Microwaving Waste Goodbye

In Malaysia, approximately 70 million tones of organic wastes are generated annually as municipal solid wastes, agricultural residues, animal wastes, sewage sludge from wastewater treatment plant and wood chips.

Most of these wastes are either incinerated or dumped in landfill. The latter requires precious open lands, while the former contributes to serious atmospheric pollution. Both of which have serious impact on the environment. The country, therefore, needs to adopt a more practical, economic and acceptable approach in managing and disposing the organic wastes.

The thing about organic wastes is that they harbour abundance volatile matter which can be converted to fuel through suitable treatment, such as pyrolysis. This possible method is receiving increasing attention as an economic and environmentally acceptable route to waste disposal due to its ability to produce fuel gases and oil.

The latest development in the pyrolysis technology is the application of heat by using microwave energy. Microwave treatment might serve as an alternative method for drying, pyrolysing and gasifying the organic wastes in one single step. The research in this method, however, has not been extensive. Published information on microwave pyrolysis design and process condition is also lacking.

A research group at the Department of Chemistry, University Malaysia Sarawak, has designed a laboratory scale microwave pyrolysis system through modification of laboratory microwave oven. The aim is to conduct chemical characterisation of the waste samples and their microwave pyrolysis products, and to optimise the microwave pyrolysis processes for optimum biofuel yield which is environmentally acceptable. The main focus is to develop an efficient, simple and low-temperature based process for converting organic wastes into useful renewable energy sources.

Preliminary studies on low-temperature microwave pyrolysis of sewage sludge suggest a fuel material potential, comparable to the lower grade coal.It is hoped that data gathered in this study will provide useful information on the microwave pyrolysis of organic wastes and the potential use of the process as an alternative for the reutilisation of wastes, which at the same time produce renewable energy sources for industries in Malaysia.

ABOUT UNIVERSITI MALAYSIA SARAWAK (UNIMAS)

UNIMAS was established in 1992. The University's mission is to generate, disseminate and apply knowledge strategically and innovatively to enhance the quality of the nation’s culture and prosperity of its people. The knowledge creation initiatives at UNIMAS are premised partly upon the wealth of natural resources and diverse socio-cultural make up of the State of Sarawak. UNIMAS commitment to research has already been recognized by the stakeholders and partners in industry through provision of endowments for the establishment of eight research chairs; these include the Tun Zaidi Chair for Medicinal Chemistry, the Tun Openg Chair for Sago Technology, the Shell Chair for Environmental Studies, and the Sapura Chair for ICT.