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8 reasons why algae should be cultivated in a tubular glass PBR instead of in plastic bags
The cultivation of algae in plastic bags is a simple way to start algae breeding quickly and easily. However, if you are planning an industrial scale production, you have to check very carefully whether the plastic bag is the right method.
This is because in industrial production, a low total cost of ownership is typically important. In addition, the productivity of the breeding facility should be as good as possible. Furthermore, production must be reliably planned and last but not least, the quality of the breeding results should also be consistently high. However, these are requirements that algae cultivation in plastic bags cannot meet.
Tubular glass PBRs, on the other hand, offer many advantages in industrial production. Here are eight reasons why Tubular Glass PBRs are better suited than plastic bags:
- No problems with biofilm build up
The polymer of plastic bags has a significantly higher surface roughness than glass. Therefore, a large amount of algae quickly locate themselves there and results in the limitation of reactor productivity.
- Easy and quick to clean
Tubular glass can be cleaned without limitations with mechanical and different chemical methods. The cleaning of the plastic bags on the contrary is too strenuous. Therefore, they are usually replaced rather than cleaned.
- Significantly Lower Operating Costs
The annual replacement of the plastic bags results in high costs due to the work being extensive and can only be completed manually. The plastic bags have significantly higher operating costs than tubular glass PBRs. In subsequent operation, tubular glass PBRs in comparison to plastic bags only create costs for frequent cleaning and the energy costs for possible pumps.
- End of life Costs
The polyethylene, from which the plastic bags are usually manufactured, gets dirty over the time of use. Therefore, it has to be disposed of for the most part at the end of use, because it cannot be reused. Tubular glass, however, can conveniently be recycled at the end of their lifespan. Potentially, the glass waste can even be sold as a renewable resource.
- Reliable Planning of Production Volume
When the plastic bags are replaced once a year, one is always able to work with new systems. Therefore, the production volume of algae cultivation in plastic bags can be easily planned, similar to tubular glass PBRs. Plastic bags, however, are more susceptible to sudden production precipitations due to biofouling or contamination.
- Up to 60% more algae production on the same area
The productivity of plastic bags is considerably poorer than that of tubular glass PBRs due to numerous reasons. Studies show that plastic bags produce between 30 and 60% less algae per year and area compared to tubular glass PBRs. Furthermore, this level of productivity can only be reached when the plastic bags are truly replaced annually.
- Service Life of up to 50 years
Plastic bags are usually replaced annually, once they are not productive anymore. Tubular glass can be used for up to 50 years at a consistent level of productivity.
- Low Total Cost of Ownership
If planning to industrially produce algae over a longer period of time (several decades), then algae cultivation in plastic bags shows a significantly poorer Total Cost of Ownership in comparison to glass PBRs. This is mainly linked to a high amount of labour costs for the annual replacement of the bags and the disposal costs of the bio contaminated plastic waste.
This article is an extract from our e-book “Algae cultivation in plastic bags in comparison to tubular glass PBRs“. If you would like to inform yourself in detail about the advantages and disadvantages of plastic bags in algae cultivation, you can download the e-book for free.
