Integrated Bio-refinery - WP2
Human activities whether industrial, agricultural or domestic create waste. The usual form of this waste is; carbon (normally as CO – carbon monoxide or CO2 – carbon dioxide), nitrogen (normally as NH3 – ammonia or NO3- - nitrates) and phosphorus (normally as PO43- - phosphates). Traditionally the carbon (C) is emitted as a gas and contributes to global warming and the nitrogen (N) and phosphorus (P) is emitted in a liquid format and pollutes water courses.
Microalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simplistic structure. Microalgae and their cousins macroalgae (seaweed) are the pollution control agents of the oceans. In autotrophic conditions, these organisms consume C, N, P as the building blocks of life and expel oxygen during photosynthesis. Microalgae are able to capture up to 1.8 kg CO2 per kg of algal biomass produced and given that arable land is not required for cultivation, the environmental benefits of this form of biomass surpass that of any other feedstock used in renewable energy production. However, production is not only limited to biofuels. Microalgae are at the primary level or the ocean trophic scale, this means that they are the food source of the oceans. Microalgae are rich in valuable nutritional materials such as carbohydrates, proteins and lipids. For example, they are good source of natural docosahexaenoic acid and eicosapentaenoic acid (Omega-3 oils) which when purified can be worth as much as £100 per kg. Also, there are some very high value compounds that occur at low levels within microalgae such as b-carotene and astaxanthin (pigments) which can be worth £2000 to £5000 per kg respectively. Other pigments such as phycoerythrin and phycocyanin can be worth as much as £36,000 to £72,000 per kg depending on purity and activity.
In this project we are constructing a near commercial scale 15,000L capacity photobioreactor to grow algae on industrial effluents. We will then also demonstrate the downstream harvesting and recovery process using a bio-refinery approach. Just like in crude oil where there crude is refined into several products, such as petrol, diesel, kerosene, bitumen etc. We will refine the algae to produce several products such as whole cell algae and a protein rich extract. Aspirationally, we also aim to demonstrate increased production of pigments by photoinduction, along with the subsequent downstream refinement process. In this way, the recycling of industrial wastes can generate new and useful products in a near 100% mass efficient way. A circular ecconomy which is highly sustainable for future generations.
Work package 2 is led by Dr Darren Oatley-Radcliffe