Process intensification in biorefining :
Speeding up production of biorenewable chemicals
Fernando Russo Abegão and Kamelia Boodhoo of Newcastle University discuss technology developments to make biorefining processes viable
The replacement of fossil fuels and chemicals is essential to mitigating climate change and to achieving net zero and sustainable development targets . Amongst the process technologies currently being developed to address these challenges , biorefining processes valorise biomass waste streams into biorenewable chemicals and fuels . To some degree , biorefineries are already playing a key role in the process of replacing fossil fuels through the policy-driven substitution of diesel and petrol by biodiesel and ethanol blends . Further pushes ahead are expected , given the current oil prices and climate of instability . However , the economic feasibility of biorefineries is frequently compromised by the need to compete with less expensive and well-established products and process technologies from oil and gas refining . In biorefineries , economy of scale is restricted by the need to harvest biomass in areas of small radius , typically up to a few tens of kilometres , in order to ensure carbon neutrality and net positive energy outputs for the biofuels produced . Additionally , in periods of high competition with low oil prices , the economic viability of a biorefinery can only be realised through a varied portfolio of high-value products . These help to balance out fuel price fluctuations . However additional equipment and processes are required to widen the product portfolio and most often the technologies are more complex than the ones used in core processes for fuels production . In terms of technology , the picture gets more convoluted due to the fact that biorefining processes are often novel and not optimised , and have to endure variability of raw materials due to geographic and seasonal variations , most often without it being possible to balance this out .
Figure 1 - Process intensification toolbox
Additionally , biomass feedstocks are rich in water and are complex mixtures that often become very diluted during fractionation processes . This is the case , for example , with hemicellulose ( HMC ) liquors obtained during wood or straw fractionation . They contain not only sugars , but also short chain acids , residual lignin , extractives and inorganics elements , dissolved , amongst other minor compounds , in low percent or ppm concentrations . These streams comprise a significant proportion of the biomass material balance in the process –
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