Friday 24 August 2012

Biogas plant under construction in Poland

Biogas Plant Under Construction in Poland

Vechta, Germany based organic waste to biogas technology supplier, Weltec Biopower has begun construction of a 2.4 MW biogas plant in Darzyno, Poland.

The company said that once complete the anaerobic digestion facility will be used to produce biogas from a mixture of liquid manure maize and, which will be supplied by farmers from the vicinity. The plant will also process potato waste of a chip manufacturer.

Four tanks with a capacity of 5000 cubic meters each provide sufficient space for the digestate.

The company explained that the substrates at the plant - located 80km from Danzig - will be fed into the four 4438 cubic meters stainless-steel fermenters via the four storage tanks and a 50 cubic metres dosing feeder.

The facility will be operated by utility company NEWD, which has previously only operated wind farms, but is now developing the country's first biogas plant with Weltec's polish subsidiary, Weltec Polska.

According to Weltec, the conditions in Poland are ideal for generating biogas, with an agricultural area of around 18.5 million hectares - 1.5 million hectares more than Germany. Liquid manure from cattle, pigs, poultry and other renewable raw materials are readily available as substrate for biogas plants.

The company added that the infrastructure conditions in Poland are also ideal, with subsidised decentralised power and heat generation, and a highly developed infrastructure for the transport of gas and district heat.

Furthermore, Weltec said that Poland's government is currently implementing policies for the development of decentralised energy supply through laws and directives - especially for biomass and biogas.

Through the 'Biogas Development Programme 2010-2020', Poland is aiming to have at least one agricultural biogas plant installed in every municipality by 2020 - there are approximately 2500 municipalities.`

source: www.waste-management-world.com

Monday 20 August 2012

A Biogas Research Institute will be established at the University of Agriculture Faisalabad

A Biogas Research Institute will be established at the University of Agriculture Faisalabad

A Biogas Research Institute will be established at the University of Agriculture Faisalabad (UAF) in collaboration with Biogas Institute of Ministry of Agriculture, (BIOMA) and People’s Republic of China. This was revealed during a meeting of UAF scientists with 4-member Chinese delegation headed by Ren Xiaobin, Deputy Director, Training and Information Research Centre BIOMA in New syndicate Hall of UAF here on Thursday.
UAF Vice Chancellor Dr Iqrar Ahmad welcomed the members of Chinese delegation and hoped that the proposed project would become a milestone for research and development activities in the field of renewable energy in the country. Dr Iqrar lauded the efforts of Punjab Chief Minister Muhammad Shahbaz Sharif for the promotion of research and development activities in the energy sector. He maintained that due to the absence of appropriate R&D mechanism, Pakistan could not have exploited its potential in renewable energy sector. He said that during last 35 years more than 7,000 biogas plants were set up but due to non-availability of sufficient human resource the system could not be sustained.
Mr Ren Xiaobin while addressing the scientists, said that Pakistan had great potential to generate renewable energy particularly through biogas. He urged the scientists to adopt latest technology in order to develop a sustainable environment friendly energy production in the country.
He said that BIOMA had set up 65 projects in various countries and provided training facility to 560 workers and experts. He added that BIOMA would provide all sort of technical assistance for the establishment of proposed Research Institute. Delegation also visited various sites of alternate energy.

Sunday 19 August 2012

Research Paper | Household Biogas Digesters

Household Biogas Digesters—A Review 

Karthik Rajendran *, Solmaz Aslanzadeh and Mohammad J. Taherzadeh 
School of Engineering, Universityof Borås, Borås 50190, Sweden;
E-Mails: Solmaz.Aslanzadeh@hb.se (S.A.); Mohammad.Taherzadeh@hb.se (M.J.T.)
*Author to whom correspondence should be addressed; E-Mail: Karthik.Rajendran@hb.se;
Tel.: +46-33-435-4855; Fax: +46-33-435-4008.
Received: 11 May 2012; in revised form: 27 July 2012 / Accepted: 30 July 2012 /
Published: 8 August 2012
Bio gas digester

Abstract:This review is a summary of different aspects of the design and operation of small-scale, household, biogas digesters. It covers different digester designs and materials used for construction, important operating parameters such as pH, temperature, substrate, and loading rate, applications of the biogas,the government policies concerning the use of household digesters, and the social and environmental effects of the digesters. Biogas is a value-added product of anaerobic digestion of organic compounds. Biogas production depends on different factors including: pH, temperature, substrate, loading rate, hydraulic retention time (HRT), C/N ratio, and mixing. Household digesters are cheap, easy to handle, and reduce the amount of organic  household waste. The size of these digesters varies between 1 and 150 m3. The common designs include fixed dome, floating drum, and plug flow type. Biogas and fertilizer obtained at the end of anaerobic digestion could be  used for cooking, lighting, and electricity.

Keywords:biogas; household digesters; bioenergy; waste management; fixed dome digesters; floating drum digesters; plug flow digesters

1. Introduction
Due to the increasing prices of fossil fuels and taxes on energy sources, finding alternative, clean
and economical sources of energy has nowadays become a major concern for households’ and nations’
economies. In addition, economic prosperity and quality of life, which are linked in most countries to
per-capitaenergy consumption, is a great determinant and indicator of economical development
Energy demand is a critical reason for extensive climate change, resource exploitation, and also
restricts the living standards of humans [5,6].  By the time fuel and fertilizer reaches rural areas, the end price is relatively expensive due to high  transport costs, leaving people to find alternative resources other thanoil [7]. Starke [8] reported wood  as the traditional source of fuel to produce energy for domestic purposes for 2.5 billion people in Asia. Many of the rural communities in developing countries are forced torely on the traditional energy  sources such as firewood, dung, crop residues, and paraffin. These traditional methods are often expensive and/or time-consuming [9–11]. Cooking accounts for 90% of energy consumption in the households of developing countries [12]. Furthermore, access to electricity in rural areas is relatively scarce [13]. Biogas is a substitute for firewood and cattle dung that can meet the energy needs of the rural population [14,15]. Biogas is a renewable source of energy that can be used as a substitute for natural gas or liquefied petroleum gas [16]. There are different models to assess the energy content of different energy sources, which includes water boiling test, controlled cooking test and kitchen performance test [17]. The energy content of 1.0 m3 of purified biogas is equal to 1.1 L of gasoline, 1.7 L of bioethanol, or 0.97 m3 of natural gas [16]. The application for rural and urban waste biogas production is widely spread. It is a challenge for engineers and scientists to build an efficient domestic digesters with the materials available, at the same time taking the local and economical considerations into the account. Although many digesters have been built, additional research and awareness are needed to meet the changing needs and conditions [18]. Biogas production can be carried out in very small reactors ranging from100-mL serum bottles in the lab up to 10,000 m3large digesters as normally used, for example, in Europe. This review deals with a summary of different household biogas digesters, their operating parameters, cost and materials used to build them, startup, and maintenance, the variety of applications employed, and associated social and environmental effects. 

 Biogas
Biogas, the metabolic product of anaerobic digestion, is a mixture of methane and carbon dioxide with small quantities of other gases such as hydrogen sulfide [19,20]. Methane, the desired component of biogas, is a colorless, blue burning gas used for cooking, heating,and lighting [21]. Biogas is a clean, efficient, and renewable source of energy, which can be used as a substitute for other fuels in order to save energy in rural areas [22]. In anaerobic digestion, organic materials are degraded by bacteria, in the absence of oxygen, converting it into a methane and carbon dioxide mixture. The digestate or slurry from the digester is rich inammonium and other nutrients used as an organic fertilizer [11,23–27]. Methane formation in anaerobic digestion involves four different steps, including hydrolysis, acidogenesis, acetogenesis, and methanogenesis. Different bacterial/archaea communities work in a syntrophic relationship with each other to form methane. In hydrolysis, complex carbohydrates, fats, and proteins are first hydrolyzedto their monomeric forms by exoenzymes and bacterial cellulosome. In the second phase (acidogenesis), monomers are further degraded into short-chain acids such as: acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, caprionic acid,lcohols, hydrogen, and carbon dioxide. During acetogenesis, these short-chain acids are converted into acetate, hydrogen, and carbon dioxide. In the last phase, methanogens convert the intermediates produced into methane and carbon dioxide. Almost one-third of methane formation is due to reduction of carbon dioxide by hydrogen

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