Converting biowaste streams into energy–leveraging microwave assisted valorization technologies for enhanced conversion

With raising concerns around the usage of fossil fuels and increasing waste there is an increased focus on finding alternate sources of energy to protect the environment as well as for sustainable development. Biomass waste has emerged as the new feedstock to produce renewable energy that can help in tackling climate changes and reduce dependence on traditional energy sources. Bioenergy production using wastes as feedstocks is an environmentally friendly and cost-effective process. However, deriving bioenergy from biomass waste streams requires pretreatment and/or innovative valorization strategies before being used as a feedstock in various conversion techniques such as thermo-chemical or biological processes. Most techniques require the application of heat to break down complex polymeric structures in the biowaste and make it more susceptible to hydrolysis. There is an increased focus on microwave heating as an alternative to conventional heating due to its various advantages such as speed, energy requirement and uniformity of heat dispersion. This review dives into a few of these aspects of microwaves and explores the application of microwaves as a standalone pretreatment technique as well as a co-pretreatment technique to enhance the performance of other thermo-chemical pretreatments. It also brings forward few of the challenges associated with the usage of microwaves and future research directions on tackling them.