科研之友
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摘要
In this study, we define the relationship between the FAS values of mixtures and their energy consumption in the composting process. Composting is the process of decomposing organic wastes by microorganisms under aerobic conditions. The resulting compost can be used in agriculture as a soil conditioner or manure to prevent erosion, and in forests and landscaping. The composting process requires external energy to provide adequate aerobic conditions. The largest use of energy in the composting process is for fans that blow air to the piles. The FAS value indicates the air-filled porosity in materials to be composted. A predetermined optimal FAS value should be ensured for oxygen supply to the composting mixtures during the composting process and to decrease the amount of the energy consumed by the fans. An increase in the FAS value decreases the air resistance in compost masses. While very high FAS values cause cooling of the masses by increasing heat transfer, very low FAS values increase the air transition resistance and causes a failure in the ventilation. Determining the optimal FAS value for the composting process increases its success and decreases energy consumption, and thus contributes to its environmental and economic sustainability. In the present study, chicken manure and sawdust were used for composting. Pine cones were added to adjust the FAS ratio of the mixtures. Pine cones have large clearance volumes and are good bulking agents; they facilitate the composting process without being decomposed. Experiments were performed in 5 compost reactors and different FAS values were obtained in each reactor. At the end of the experiments, the process temperatures, CO2/O-2 concentrations, moisture and volatile solids contents, and energy consumption values of the fans were evaluated. The composting process was most successful in the R10 and R15 mixtures with FAS values in the range of 30-32%. The lowest energy consumption was obtained in the mixture with a FAS value of 34%; the temperature in this reactor did not increase, and the organic matter loss was low. When the FAS value decreased below 30%, the effectiveness of the process was negatively affected, whereas the energy consumption increased. According to the results, when composting mixtures of chicken manure and sawdust, pine cones can be used as bulking agents. It has been determined that when 15% pine cones are added to the compost mixture, the success of the process increases, and the energy consumption of the system decreases.
- 出版日期2015-8
