Abstrait
Concept and challenges of modern biorefineries
Alex Michine
International R&D community and technology developers for the last decades. However, despite intense efforts, real breakthrough has not been achieved yet. This has been mainly due to a biased view, focusing solely on a certain end product – for example cellulose pulp or ethanol and considering by-products as low value waste streams for energy applications. With the new wave of lignocellulosic biomass fractionation technologies being demonstrated at a pilot scale, success stories are closer than they have ever been. Biomass fractionation to high purity intermediate building blocks of cellulose to C6 sugars and hemicellulose to C5/C6 sugars and lignin, instead of just one main product, provides a way to produce a diversity of products and establish novel bio-based value chains. Especially important is the availability of higher purity lignin for different direct drop-in or after processing (depolymerization etc.) applications, which compared to the conventional lignins derived from pulp mills or ethanol refineries provides totally new applications and perspectives to enable the increased use of biobased raw materials in various industries.
A biorefinery is a facility where different low-value renewable biomass materials are the feedstock to the processes where they are transformed, in multiple steps including fractionations, separations and conversions, to several higher-value bio-based products. Examples of these products can include fibres, food, feed, fine chemicals, transportation fuels and heat. A biorefinery can be formed by a single unit or can combine several facilities targeted for a single purpose that further process products as well as by-products or wastes of combined facilities. In biorefining one can find similarities to oil refining, with the exception that in oil refining the raw material comes from fossil resources. According to the International Energy Agency ‘Biorefineries will contribute significantly to the sustainable and efficient use of biomass resources, by providing a variety of products to different markets and sectors. They also have the potential to reduce conflicts and competition over land and feedstock, but it is necessary to measure and compare the benefits of biorefineries with other possible solutions to define the most sustainable option.’1 Although it is possible to produce the same products in a biorefinery as in an oil refinery, this is not the target, which instead is to produce products which can replace the products from oil refining.