scholarly journals Empirical Studies into Demand Based Reactor Sizing in Low-Cost Biogas Production for Domestic Utilization

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Olayinka Omotosho ◽  
Adebayo Oke
Keyword(s):  
Rural Areas ◽  
Biogas Production ◽  
Low Cost ◽  
Empirical Studies ◽  
Total Yield ◽  
Gas Production ◽  
Management Of Resources ◽  
Domestic Use ◽  
Substrate Ratio ◽  
Biogas Reactor

A low-cost biogas reactor incorporating a hydro-pressurizing and gas dispensing unit which was able to deliver biogas at a rate of 6.25 x 10-5m3/s and calculated pressure of 58.7N/m2 was designed and fabricated for the purpose of this study.  The substrate loading intervals for the reactor were varied at 6, 7, 8, 12, 13, 17 and 33 days interval to determine which of the intervals gave the optimum yield in gas production. The fabricated unit had the highest average daily biogas production level and optimum total yield to substrate ratio at substrate feed interval of 13 days. Results obtained from the study were used to propose a biogas reactor sizing guideline for the low-cost biogas reactor design for domestic use. The proposed guideline would help in adequate deployment and management of resources for waste conversion and renewable energy production in rural areas.

scholarly journals The anaerobic digestion of sheep manure in self-designed low-cost biogas reactor

2018 ◽  
Vol 12 (2) ◽  
pp. 13-23 ◽  
Author(s):  
Gábor Nagy ◽  
Alexandra Takács ◽  
András Arnold Kállay ◽  
Dóra Mentes
Keyword(s):  
Main Product ◽  
Low Cost ◽  
Base Material ◽  
Solid Material ◽  
Gas Production ◽  
Small Scale ◽  
Fluid Displacement ◽  
Data Collector ◽  
Sheep Manure ◽  
Biogas Reactor

One of the possible utilisation methods for organic wastes is anaerobe decomposition (fermentation). The main product of this process is biogas which is usually used for energy purposes due to its composition (mainly methane and carbon dioxide). The residual solid material after fermentation can be used as soil conditioner. Lab-scale fermentation can be carried out using the “VDI 4630 – Fermentation of organic materials Characterisation of the substrate, sampling, collection of material data, fermentation tests” standard. Based on the conditions described in the standard, a small-scale low-budget reactor system were prepared. The temperature during the holding time was controlled with water bath and the gas production was determined with fluid displacement method. A peristaltic pump was used for the recirculation of the gas to mix the base material. Furthermore, the temperatures of the environment, the water baths and the inside of each reactor was automatically registered on a data collector.

scholarly journals Modelling of anaerobic digester biogas production: case study of a pilot project in Morocco

2013 ◽  
Vol 3 (4) ◽  
pp. 381-391 ◽  
Author(s):  
Youssef Abarghaz ◽  
Khiyati Mohammed El Ghali ◽  
Mustapha Mahi ◽  
Christine Werner ◽  
Najib Bendaou ◽  
...  
Keyword(s):  
Rural Areas ◽  
Environmental Science ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Principal Component ◽  
Pilot Project ◽  
Gas Production ◽  
Input Material ◽  
Demand Reduction ◽  
Volume Measurements

An anaerobic digestion pilot system was implemented in June 2010 in the Moroccan village of Dayet Ifrah. The input material consists of toilet wastewater and cattle manure. Biogas is produced under anaerobic conditions. It is used for heating and cooking. This biogas system could be an useful sanitation technology due to its ability to treat wastewater. The biogas system was monitored over 86 days in summer 2012 to measure gas production. The average gas production recorded was about 1,870 l per day. This amount is sufficient for a farming family composed of 17 people. Our work seeks to find the most appropriate formula to predict biogas production under Moroccan conditions. We compared and ranked different formulas by applying principal component analysis and the ELECTRE III method. The variables studied were the chemical oxygen demand reduction and biogas volume measurements. The results show that the formula of Vedrenne is the most appropriate equation to predict biogas production in Moroccan rural areas (see Vedrenne (2007) ‘Study of Anaerobic Degradation Processes and Methane Production During Storage of Manure’. Environmental Science Thesis. ENSA, Rennes).

scholarly journals Portable Biogas Digesters for Domestic Use in Jordanian Villages

Recycling ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 21 ◽  
Author(s):  
Ammar Alkhalidi ◽  
Mohamad K. Khawaja ◽  
Khaled A. Amer ◽  
Audai S. Nawafleh ◽  
Mohammad A. Al-Safadi
Keyword(s):  
Food Waste ◽  
Rural Areas ◽  
Biogas Production ◽  
Management Systems ◽  
Animal Waste ◽  
Small Scale ◽  
Human Waste ◽  
Energy Needs ◽  
Natural Energy ◽  
Domestic Use

Essential energy needs are not always met in poor and rural areas of developing counties; therefore, natural energy sources are necessary to mitigate this problem. Rural areas inhabitants utilize methane as a replacement for cooking gas to reduce their gas bill. Methane gas can be produced from a biogas digester; however, operating a large digester in a densely populated village in Jordan can be challenging due to inefficient village waste management systems. On the other hand, using a small-scale portable biogas digester to generate biogas could overcome these problems. In this work, three biogas digester feedstocks for a small portable biogas digester from natural sources available in Jordanian villages such as human and animal waste were designed and evaluated. The three feedstocks are food waste, human waste, and a mixture of human and food waste. The parameters tested were the digester size and the biogas production. The results showed that the best digester for portable application was that which digested a mixture of human and food waste; for a five-member family, this type of digester provided 115% of the family’s cooking gas requirements with a digester volume of 0.54 m3. This design, while applicable for a typical rural Jordanian family, can also be utilized globally.

scholarly journals Potential pitfalls of FISH microscopy as assessment method for anaerobic digesters

2016 ◽  
Author(s):  
Christian Abendroth ◽  
Sarah Hahnke ◽  
Michael Klocke ◽  
Olaf Luschnig
Keyword(s):  
Microbial Activity ◽  
Biogas Production ◽  
Assessment Method ◽  
Gas Production ◽  
Anaerobic Digester ◽  
Fish Analysis ◽  
Metabolic State ◽  
Anaerobic Digesters ◽  
Biogas Reactor

AbstractIn the present work we investigated how the state of a biogas reactor impacts the enumeration of prokaryotic cells by fluorescencein situhybridisation (FISH). Therefore, the correlation between gas production and FISH hybridisation rates was analysed in different anaerobic digester sludges. High gasification activity coincided with high hybridisation rates. Low hybridisation rates were especially achieved with reactor samples subjected to long starvation periods showing low biogas production.Based on our findings we conclude that samples for FISH analysis should be fixed as soon as possible to prevent a loss of microbial activity resulting in lower FISH signals. Furthermore, the location of sampling is of importance, since samples from different fermenters within the same biogas plant also varied strongly in their FISH hybridisation rate. Our results indicate that FISH could be a useful method for assessing the metabolic state of microorganisms in anaerobic digester plants.

Effect of H3PO4 Pretreatment on Biogas Production of Rice Straw during Anaerobic Digestion

2014 ◽  
Vol 953-954 ◽  
pp. 216-219
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu
Keyword(s):  
Anaerobic Digestion ◽  
Rice Straw ◽  
Biogas Production ◽  
Low Cost ◽  
Gas Production ◽  
Methane Content ◽  
Pretreatment Conditions ◽  
Peak Value

To improve the gas production ability, relatively low cost H3PO4was chosen as the pretreating agent in this study. Rice straws were pretreated by four different weight percentages (2%, 4%, 6% and 8%) of H3PO4retting for seven days in an biochemical incubator at (25±1) °C, and the effects with different conditions of H3PO4pretreatment on anaerobic digestion of rice straws for variation of components and anaerobic digestion performance (under temperature of (35±1) °C) were studied. The results showed that the peak value of biogas production was attained on the 1stday for using 6% H3PO4pretreatment on rice straw, which is 2284 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.8% to 43.1%, with the highest recorded at the 12thday of the 2% H3PO4- treated rice straw. The cumulative biogas production of 6% H3PO4pretreatment was the highest, about 16 474 mL.

scholarly journals Does Social Support Affect the Health of the Elderly in Rural China? A Meta-Analysis Approach

2019 ◽  
Vol 16 (18) ◽  
pp. 3471 ◽  
Author(s):  
Natuya Zhuori ◽  
Yu Cai ◽  
Yan Yan ◽  
Yu Cui ◽  
Minjuan Zhao
Keyword(s):  
Social Support ◽  
Rural Areas ◽  
Rural China ◽  
Statistical Significance ◽  
Empirical Studies ◽  
Relevant Literature ◽  
The Elderly ◽  
Significant Difference ◽  
Meta Regression ◽  
The Impact

As the trend of aging in rural China has intensified, research on the factors affecting the health of the elderly in rural areas has become a hot issue. However, the conclusions of existing studies are inconsistent and even contradictory, making it difficult to form constructive policies with practical value. To explore the reasons for the inconsistent conclusions drawn by relevant research, in this paper we constructed a meta-regression database based on 65 pieces of relevant literature published in the past 25 years. For more valid samples to reduce publication bias, we also set the statistical significance of social support to the health of the elderly in rural areas as a dependent variable. Finally, combined with multi-dimensional social support and its implications for the health of the elderly, meta-regression analysis was carried out on the results of 171 empirical studies. The results show that (1) subjective support rather than objective support can have a significant impact on the health of the elderly in rural areas, and there is no significant difference between other dimensions of social support and objective support; (2) the health status of the elderly in rural areas in samples involving western regions is more sensitive to social support than that in samples not involving the western regions; (3) among the elderly in rural areas, social support for the older male elderly is more likely to improve their health than that for the younger female elderly; and (4) besides this, both data sources and econometric models greatly affect the heterogeneity of the effect of social support on the health of the elderly in rural areas, but neither the published year nor the journal is significant. Finally, relevant policies and follow-up studies on the impact of social support on the health of the elderly in rural areas are discussed.

scholarly journals Green and Blue Space Availability and Self-Rated Health among Seniors in China: Evidence from a National Survey

2021 ◽  
Vol 18 (2) ◽  
pp. 545
Author(s):  
Chensong Lin ◽  
Longfeng Wu
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Empirical Studies ◽  
National Level ◽  
The Elderly ◽  
Coverage Ratio ◽  
Self Rated Health ◽  
Health Promoting ◽  
Major River ◽  
Urban And Rural Areas

Many empirical studies have shown evidence of multiple health benefits provided by green and blue spaces. Despite the importance of these spaces, investigations are scarce in details for blue spaces rather than green. Moreover, most research has focused on developed regions. A limited number of studies on blue spaces can be found in China with a focus on the city level. Outcomes have been mixed due to varying research scales, methodologies, and definitions. This study relies on a national-level social survey to explore how the self-rated health (SRH) of senior individuals is associated with local green and blue space availability in urban and rural areas. Results indicate that the coverage ratio of overall green spaces and waterbodies around a resident’s home have marginal effects on SRH status in both urban and rural areas. In urban areas, living close to a park can is marginally beneficial for older people’s health. Regarding different types of blue spaces, the presence of a major river (within 0.3–0.5 km) or coastline (within 1 km and 1–5 km) in the vicinity of home negatively affects SRH among the elderly in urban areas. Close proximity to lakes and other types of waterbodies with a water surface larger than 6.25 ha did not significantly influence SRH. These findings not only evaluate general health impacts of green/blue space development on senior populations across the county but inform decision makers concerning the health-promoting qualities and features of different green/blue spaces to better accommodate an aging population in the era of urbanization.

scholarly journals Effect of Mixing Regimes on Cow Manure Digestion in Impeller Mixed, Unmixed and Chinese Dome Digesters

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2540
Author(s):  
Abiodun O. Jegede ◽  
Grietje Zeeman ◽  
Harry Bruning
Keyword(s):  
Urban Areas ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Gas Production ◽  
Cow Manure ◽  
Volatile Solid ◽  
Treatment Efficiency ◽  
Ambient Temperatures ◽  
Ch4 Production ◽  
Mixing Regime

This study examines the effect of mixing on the performance of anaerobic digestion of cow manure in Chinese dome digesters (CDDs) at ambient temperatures (27–32 °C) in comparison with impeller mixed digesters (STRs) and unmixed digesters (UMDs) at the laboratory scale. The CDD is a type of household digester used in rural and pre-urban areas of developing countries for cooking. They are mixed by hydraulic variation during gas production and gas use. Six digesters (two of each type) were operated at two different influent total solids (TS) concentration, at a hydraulic retention time (HRT) of 30 days for 319 days. The STRs were mixed at 55 rpm, 10 min/hour; the unmixed digesters were not mixed, and the Chinese dome digesters were mixed once a day releasing the stored biogas under pressure. The reactors exhibited different specific biogas production and treatment efficiencies at steady state conditions. The STR 1 exhibited the highest methane (CH4) production and treatment efficiency (volatile solid (VS) reduction), followed by STR 2. The CDDs performed better (10% more methane) than the UMDs, but less (approx. 8%) compared to STRs. The mixing regime via hydraulic variation in the CDD was limited despite a higher volumetric biogas rate and therefore requires optimization.

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