Low-Cost Algae Production—Is It Finally With Us?
May 13, 2012
e believe that algae is the most promising next-generation biomass feedstock. But historically, using conventional production systems has prevented cost-effective cultivation. Issues include high contamination risk, very low biomass concentration, high capital expenditures, increasingly high operational costs and the use of land-based open ponds and tube reactors.
Though the cultivation of algae using man-made or natural ponds was initially simple, turning it into a viable feedstock has always been problematic.
So our industry has always needed a system that could enable higher production levels, lower capital and operating costs, greater biomass density, better environmental control, and above all, industrial scalability.
Algasol Renewables offers something entirely new: a floating, flexible, multi-compartment photobioreactor (PBR) that can be deployed either on land, in salt water ponds or ditches, or in any body of water.
The company’s productivity results have indicated that growing algae in floating bags can be much more efficient than other cultivation methods.
Algasol claims that because they are shallow, these PBRs achieve optimal light exposure with outstanding productivity results; and because they float in a cushion of water, they can maintain optimum temperature at low cost.
Algasol’s thin and flexible polymer PBR, which grows algae in fresh or slightly saline (brackish) water, floats in saltier water – whether on land or in the actual sea. That’s the key to the company’s patent: the bag floats because its water is relatively less dense than what it is floating in. That density can be controlled in a number of ways, allowing the bags to be upended to facilitate harvesting, or lowered into the ocean in case of storm.
Compared to other closed algae systems, the company’s PBR technology has many advantages, including site flexibility, low cost materials, easy scalability, optimal light exposure, isolation of the crop from predators, very high biomass concentration, low energy consumption and effective weather protection.
“This environmentally-friendly technology won Frost & Sullivan’s 2010 Global Algae Biofuels Award.”
Miguel Verhein, Algasol’s executive director, says that his company is planning to build the world’s largest and most cost-efficient operating algae plantation. The company has had all patent claims approved in several countries, in effect it is in late stage of patent issuance in 70 countries, including China, Brazil, India, Mexico, the US and Europe. It has partnerships with NASA and the Lawrence Berkeley National Laboratory, and with universities in the US and Europe.
Early on, the company wanted a PBR with industrial scalability, low-cost materials and a design that could significantly lower both initial and operating costs. The result was the flexible multi-compartment PBR floating on water. This environmentally-friendly technology won Frost & Sullivan’s 2010 Global Algae Biofuels Award.
I asked Miguel to describe how Algasol’s system evolved, how it could enable renewable energy, and the company’s strategy and vision. I’ll let him speak.
The Search for a Solution
“The climate change trend was pretty obvious in the 80s. I started to look for alternatives to run a diesel engine. Obviously, I came across vegetable oil because Rudolph Diesel, the investor of the diesel engine, presented his machine at the World’s Fair in Paris in 1900 powered by peanut oil. This was the starting point.
“So, I began experimenting with waste oil, but soon realized that there wasn’t enough of it. Then I began looking into algae as a solution. The DOE had commissioned a research program during the second oil crisis in 1978 called ‘The Aquatic Species Program.’ This basically outlined how oil and fuels could be made from algae. Basically, fossil fuels from the very beginning were algae. But the problem was the cost. We needed a production system that would allow for the biomass required.
“We have sunk the photobioreactors to 210 feet – the depth that submarines go to when they want to avoid tsunamis or storms.”
“There are two things we have known for the last 60 years: that Capex (Capital Expense) and Opex (Operating Expense) have to be at rock bottom and industrial scalability has to be achieved. Then, in 2004, I imagined the Food for Fuel debate was going to hit the industry very hard, which it did.
“So it was not a big leap to understand that a production system should be based in the ocean. And we instinctively understood the productivity system, the photobioreactors, had to be not just cheap, but dirt cheap. It needed to be like going from a computer in the 70s that cost half a million dollars to a PC that cost just $10,000.
Building a Better Productivity System
“Traditional cultivation systems such as ponds and tubes have inherent drawbacks.
“Ponds have been used for a very long time. But the problem with the open pond system is, first of all, contamination. If it gets contaminated, then productivity can be lost.
“The second problem is that the algae to water ratio is extremely low. Not much algae in a very great amount of water.
“Third, it is a high energy consuming system, but interestingly enough, it was the cheapest system available at first when it came to Capex because it wasn’t that difficult to dig a hole and put cement around it. However, a number of countries are now asking to have these holes restored to how they looked before the hole was dug and cement was placed around it. So Capex-wise, it is not that cheap any more.
“Obviously, the next step was to try something that was closed and the tube system was invented. But the tubes are vertical instead of horizontal. That means that during the day, you are going to have shade on one side of the photobioreactors. In addition, the cost for the tubes is incredibly high. The support structure for the tubes costs a lot of money and tubes per hectare cost in the millions.
“Also take into consideration that you have to aerate these tubes with carbon dioxide. Carbon dioxide doesn’t travel too well, so this is a limitation. This involves cost, both Capex and energy. On top of that, you have a closed system, with the sun fueling photosynthesis. That makes for high temperatures, a problem because we are going to get algae soup, or a crashed culture, instead of biomass. The only way to solve that so far is by hosing those tubes down, which involves more energy, or putting canopies over the tubes, which reduces insolation.
“…density can be controlled in a number of ways, allowing the bags to be upended to facilitate harvesting, or lowered into the ocean in case of a storm.”
“Now, imagine that you had a plastic Ziploc® bag and you fill it with fresh water and you throw it in the tub. Soon, the water inside will spread evenly inside the bag. By spreading evenly inside the bag its thickness is going to be minimal.
“And that is what happens with our polymer bags. The thickness is never any greater than two inches.
“Of course, that Ziploc bag will sink in the bathtub, since it has fresh water inside and out. But if we have salt water and we place a plastic bag on top of it with fresh slightly less saline water inside, it will float. Between the oceans and the great amount of brackish water on land, we have plenty of salty water. And because the patent is not about floating on water but about density difference: that opens up a whole world of possibilities.
Overcoming Limitations to Achieve Scalability
“Our design has solved a number of limitations. Even though one hectare of Algasol bags cost a fraction of the tube systems or even open ponds, it is a controlled environment so we don’t have a contamination issue.
“In addition, thanks to the surrounding water, we have natural temperature control for free!
“A third benefit is that algae are now spread evenly in the floating PBR and optimal light exposure is achieved. This is what we want because we are helping the photosynthetic process.
“Thanks to this optimum light exposure, we achieve significant yields in algae production and get far superior productivity in grams per square meter per day.
“Our technology is modular. What does that mean? It means you can put together a lot of bags to get a very large surface. At one hectare, “Alga6” is our largest commercial model. We can get the price down to $90,000 per hectare and with higher volume down to $35,000 per hectare, including harvesting valves and our patented aeration system. When you look at industrial scalability and price per hectare, that is a strong advantage.
“…because the patent is not about floating on water but about density difference: that opens up a whole world of possibilities.”
Environmental Sense and Protection Systems
“Again, Algasol’s system is modular. That way, if something breaks it can be easily replaced.
“But what happens if we are in the Gulf of Mexico and we have Katrina II coming from the southeast and 1000 hectares of Algasol bags? We won’t have time to haul them all to shore and gather them in a safe place. So we have our proprietary Integrated Weather Protection System: we just use our density difference technology to submerge the bags and with density difference the PBRs will surface after the storm passes.
“We have sunk the photobioreactors to 210 feet – the depth that submarines go to when they want to avoid tsunamis or storms. And the MEDISUB Hyperbaric Research Institute in Mallorca has certified that this pressure won’t break our PBRs.
“Accidents do happen, plastic bags can break. The difference is that we are dealing with biodegradable live organisms. So if a disaster happens here we are not going to ruin a whole coast line. In addition, freshwater algae die in salt water.
“If we want to make a difference when it comes to renewable energy or products made from algae, we have got to break the cost barrier and that applies to the processing, too. If we are producing algae feedstock, we need to refine it further to get it into fuels or chemicals. There are many players involved but they are not all going to be biofuel producers, but also chemical companies and big agriculture companies making high value products and proteins that will be big drivers. If they have a platform to grow large quantities of algae inexpensively, then this is the future we are looking at.
“The fact is that biomass is in great demand, photosynthetic or otherwise. Once everything falls into place and we have standardized algae productivity systems with integrated downstream equipment, we are going to look back in the not so distant future at what we have accomplished and children are going to say, ‘So you actually used fossil fuels?’”
Thank you Miguel!
Earlier this month, my company agreed to work with Algasol to develop an integrated algae growth and harvesting system. I encourage other companies in the process chain to do the same.