Recep Külcü

Composting of spent mushroom compost, carnation wastes, chicken and cattle manures

This study has purposed to determine the optimum mixture ratio of used mushroom compost, chicken manure, cattle manure and carnation waste for composting. For this purpose, these materials have been mixed in seven various ratios (R1-R7) and composted in the experimental composting reactors. The highest dry material losses and temperature values have been obtained by the R4 which contains 50% carnation waste, 25% chicken manure and 25% spent mushroom compost. Beside R4, mixtures of R2, R5 and R6 have also provided high process temperature and dry material loss values. The lowest dry material loss and temperature values have been obtained in the R7 which contains only carnation wastes. In the study, it has also seen that FAS (free air space) parameter is effective on the process and must be in the interval of 24-32%.

Modeling Spatio-Temporal Dynamics of Optimum Tilt Angles for Solar Collectors in Turkey

Quantifying spatial and temporal variations in optimal tilt angle of a solar collector relative to a horizontal position assists in maximizing its performance for energy collection depending on changes in time and space. In this study, optimal tilt angles were quantified for solar collectors based on the monthly global and diffuse solar radiation on a horizontal surface across Turkey. The dataset of monthly average daily global solar radiation was obtained from 158 places, and monthly diffuse radiation data were estimated using an empirical model in the related literature. Our results showed that high tilt angles during the autumn (September to November) and winter (December to February) and low tilt angles during the summer (March to August) enabled the solar collector surface to absorb the maximum amount of solar radiation. Monthly optimum tilt angles were estimated devising a sinusoidal function of latitude and day of the year, and their validation resulted in a high R2 value of 98.8%, with root mean square error (RMSE) of 2.06°.

The prospective of potential biogas plants that can utilize animal manure in Turkey

The feasibility study of potential biogas plants was conducted on a nationwide scale that may be established in each province of Turkey using potentially 10% of all annually collected animal manure. The analysis was carried out using the centralized anaerobic digestion model at thermophilic temperatures. Both equations and data used to calculate the capital and operating cost of biogas plants, as well as combined heat and power system were obtained from the available literature. The production of methane, electrical and heat energy, digestate, revenues, and CO2 savings due to biogas process were evaluated. The economic viability of biogas plants was evaluated based on the net present value (NPV), benefit-to-cost ratio (B/C ratio), internal rate of return (IRR), and payback period (PBP) based on the inclusion and exclusion of heat revenues at two different electricity purchase prices (0.066 and 0.11 ş/kWh). The results showed that the highest amounts of electrical and heat energy generated were for East Marmara (380.22 GWhe/year and 434.54 GWht/year), respectively, while those of the lowest production were for Istanbul region, 5.25 (GWhe/year), and 6.00 (GWht/year), respectively. The revenues from the produced electrical energy ranged from 0.35 Million Euros per year for Istanbul region to 25.09 Million Euros per year for East Marmara region while the heat revenues from biogas production ranged from 0.20 Million Euros per year for Istanbul region to 14.43 Million Euros per year for East Marmara region. It has been concluded that certain financial mechanisms have to be put into effect, such as increasing market price of electricity produced from biogas plants to give an incentive to biogas producers, as well as fundraising to support construction of biogas plants, and offering both long-term credits and tax breaks for investors.

Modelling of Global Solar Radiation on Horizontal Surfaces for Mersin City

Turkey is rich in solar energy potential due to its geographical location. Turkeys average annual sunshine duration is 2737 hours and the solar energy potential is 1527 kWh / m2 year. The major solar energy regionsare South Eastern Anatolia Region and the Mediterranean regions in Turkey. In this context, Mersin province is located in the provinces of maximum solar radiation in Turkey. Calculations of all the factors affecting the solar radiation from the atmosphere to the earth; creates a huge workload and the results cannot be obtained with sufficient accuracy.Therefore calculating the solar radiation coming to the earth models have been developed. In this study, the models for the prediction of solar radiation for Mersin city were evaluated using measured solar radiation data.Statistical aspects compliance of studied models were tested and validated which models the closest predicting to measured value. Introduction Energy is essential input of socio-economic prosperity and forward-looking development of todays technology. Therefore, region and country based energy policies and alternative strategies are developing in order to provide adequate, reliable and least damaging to the environment. This matter has a different position and property in Turkey. Turkey is dependent on importation for energy at a rate exceeding 70%. This rate is increasing day by day. Therefore, government and the community have to apply some special policy and specify behavior pattern. Therefore, government and the community have to requires apply some special policies and behavior pattern [1]. While the gap between Turkeys energy production and consumption has been increasing from 1990 to 2004, in the later years of 2010 Turkeys energy production has provided just %28-30 of our consumption. While Turkey’s energy production is 34,47 MTEP in 2012, energy demand is 121 MTEP level in the same year [1].Renewable energy sources aren’t imported therefore it’s national and reliable energy sources.Also these energy sources aren’t run out and not produce exhaust and greenhouse gases emissions unlike conventional energy sources. The potentials of Renewable energy sources of Turkey showed in Table 1. Table 1. Renewable energy potentials of Turkey [2] Renewable Energy Source Specify Natural Potentials Technical Potentials Economical Potentials Solar Energy Electricity(TWh/year) 977000 6105 305 Thermal(MTEP/year) 80000 500 25 Hydro Energy Electricity(TWh/year) 433 216 127.4 Wind Energy Electricity (TWh/year) 400 110 50 Wave energy Electricity (TWh/year) 150 18 Geothermal Energy Thermal(MWt) 31500 750