Review: Bio-polyethylene from Wood Wastes

Abstract

There is a global trend of substitution of fossil fuels for renewable energy sources, which are preferred by reasons including sustainability, reduction of greenhouse gases that contribute to climate change, regional and social systems advancement, among others. This review is part of the studies carried out on the integral use of wood industrial wastes due to its low costs and high availability. A possible high-value product is ethylene, obtained by catalytic dehydration of second-generation bioethanol from lignocellulosic materials and which can be an effective alternative for the production of polymers such as polyethylene (PE), which is conventionally obtained from petroleum. Biobased polyethylene or biopolyethylene (BioPE) may potentially contribute to close a pine biorefinery scheme to obtain high-value products, using processes of low pollution and contributing to the global environmental balance. The process involves the following stages: pretreatment, enzymatic saccharification, fermentation, dehydration, and polymerization. This review includes the different processes for second generation (2G) bioethylene productions from pine wastes as an example and the technologies that can potentially be applied on an industrial scale for BioPE production, focusing on the catalytic dehydration of 2G bioethanol through the use of catalysts able to achieve high ethanol conversions and ethylene selectivity.