Journal of Environmental Treatment Techniques
2021, Volume 9, Issue 1, Pages: 211-217
J. Environ. Treat. Tech.
ISSN: 2309-1185
Journal web link: http://www.jett.dormaj.com
https://doi.org/10.47277/JETT/9(1)217
Comparative Biodrying Performance of Municipal
Solid Waste in the Reactor under Greenhouse and
Non-greenhouse Conditions
Katitep Ngamket, Komsilp Wangyao, Sirintornthep Towprayoon*
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The Joint Graduate School of Energy and Environment (JGSEE), King Mongkut’s University of Technology Thonburi, Center of Excellence on Energy
Technology and Environment (CEE), PERDO, Ministry of Higher Education, Science, Research and Innovation, Bangkok
Received: 01/09/2020
Accepted: 05/11/2020
Published: 20/03/2021
Abstract
The high moisture content of municipal solid waste yields a lower energy content of solid fuel that affects the thermal conversion
efficiency. Biodrying is an alternative drying method using bio-heat generated by microbial metabolism to reduce the moisture content of
municipal solid waste. This research was conducted in three pilot-scale biodrying reactors, two under greenhouse conditions compared with
one conventional non-greenhouse condition. Two bunkers with greenhouse cladding were connected with aerators, and airflow rates were
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set at 0.4 and 0.6 m /(kgwaste·day), respectively. Meanwhile, a passive aeration method was applied to the non-greenhouse bunker. This study
aims to investigate the effect of the greenhouse condition on the biodrying process and assess the performance of the drying process through
different operating conditions. The result shows that the greenhouse mainly affects the air temperature rise in the reactor. The aeration rate
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is positively correlated with weight reduction (r = 0.93). At 0.6 m /(kgwaste·day) airflow rate, the treatment can reach a moisture content less
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than 30% on average within ten days, while at 0.4 m /(kgwaste·day) airflow rate, it takes 15 days to reduce the moisture content to less than
3
0%. Biodrying under the greenhouse condition with active aeration potentially achieves desirable moisture content reduction and heating
value increase more efficiently than the common biodrying. However, the airflow rate is a crucial factor in determining the suitable drying
time in biodrying under the greenhouse condition.
Keywords: Biodrying, Greenhouse, Municipal Solid Waste, Refuse Derived-Fuel, Solar Radiation
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There are many available drying methods for MSW, such as
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Introduction
thermal drying and biodrying. The benefit of thermal drying is the
shorter drying period (2.64±1.44 h) [2]. Meanwhile, the drying
time of biodrying is about 16±7 days [2]. Nonetheless, thermal
drying could have higher maintenance and operation costs for
large-scale drying applications. Biodrying is an alternative drying
method that uses metabolic energy from biodegradation for water
evaporation in MSW or wastewater sludge.
Aeration is a critical concern for heat generation from aerobic
decomposition. The various