Organic waste treatment : mechanical and chemical aspects

Abstract

Lebanon aims to be one of the countries that utilizes their waste and tries to reduce waste disposal. Transforming waste cooking oil (WCO) to biodiesel can be one of many steps towards reducing pollution and increasing waste treatment. This multidisciplinary project aims to design and study the fluid mechanical aspects and chemical process of a device that converts WCO to biodiesel. One of the best methods to transform WCO into biodiesel is the process of transesterification. The reaction will take place in a reactor tank according to several conditions such as maintaining a temperature of 60ºC and uniform mixing. The device is designed for domestic use, one machine for an apartment complex of 10 households. In order to check for proper mixing, several impeller designs were studied in ANSYS Fluent. The results showed that the second design, the three circular blade ends gave the best mixing by reaching a maximum velocity of 6.8m/s. In addition, two tank supports, are analyzed for static stability and free vibration using MSC Patran which showed that both structures are statically safe. However, some modifications were made in order to avoid reaching resonance frequency by increasing the width of the vertical bars from 9mm to 20mm. Finally, the feasibility of this domestic machine is checked and the readiness of consumers to buy it is estimated through a statistical study.