Kamil Ekinci

Composting Short Paper Fiber with Broiler Litter and Additives: Part I: Effects of Initial pH and Carbon/Nitrogen Ratio On Ammonia Emission

Short paper fiber (SPF), a by-product of the paper mill industry, was cocomposted with broiler litter (BL) to determine decomposition rate and NH3-N loss as functions of C/N ratio and pH of the compost mixes. The SPF generally had a high C/N ratio >200 while the BL, consisting of bedding material (sawdust) and poultry manure, had a low C/N ratio of 10–12. A total of seven series (27 tests) of pilot-scale studies were conducted using two different SPFs mixed with BL. Additives used for pH control were alum (aluminum sulfate), HiClay® Alumina and sulfuric acid. Mixing ratios [SPF/(SPF+BL), kg/kg(dry basis)] used were 0.8 to 0.4. Test conditions were C/N of 17 to 49, pH of 6.6 to 8.3, initial temperatures of −1 to 22°C, composting temperature of 60°C, water content of 50-55% w.b. and remixing two times per week. Composting temperature was controlled using forced ventilation with a high/low fan setting. Composting trials lasted two weeks. Ammonia loss, O2, CO2, compost temperatures and dry solids loss were measured. Evaluations of ammonia emissions versus initial C/N and pH showed: (1) NH3-N loss decreased as initial C/N increased, even above C/N = 38; (2) NH3-N loss decreased rapidly below pH = 7 and increased rapidly for initial pH above 8. Addition of alum and/or sulfuric acid was found to decrease NH3- N loss while HiClay® Alumina had little or no effect. Results on dry solids loss are not presented in this article.

Composting Short Paper Fiber With Broiler Litter And Additives: II. Evaluation and Optimization Of Decomposition Rate Versus Mixing Ratio

Short paper fiber (SPF), a by-product of the paper mill industry, was cocomposted with broiler litter (BL) to determine the mixtures kinetic parameters as functions of initial C/N ratio and mixing ratio. An equation describing throughput capacity of composting facilities as a function of kinetic parameters was used to optimize mixing ratio (MiR) for maximization of composting short paper fiber. MiR [SPF/(SPF+BL), kg/kg(dry basis)] used were 0.8 to 0.4 in five series of pilot-scale studies. Test conditions were C/N of 15 to 49, pH of 7.0 to 8.0, composting temperature of 60°C, moisture of 50-55% w.b. and remixing 2 times per week. Composting trials lasted 2 weeks. Ammonia loss, O2, CO2, compost temperatures and dry solids loss were measured. Maximum decomposition, based on dry solids loss, occurred in the [C/N] range of 30-38. Maximum decomposition was 0.11 kg.kg−1.day−1 based on the first order kinetic model with β = 0.73 (MiR = 0.75). Evaluated β remained above the ash levels of the mixes for only MiR >0.25. Optimum mixing ratio was 0.7 (7 part SPF and 3 part BL) for maximization of short paper fiber composting. This occurred for a C/N of ≈35.

Composting Process Optimization – Using On/Off Controls

Despite the commercialization of a variety of different composting systems, the design and operation of composting systems to minimize the cost of producing compost remains a major goal. Evaluation of how system design and management affects the time required to stabilize compost is critical to optimizing the process. In this study, analytical equations relating biological and physical factors and compost temperature, moisture, oxygen level and decomposition rates for aerobic composting are developed. The study focused on the effects of intermittent aeration on the composting operation. A multi-parameter kinetic model in conjunction with heat and mass balance equations were used to predict and optimize the performance of composting systems. Equations evaluating airflow and on/off fan cycle times on composting temperature, oxygen and moisture were developed. Kinetic data from pilot scale experiments using three different feedstocks: municipal solid waste, biosolids/woodchips, and grass/leaves/brush were used in the derived equations to evaluate the composting systems operation.

Energy Analysis of the Tillage Systems in Second Crop Corn Production

ABSTRACT The aim of this experiment, to examine the energy input and output in the second crop corn production using four different tillage systems for soil preparation: (1) minimum tillage with stubble (MTS), (2) minimum tillage without stubble (MT), (3) conventional tillage with stubble (CTS), and (4) conventional tillage without stubble (CT). Corn was sown as a second crop just after harvest of wheat. Direct and indirect energy inputs consisting of machinery, fertilizers, seeds, irrigations and chemicals were converted into energy units according to their amounts being consumed. The machinery and fuel energy inputs for the tillage operation were reduced 53.7% with MT compared to CTS. The total energy input for producing corn utilizing CTS was 20,608 MJ/ha, compared to 19,102 MJ/ha for producing corn with MT. When the grain yield was taken into account, the energy output/input ratios for MTS, MT, CTS and CT were estimated to be 6.3, 7.6, 6.6 and 7.0, respectively. The tillage systems did not statistically affect uniformity of plant spacing, but statistically affected the yield. The grain yield was the greatest (8,719 kg/ha) in CT compared to the other tillage treatments.

Modeling Composting Rate as a Function of Temperature and Initial Moisture Content

A 5×5×2 factorial design was used to determine the effects of temperature and initial moisture content on the decomposition rate of paper mill sludge with broiler litter composted in a laboratory-scale incubatorbioreactor system. The composting system included ten 4 L volume (filled to 2.76 L) small-scale bioreactors. A first order kinetic model based on CO2 captured using 200 ml of 3.0 N NaOH was used to calculate the decomposition rates. Data on monitored process variables showed that the composting process was not oxygen or moisture limited. Regression analysis applied on the decomposition as a function of temperature and moisture showed that the maximum decomposition occurred around 58°C and 44% w.b. (ash free moisture of 62% w.b.) using the 2-D Gaussian model (R2=0.96). The utilization of this result on operating cost of composting showed that operating the system at 60°C would require 31% of the energy cost of operating at 50°C.

Quantifying soil respiration in response to short-term tillage practices: a case study in southern Turkey

Abstract The study aimed at quantifying the rates of soil CO2 efflux under the influence of common tillage systems of moldboard plow (PT), chisel plow (CT), rotary tiller (RT), heavy disc harrow (DT), and no-tillage (NT) for 46 days in October and November in a field left fallow after wheat harvest located in southern Turkey. The NT and DT plots produced the lowest soil CO2 effluxes of 0.3 and 0.7 g m−2 h−1, respectively, relative to the other plots (P < 0.001). Following the highest rainfall amount of 87 mm on the tenth day after the tillage, soil CO2 efflux rates of all the plots peaked on the 12th day, with less influence on soil CO2 efflux in the NT plot than in the conventional tillage plots. Soil evaporation in NT (64 mmol m−2 s−1) was significantly lower than in the PT (85 mmol m−2 s−1) and RT (89 mmol m−2 s−1) tillage treatments (P < 0.01). The best multiple-regression model selected explained 46% of variation in soil respiration rates as a function of the tillage treatments, soil temperature, and soil evaporation (P < 0.001). The tillage systems of RT, PT, and CT led, on average, to 0.23, 0.22, and 0.18 g m−2 h−1 more soil CO2 efflux than the baseline of NT, respectively (P≤0.001).

Composting and Value-Added Utilization of Manure From a Swine Finishing Facility

Swine manure and wood shavings used as a drying bed were removed from a High-Rise™ hog facility following two production cycles. The manure was composted in aerated pilot-scale vessels for four weeks or a mechanically turned windrow for ten weeks. Total dry matter losses during the pilot-scale studies were 30 and 32.5 % for continuously and intermittently aerated systems, respectively. Compost from both systems was stable with emission rates of 0.07-0.11 mgCO2 h−1 gvs−1. Moisture, O2, CO2 and NH3 use/losses during the process as well as chemical properties of the initial and composted manure are presented. Incorporation of the compost at a 5% amendment rate (v/v) into a standard pine bark container medium significantly (P = 0.05) increased growth of two woody plant species. Higher amendment rates were toxic to some plants due to high initial NH4+ concentrations in the medium. The compost significantly (P=0.05) increased growth and suppressed Pythium root rot of poinsettia when incorporated at 10% (v/v) into a standard sphagnum peat mix. The compost can be utilized as a value-added disease-suppressive product in the ornamentals industry.

Strategy development and determination of barriers for thermal energy and electricity generation from agricultural biomass in Turkey

The present work deals with determining barriers for thermal energy and electricity generation from agricultural biomass in Turkey. Strategy development and determination of barriers were investigated in accordance with the work program requirements for the project entitled “Exploitation of Agricultural Waste in Turkey” under the European Life Third Countries Program. The study has been organized and presented according to the following three phases: (i) market barriers for electricity and thermal energy generation (ii) identification of barriers to the promotion of agricultural waste exploitation in Turkey, and (iii) conclusions for strategy development.

Effect of harvesting hour on some physical and mechanical properties of Rosa damascena Mill.

BACKGROUND Mechanization of Rosa damascena flower harvest is limited because of the asynchronous flowering period, the necessity for the harvest operation to take place in the early hour of the morning, and a lack of knowledge regarding the physical-mechanical properties of R. damascena. This study investigated the effect of harvesting hour on some physical-mechanical properties of R. damascena. RESULTS The terminal velocity of the rose flower ranged from 4.00 to 2.38 m s(-1) . The highest picking force was found to be 6.29 N for the harvesting hour of 06:00 am. Tear forces of petal changed from 1.54 to 0.97 N for the harvesting hour of 06:00 am and 12:00 pm, respectively. The tension force of pedicel varied between 8.25 and 7.76 N. The weight of the rose flower was measured as an average of 1.61 and 1.50 g at 06:00 am and 12:00 pm, respectively. Horizontal and vertical projection areas of rose flowers were positively correlated with harvesting hour, with an R(2) of 0.97 and 0.75, respectively. Results showed that there was a minor loss in colour for both inner and outer surfaces of petals. CONCLUSION The results of physical-mechanical properties of R. damascena obtained from this study should be considered for the operation of flower harvest mechanization.

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.