The utilization of biomass waste as a raw material for renewable energy is a global concern. Pyrolysis is one of the thermal treatments for biomass wastes that results in the production of liquid, solid and gaseous products. Unfortunately, the complex structure of the biomass materials matrix needs elevated heating to convert these materials into useful products. Microwave heating is a promising alternative to conventional heating approaches. Recently, it has been widely used in pyrolysis due to easy operation and its high heating rate. This review tries to identify the microwave-assisted pyrolysis treatment process fundamentals and discusses various key operating parameters which have an effect on product yield. It was found that several operating parameters govern this process such as microwave power and the degree of temperature, microwave absorber addition and its concentration, initial moisture content, initial sweep gas flow rate/residence time. Moreover, this study highlighted the most attractive products of the microwave pyrolysis process. These products include synthesis gas, bio-char, and bio-oil. The benefits and challenges of microwave heating are discussed.

Xylitol is an alternative sweetener that is recommended for use in food and pharmaceutical products, as it has some health benefits. It is currently produced on a large scale using a chemical reduction that requires high energy and is costly. Biological conversion of xylitol using microorganisms is an alternative process that is environmentally friendly and cost-effective. This process has been studied in an effort to provide one that is high yielding and competitive with chemical processes. This article reviews recent studies in the development of biological conversion processes for the production of xylitol, including biomass conversion, fermenting microorganisms, and new technology for full-scale process development.