ALGAL CELL EFFICIENCY
Further to the LED light optimization, research has also identified and patented additional technology that enhances the productivity of the algae cells.
This technology focuses on converting the ‘un-utilised’ energy generated by the photosynthesis process 'squandered' by the algae. It has been successfully licensed in horticulture applications and has been proven to enhance growth rates.
The reactor system is filled with water and the pump started to recirculate the water around the reactor. The control systems are initiated and switched into automatic to set the temperature. When the temperature attains the desired limit, the CO2 blower and LED lights are switched on at low-level and the algae are inoculated into the reactor. As the algae grow, the control system measures the quantity of algae in the system and adjusts the CO2 and LED light output to meet the requirements of the algae and maintain the maximum growth rate.
As the reactor reaches steady state and the concentration of the algae is observed to plateau, allow of algae is sent to the harvesting system, where the algae are concentrated, separated from the water and harvested as a paste. The water is transferred into a water treatment section of the plant, where inhibitors are removed from the water and trace elements and nutrients added to the water, before being re-circulated to the start of the reactor, together with a % of the mature algae cells, which are used as the inoculum for the reactor.
The algae paste is then subjected to high shear, to break-open the algae cells and release the oil. This allows the cell to be separated into fractions and be refined, thus maximising the value of the algae products. The crude oil must be processed further in order to enable its use as a transport fuel. Depending on the scale of the plant, this may be better served by collocating the algal oil upgrading facility with an existing oil refinery.
The PE3R provides an optimal environment for algae production, by monitoring and controlling the reactor conditions within specified limits. Utilising the best available technology within the biotechnology process industries the environment control extends to the supply of nutrients, preventing wastage, and also the removal of inhibitors which might otherwise restrict the growth of algae.
The control system is also configured to enable the reactor to be segregated into zones to initially maximise the growth of algae cells and then switch the cells from growth to product expression (for example to maximise oil content in the cell),
The lntent of the project is to build a pair of full-scale Algae Photo-Bio-Reactor modules, which wlll be coupled logether and allow the lesting and demonstration of the algae PBR, By building and tesiing the system at full-scale, the issues with process scale-up and product reljability of the module construction are ellminated, so enabling the rapid deployment and commercialisation of the technology following successf ul demonstration.
Simon Carves have undertaken work to develop the reactor design according to engineering best practice and integrate the latest biotechnology methods, instruments and control systems that are seen to be key to achieving optimal productivity.
In addition to the biotechnology and engineering specialists within Simon Carves, the project will be supported by one of the founding technology developers (Dr Newbold), who will provide know how and support to ensure the demonstration of the technology is achieved efficiently.
It is often perceived that an industrial scale process will adversely impact the environment, however the operation of the system and growth of the algae actually utilise 002 as a feedstock and release oxygen, therefore when the operation of the system is coupled with renewable power generation, the resultant algal products are not just sustainable, but also have a negative carbon foot-print (sequester 002) and so act to reduce the impact of global warming from other industrial processes and improve air quality.
The algae production process is low impact:
The growth of algae occurs in an aqueous (water-based) environment and the oil is produced within the algae cells, as such there is no flammability hazard associated with the growth of algae.
As the algae are harvested and concentrated to enable the oil to be extracted from the algae cells and refined, the hazards associated with the process increase. However, this will be performed in a small area of the plant, appropriately design and controlled. The resultant crude oil must be refined further (which will be performed off-site) before it is suitable for use as a transport fuel and even then the resultant oil is a long-chain hydrocarbon and does not possess the characteristics of petrol, which contains short-chain hydrocarbons leading to its Volatility, instead, the algal oil will exhibit the characteristics of heavy oil diesel fuel.