AlgaeFlow - Novel acoustic microalgae harvester for sustainable biomass production

Lead Research Organisation: University of Cambridge
Department Name: Chemical Engineering and Biotechnology

Abstract

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.

Technical Summary

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.

Planned Impact

As described in proposal submitted to IUK

Publications

10 25 50
 
Description The most significant technical achievement from the award was the discovery that piezoelectric tubes can be used for rapid two phase acoustic separation ie membrane filters can be replaced by a technology capable of 'invisible' filtration.
This discovery has led to variants on this powerful physical manipulation approach that can separate a range of micro and nanoparticle systems at low powers. It particular, it does not need chemical reagents and does not damage delicate cellular or viral agents, making it particularly advantageous for bioprocessing.
As a result it can be used as a key agent in processes targeting the manufacture of therapeutic products, by separating and purifying components with invisible acoustic fields.
The award objectives were to (1) build a cost-effective linearly focused acoustic microalgae-harvesting device for lab-scale testing and (2) test the feasibility of a minimum energy attraction point to concentrate microalgae for enhanced bioproduction and (3) design acoustic field generation that remains consistent in focusing action at any scale " - All of these key award objectives were fully met.
Exploitation Route The findings have already been taken forward in the Proflow IUK project (currently half way through) to build a scaled up commercial system based on Algaeflow findings. This system is now being integrated into the pilot plant which has recently been engaged by Algaecytes. It is intending to make use of this acoustic technology for algal harvesting.
Other IUK projects have started more recently, directly benefitting from the knowledge acquired during this project, namely Cellflow which targets purifying T-cells for cellular therapeutics and Vectorflow which takes this purification technology to viral vector production for gene therapy
Sectors Agriculture, Food and Drink,Chemicals,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Description The findings have already been taken forward in the Proflow IUK project (currently half way through) to build a scaled up commercial system based on Algaeflow findings. This system is now being integrated into the pilot plant which has recently been engaged by Algaecytes. It is intending to make use of this acoustic technology for algal harvesting. Other IUK projects have started more recently, directly benefitting from the knowledge acquired during this project, namely Cellflow which targets purifying T-cells for cellular therapeutics and Vectorflow which takes this purification technology to viral vector production for gene therapy.
First Year Of Impact 2017
Sector Healthcare,Manufacturing, including Industrial Biotechology
 
Description CellFlow
Amount £207,000 (GBP)
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 03/2018 
End 02/2020
 
Description IBCarb
Amount £98,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start  
 
Description InnovateUK
Amount £222,000 (GBP)
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start  
 
Description Cambridge Researcher Collaborations 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution -Ottie Croze (Physics ) Modelling the spatial/temporal behaviour algae -Matthew Davey/Alison Smith (Plant Sciences) Testing larger scale separation -Andrew Flewitt (Cape) in relation to thin film piezoelectric devices and high frequency operation (which has potential for rapid macro -separations of small molecules) -Michael De Boulder (IfM) who wants to use the acoustic standing waves for patterning CNT aggregates. -Tuomas Knowles (Chemistry) for nanoscale particle focusing in combination with fluorescent imaging
Collaborator Contribution The partners are bringing new applications for ultrasound devices that build on the work in the project.
Impact Too early for outcomes to arise.
Start Year 2017