AlgaeFlow - Novel acoustic microalgae harvester for sustainable biomass production

Although microalgal systems offer many advantages for chemical production (e.g. higher productivities per acre, valuable co-products), industrial-scale manufacture faces significant techno-economic challenges that must be overcome before algal biomass can be produced sustainably. To address this important challenge, this study investigates a cost-effective, in-line cell harvesting system based on scale independent acoustic profiling, with a view to improving the efficiency and lowering the cost of commercial microalgae production by several orders of magnitude. This multi-disciplinary innovation is enabled only by converging world-leading bioprocess expertise from the University of Cambridge (UC) with LabXero's (LX) cross-sector bio-sample extraction IP leveraged from the medical diagnostic/agri-food domains and AlgaeCytes (AC) and Unilever (UL) end-user input. As a platform technology, applications exist beyond microalgal production for the wider benefit of industrial biotechnology.

This pioneering collaborative R&D project brings together the multidisciplinary expertise of University of Cambridge (worldleading downstream bioprocessing experts), LabXero Ltd (innovative bio-sample extraction SME), AlgaeCytes (dynamic algal product producer) and Unilever (global consumer goods company), to investigate the feasibility of a novel acoustic cell-harvesting system to improve the efficiency of industrial-scale microalgal lipid production. The proposed harvester will be based on high quality acoustic resonance that induces oscillatory flow, leading to conditions that concentrate microalgae particles. To determine the detailed nature of flow conditions required for efficient microalgae extraction and its commercial scaling potential, we will analyse the axial dispersion properties of linear and focused flow by: (1) Construction of flow chamber apparatus of different aspect ratios and volumes, (2) Flow visualisation through tracers with different combinations of net flow and oscillation conditions, (3) Fluid mechanical simulation of the 3D flow profile under these conditions, (4) Models for the quantification of axial flow under high frequency forcing conditions, (5) Axial dispersion using both fluid marker particles and microalgal particles. An experimental backbone to the work will be pulse dye tracer methods and flow dye streamlines to visualise microalgal flow, and therefore characterise the acoustically-driven harvester developments by LabXero. The key results sought for this project are the precision and concentration factors achieved with the proposed acoustic focusing technology, its potential under more optimised physical conditions, and importantly, the stability of the minimum energy attraction point with scaling of the harvester, which directly influences the economics of biomass production.

As described in proposal submitted to IUK