Factors that influence the economic efficiency of algae cultivation through the glass components of a photobioreactor

[Global] A glass PBR for algae cultivation can be configured in a variety of ways in order to achieve a high level of efficiency. The costs do not have to increase, quite the opposite is true: The Total Cost of Ownership (TCO) can be significantly reduced by using a high end glass PBR. This is ensured on the one hand by innovative concepts and on the other by the use of high quality components for the construction of a PBR. This markedly improved economy of a high end glass PBR is noticeable in all phases of its lifecycle.

In the following, we will briefly present the most important influencing factors that positively affect the productivity and cost of the PBR system when using glass components.

Higher output and lower costs using a vertical system design for PBRs

In recent years, the fundamental question of a vertical or horizontal system design has become more and more prevalent when considering a new PBR reactor system. Horizontal reactors have been widely used in the past. Most recently, the tried and tested vertical system design has been implemented more and more. Justifiably so, since the system structure requires no pumps at all. This pump free operation has two enormous economic advantages: It significantly reduces costs an increases productivity.

Significantly reduced costs and higher quality through the use of standardized system components

When investing in a photobioreactor the operator sometimes assumes that a customized PBR with its own designs and components is the best way to squeeze every last ounce of productivity out of the system. However, this productivity gain is almost always disproportionate to the corresponding investments costs of such an individualized system. A PBR comprised from standard components, which was conceptualized for cost optimization, typically costs only 20% of an individually customized PBR with the same volume.

Cost savings and higher productivity using innovative PBR components

During the operational phase of algae cultivation, customers are often faced with new challenges. For some of these challenges the suppliers can develop and offer new component solutions, as they deliver a clear advantage: they make a glass PBR even more economical by lowering costs and increasing productivity of the system. Two such current examples are the development of professional connectors for the glass tubing and the development of new manifolds for fence reactor systems. Using professional tube connectors, you can quickly and safely connect the individual tubing sections. Additionally, instead of connecting individual tubing with u-bends, the manifold tubing component makes it possible to connect 8-10 layers at once.

Optimized PBR components reduce costs and provide greater efficiency

Existing PBR components are also constantly being improved, in order to provide customers with the best price/performance ratio. For example the current version of the professional tubing connectors offer one seemingly insignificant innovation step but with great benefits: they can now be manufactured shorter, so that they are even easier to install and cost much less. Furthermore, different tubing wall thicknesses are being examined to find an optimal solution between form and function. It has been shown that thinner walled tubing can lead to increased productivity of a PBR. A one year field test showed a 10% increase in output with thinner walled glass.


Using high quality components in your PBR lowers the TCO of the PBR as well.

Tighter length tolerances for a hassle free setup

Tubing length tolerances can vary from supplier to supplier. High end suppliers manufacture their 5.5 meter long tubing with a tolerance of 2 millimeters leading to an effortless and quick installation process of the PBR.

Commission without breakage lowers TCO significantly

Glass breakage can make system installation and commissioning of a PBR a costly and laborious affair. Two factors typically influence glass breakage under PBR operating conditions: for one, the proper and uniform annealing during manufacturing of the tubing, so that no residual stresses remain “frozen” in the glass. Secondly, the proper tube end processing is crucial, because after cutting the tubing to standard length, the fine micro-fissures have to be “healed” by re-melting the tube ends with a flame polish. If this is not done correctly, the customer may face problems during assembly and commissioning of the PBR.


The quality of the glass components also influences the TCO during operation of the PBR.

Avoid breakage in production

Because of glass breakage the system startup of a PBR with substandard glass tubing can be laborious. Even during operations, such a breakage event can occur. For instance, when a pump system malfunctions, hydrostatic overpressure or friction loss lead to pressure build-up in the PBR. With high quality tubing on the other hand, such events are extremely improbable.

Reduced biofouling

Biofouling is found especially in those areas of the PBR where small gaps are located. Bacteria accumulate in these areas leading to the dreaded biofouling. In the end, this compromises the algae culture and therefore should be avoided if possible. For this reason, photobioreactors are periodically cleaned using chemical agents and solvents like hydrogen peroxide, citric acid, sodium hydroxide or hydrochloric acid. When choosing PBR components, their chemical resistance to these common cleaners has to be considered.


Download your free guide now: How using a PBR with high end glass components makes algae cultivation more economically viable.


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