Interview with Dr. Mikhail Pletnev: Algae Technologies and Environmental Solutions

KELP FARMS team interviewed Mikhail Pletnev – a chemical technologist, Doctor of Chemical Sciences, and expert from the Russian Academy of Sciences.

Mikhail Pletnev headed departments at the Institute of Fine Chemical Technologies at RTU MIREA, Moscow State University of Fine Chemical Technologies named after M.V. Lomonosov, and Belgorod State University. He worked as editor of the international journal SOFW Journal, conducted research and development in two private companies and NPO «SynthesisPAV». He is the author of several monographs, textbooks, and implemented developments. In the 2000s, he became interested in producing biofuel and other products from algae and waste oil materials. His lecture course on this topic was published in 2011 on the website of the International Centre for Science and High Technology ICS-UNIDO.

How and why did you become interested in algae?

Everything started with biofuel: there was interest in developing biofuel technologies, initially mainly using plant and waste oil materials. There was demand for this in the 2000s. Back then, in 2007-08, many Russian companies bought my report on biodiesel, including the Nizhny Novgorod Oil and Fat Plant, EFKO Group, and several other companies. But in 2008, the crisis hit, and all this considerably declined. Although in many countries, interest in biofuel continues.

When I started working on this issue, I concluded that oil palm is the best food raw material for this purpose. It’s the most productive – a lot of palm oil is produced worldwide, so it’s quite difficult to compete with it. But the disadvantage is that it displaces tropical forests, which are the «lungs» of the planet, and like other oil crops, it grows on farmland. The more we use farmland for plant biomass intended for technical rather than food purposes, the worse it is – after all, there isn’t enough farmland. So we thought: why not try using algae, which actively produce triglycerides? Although these triglycerides are, of course, specific and somewhat different from those produced by land crops. Nevertheless, they are suitable for biofuel production.

There are algae (mainly microalgae) that produce up to 30-40% oils from their biomass, and this oil is suitable for biofuel production. Test batches were made, some airlines even made test flights using such algae biofuel, adding it to regular aviation kerosene. About ten species of hardy algae that actively produce oils have been identified.

At the same time, it became clear that biofuel is profitable to make when you also produce some high-tech expensive products for pharmaceuticals and cosmetics, food colorings, and bio-additives. These are products with high added value, so overall biomass processing becomes more profitable.

Active work began in the 1990s. Many companies were interested in this. All the largest biofuel producers are now in Europe and the USA. These include Finnish Neste, Shell Renewable Diesel, ADM and Renewable Energy Group. They are developing algae technologies and creating joint ventures with companies that specialize in growing algae.

For fuel production, you need quite high productivity and industrial bioreactors. Most often these are tubular bioreactors where continuous circulation occurs with adequate light and heat supply. Additionally, algae are grown in open pools and in coastal areas, in special enclosures where circulation happens simply under the sun. But here it’s harder to control temperature, and there’s no heating possibility. Such microalgae farms currently exist mainly in equatorial zones where water is consistently warm. If water temperature drops to 20-21°C at night, productivity decreases sharply, making algae biomass cultivation impractical.

How else can algae be used?

Different types of algae have been used for a long time. The oldest history is probably with the Japanese and Chinese, who widely consume them as food, like sea cabbage. Various ingredients are extracted from algae to produce food colorings and bioactive additives. But for technical needs, for producing biofuel or bioplastics, large-scale production is necessary. There are still no such large productions in the world, only experimental ones.

Do these technologies pay for themselves?

Let’s say they’re on the edge of profitability, but still can’t pay for themselves yet. It’s difficult to compete with oil and gas raw materials. On the other hand, there are large algae farms, for example in Hawaii, that grow raw materials for bio-additive production in quite large quantities. These are economically viable – it’s profitable.

There’s an algae called Botryococcus braunii. Besides producing triglycerides, it also produces unsaturated hydrocarbons in huge quantities – 50% or more of its own mass. As this hydrocarbon is produced, it floats up and swims on the ocean surface, even having a «kerosene» smell characteristic of unsaturated hydrocarbons. They can be directly processed into biofuel or used to extract hydrocarbons like squalene, which are used in pharmaceuticals and cosmetics production.

Let’s talk more about biofuel production. What can it be made from?

By the way, biodiesel fuel was first used by engineer Rudolf Diesel himself at the beginning of the last century: he took plant peanut oil and fueled the engine he designed and patented. Back then, oils were used directly.

Now biofuel is produced from rapeseed, sunflower, waste oils, and also from algae. The technology is roughly the same. When algae or plants reach sufficient oil content, everything is collected, concentrated, and algae are dehydrated. This mass is ground, crushed, and then oil extraction is performed. Oil is extracted with ordinary hydrocarbon solvent, dried, and transesterified with methanol. Oils and fats themselves are triglycerides of fatty acids, and they’re too heavy to be used directly as diesel fuel. To reduce molecular weight, a transesterification reaction is needed – interaction with methanol or other alcohol; this releases glycerin. Glycerin is also a commercial product. If properly purified, it becomes pharmaceutical-grade glycerin that can be used in organic synthesis and in cosmetics as a moisturizing agent.

Methyl esters of fatty acids are biodiesel fuel. European biodiesel is mainly based on rapeseed and sunflower, as well as waste oils. They also try making it from jatropha oil, but this is more in middle and southern regions. Jatropha is a high-productivity technical crop, good because it doesn’t compete with food production for farmland, as it can be grown on depleted soils.

Southeast Asia produces methyl esters of fatty acids from palm oil. This is the most productive land crop, difficult for oil rapeseed, soy, and sunflower to compete with. But palm still falls dozens of times behind microalgae in productivity. Microalgae produce oil literally in days: ten days, maximum two weeks – and you can already harvest. Rapeseed, for example, needs to be grown for three months!

How complex is the biofuel production process? Do investments in such production pay off?

This is still unprofitable and subsidized. These are high-tech processes still being developed, especially regarding next-generation biofuel (like NEXBTL). There are no large modern productions comparable in capacity to oil refineries yet.

Many productions can only pay off through crops that produce something more expensive, like food colorings and bio-additives. There are complex projects for oil production together with various bio-additives and pharmaceutical substances. Pharmaceuticals mainly use antioxidants, which can also be extracted from algae. They also produce fish and livestock feed with high protein and carbohydrate content – after extracting oils that go to biofuel.

Press cake can also be used as bio-fertilizer. There are also technologies for producing bioplastics (like polylactates and polyhydroxybutyrates) based on algae cultures. But all this is still not very developed – questions of competitiveness and production scaling arise. It’s one thing to grow algae in a small photobioreactor, another to scale this to large-tonnage process. The larger the production volume, the more profitable, the lower the unit production costs.

But besides profit, this is saving our planet, which is horribly polluted with plastic. And factories producing plastics release up to 400 million tons of CO2 into the atmosphere annually! Do you know cases where people, despite their own benefit, engaged in something that helps the environment?

Such projects exist, for example, used in complex treatment of domestic and industrial wastewater. Algae have been tried for absorbing atmospheric emissions from factories and power plants: carbon dioxide, soot, and other atmospheric pollutants can be directed to algae trays and bubbled through water. These emissions can actually serve as food for algae, for building biomass.

Additionally, power plant emissions are hot, so this solves the heating problem – you can regulate temperature so productivity doesn’t drop. Thus, emissions are cleaned while algae biomass grows, which can then be used to produce various useful things. Though you need to somehow separate heavy metals formed, for example, after burning coal. All other biomass is suitable for making products the market demands. Such technology has been used in Europe, USA, and Asia. These projects are still being implemented, as some enterprises are fined for excessive emissions, and this is exactly a solution to environmental problems: carbon dioxide and other pollutant emissions into the atmosphere are reduced, environmental conditions in the region improve. But this is a complex process requiring very expensive special equipment, and there’s no serial production of such equipment – it’s still custom production.

Regarding plastic household waste, that’s a separate topic. In developed countries, this problem is gradually being solved by implementing recycling technologies: 1) at the plastics and products manufacturing stage, using recycled plastic; 2) through separate collection of household waste in special containers with further plastic separation by types, grinding and cleaning at recycling plants, restoring commercial value; 3) through consumer education, starting from school. To reduce the flow of small plastic waste polluting the environment, EU countries now make plastic bottle caps and Tetra Pak bag caps non-detachable from containers, facilitating recycling. For unsorted and hard-to-identify plastic waste, pyrolysis and hydrocracking technologies are used, converting it to liquid fuel.

Can algae be used for wastewater treatment?

Algae have long been used in biochemical wastewater treatment. This is so-called «activated sludge,» which may include algae, but mainly consists of bacteria and fungi. This is a symbiosis of microorganisms capable of treating domestic and even industrial effluents, if they’re not too toxic for activated sludge. This also builds biomass, providing biological treatment and photochemical oxidation of water pollutants. The output water is cleaner, without pollutants.

Could biosanitary algae farms help here, for example, those same cystoseira that KELP FARMS works with?

Yes, at treated wastewater discharge points, you can certainly place algae farms and additionally clean water. I know such post-treatment systems exist using green and brown algae and microalgae, chlorella or spirulina, for example. All this is very developed in Japan and China. Several algae projects are developing in Spain. Generally, in using algae for bioremediation, biofuel production and other substances, Chinese lead in patents: about 70% of patents.

Which algae types are most suitable for cosmetics production, and what kind?

Based on algae farms existing in Japan, enzymes, omega-3 fatty acids, antioxidants, food colorings and other ingredients are produced. Since their sea isn’t very warm, Japanese created several algae farms in the Philippines. Perhaps the widest range of cosmetic ingredients and dietary supplements from algae is from Hawaiian company Cyanotech – Nutrex. It uses spirulina and Haematococcus pluvialis as producers.

Using ingredients extracted from algae, both therapeutic and regular cosmetics are produced: cosmetic creams, serums, lotions with antioxidant, nourishing and moisturizing functions, as well as bioactive anti-aging cosmetics. Cosmetic formulations often include carotenoids and tocopherols, and there are algae specialized in their production.

Say there’s an algae farm – what can be produced there, from start to finish, if used to maximum capacity?

We’ve already talked much about the oil component, good for biofuel production. It’s also known that algae oil is used to make natural cosmetic components like emulsifiers and emollients. The second component is polysaccharides, starch-like substances. By breaking them down, you can extract sugars and make natural sweeteners, sugar substitutes less caloric than sucrose.

These include cellulose components and various secondary components that algae produce as filters for self-protection from excessive sun: chlorophyll, red and yellow filters absorbing ultraviolet. These bioactive components are also used in cosmetics: as sun protection and for evening skin tone, reducing skin irritation and inflammation.

Natural dyes are expensive products: those used in cooking for decorating cakes and pastries. Some such dyes can probably color fabrics too: make something like cochineal – dye extracted from insects.

When we’ve separated all this, we have press cake that can go to organic fertilizers and feed premixes. After all, algae washed ashore after storms are collected and used as fertilizer. This is absolutely natural product containing no chemicals, causing no environmental harm. Such fertilizer is very nutritious for plants.

Additionally, remaining biomass can be dried, briquetted and used as fuel, much less harmful to the environment than fossil fuel, being renewable raw material that plants produce. Essentially, CO2 is closed in a cycle. Plants or algae again absorb it from atmosphere through photosynthesis, and this carbon dioxide goes to biomass production, which is burned in some way. This again produces CO2, which again participates in algae biomass photosynthesis – the carbon cycle closes. The same carbon dioxide circulates constantly, without worsening the greenhouse problem.

Aviation biofuel also significantly reduces CO2 emissions. If 20% biofuel is added to regular diesel fuel, this correspondingly reduces harmful emissions by about 20%. This is so-called sequestered carbon dioxide: through photosynthesis cycle, it returns to fields where it’s absorbed by oil crops. The carbon footprint from this biofuel is significantly smaller than from regular fossil fuel.

What’s the relevance of such ecological technologies in your opinion?

There’s obvious environmental benefit – reducing pollution and cutting greenhouse emissions. It’s one thing when the same antioxidant is obtained synthetically in 20 chemical stages – how many effluents, how much waste, how many atmospheric emissions! Here, through biosynthesis, antioxidant is produced in one simple stage – just break down obtained plant biomass into components and extract what’s needed. No new carbon dioxide is produced, the same CO2 circulates in atmosphere without replenishment from fossil fuels.

Global warming unfortunately doesn’t stop. It’s believed that by 2050 the atmosphere will become much more saturated with carbon dioxide, and world ocean and land will warm considerably. Some countries began actively pursuing environmental projects, but now due to unfavorable international situation, many such projects are postponed. This makes using ecological technologies, including those using algae, more important, at least where it’s possible to implement them.