Biodrying Process Variations Based on Air Flow Regulation Strategy

Abstract

Biodrying process is an effective method of exploiting the self-heating nature of municipal solid waste for energy-oriented applications. The current investigation is carried out to study the effect of air flow variations in biodrying process using mixed municipal solid waste substrates of high moisture content. The pilot-scale static biodrying reactor of 0.565 m3 capacity for treating mixed municipal solid waste substrate has been studied for 11 days of time. Two case studies were conducted at air flow rates of 40 and 80 lpm, and air evacuation test, as well as air stop test, has been carried out at specific interval during the experiment. The self-heating temperature is lesser (maximum 49.9 °C) when air flow rate is doubled, while maximum matrix temperature of 58 °C has been observed at an air flow rate of 40 lpm. The aerotactic nature of biological reactions in the process has been revealed from the air evacuation and air stop test results, with a sudden rise in temperature of reactor matrix in the direction of air removal. Therefore, in biodrying process not only the oxidation process but also the nutrients enriching reduction reactions have a pronounced impact. Considering the overall biodrying efficiency, under similar experimental conditions the moisture reduction has been increased by 2.3 times when the air flow rate was increased by twofold. The results obtained in these investigations are innovative and extremely useful in the decision-making process of fixing the duration of biodrying process. The delineation of biodrying process presented in this study is a significant contribution to the field of technology development.