Enhancing efficiency of ultra-fine air-classification of powders to facilitate global reductions in carbon emissions from food and transport
This project is led by Dr Baldeep Kaur, with Professor M Bradley and Dr Atul Sharma
Researcher: Zaki Hussaini
The aim of the project is to improve the sharpness of cut of air classifiers with very fine particles, by combining detailed scientific study and modelling of the gas-solid dynamics with empirical test and refinement.
31% of global warming effects arise from food production, 18% from meat. Plant based diets could reduce this greatly but the nature and proportion of proteins in plant materials as grown are not satisfactory to produce meat substitutes acceptable to most consumers. Protein-shifting though not new, has suddenly become a disruptive technology that could overcome this barrier, by processing plant materials especially legume flours to select and refine the proteins that make high quality, widely-acceptable meat substitutes.
Protein shifting requires the plant material to be milled very fine then classified by size. Milling can be achieved but classification to select the extremely fine size, desirable proteins is not currently possible without producing large amounts of waste (much desirable material thrown away in over-size). Successful and economical protein-shifting requires a higher level of selectivity (“sharper cut”) in the ultrafine size range (5 - 10 microns).
The only physically possible technology for separating powders by size in this range in the necessary quantities is air classification although to date there has been little detailed scientific research into air classifier design.
Bradley Pulveriser Enterprises, who are sponsoring this project, has already undertaken some CFD modelling to inform improvements in design of their air-classifiers, with good results. This has strong promise in moving the limits of air classifier technology towards the goal.
The same limitation with current air classification technology is also a stumbling block for large scale production of improved batteries for electric vehicles; quicker charging and higher charge capacity require finer particles but these require a narrower “cut” of sizes than currently achievable. It also has the potential to facilitate dust removal from fine metal powders for additive manufacturing.