15% higher cumulative methane production has been achieved. This research also verified the advantages of co-digestion over mono-digestion. Keywords: Anaerobic Digestion, Co-digestion, Source Separated Organics (SSO), Manure

Research on Feasibility of Mesophilic Anaerobic Digestion of Mixture of Grass Cutting’s from Greenings and Sludge from Wastewater Plants

2015 ◽  
Vol 8 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Xie Jinliang ◽  
Zhu Tongqi ◽  
Du Hao ◽  
Hu Xiaoli ◽  
Wang Ye
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Dry Weight ◽  
Weight Percent ◽  
Gas Production ◽  
Experimental Results ◽  
Sludge Digestion

This paper studies the feasibility of joint digestion processing of grass cuttings from city greening and sludge from wastewater plant and selects respectively 10%, 20%, 30%, 40% and 50% dry weight percent for grass cutting’s and sludge. The experimental results indicate that the gas production rate of the sludge digestion system will grow with growth of added grass cuttings. When the percentage of added grass cuttings is 50%, the gas production rate of the digestion system can reach 348 L/kg.TS, compared to the value without grass cutting. The gas production rate increases by 30%. Therefore, the joint digestion processing of the grass cuttings from sludge of wastewater plant is feasible.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

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