The first Fitoplan made by Exenia.
The idea behind the rector Fitoplan was born in the 90 'by a research group of CNR (Italian National Research Committee). All lighting systems were previously installed above or around the biomass, irrespective of the geometry of the reactor. At that time there were only flat panels, which are simpler to construct but do not use light efficiently: they waste a lot of it.
Commonly, bags of disposable plastic are used for the production of biomass, illuminated only from the back side. Most of the light was dispersed by the large amount of water, preventing reach high concentrations, generally not exceeding 25 x 106 cells / ml. Because of the low concentration, it was necessary to build large algae room and handle hundreds of cubic meters of sea water. The average area occupied by the bags was really important, from 200 to 300 m2. Moreover, the continuous removal of biomass and subsequent refilling of the bags required the use of many workers, hydraulic pumps for the handling of large masses of water, etc ...
The idea of using all the photons emitted by the lamps was the key to developing the annular reactors. The annular reactors consist of two concentric cylinders, one with a larger diameter and one with a smaller diameter. The proportion of the volume enclosed between the two cylinders forms the culture chamber. Putting the lamp inside the smaller cylinder, we can use the light as efficiently as possible, never surpassed by any other configuration.
The development lasted almost three years, in search of suitable materials able to withstand thermal stresses and strong artificial light, scratches, lasting “crystal clear” for a very long time. The right proportions were the second goal to achieve. The amount of light that had to reach the biomass should not be too low or too high. But no one imagined at that time the possibility to reach and exceed concentrations of 1 x 109 cells / ml. We had to recalibrate the recipes of nutrients, change the geometry of the reactors, change lamps type and review the fluid flow inside the reactor. After many trials and many failures, in 1996 the first Fitoplan reactor was born. The first installation outside of the research centers was at the CBF in Montepaldi (Florence), a spin-off of the University of Florence and Exenia, the R & D company of the SCFN network, of which Separeco is the industrial partner.
The first Fitoplan system
The first Fitoplan system was completely manual. In the picture above you can see the very first cluster sold in 1997 to the company Panittica Pugliese (Italy). The first Fitoplan had very large electrical boxes, occupying large spaces in the front panel of the cluster. There were no controls of any kind, only the safety-electric switches. The pH control was not integrated in the system and the operator had to check it out cyclically with a portable instrument and, on the basis of the readings, adjust the flow of CO2 on the pressure reducer.
Over the years the project was completed and electronic controls were added like pH and temperature. In 2005 we delivered the first Fitoplan standard system, with automatic electronic controls, an industry first. We reduced the size of the electrical boxes and updated the design of the structure, which now bear the reactors and all the instruments on board, piping included.
In 2012 it was introduced the software control and the system was equipped with PLC; Fitoplan Electronic was born. Old lighters boxes with transformers were replaced with new high-efficiency electronic igniters, just a novelty introduced by Osram in 2013. The new igniters can save about 30% on energy consumption by avoiding the energy loss typical of transformers. We added the control of the air flow and, on request, the automatic control of the concentration. For the first time software control was included in a microalgae growing system. A web server that allows you to monitor the growth of biomass with graphs and charts was included in the control box.
The area occupied by the production system in its basic version, 6 cylinders, is 2 m2. Clusters of 6 cylinders can be arranged next to one another to form a multi-cluster of 12, 18, 24 or 36 cylinders. In these cases, each cluster is a standalone unit. The air, the CO2 and water service are distributed with a backbone installed on the inner wall behind the clusters.
The energy consumption for lighting indoor photo bioreactors is equal to 0.5 kW each.
Having regard to the particular geometry of the Fitoplan reactor, it is possible to evaluate the use of mixed light cycles (artificial / natural light) to reduce the energy requirements to approximately 1/3 of the total amount. The electrical energy savings obtained is around 60%, due to the minimum volume of the liquid medium illuminated, liquid that contains a concentration of cells produced up to 50/100 times higher than conventional systems.
Last frontier: the supercluster
New markets require new solutions. In particular, large companies that produce huge amounts of fingerlings have requested better performing systems, capable of producing large amounts of biomass: some of these have required a fully automated system.
This challenge has been taken. In 2015 the new Jumbo clauster was born, able to group up to 60 reactors in a single cluster. We cleared the top of the rectors to facilitate the periodic cleaning and an automatic control system of the production was added, with dedicated operation recipes for to the different strains. The system automatically picks up the biomass sending it to the collection tank and provides for the recovery of the culture medium, refilling the remaining biomass. The system controls the density and all vital values, sending them to the PLC installed on board. The system uses compressed air circulation pumps, reducing to zero the danger of suffering an electric shock even in case of failure or breakage. Moreover, the system can be replicated into multiple units, remotely controlled by a computerized system that allows to check every single cluster and each single reactor. The computer system is able to control also the preparation of the culture medium, keeping it mixed at the right temperature, ready to be sent to the reactor as soon as necessary. The system works with different recipes based on microalgae strains that are to be grown. The supercluster of 48 reactors is shows here below.