J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 Original Research Article Biogas Potential in Görükle Campus of Uludağ University 1* 1 2 1 İlknur Alibaş , Hilal Erdoğan , Aslıhan Yılmaz and Kamil Alibaş 1 Uludağ University, Faculty of Agriculture, Department of Biosystems Engineering, Bursa, TURKEY 2 Uludağ University, Graduate School of Natural and Applied Sciences, Bursa, TURKEY Received: 03.09.2016; Accepted: 08.10.2016; Published Online: 16.10.2016 ABSTRACT In this study, the potential of animal manure of the Application Research Centres of the Faculty of Agriculture and the Ranch of Veterinary Medicine and located within the boundaries of Görükle Campus at Uludağ University, the waste of rapeseed, sunflower, and wheat production of the Agricultural Research and Application Centre at the Agricultural Faculty and food waste of all dining halls, restaurants and cafeterias, particularly the Central Dining Hall, situated on the campus was determined in order to determine the biogas potential of the campus. As the dry matter, based on the organic waste potential, the biogas potential relating of the campus was calculated to be 499962.91 m3. It was determined that 17.95% of this potential consisted of animal manure, 46.15% of it consisted of agricultural production waste and 35.90% of it consisted of food waste. It was calculated that the electric energy potential obtained by transforming the biogas potential into electric energy by means of a generator was 980.22 MWh. Keywords: Animal manure, Biogas, Agricultural wastes, Electricity, Food wastes INTRODUCTION As world population continues to grow, energy requirements increase, fossil fuels begin to diminish and industrialization increases day by day, it may not be possible to provide the amount of energy demanded by the world (Kabir et al. 2013, Karray et al. 2016, Zhu and Hiltunen 2015). These problems have become much more important the use of renewable energy sources (Maghanaki et al. 2013). Biomass from agriculture wastes is used as a renewable energy source for bio fuels and biogas (Isoda et al. 2014). Agricultural wastes have a great value in terms of economic and ecological. Moreover, the use of these wastes reduces the pollution (He et al. 2016, Briassoulis et al. 2012). In the last decade, biogas production has experienced a great development in the Europe. Today, 4% of used energy in the European is derived from biomass. The European Union aims to obtain 20% of the total energy consumption and 10% of the fuel used in transportation from renewable sources by 2020 (Havukainen et al. 2014). Besides, by 2020, the European countries should increase the use of biogas to 8% (Thöle et al. 2016, Lübbers et al. 2016). Even if the European countries is the most important producer of biogas, it has also a great interest in the biogas sector in the US, Latin America, Asia and Africa. Besides, the biogas sector is quickly emerging in India and China (Moreno et al. 2015). Growth figures in Turkey’s energy sector are quite high compared to developed countries. Turkey ranks first in Europe with regard to demand of natural gas and electricity for the last 10 years (Alibaş et al. 2015, Ozsoy and Alibaş 2015). Turkey’s primary energy supply is composed of natural gas, coal, hydraulic, coal, liquid fuels and renewable sources with the rates of 47.9%, 30.2%, 16.1%, 0.9% and 4.9%, respectively. To reduce of dependence on foreign countries in energy, the share of renewable energy sources has been increasing in Turkey. The share of renewable energy production in Turkey was 0.3% in 2000 while this share increased to 4.9% in 2014 (TUIK 2016). In this regards, biogas within all renewable energy resources has also become a popular energy source in Turkey, nowadays. Seventy-two biogas plants have been established in Turkey. The installed power capacity and the annual energy production of these plants are 383 MW and 1858 GWh, respectively (Anonymous 2016). Biogas, which is produced from renewable raw materials, is a feasible and easily storable energy source. Microbiological processes become active during the production of biogas resulting from anaerobic fermentation of waste organic substances (Agulier-Virgen et al. 2014, Koening and Dehn 2016, Pizzuti et al. 2016). Being composed of methane (50%-60%), carbon dioxide (40%-50%), nitrogen (N2; 5%), hydrogen * Corresponding author: ialibas@uludag.edu.tr 79 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 sulphide (N2, <1%) non-methane organic components (NMOC; 2700 ppmv), biogas is colourless, odourless gas and lighter than air (Aguilar-Virgen et al. 2014, Barros et al. 2014, Amini et al. 2012, Schneider et al. 2012). Biogas, with a density of 0.83 and an octane number of 110, is also a gas burning through bright blue flame (Alibaş 1996). The heating value of natural gas and methane is 37.3 Mj.m-3 whereas the heating value of biogas ranges between 26.7 – 29.8 Mj.m-3 depending on content of methane (Ozsoy and Alibaş 2015, Alibaş et al. 2015). Organic wastes are generally composed of animal manure, agricultural wastes, food wastes, human feces and household wastes. However, cattle manure contains methane bacteria that provide anaerobic fermentation, this manure has a great importance (Ozsoy and Alibaş 2015, Alibaş et al. 2015). The aims of this study were to i) fix the annual waste potential as a solid matter from agricultural wastes, animal manure and food wastes ii) determine the annual biogas potential from waste potential as a solid matter and iii) identify the annual electricity from biogas potential in Görükle Campus of Uludağ University. MATERIALS AND METHODS Material In the present study, animal populations, the amount of agricultural product and food wastes in all dining hall, cafeterias and restaurants in rural areas of Görükle Campus of Uludağ University. Data regarding to food wastes from all dining hall, cafeterias and restaurants in campus were regularly measured with electronic balance after dinner throughout two months. Animal populations and plant production’s data were taken from declarations concerned contacts in Faculty of Agriculture and Veterinary Medicine. Organic Animal Manure Calculation Methods All calculations related to organic animal manure were taken from various researches in literature (Alibaş 1996, Alibaş et al. 2015). Daily manure production as a solid matter was calculated using the following equation Eq. (1): 𝑫𝑴𝑷(𝑺𝑴) = 𝑺𝑴 × 𝑭𝑴 Eq. (1) where DMP(SM) is daily manure production as a solid matter (kg(SM) day -1 AU-1), SM is solid matter content (%) and FM is fresh manure production (kg day-1 AU-1). In this study, the amount of total obtainable solid matter was calculated by the following equation Eq. (2): 𝑻𝑶𝑺𝑴 = 𝜸 × 𝑫𝑴𝑷(𝑺𝑴) Eq. (2) where TOSM is the amount of total obtainable solid matter (kg day-1 AU-1(SM) ) and γ is staying time in the barn (%). Animal unit was determined using the following equation Eq. (3): 𝑨𝑼 = (𝑨𝑷 × 𝑨𝑨𝑾)/𝑳𝑹𝑨𝑾 Eq. (3) where AU is animal unit (kg), AP is average animal population, AAW is average animal weight (kg) and LRAW is the average weight of large ruminants (454 kg). Annual animal manure potential as a solid matter as t -1(SM) y was calculated by the following equation Eq. (4): 𝑨𝑨𝑾𝑷(𝑺𝑴) = ((𝑨𝑼 × 𝑻𝑶𝑺𝑴)/𝟏𝟎𝟎𝟎) × 𝟑𝟔𝟓 Eq. (4) where AAWP(SM) is annual animal manure potential as a solid matter (t -1 (SM) y ). The annual amount of biogas from animal manure as m3 y-1 was determined by the following equation Eq. (5): 𝑨𝑩𝑨𝒂𝒏𝒊𝒎𝒂𝒍 = 𝑨𝑨𝑾𝑷(𝑺𝑴) × 𝑩𝑨𝒂−𝒔𝒎 Eq. (5) where ABA is the annual amount of biogas from animal manure (m3 animal y -1) and BAa-sm is the amount of availability of biogas (m3 t-1). Annual theoretical electricity amount from animal manure was calculated by the following equation Eq. (6): 𝑬𝒕−𝒂𝒏𝒊𝒎𝒂𝒍 = (𝑨𝑩𝑨𝒂𝒏𝒊𝒎𝒂𝒍 × 𝑰)/𝟑. 𝟔 Eq. (6) 80 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 where Et-animal is annual theoretical electricity amount from animal manure (kWh y -1) and I is the heating value (Mj m-3). The amount of annual effective electricity from animal manure as kWh y-1 was determined using the following equation Eq. (7): 𝑬𝒂𝒏𝒊𝒎𝒂𝒍 = 𝑬𝒕−𝒂𝒏𝒊𝒎𝒂𝒍 × 𝜼 Eq. (7) where Eanimal is the amount of annual effective electricity from animal manure (kWh y -1) and η is the average yield of electrical engines (25%). 2.3. Organic Agricultural Waste Calculation Methods All calculations related to organic agricultural wastes were taken from various studies in literature (Alibaş 1996, Alibaş et al. 2015). The amount of moist agricultural waste as t y-1 was calculated using the following equation Eq. (8): 𝑴𝑽𝑾𝑨 = 𝑶𝑾𝑪 × 𝑷𝑨 Eq. (8) where MVWA is the amount of moist agricultural waste (t y-1), OWC is the coefficient of organic waste and PA is the amount of average agricultural production. The annual agricultural waste potential as a solid matter was calculated by the following equation (Eq9): 𝑨𝑽𝑾𝑷(𝑺𝑴) = [(𝟏𝟎𝟎 − 𝑴𝑹)/𝟏𝟎𝟎)] × 𝑴𝑽𝑾𝑨 Eq. (9) where AVWP(SM) is the annual agricultural waste potential as a solid matter (t -1 (SM) y ) and MR is the moisture ratio (%). The annual amount of biogas from agricultural wastes as m3 y-1 was determined using the following equation Eq. (10): 𝑨𝑩𝑨𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 = 𝑨𝑽𝑾𝑷(𝑺𝑴) × 𝑩𝑨𝒗−𝒔𝒎 Eq. (10) where ABAagriculture is the annual amount of biogas from agricultural wastes (m 3 y-1) and BAv-sm is the amount of available of biogas from agricultural wastes (m3 t -1(SM) ). The annual theoretical electricity amount from agricultural wastes was calculated by the following equation Eq. (11): 𝑬𝒕−𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 = (𝑨𝑩𝑨𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 × 𝑰)/𝟑. 𝟔 Eq. (11) where E is the annual theoretical electricity amount from agricultural wastes (kWh y-1t-agriculture ) and I is the heating value (Mj m-3). The annual effective electricity amount from agricultural wastes was determined using the following equation Eq. (12): 𝑬𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 = 𝑬𝒕−𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 × 𝜼 Eq. (12) where E -1agriculture is the annual effective electricity amount from agricultural wastes (kWh y ) and η is the average yield of electrical engines (25%). 2.4. Food Wastes Calculation Methods The daily humid food wastes from facilities in campus were regularly measured with electronic balance after dinner throughout two months. Moisture content of food wastes was to be 82.61% in this study (Ulusoy et al. 2016). Food wastes from all facilities in active and passive season were taken in Table 1. According to Table 1, active season was defined to be continued education and this season was considered to be 200 days. Passive season was consisted of semester and weekend holidays and this term was taken as 165 days in this study. Food wastes potential as a solid matter was calculated using the following equation Eq. (13): 𝑨𝑭𝑾𝑷(𝑺𝑴) = [(𝟏𝟎𝟎 − 𝑴𝑹)/𝟏𝟎𝟎)] × 𝑴𝑭𝑾𝑨 Eq. (13) where AFWPSM is the annual food wastes potential as a solid matter (t -1 (SM) y ), MR is moisture content (%), MFWA is the annual food wastes potential as a humid matter The annual amount of biogas from food wastes was determined by the following equation Eq. (14): 𝑨𝑩𝑨𝒇𝒐𝒐𝒅−𝒘𝒂𝒔𝒕𝒆𝒔 = 𝑨𝑭𝑾𝑷(𝑺𝑴) × 𝑩𝑨𝒇−𝒔𝒎 Eq. (14) where ABAfood-wastes is the annual amount of biogas from food wastes (m 3 y-1) and BAf-sm is the amount of availability of biogas (m3 t-1). Annual theoretical electricity amount from food wastes was calculated by the following equation Eq. (15): 81 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 𝑬𝒕−𝒇𝒐𝒐𝒅𝒘𝒂𝒔𝒕𝒆𝒔 = (𝑨𝑩𝑨𝒇𝒐𝒐𝒅−𝒘𝒂𝒔𝒕𝒆𝒔 × 𝑰)/𝟑. 𝟔 Eq. (15) where Et-foodwastes is the annual theoretical electricity amount from food wastes (kWh y -1) and I is the heating value (Mj m-3). The annual effective electricity amount from food wastes was determined using the following equation Eq. (16): 𝑬𝒇𝒐𝒐𝒅−𝒘𝒂𝒔𝒕𝒆𝒔 = 𝑬𝒕−𝒇𝒐𝒐𝒅𝒘𝒂𝒔𝒕𝒆𝒔 × 𝜼 Eq. (16) where E -1food-wastes is the annual effective electricity amount from food wastes (kWh y ) and η is the average yield of electrical engines (25%). The annual theoretical electricity amount and the annual theoretical electricity amount from all organic wastes were calculated using the following equations Eq. (17) and Eq. (18): 𝑬𝒕 = 𝑬𝒕−𝒂𝒏𝒊𝒎𝒂𝒍 + 𝑬𝒕−𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 + 𝑬𝒕−𝒇𝒐𝒐𝒅𝒘𝒂𝒔𝒕𝒆𝒔 Eq. (17) 𝑬 = 𝑬𝒂𝒏𝒊𝒎𝒂𝒍 + 𝑬𝒂𝒈𝒓𝒊𝒄𝒖𝒍𝒕𝒖𝒓𝒆 + 𝑬𝒇𝒐𝒐𝒅−𝒘𝒂𝒔𝒕𝒆𝒔 Eq. (18) where Et is the annual theoretical electricity amount from all organic wastes (kWh y -1) and E is the annual effective electricity amount from all organic wastes (kWh y-1). Table 1. Daily humid food wastes from all dining halls, cafeterias and restaurants in the Uludağ University Campus. Daily Humid Food Daily Humid Food Wastes Facilities Wastes in Active season, in Passive season, kg kg Central Dining Hall 4000 3000 Credit & Dormitories Intuition Dining Hall 750 5 Aytu Cafeteria & Restaurant 15 4 Unpa Cafeteria & Restaurant 30 15 Ilkim Cafeteria & Restaurant 10 5 Han Cafeteria 0.5 0.1 Kampus Cafeteria 0.5 0.1 Yagmur Cafeteria 0.5 0.1 ZiyadeInn Cafeteria & Restaurant 2 2 Agaoglu-1 Cafeteria & Restaurant 20 0.1 Agaoglu-2 Cafeteria & Restaurant 5 0 Ekim Cafeteria 0.5 0.1 Yildiz Cafeteria 1 0.25 Mimoza Cafeteria & Restaurant 7.5 2 Sinem Patisserie 2 1 Holiday Inn Hotel – Cafeteria & Restaurant 10 10 Besaş A.Ş. Factory & Cafeteria 3 3 Total 4857.5 3047.75 RESULTS AND DISCUSSION The annual amount of organic wastes from animal manure as the dry matter obtained from the Ranch of the Faculty of Veterinary Medicine located on Görükle Campus of Uludağ University is given in Table 2, and the annual amount of biogas and the amount of electric energy obtained from this waste are given in Table 3. Accordingly, 54.90% of the biogas obtained from the Ranch of the Faculty of Veterinary Medicine can be obtained from poultry, 42.36% of it can be obtained from bovine animals and 2,17% of it can be obtained from sheep and goats. The biogas potential that can be obtained from the Ranch of the Faculty of Veterinary Medicine can cover approximately 1.67% of the natural gas spent for heating and electricity on the campus in 2015. 82 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 Table 2. Organic waste potential from animal manure as a dry matter in farm of Veterinary Medicine. Solid Daily manure Average Annual animal Fresh manure matter production as Staying Total Solid Animal Animal manure potential as a production content a solid matter in the barn Matter Population Weight Animal solid matter Animals (kg/dayAU) (%) (kg/dayAU) (%) (kg/dayAU) (Unit) (kg) Unit (ton/year) Cattle 33.331 12.7 4.23 65 2.75 179 454 179 179.77 Chicken 25.292 25 6.32 99 6.26 15450 2 68.061 155.51 Goats 16.440 31.7 5.21 13 0.68 185 50 20.37 5.04 Pig 35.424 9.2 3.26 80 2.61 13 60 1.72 1.63 Quail 26.616 59.7 15.89 99 15.73 800 0.135 0.24 1.37 Sheep 16.440 25 4.11 13 0.53 93 50 10.24 2.00 Total 16720 345.31 Table 3. Annual biogas potential and electricity from animal manure in farm of Veterinary Medicine. Annual animal manure Amount of Annual theoretical electricity Annual electricity from potential as a solid matter Availability of biogas Biogas Amount Heating Value from animal manure animal manure Animals (ton/year) (m3/ton) (m3/year) (Mj/m3) (MWh/year) (MWh/year) Cattle 179.77 202 36313.05 27.0 272.35 68.09 Chicken 155.51 300 46652.52 28.9 374.52 93.63 Goats 5.04 270 1360.34 28.0 10.58 2.65 Pig 1.63 300 490.49 28.9 3.94 0.99 Quail 1.37 300 409.76 28.9 3.29 0.82 Sheep 2.00 251 501.36 28.0 3.90 0.98 Total 345.32 85727.52 668.58 167.16 Table 4. Organic waste potential from animal manure as a dry matter in the ranch of Faculty of Agriculture. Solid Daily manure Average Annual animal Fresh manure matter production as Staying Total Solid Animal Animal manure potential as a production content a solid matter in the barn Matter Population Weight Animal solid matter Animals (kg/dayAU) (%) (kg/dayAU) (%) (kg/dayAU) (Unit) (kg) Unit (ton/year) Cattle 33.331 12.7 4.23 65 2.75 7 454 179 7.03 Goat 16.440 31.7 5.21 13 0.68 76 50 20.37 2.07 Quail 26.616 59.7 15.89 99 15.73 500 0.135 0.24 0.85 Sheep 16.440 25 4.11 13 0.53 238 50 10.24 5.11 Ostrich 26.616 25 6.65 25 1.66 13 100 2.86 1.74 Total 834 16.80 83 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 The annual amount of animal manure of the Ranch at the Faculty of Agriculture as the dry matter is given in Table 4, and the annual amount of biogas obtained from this amount of waste is given in Table 5. According to this, 45.60% of the annual biogas potential of the Ranch of the Faculty of Agriculture, which is 4039.63 m3, is obtained from sheep and goats, 35.15% of it is obtained from bovine animals and 19.25% of it is obtained from poultry. The biogas potential that the Ranch at the Faculty of Agriculture can obtain from the animal manure can supply approximately 0.08% of the annual biogas consumption of our University. The annual biogas potential from the animal manure, which the ranches of both the Faculty of Veterinary Medicine and Agriculture will provide, corresponds to 1.75% of the total natural gas consumption spent for the total heating and electricity of the campus. The organic waste potential of the Agricultural Application and Research Centre (TUAM) derived from the annual agricultural production as the dry matter is given in Table 6, and the annual potentials for biogas and electric energy which can be obtained from the plant waste are given in Table 7. Accordingly, 82.53% of the biogas potential, which can be obtained from the agricultural production, can be derived from wheat, 13.77% of it can be derived from canola and 3.70% of it can be derived from sunflower production wastes. The organic waste potential, which our university can provide from the agricultural production waste, has the potential to supply approximately 4.50% of the amount of natural gas consumed on the campus in 2015. The biogas potential, which the Faculty of Agriculture can derive from both the animal and agricultural production waste, has the value of 230759.27 m3. This value can cover the energy of the Faculty of Agriculture. Also, this value constitutes approximately 4.60% of the total natural gas consumption of the university. Ozsoy and Alibaş (2015) determined the biogas potential, which can be derived from the wastes from animal manure in Nilüfer district of Bursa province, where the campus of Uludağ University is located, to be 5443164.57 m3. According to the results of this study previously carried out, it can be said that the biogas potential which can be obtained from the organic waste of Agricultural Research and Application Centre of Faculty (TUAM) of Agricultural Faculty equals to approximately 4.24% of the agricultural biogas potential of Nilüfer district. 84 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 Table 5. Annual biogas potential and electricity from animal manure in the ranch of Faculty of Agriculture. Annual animal manure Biogas Heating Annual theoretical electricity from Annual electricity from potential as a solid matter Amount of Availability Amount Value animal manure animal manure Animals (ton/year) of biogas (m3/ton) (m3/year) (Mj/m3) (MWh/year) (MWh/year) Cattle 7.03 202 1420.06 27.0 10.65 2.66 Goat 2.07 270 558.84 28.0 4.35 1.09 Quail 0.85 300 256.10 28.9 2.06 0.52 Sheep 5.11 300 1283.05 28.9 9.98 2.50 Ostrich 1.74 300 521.58 28.0 4.19 1.05 Total 16.80 4039.63 31.22 7.82 Table 6. Organic animal waste potential from agricultural wastes as a dry matter in Agricultural Research and Application Centre of Agricultural Faculty. Agricultural Annual amount of agricultural Moisture Coefficient of Moist agricultural wastes Annual agricultural waste products production content organic wastes (t/year) potential as a solid matter (t/year) (%) (%) (t /year) Rapeseed 105000 14.5 0.59 61950 52.97 Sunflower 28200 14.5 0.59 16638 14.23 Wheat 328000 14.0 1.50 492000 423.12 Total 570588 490.32 Table 7. Annual biogas potential and electricity from agricultural wastes in Agricultural Research and Application Centre of Agricultural Faculty. Annual agricultural waste Amount of Biogas Heating Annual theoretical electricity Annual electricity from Agricultural potential as a solid matter Availability of biogas Amount Value from agricultural wastes agricultural wastes Products (t /year) (m3/ton) (m3/year) (Mj/m3) (MWh/year) (MWh/year) Rapeseed 52.97 600.00 31780.35 29.80 263.07 65.77 Sunflower 14.23 600.00 8535.29 29.80 70.65 17.66 Wheat 423.12 450.00 190404.00 28.10 1486.21 371.55 Total 490.32 230719.64 1819.93 454.98 85 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 The waste values as the annual organic dry matter of dining halls, cafeterias, and restaurants located on Görükle Campus of Uludağ University and the amounts of biogas and electric energy that can be obtained from this waste are given in Table 8. According to this, 87.83% of the biogas potential which was calculated from the food waste to be 110578.41 m3 can be derived from the Central Dining Hall, 10.23% of it can be derived from Credit and Dormitories Institution dining hall and 1.94% of it can be derived from other cafés and restaurants. The biogas potential, which can be obtained from the food waste, has the potential to cover 3.49% of the natural gas consumed in 2015 on the campus. The biogas potential that the university can derive from all organic waste and the value of electric energy, which can be obtained from this potential, are given in Table 9. According to Table 9, 17.95% of the total biogas potential of the campus can be derived from animal manure, 46.15% of it can be derived from the agricultural production and 35.90% of it can be derived from the food waste. The biogas potential which can be derived from the animal, agricultural production and food wastes has the potential to cover 1.75%, 4.48% and 3.49%, respectively, of the amount of natural gas consumed in 2015 on the campus. All the organic waste can cover 9.71% of the natural gas consumption of the campus. The biogas potential obtained from the animal manure of Nilüfer district determined by Özsoy and Alibaş (2015) has a value that is equal to the amount of natural gas consumed for heating and electricity on the campus. In the forthcoming years, in case a high-capacity biogas plant is established within the boundaries of Uludağ University, it will be possible to utilize the organic waste which can be obtained from the agricultural areas of Nilüfer District in this plant. Likewise, in order for the feasibility of the biogas plant to be ensured, it is suitable for the organic waste to be transported from maximum 20 km distance as one way. The distance of Uludağ University to the borders of Nilüfer District is less than this value determined as approximately 20 km. 86 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 Table 8. Organic waste potential, annual biogas potential and electricity from food wastes in all dining halls, cafeterias and restaurants of Uludağ University. Annual food Annual food Amount of Annual theoretical Annual wastes as a Moisture wastes as a Availability Biogas Heating electricity from electricity from humid matter content solid matter of biogas Amount Value food wastes food wastes Facilities (t/year) (%) (t /year) (m3/t) (m3/year) (Mj/m3) (MWh/year) (MWh/year) Central Dining Hall 1295.00 82.61 225.20 700.00 157640.35 28.1 1230.47 307.62 Credit & Dormitories Intuition Dining Hall 150.83 82.61 26.23 700.00 18359.93 28.1 143.31 35.83 Unpa Cafeteria & Restaurant 8.48 82.61 1.47 700.00 1031.66 28.1 8.05 2.01 Agaoglu-1 Cafeteria & Restaurant 4.02 82.61 0.70 700.00 488.93 28.1 3.82 0.96 Aytu Cafeteria & Restaurant 3.66 82.61 0.64 700.00 445.53 28.1 3.48 0.87 Holiday Inn Hotel Cafeteria & Restaurant 3.65 82.61 0.63 700.00 444.31 28.1 3.47 0.87 Ilkim Cafeteria & Restaurant 2.83 82.61 0.49 700.00 343.89 28.1 2.68 0.67 Mimoza Cafeteria & Restaurant 1.83 82.61 0.32 700.00 222.77 28.1 1.74 0.44 Besaş A.Ş. Factory & Cafeteria 1.10 82.61 0.19 700.00 133.29 28.1 1.04 0.26 Agaoglu-2 Cafeteria & Restaurant 1.00 82.61 0.17 700.00 121.73 28.1 0.95 0.24 ZiyadeInn Cafeteria & Restaurant 0.73 82.61 0.13 700.00 88.86 28.1 0.69 0.17 Sinem Patisserie 0.57 82.61 0.10 700.00 68.78 28.1 0.54 0.14 Yildiz Cafeteria 0.24 82.61 0.04 700.00 29.37 28.1 0.23 0.06 Han Cafeteria 0.12 82.61 0.02 700.00 14.18 28.1 0.11 0.03 Kampus Cafeteria 0.12 82.61 0.02 700.00 14.18 28.1 0.11 0.03 Yagmur Cafeteria 0.12 82.61 0.02 700.00 14.18 28.1 0.11 0.03 Ekim Cafeteria 0.12 82.61 0.02 700.00 14.18 28.1 0.11 0.03 Total 1474.42 256.39 179476.12 1400.91 350.26 Table 9. Total Biogas potential and electricity from all wastes in Campus of Uludağ University. Annual Waste Potential as a dry matter Biogas Amount Annual theoretical electricity Annual electricity (t/year) (m3/year) (MWh/year) (MWh/year) Animal Manure 362.12 89767.15 699.80 174.98 Agricultural Wastes 490.31 230719.64 1819.93 454.98 Food Wastes 256.39 179476.12 1400.91 350.26 Total 1108.82 499962.91 3920.64 980.22 87 J. BIOL. ENVIRON. SCI., 2016, 10(29), 79-88 CONCLUSIONS In this study, the biogas potential obtained from the organic waste of Görükle campus of Uludağ University was calculated to be 499962.91 m3. It was determined that 17.95% of the biogas potential of the campus consisted of the animal manure obtained from the ranches of Faculty of Veterinary Medicine and Agriculture, 46.15% of it consisted of the agricultural production waste of Agricultural Research and Application Centre (TUAM) of Agricultural Faculty, and 35.90% of it consisted of the left and dumped food waste in the all dining hall, restaurant, and cafeterias located on the campus. 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