Composting process optimization - using on/off controls

• Published in: Compost science & utilization Vol. 13; no. 4; pp. 288 - 299
• Main Authors: Keener, H.M, Ekinci, K, Michel, F.C. Jr
• Format: Journal Article
• Language: English
• Published: Emmaus,PA Taylor & Francis 01.09.2005; JG Press; Taylor & Francis Ltd
• Subjects: aeration; aerobic conditions; Agronomy. Soil science and plant productions; Biological and medical sciences; Biological treatment of sewage sludges and wastes; biosolids; Biotechnology; composting; Environment and pollution; equations; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; heat balance; Industrial applications and implications. Economical aspects; mass balance; mathematical models; MSW composts; optimization; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; simulation models; Soil-plant relationships. Soil fertility. Fertilization. Amendments; systems analysis; wood chips; yard waste composts; Composting; Waste treatment; Optimization; Waste reuse; On off effect
• ISSN: 1065-657X; 2326-2397
• DOI: 10.1080/1065657X.2005.10702253

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.