Use of Food Waste for Generation of Biogas

Biogas is a mixture of colorless, flammable gases obtained by the anaerobic digestion of organic waste materials. It is an alternative source of energy. The major composition of biogas is methane (CH 4) 50-70%. It can be used for cooking and power generation, while the residues from the process are used as fertilizers. In this experimental work, an equal ratio of 2.5kg kitchen waste and 2.5kg water with small amount (1.75kg) of cow dung was weighted. The 1.75kg of cow dung was mixed with 1.5kg of water fed into 13.5 liter constructed digester and after some days, 2.5kg kitchen waste was mixed with 1kg of water and also fed into the digester. Then allowed to ferment for period of 22 days and a pressure range of 0psi-70.5psi was obtained. A graph of pressure (psi) against time (hrs), volume (liters) against time (hrs) and Pressure (psi) against volume (liters) of gas shows increase in pressure (psi) with time (hrs) and an increase in pressure with decrease in volume. A combustion test was also carried out which showed that for every 1 minute the temperature of water increases. The result from analysis of biogas composition done revealed the following: CH 4 (67.58%), H 2 (5.16%), CO 2 (20.29%), N 2 (8.46%), O 2 (1.06%) and H 2 S (2.36%) which has proved that really kitchen waste is a good raw material for production of biogas. INTRODUCTION Fossil fuel provides the bulk of the world's primary source of energy. Since they are non-renewable natural resources with little to conserve the earth's supply, supplies of fossil fuel (especially oil and gas) may soon get completely depleted. Additionally, the rising cost of petroleum and allied products most especially in Nigeria has triggered a need to develop alternate sources of energy, one of which is biogas production. In Nigeria, majority of the population are rural dwellers without access to gas or electricity and therefore depend on firewood for cooking and lightening. Unfortunately, this has contributed immensely to the rapid rate of deforestation and desert encroachment. The establishment of biogas plants in these communities would greatly ameliorate these problems and help preserve the environment. Biogas is distinct from other renewable energy source such as solar energy, wind energy, thermal and hydro sources of energy because of its characteristics of using controlling and collecting organic waste and at the same time producing fertilizer and water for use in agricultural irrigation. Anaerobic digestion process produces a higher biogas yield when running on a mixture of animal manure and vegetable/crop waste rather than animal manure alone, and biogas production is considered the most suitable bio energy technology in china (Wu CZ et al 2009). The slurry and residues from the biogas process can also be used as an organic fertilizer to replace the use of chemical fertilizer on the farm (HUGO 2008; Zhou Cx et al 2004; Liu y et al 2008 and chem. RJ 2007). The composition of biogas is typically methane (50-70%), carbon-dioxide (30-40%) and the rest is made up of traces of elements of hydrogen sulphide. Biogas can be used in gas engine to convert the energy in the gas into electricity and heat. Biogas is characterized based on its chemical composition and the physical characteristics which result from it. It is primarily a mixture of methane (CH 4) and inert carbonic gas (CO 2). However the name 'biogas' gathers a large variety of gases resulting from specific treatment processes, starting from various organic waste-industries, animals or domestic organic waste etc.

Physical Science International Journal

Anaerobic digestion is an effective method for organic pollution reduction and bio-energy production and has increasing applications worldwide. Produced biogas consists mainly of 50-70% methane (CH 4) and 30-50% carbon dioxide (CO 2). The most common utilization route of biogas is for electricity production, often combined with utilization of the excess heat. This widens up the opportunities to utilize biogas in distant energy consumption locations. The most common methods for biogas upgrading include water washing, pressure swing adsorption, polyglycol adsorption, and chemical treatment, which are performed outside the anaerobic reactor and require investments in

The Educator Journal

This research was conducted to determine the efficiency of biogas generation from kitchen garbage and to present the various biogas production processes. The anaerobic digestion of kitchen waste produces a valuable energy resource, and the activity-based laboratory approach was applied for this purpose. The anaerobic breakdown is a microbiological process that produces biogas, mainly composed of methane and carbon dioxide. Biogas can be utilized as a source of energy and for a variety of other purposes. On the other hand, any potential applications require knowledge and information on the composition and quantity of components in the biogas produced. Sodium hydroxide must be added to maintain alkalinity and pH in the digester. The cow dung slurry, as well as kitchen garbage, were added to this reactor. This mixed Inoculum was combined to produce biogas in a small-scale activity. The production of biogas and methane from starch-rich and sugary material is determined on a small scale ...

2019

Anaerobic digestion is an effective method for organic pollution reduction and bio-energy production and has increasing applications worldwide. Produced biogas consists mainly of 50-70% methane and 30-50% carbon dioxide. The most common utilization route of biogas is for electricity production, often combined with utilization of the excess heat. This widens up the opportunities to utilize biogas in distant energy consumption locations. The study sort to design, build a laboratory-scale biogas digester and test and optimize the gas production from different types of organic kitchen wastes. Biomass Kitchen waste was collected, as feedstock for a laboratory-scale anaerobic digester (10L capacity) to produce biogas. This was done within a temperature range of 25°C-35°C and in an alkaline environment maintained by adding a medium of sodium hydroxide. It was set to operate at constant gas pressure. The study has shown that using the displacement of water method in an inverted siphon system, we can sustain high pressure of the stored gas. The same idea can be used to pump this biogas to places far away from the digester for consumption. The biogas produced was then analyzed for its energy potential. The power potential of biogas produced by co-digesting kitchen waste and cow dung was found to be 22,461.77W/m 3. Pure methane has a power potential of 37,258.9W/m 3. Therefore, the methane percentage in the biogas collected in this study was 60.29%. The gas was also taken through gas chromatography to assess its constituents. Cow dung and starch were found to produce a higher percentage of methane. It is envisaged that the gas generated and the process friendly cost, will be a perfect alternative source of cleaner, safer and cheaper energy source as compared to the expensive and environmentally unfriendly traditional sources such as firewood, charcoal and petroleum products. This has great domestic and commercial application if exploited.

2014

Currently, much of our biodegradable wastes such as kitchen wastes, agricultural wastes & animal wastes are used to produce Biogas, a powerful greenhouse gas. Anaerobic digestion (AD) is a treatment that composts these wastes in the absence of oxygen, producing a biogas that can be used to generate Heat & Power. Producing renewable energy from our biodegradable wastes helps to tackle the energy crisis. It is effectively a controlled and enclosed version of the anaerobic breakdown of organic wastes which releases methane. AD produces a biogas made up of around 60 per cent methane and 40 per cent carbon dioxide (CO₂). As well as biogas, AD produces a solid and liquid residue called digestate which can be used as a soil conditioner to fertilise land. The amount of biogas and the quality of digestates obtained will vary according to the feedstock used. More gas will be produced if the feedstock is more liable to decompose.

American Journal of Energy Engineering

This study focuses on production of biogas from kitchen waste using modified digester. The digester has been placed in four different conditions. As the result shows, production of gas gradually increased and peaked to 0.360, 0.260, 0.150 and 0.116m 3 at 9 th , 12 th , 17 th and 23 th days of the 1 st , 2 nd , 3 rd and 4 th sets respectively. Due to depletion of the developed culture and organic content of the waste, gas production becomes decreased and then nearly zero at 22 th and 29 th days of the 1 st and 2 nd sets. But For the last two cases production is not completed within thirty days. Finally, 10kg of food waste has been produced a total of 2.292, 1.783, 1.172 and 0.962m 3 of biogas from the 1 st , 2 nd , 3 rd and 4 th sets respectively and the best waste/water ratio is 1:2. Temperature, particle size and pH are the main factors affecting microbial activity and then methane production. Of those, temperature is the most important factor. Low pH decrease's the biogas production by facilitating hydrolysis and acidogenesis reactions and makes bacteria's to utilize the waste more readily. Generally, production of biogas in Shoarobit is more feasible, and takes short time than in Debre Berhan town.

In this paper we present the various elementary traversal approaches for mining frequent pattern to find out association rules. We start with a formal definition of association rule and its basic algorithm. We then discuss the association rule mining algorithms from several perspectives such as breadth first approach, depth first approach and Hybrid approach. Frequent pattern mining has been focused themes in data mining research for over a decade. Abundant literature has been dedicated to this research and tremendous progress has been made, ranging from efficient and scalable algorithms for frequent itemset mining in transaction databases to numerous research frontiers, such as sequential pattern mining, structured pattern mining, correlation mining , associative classification, and frequent pattern-based clustering. Keyword-association rules,frequent pattern mining,breadth first,defth first,hybrid approach.

Ayacucho. La batalla final por la independencia, 2024

El artículo aborda en la primera parte y desde la perspectiva del representante austríaco en Río de Janeiro las noticias recibidas sobre la Batalla de Ayacucho. La víctoria militar, sin embargo, no sería suficiente para que la independencia fuera reconocida por todas las potencias europeas. Por ello, en la segunda parte se hace un acercamiento a las discusiones que tuvieron lugar entre Metternich -representante del legitimismo- y Canning, quien favorecía el reconocimiento de los nuevos Estados americanos.

Appel a communication “Parler d'Israël dans les universités françaises : Perspectives plurielles après le 7 octobre” Dimanche 17 novembre 2024, de 14h à 18h au 119 rue La Fayette, 75010 Paris. Organisateur : Institut universitaire d'études juives Elie Wiesel Paris.