BAOJ Nutrition. Economic Efficiency Comparison of Different Instalations for Bio-Energy and Compost Production

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1 BAOJ Nutrition Atanasov, et al., BAOJ Nutrition : 5 3: 045 Review Economic Efficiency Comparison of Different Instalations for Bio-Energy and Compost Production Atanasov, D. Anna Aladjadjiyan 2 * and D. Penkov 1 Agricultural University, Faculty Economics Dept. Economics, Mendeleev 12, Bg-4000 Plovdiv, 2 Agricultural University, Faculty Economics Dept. Mathematics, Informatics And Physics, Mendeleev 12, Bg-4000 Plovdiv, 3 Agricultural University, Faculty Agronomy Dept. Animal Breeding, Mendeleev 12, BG-4000 Plovdiv, Abstract Agriculture despite its multifunctionality and importance to society is one of the sectors that have serious negative impact on the environment. Agriculture is a main contributor to soil degradation in and therefore re-cultivation of land is a very important task. The possibilities for using composted either municipal waste or residues from biogas production for soil re-cultivation, suggested by the development of INEMAD project, should be assessed and popularized. The advantages and disadvantages should be analyzed and discussed. The possibilities for production and marketing of bio energy and dig estate from municipal waste or from anaerobic digestion of animal manure are discussed. The processing of municipal waste for producing compost of organic origin that can be used for soil re-cultivation (to recover nutrients and improve structure) reduces the dunghill areas as well as the Greenhouse Gas emissions. Key Words: Animal Manure; Biogas; Economic Efficiency; Introduction In the European Union (EU), over the past years there has been an increasing interest in projects for production and use of biogas. According to Warren (2012), biogas production is a process which uses anaerobic conditions together with microorganisms and organic substrates in order to produce a mixture of gases, mainly carbon dioxide and bio-methane. Organic substrates that can be used as a feedstock are energy crops, manures, industrial wastes, sewage sludge, and the organic fraction of municipal solid wastes. The production of biogas is economically and environmentally beneficial as it captures and recovers the methane and carbon dioxide. It is beneficial to remove methane and carbon dioxide as they are both considered greenhouse gases which may have a negative impact on the environment. The biogas could be used for heating, electricity, vehicle fuel, etc [1]. has good infrastructure and also an appropriate legal framework for waste management. It is not always necessary to build sophisticated technologies for biogas (e.g. additional treatment systems or biogas fuel cells). Most suitable, from an economic perspective, plants for production of biogas are the co-generation systems. It is difficult to determine the amount of available raw materials for biogas production in the country, but agricultural production and related industries/consumption generate a significant amount of organic material designated as agricultural waste. Their use for biogas is appropriate and recommended. Another source of raw material for biogas production is the households waste. This paper is focused on identifying the economic performance of various bioenergy power plants, as well as their positive impact on the environment. Data from two bioenergy plants, working near the largest cities in Sofia and Plovdiv was interpreted to analyze the efficiency of using municipal waste as a resource for energy and compost production. Also information from a large pig farm was obtained in order to evaluate the possibilities for efficient production of heat and electricity from animal manure. *Corresponding Author: Agricultural University, Faculty Economics Dept. Mathematics, Informatics And Physics, Mendeleev 12, Bg Plovdiv,, anna@auplovdiv.bg Sub Date: October 23 rd, 2017, Acc Date: November 11 th, 2017, Pub Date: December 4 th, Citation: Atanasov, D. Anna Aladjadjiyan and D. Penkov (2017) Economic Efficiency Comparison of Different Instalations for Bio- Energy Copyright: 2017 Atanasov, et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

2 Page 2 of 5 The first case study the Han Bogrov plant describes a Plug-flow installation for biological treatment of waste from the territory of Sofia municipality in order to generate heat and electricity, as well as to use the compost after the process for re-cultivation of land. The capacity of Han Bogrov is tons of raw waste per year, divided in two technological lines: bio waste (including food waste from retailers and households) tons/year and green waste from parks and gardens tons/year. The second case study Kalchevo pig farm defines a Mixed up-flow cylindrical plant working in the south-eastern part of. This is an economically efficient possibility for medium and big agricultural producers to deal with the by-products from their enterprises. Pig farms have great potential for biogas production. The installation, described below, allows to be constructed according to the capacity needs of different size production units. In our case the farm uses 300 m3 installation, which annual capacity is about tons of sewage. The third case study the Shishmantsi plant, better known in the region as Eco enterprise, working near Plovdiv is an installation for converting non-hazardous municipal solid waste (MSW) into compost. The capacity of the plant is ton/year and is designed by the technical and technology company Tescam SARL France. Materials and Methods Case Study 1 Plug-Flow Plant Han Bogrov Sofia Municipality, Western Common Information: The plant Han Bogrov near Sofia is a municipal enterprise for biological treatment of waste. The main field of activity is receiving waste from the territory of Sofia municipality and its treatment to generate energy (heat and electricity) for its internal needs and for the market, as well as selling the compost after the process or using it for re-cultivation of land. The total capacity of the plant Han Bogrov is tons/year of raw waste. It consists of two production lines: Installation for bio-waste treatment (including food waste from retailers and food waste from households) tons/year and Installation for treatment of green waste from parks and gardens tons/yr. After its collection from the territory of Sofia municipality the waste is transported to the plant, where the treatment goes through the following stages: Receiving (incl. weighing of waste and issuing a receipt with the specific code); Initial mechanical treatment: Removal of impurities; Preparing a suitable for use suspension from ground waste and water; Production of biogas consists of two phases: (1) Acid phase carried out in a buffer tank; (2) Methanogenesis in the bio reactor (digester); The biogas received from the process is subjected to the following treatments: (1) Desulfurization; (2) Cooling; (3) Burning in co-generators for simultaneous production of electricity and heat; Pasteurization of the fermentation product; Dehydration of the pasteurized fermentation product; Mixing of the dehydrated material with the large fraction from the fine processing of green waste compost - the main purpose of this is to obtain a suitable for composting structure; Composting in indoor tunnels for two weeks. Fine treatment of the compost, received from the processing of biowaste; Economic Efficiency and Financial Indicators The benefit/cost ratio is used to estimate the economic incentives and logic of this investment. Of course the outcomes of such project are not only economically important, but also have environmental and social benefits. Figure 1 : Demonstrates one of the most practical installations for treatment of biodegradable materials in order to produce biogas, electricity and heat. Source: [2]. The total investment in the Han Bogrov plant is The economic life cycle of the project is calculated at 20 years. In this case the depreciation cost would be 5 % annually, which equals to * 0.05 = /year.

3 Page 3 of 5 The cost of running the business, including transport of input and output materials, salaries, electricity, water, etc., if the installation works on full capacity is approximately 40 /ton or /year. Total cost (if alternative cost of capital is not included) is = /year. The potential income from selling electricity to the National Electric Company (NEC) is equal to the amount of electricity produced (approximately MW/24 hour, 365 days a year) multiplied by the price guaranteed by the Commission for Energy and Water Regulation (CEWR) approximately 102 /MW. Income from electricity = * 365 * 102 = /year. The income from electricity covers % of the total cost. The difference between total cost and income from electricity is euro. According to one of the plant s managers, engineer Savov, the digestate (compost) has yield between 50 and 60 % of the initial organic material (approximately 55%). This means that tons * 0.55 = tons. The self-cost of compost production could be calculated by dividing to tons. The result is euro/ton. At this point we don t have information how much compost and at what price is going to the market. Sofia municipality is using some of the compost for re-cultivation of land. However the market price of the compost, depending on its type, quality, purity, etc. is between 110 BGN/ ton and 230 BGN/ton [3]. Converted to euro this is between /ton and /ton. If the compost is sold at /ton or at higher price, the benefit/cost ratio would be =>1, which means that the plant works efficiently. Case Study 2 Mixed Up-Flow Cylindrical Plant in Kalchevo Pig Farm, Yambol Region, South-Eastern Another type of installation for treatment mainly sewage from animal breading farms is the mixed up-flow cylindrical plant Figure 2. mixed up-flow cylindrical plant Source: [2]. Main Features: This anaerobic digestion process uses the manure as-it-is (liquid content + solid content); consequently, the cylindrical digester will be provided with a helical mixing system, an external timed recirculation pump and a nozzle system on the bottom to assure the sewage movement and the up-flow and crust-breaking effect. The digester will be daily fed with fresh sewage, while the digested sewage will come out after an average residence time in the tank of about 20/25 days. Suitable For: Farms that plan to manage the sewage as sole homogeneous product and to make the best of it from the energetic and economic point of view, as this system keeps the whole solid fraction of the manure, thus increasing the biogas production. It can also be suitable for mediumsized farms having yet biomasses to be added and digested together with the manure. This plant too has considerable environmental advantages, but it is necessary to consider that: the not-separated sewage shall be managed with suitable machinery during the pumping stage; the digester needs more electromechanical components; the plant has a higher power consumption and any additions of substances containing nitrogen involve the need of a larger land for the company balance provided for the agronomic use plan [4]. This type of plant is used in the second case we describe in the study. Pig farms have great potential for biogas production in. Nearly 50% of all pigs are grown in 0.04% of the enterprises (76 large holdings with an average number of heads). Common Information: The pig farm is situated in Kalchevo village, which is in the region of Yambol, south-eastern part of. The main field of activity is fattening pigs for the market. In the last 10 years the farm capacity has been growing and at the moment is approximately heads (incl sows, growing pigs with body weight 8 30 kg. Duration: 63 days and pigs for fattening with body weight over 30 kg. And duration 85 days). One of the main issues that the enterprise has to deal with is the by-products (pig sewage and dung) from the production process. According to prof. Pavlov and prof. Andreev the amount of faeces and urine released from a pig depends on its live weight. A sow with 220 kg live weight releases an average of 7-8 kg faeces and 6-7 litres urine per day. This is equal to about 5 tons/year. The average daily quantity of sewage (faces and urine) from pigs less than 110 kg is 3 kg and 2.5 kg respectively, which is approximately 2 tons/year [5]. The total amount of sewage that the farm produces per year would be: saws * 5 tons pigs * 2 tons = tons. Economic Efficiency and Financial Indicators: One ton of sewage treated in the plant is converted to 28 kw electricity [2]. Average 80 tons of pig sewage a day converts to 28*80 = 2240 kw or 2.24 MW. The potential income from selling electricity to the national electric company (NEC) is equal to the amount of electricity produced (approximately 2.24

4 Page 4 of 5 MW/24 hour, 365 days a year) multiplied by the price guaranteed by the commission for energy and water regulation (CEWR) approximately 102 /mw. Income from electricity = 2.24*365*102 = /year. The compost, left from the process doesn t go to the market. It is used for improving the agricultural land s quality. Installation for 100 m3 consisting of a concrete type tank + digester + works + cleaning system is The cost of the generator CHP of TEDOM MIKRO T30 SP BIO is [1]. The capacity of the farm suggests three such installations to manage the whole amount of sewage. The overall cost of installation is 3* = Other calculations showed that further were used for buying suitable land for building the plant and for all preparation works that had to be done there, which brings the sum of investment up to The life cycle of such installation, according to experts is approximately 10 years, which means that the depreciation cost would be 10 % annually or Each year the cost of running the plant (incl. Materials, repairs, electricity, water, salaries to the workers, transport cost, etc.) Are estimated at As in the previous case we don t include the alternative cost. The benefit/cost ratio, even without calculating the benefit from compost would be higher than 1. Economic efficiency = benefits /cost = / = 1/16. The net profit is /year. Case Study 3 Installation for Municipal Solid Waste Treatment, Shismantsi, Plovdiv Region South-Central Common Information The installation, known as Eco Enterprise Shishmantsi was open in The total investment was euro, including euro from the national budget [9].The capacity of the plant is tons/year. The installation is designed for processing of non-hazardous municipal solid waste (MSW) from the city of Plovdiv and other regional municipalities. The project is implemented through the technical solution and technology company TescamSarl. About 85% of the msw from plovdiv is transported to the depots, and approximately 52% of the total amount of waste is biodegradable. The plant is built in the village of shishmantsi, located 30 km from Plovdiv. After primary separation of the waste, the organic component is used for composting. The plant accepts only non-hazardous waste. Technological and sub-sections: primary processing and refining adoption of waste; pre-treatment roughly separation and segregation of selection of organic waste preparation of fermentation; separation pressing, packaging and baling of plastics; fermentation first phase of composting, fermentation of fermentation and maturation second phase of composting - compost maturation; refining cleaning the compost from non-composted biofilters cleaning the air aspirated by fermentation chambers; Monitoring, control and automation of the parameters of the fermentation ; The generated in the process waste, with no valuable properties to be recycled is disposed of in a depot (landfill waste storage) for non-hazardous and solid waste, which is an integrated part of the installation. The final product, the compost is an organic fertilizer of about 36% water, and 30-38% organic substance in dry mass. Its quality depends on the nutrient contents n-p-k, as well as the content of metals and organic toxicants. Economic Efficiency and Financial Indicators The Average Quantity Of Solid Municipal Waste Processed In The Plant For 2013 Is Tons Per Month, Or Tons For The Whole Year, Tons From Which Is Biodegradable Waste. The Electricity Consumed In The Process Of Treating The Waste Is Approximately Mw/Ton. Its Average Price For Business Enterprises Is /Kw Or / Mw [6]. Annual Electricity Cost For The Process Is *0,007* = In Shishmantsi 75 Full Time Workers Are Employed. The Average Monthly Payment (Salaries And Social Security) In Plovdiv Region For Is [7]. The Cost of Labour Is 75*357.90*12 = /Year. Depreciation cost is based on 20 years life cycle of the project, which means *0.05 = /year. The annual total cost of the enterprise = = , (excl. transport cost, water, chemicals, repairs, etc. for which we don t have official information). The income of eco enterprise comes mainly from the municipal budget as subsidies and it is / ton processed solid wastes. This is equal to 6 800*12*14.83 = Obviously the income from subsidy doesn t cover the cost. At this point the difference between the two is and if all other above described expenses are added to the equation, the negative result would be a lot higher. This figure should be covered as much as possible by the income from compost. The biodegradable waste of tons with average yield of 55% converts to tons of compost, which market price is between /ton and 117, 35 /ton. Even if the total income (compost + subsidies) doesn t cover the total cost of the enterprise, the project is good for the region. It has more ecological and social meanings than economical. Furthermore the positive impact of compost, used to

5 Page 5 of 5 improve the quality of the municipality s agricultural land should be mentioned. Conclusion World population in recent decades is constantly growing. More people need more food and row materials, more natural resources. This pushes agriculture to produce it, which in many cases is associated with more by-products and waste. Municipal waste is also becoming real issue in most parts of the world. One option for ensuring sustainable development on local and regional level is to use by-products from agriculture and municipal waste for production of energy and compost. This could make sense from an economical perspective, as shown in the above described cases. It is difficult to compare the efficiency of different installations for alternative energy production, because regional and local conditions vary greatly. Economic performance should not be the only aim of such projects, but their environmental and social benefits too. Acknowledgement References electricity_prices_evn_business_ pdf Warren, Katie (2012) A techno-economic comparison of biogas upgrading technologies in Europe Present work has received funding from the European Union s Seventh Framework Programme (FP7/ ) under grant agreement n as a part of project INEMAD.