Biorefineries, Resource and Energy Recovery

If mankind is to avoid excessive global warming a switch to low carbon energy and new industrial approaches that move us closer to a circular economy will be essential. This special issue on “Biorefineries, Resource and Energy Recovery” covers a range of related activities and opens with the review by Demirhan et al (2019) who urge that we adopt an energy systems engineering approach in order to tackle the complex energy and environmental problems confronting us. Guan et al (2019) developed a process flowsheet and examined the economic feasibility of converting woody biomass into a biofuel. Their process scheme is based upon several promising experimental processes for lignin depolymerization, such as hydrodeoxygenation and hydrogenolysis, Lignocellulosic biomass is a renewable source not only available as wood from a forest but as an agricultural waste. Li et al (2019) are concerned with how best to exploit these resources. Using anisole a model for lignin they examined how a high quality liquid fuel can be obtained by catalytic hydrodeoxygenation. This up-grading effectively eliminates oxygenated compounds. Cova and Luque (2019) also focussed upon a novel form of catalysis. Mechanochemistry can offer a number of advantages over conventional processes including normally being faster and cheaper. Omer et al (2019) are also concerned with exploitation of what is currently an agricultural waste. They examined whether Abelmoschus esculentus okra as whole stalks is suitable for pulp and paper production.

The production of biodiesel from sources such as Crotalaria juncea inevitably produces glycerol as a bioproduct. The quantity of glycerol is so large that it is effectively a waste. Unfortunately its calorific value is also relatively low. Baidya et al (2019) looked at using this glycerol, after purification, as a substrate for producing succinic acid via a microbial route. One potential upgrade of the succinic acid would be its hydrogenation to produce 1,4-butanediol (BDO) and this too is examined in their paper.

The Collection concludes with papers relating to less traditional biofuels and also the exploitation of low grade heat that is otherwise wasted. Oleaginous microorganisms are among the most promising feedstocks for the production of lipids for biofuels and oleochemicals, and Patel et al (2019) review the various types of oleaginous microorganisms, their lipid accumulating capabilities, lipid extraction techniques, and the pretreatment of cellular biomass for enhanced lipid recovery. In the biorefining of microorganisms such as microalgae biomass it is necessary to process high-solids (> 10%) slurries. To date there is little knowledge of how processes for weakening and rupturing microalgae affect the rheological properties of these materials. Mettu et al (2019) seek to fill this gap by examining the rheological properties of concentrated slurries of the marine microalgae Nannochloropsis sp. In addition to turning to biofuels, society needs to minimise waste, including where possible the waste of low-grade heat. Wang et al (2019) explore through mathematical modelling the performance of a non-inertive-feedback thermofluidic engine. This devise is a two-phase thermofluidic oscillator capable of utilizing low grade heat by inducing persistent thermal-fluid oscillations that convert heat into useful work via the creation of oscillatory fluid motion.

Keywords: Biofuels, energy systems engineering, catalyst, low grade heat utilisation


  • Robert Field

    Robert Field studied chemical engineering at the University of Cambridge as an undergraduate and postgraduate. His research has concentrated upon the physical phenomena governing the performance, particularly limitations to performance, of both pressure driven and activity driven membrane processes. Besides his world-leading contribution to the development of the concepts of critical flux and threshold flux for membrane processes, he has published in the area of heat transfer.

Articles (8 in this collection)

  1. Energy systems engineering - a guided tour

    Authors (first, second and last of 4)

    • C. Doga Demirhan
    • William W. Tso
    • Efstratios N. Pistikopoulos
    • Content type: Commentary
    • Open Access
    • Published: 10 April 2019
    • Article: 11