scholarly journals Enhancing biogas quality of indigofera plant waste through co-digestion with cow dung

2018 ◽  
Vol 154 ◽  
pp. 02001 ◽  
Author(s):  
Finda Sihta ◽  
Suyitno ◽  
Atmanto Heru Wibowo ◽  
Retno Tanding

The production process of indigofera plants yields 10% of blue natural dyes and wastes are 90%. The biomass wastes from the extraction of indigofera plants are classified as difficult to process in an Anaerobic Digester (AD) because of the large content of hemicellulose in the Indigofera stems. Therefore, the study reports the anaerobic digestion of Indigofera plant wastes co-digested with cow dung for enhancing the biogas quality. The digestion process was conducted in a vessel of 160 L with various weight ratios between Indigofera biomass and cow dung by 0%, 25%, 50%, 75%, and 100%. The results show that the AD reactor temperature kept above 29.5°C with a pH between 6-7 were the key factors for enhancing the biogas quality. The co-digestion between 50% indigofera wastes with 50% cow dung yielded biogas with a CH4 content of about 42% and H2S concentration below 40 ppm showing that the biogas has the potential to be further improved in quality and can be used to fuel the stove and power generation.

Author(s):  
Prajwal Sapkota ◽  
Laxman Poudel

Bio-gas has been one of the sources of renewable energy and has been used from long time. It is produced by the anaerobic digestion or decomposition of organic compounds and has different process. The digestion process is carried out by bacteria present in the waste and it is highly dependent on the bacteria which work differently on different temperatures. The rate of anaerobic digestion is highest at hemophilic temperature (55°C). Similarly, it is moderate at mesophilic temperature (35°C) and is lowest at psychrophilic (below 20°C). Thus, to attain the highest digestion rate a thermophilic heating system has beend eveloped. The heating system uses five heat exchangers to heat the influent at digester which is of 35m3 volume, to maintain temperature at 56°C. The volume of bio-gas production from this system which uses cow dung as digestingmaterial is about 28 m3 per day.


2016 ◽  
Vol 848 ◽  
pp. 56-59
Author(s):  
Duongruitai Nicomrat ◽  
Parinya Somkid ◽  
Kitti Chuaiwan

At present, charcoal briquette fuel, a source of heat energy and mostly made from agricultural waste materials, are popular in the markets because of their high constant heat output. It helps reduce pollution, and produce no sparks while burning, but varied due to different types of materials, burning protocols, temperature, and pressure used. In this study, the research team have studied the characteristics of high quality fuel briquettes for possible further development of standard indicators of briquette fuel production process. In the study, key factors of the Charcoal fuel features composed of high qualities of physical characteristics and electrical induction. Activated carbon and coconut shell charcoal types were showed to be great materials. The production process involved aerobic burning at 800-900oC for at least 3 hours, grinding and mixing with starch binder. The briquettes’ electrical conductivity was especially lower than 10 kΩ. High heat production was obtained at least 6000 Cal/g while ground charcoal possessed with the sizes were varied. Under microscopy, the charcoal particle sizes were in a range of 50-100 μm for 30-50% (w/w), size of 10-50 μm for 20-40% (w/w) and distinctive numbers of holes greater than 300 μ to 1 mm were rarely observed. Therefore, with key characteristics of charcoal briquette fuel, it could be further applied for development the indicator as well as instruments to measure the quality of the briquette.


2019 ◽  
Vol 4 (6) ◽  
Author(s):  
KO Ansah Amano ◽  
E Appiah-Danquah ◽  
E Adom ◽  
AG Ntiri-Asiedu ◽  
ES Amoamah ◽  
...  

Management of waste is a key concern in several communities in Ghana. The exponential growth in waste generation imposes serious threats such as environmental pollution, health risk and scarcity of dumping site to our society. A large variety of organic rich materials inherent in this waste have high potential to be treated by the use of anaerobic digestion. In this study, eight (8) Laboratory scale biodigesters were used for the anaerobic co-digestion of household and market waste with cow dung as inoculum, controlled at a pH range of 6.53-7.04 and at a mesophilic temperature of 35±2˚C. The study was also conducted in batch mode at a hydraulic retention time of 21 days. The anaerobic co-digestion process was developed and optimized at varying feedstock to inoculum ratio to determine the potential biogas yield from each proportion. The results obtained indicate sample S8, containing market waste and inoculum in the ratio of 6:1 produced the optimum concentration of methane (51% v/v biogas) while the least was recorded by sample S2 primarily made up of market waste. ANOVA results show that the concentration of methane produced from the substrate is significantly affected by the hydraulic retention time and pH value of the anaerobic digestion process.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2713 ◽  
Author(s):  
Alla Mohammed Alrefai ◽  
Raid Alrefai ◽  
Khaled Younis Benyounis ◽  
Joseph Stokes

Cassava is a form of food that is rich in starch abundant in many countries. Several bio-products can be extracted from its starch and used as an alternative for oil-based products. This study primarily aims to investigate the influence of the starch isolated from cassava peel on the quantity and quality of the biogas produced via anaerobic digestion. Beating pre-treatment was applied for the first time to isolate the starch and mechanically pre-treat the substrate. The influence of temperature, volatile solid and sludge quantity investigations were analysed with the aid of Design of Experiments (DOE). An optimisation process was applied in calculating the energy balance at the optimal results and this was needed in evaluating the impact of the starch on the biogas produced. The study revealed that the influence of the starch on the biogas quality is quite low and, as such, negligible. The largest biogas volume as obtained was 3830 cc at 37 °C, 4.2 g-VS and 50% sludge quantity, while at the same time the maximum CH4 g−1-VS was 850 cc g−1-VS at 37 °C, 1.1 g-VS and 50% sludge quantity. The optimal results show the energy gain could be achieved based on the set criteria.


2021 ◽  
Vol 16 (2) ◽  
pp. 84-94
Author(s):  
Fahmi Arifan ◽  
Abdullah Abdullah ◽  
Siswo Sumardiono

Organic waste has high COD and BOD content, so it is dangerous if disposed of directly into the environment. Organic waste processing, such as waste from livestock manure and liquid tofu waste, requires a process that can reduce COD and BOD levels as well as produce valuable products. Anaerobic digestion method is the proper process to convert complex compounds in waste into simpler compounds with methanogenic bacteria into a renewable energy product, namely biogas. On the other hand, the anaerobic digestion process can reduce COD and BOD levels in the biogas formation process. This study uses raw materials such as cow manure and chicken manure, and liquid tofu waste. The variables that produced the largest biogas were those with a ratio of 70% cow dung, 15% chicken manure, and 15% tofu liquid waste with a total of 3,251.5 mL. Then, the COD and BOD levels decreased significantly with more than 98% COD removal, and more than 95% BOD removal in all variables at the end of the anaerobic digestion process.


2021 ◽  
Vol 2 (2) ◽  
pp. 139-144
Author(s):  
Gabriella Marsaulina ◽  
◽  
Taufik Taufikurahman ◽  
Andira Rahmawati

Water hyacinth (Eichhornia crassipes) is a plant species commonly used for phytoremediation to reduce high chromium content in tannery liquid waste in Garut, West Java. Water hyacinth materials harvested from the phytoremediation can be used for the anaerobic digestion process to produce biogas and bio-slurry. This study aimed to determine the reduction of chromium content found in water hyacinths due to the anaerobic digestion process, and utilization of bio-slurry from the anaerobic digestion process as a biocomposite material. The anaerobic digestion process was carried out for 33 d using biodigesters and the composition of the biodigesters were varied into 100% dried water hyacinths and 80% water hyacinths with the addition of 20% cow dung. The bio-slurry from the anaerobic digestion process was then used for making biocomposites with 3 different compositions, i.e., 75 and 25%; 50 and 50%; and 25 and 75% of cement and bio-slurry, respectively. The average chromium content found in water hyacinths from the phytoremediation process without anaerobic digestion process was 41.964 mg/l. The results show a reduction in the amount of chromium after the anaerobic digestion process was found in each composition of bio-slurry, which were 15.979 mg/l (100% water hyacinth) and 14.861 mg/l (80% water hyacinth + 20% cow dung). Biodigester with a composition of 80% water hyacinth + 20% cow dung produced the highest average volume of biogas which was 0.424 l. The biocomposite of 75% cement and 25% bio-slurry had the highest compressive strength value of 30.598 MPa and water absorption capacity of 37.25%. It can be concluded that biocomposite with the composition of 75% cement and 25% water hyacinth bio-slurry is promising to be used as an alternative material for buildings.


Author(s):  
Matthew Wade

Mathematical modelling of bioprocesses has a long and notable history, with eminent contributions from fields including microbiology, ecology, biophysics, chemistry, statistics, control theory and mathematical theory. This richness of ideas and breadth of concepts provide great motivation for inquisitive engineers and intrepid scientists to try their hand at modelling, and this collaboration of disciplines has also delivered significant milestones in the quality and application of models for both theoretical and practical interrogation of engineered biological systems. The focus of this review is the anaerobic digestion process, which, as a technology that has come in and out of fashion, still remains a fundamental process for addressing the global climate emergency. Whether with conventional anaerobic digestion systems, biorefineries, or other anaerobic technologies, mathematical models are important tools that are used to design, monitor, control and optimise the process. Both highly structured, mechanistic models and data-driven approaches have been used extensively over half a decade, but recent advances in computational capacity, scientific understanding and diversity and quality of process data, presents an opportunity for the development of new modelling paradigms, augmentation of existing methods, or even incorporation of tools from other disciplines, to ensure that anaerobic digestion research can remain resilient and relevant in the face of emerging and future challenges.


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