"Bubblebrush and Wavywind": An introduction to LGem's Photobioreactor System

[Netherlands] Algae-related companies which provides professional technical services, such as construction of photobioreactors (PBRs) for the niche market of algae industry have been facing challenges. These challenges include technical breakthrough and market competitions. As one of the oldest PBR builder in Europe, founders of LGem B.V. generously shared their interesting entrepreneurship experience with Algae World News readers on how the company stands out among other competitors.

LGem, based in Netherlands, is the first company which specialize in building PBR for cultivation of microalgae. Earlier in 2005, one of the founders, Obbo Hazewinkel, a chemical engineer, came out with an idea of growing oil-producing microalgae using closed-loop PBR made of plastic sleeves. This innovative cultivation process granted the team of 5 members a € 300.000 innovation fund from the Dutch Ministry of Economic Affairs —  to continue their R&D as well as demonstration of the innovative idea.

Sander Hazewinkel, one of the founder of LGem, showed Algae World News editor, Tian, a roll of plastic sleeve which they used to grow microlagae earlier in 2006.
Sander Hazewinkel, one of the founder of LGem, showed Algae World News editor, Tian, a roll of plastic sleeve which they used to grow microlagae earlier in 2006.

In the plastic sleeves, microalgae were grown in liquid culture media, and carbon dioxide enriched air was pumped into the sleeves as well. Under proprietary conditions, a “two-phase” environment – the liquid phase and the gaseous phase is created in the closed system.

However, the idea of using plastic sleeves to grow microalgae was soon dropped because of its short life-span and not being environmental friendly. According to Sander, after harvesting each batch of microalgae, the plastic sleeves were replaced by new ones. That would have created huge amount of environmental waste which are difficult to be degraded. It also comes at a very high OPEX.

“Therefore, we switched to the use of specially compounded PVC tubes. These PVC tubes have longer life-span and they are cost-effective.” Sander said.

When being asked if tubes made of other materials would be better than the PVC ones, Sander told us that they are currently availing thin-walled (0.5 mm-1.2 mm) PMMA with the same mechanical properties (for connections etc.) as the PVC, but with a longer life expectancy.

But when being asked about tubes made of glass, Sander explained that despite the longer life-span of glass tubes, the major problem is that most glass tubes are not long enough and thus, they require large amount of joints and connections. Another issue is that these connections are unsanitary and therefore not suitable for growing microalgae.

“You will need to purchase thousands of  “unsanitary” joints to connect the glass tubes in order to scale-up. And the joints and rubber rings are expensive consumables.”

LGem PVC tubes, located in a 5,000 m2 greenhouse
LGem PVC tubes, located in a 5,000 m2 greenhouse, were filled with Nannochloropiss Gaditana. Each stretch of PVC tube is 125 m long, and it does not require large amount of connecting joints and pipe’s sockets like the glass tubes do. The total length of the PVC tube in this particular PBR system is 6 km. The total volume of microalgae culture is about 15,000 L, occupying a land area of 500 m2.

“We have experimented many types of tubes in the past few years, and we found that PVC tubes are the most affordable ones to serve our purpose.” Sander said.

The company has developed sanitary  jointing techniques for PVC tubes to minimize “dead zone” where the algae biomass would become adhered or accumulated. Along with a compatible chemical cleaning method, LGem’s PBR system prevents contamination and biofouling. Maintenance and cleaning are easy and fast.

Sander demonstrated that the PVC tubes are transparent, UV-stable, thin (0.5 mm) durable, and elastic. This allows maximum light penetration and prevents breakage due to thermal expansion. We observed that there is no biofouling in the tubes.
Sander demonstrated that the PVC tubes are transparent, UV-stable, thin (0.5 mm) durable, and elastic. This allows maximum light penetration and prevents breakage due to thermal expansion. We observed that there is no biofouling in the tubes.

The company’s CEO, Eugene Roebroeck, mentioned that the two-phase cultivation system is a technology breakthrough for tubular PBR system.  There is a name for this two-phase cultivation technique, which is called “Wavywind and Bubblebrush” process.

“The “Wavywind and Bubblebrush” process is patented in year 2011, and we share this joint patent with Georg Fischer, who developed and manufactures the PVC tubes.” said Eugene.

Eugene Roebroeck, the CEO of LGem, showed us different types of tubes that the team had tested before. LGem eventually collaborates with Georg Fischer and uses the PVC tubes to build PBRs.
Eugene Roebroeck, the CEO of LGem, showed us different types of tubes that the team had tested before. LGem eventually collaborates with Georg Fischer and uses the PVC tubes to build PBRs.

What is special about the “Wavywind and Bubblebrush” process?

The two-phase cultivation system pumps both air and culture broth into the tubes. Culture broth is continuously pump into the system whereas air is pumped in as in rhythmic pulse. Together they generate wave that is pushed by high velocity air stream, thus creates “Wavywind”. When the wave is traveling along the tube, bubbles are formed, and keeping the internal tube wall from fouling. The bubbles which clean up the tube wall works like a internal brush and thus it is known as “Bubblebrush”.

The Wavywind technology allows a stream of air (pumped in from the blue tubes) to travel twice the velocity of culture fluid. The fast air stream creates bubbles and Eddies, results in an unique stirring effect that prevents fouling and oxygen accumulation.
The Wavywind technology allows a stream of air (pumped in from the blue tubes) to travel twice the velocity of culture fluid. The fast air stream creates bubbles and Eddies, results in an unique stirring effect that prevents fouling and oxygen accumulation.

The system is also extremely energy saving.

“Our systems need less than 150 Watts per 1,000 liter of culture volume for pumping and aeration in single mode.” Sander elaborated.

So far, there are 22 PBR systems of different sizes have been sold to companies and institutions in Europe, North- and South- America and Australia, which include:

  • Synthetic Genomics Institue
  • Centre for Applied Biotechnology Uni Research AS, Bergen Norway
  • Geneva flyover bridge, Garden Festival
  • University of Wildau, Germany
  • AgroTech, Denmark
  • University of Wageningen, the Netherlands
  • Algaeparc, the Netherlands
  • Universidad Autónoma de Querétaro, Mexico
  • Plastica Alfa, Italia,
  • University of Queensland, Australia
  • University of Applied Sciences Zeeland

On contrary, the two-phase system reduces the cultivation volume, since the gaseous phase in the tube occupied a significant space inside the PBR. According to Eugene, slight reduction of volume compensates the fouling problem. Fouling prevents light from entering the tubes and greatly reduces photosynthetic efficiency of microalgae.

Watch the video of the flow of microalgae culture in the LGem tube.

Why LGem?

Why do algae growers choose Lgem’s PBR system?

“Top quality made affordable without compromise.” Sander said.

“All piping components of the PBR system products are fine-tuned, ensuring  our clients the highest possible quality for growing various algae strains. And that’s why we have positive referrals and mentions.” Sander said.

Algae World News would like to thank LGem B.V. for sharing their experience with us. We also thank Sander and Eugene for their warm hospitality in Netherlands. LGem also generously supports our work in propagating algal biotechnology around the world via Algae World News online platform.

 

Exclusively reported by Algae World News

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