Study on thermal drying efficiency and odor emission characteristics of municipal solid waste (MSW)

Abstract

Thermal drying efficiency and odor emission characteristics under different temperature of municipal solid waste (MSW) were studied. The results showed that: water content decreased sharply with disturbance thermal drying mode. The highest peak of total amount of odor was at 600°C and the lowest was at 500°C. The highest peak of odor concentration was at 700°C, followed by 200°C、 600°C and 800°C. From the view of engineering application, considering total amount of odor and the odor concentration, thermal drying temperature should be 100°C, 300°C, 400°C and 500°C. Introduction Incineration technology is thought to be the most effective means of urban garbage harmless, reduction and recycling, but the moisture contents of MSW in China were generally more than 50% and calorific value were lower and, the high moisture contents has become main source of leachate during landfill, incineration and composting treatments. Therefore, the important pre-treatment is to reduce the moisture content before MSW incineration. Biological drying technology was usually used in MSW incineration plants in order to reduce the moisture contents of raw MSW. Namely, using thermopiles aerobic fermentation process of organic matter degradation, as well as process control, to promote water evaporation and realize the rapid removal of moisture. Thermal drying technology is generally used for sludge, research on MSW thermal drying is rare. The use of thermal drying process will inevitably produce odor . Xiong Y G et al have studied odor discharging characteristic of sludge indirect and direct thermal drying process [8, . Due to MSW thermal drying process has not carried out, therefore, study of odor emission characteristics concentrated more in biological drying or compost field , less research focused on odor emissions during the process of MSW thermal drying. In this study, self-made thermal drying device [11] was used to disclose MSW thermal drying efficiency and odor volatilization characteristics, so as to provide a theoretical basis in MSW thermal drying engineering application. Materials and methods The experiment was conducted in March 2015. Amounts of 100kg [12,13] of MSW were collected in MSW transfer station in Beijing, and the thermal drying simulation experiment is carried out in the self-made thermal drying device. Weight loss method was used to determine moisture contents. Odor samples were collected, tested and analyzed at different drying temperature according to the references [14] and GB/T14675-1993. 4th International Conference on Mechatronics, Materials, Chemistry and Computer Engineering (ICMMCCE 2015) © 2015. The authors Published by Atlantis Press 849 Results and discussion (1) Thermal drying efficiency of MSW Three ovens were prepared and 20kg MSW were put into each ovens after temperature set to 100°C. Baking time lasted for 10 hours and moisture was tested every 10 minutes, every 3 hours and every 30 minutes with manual flip 1 times. The drying efficiency of three different drying modes is shown in Figure 1. thermal drying time (h) 0 2 4 6 8 10 12 m oi st ru e co nt en t ( % ) 0 10 20 30 40 50 60 70