While algae are highly efficient converters of solar energy into renewable biomass, most algae known to scientists prefer to store solar energy rather in sugars, such as sucrose and starch, than in the desired oils, i.e. triacylglycerides (TAGs) and phospholipids. In the presence of light, carbon dioxide and some micronutrients, most algae only store about 15-20% of their dry weight in oil. Only under certain conditions are algae capable and willing to flip a switch (aka: lipid trigger) and store the tapped solar energy in the more valuable form of oils rather than sugars within their cell bodies. Until the SGT LipiTrigger™  discovery, all conditions examined where algae successfully production and stored higher oil, they also responded with stunted growth. In the 1990s, the Department of Energy's aquatic species (ASP) program spent many years trying to increase algae oil production and at the same time maintaining high algae growth. The federal government halted this algae research program a decade ago without successfully finding the enigmatic “lipid trigger”. Today, technology has advanced, oil prices have climbed, and the Department of Energy announced it was again in the hunt for better algae oil-production.
Scientists at Sustainable Green Technologies Inc. have found a simple and cost effective way to trigger algae to increase their oil content from 15 percent to more than 50 percent of their dry weight, without stunting growth. This is SGT’s proprietary LipiTrigger™ solution. If algae can produce more oil and achieve high growth, than a given acre of land would yield more biofuel, ultimately driving prices down.

Fossil fuels, such as coal, petroleum oil and natural gas, are finite, non-sustainable energy resources. Once consumed to depletion they cannot be replaced within human life times. Use of fossil fuels in combustion engines or gas turbines emit into the atmosphere the green house gas carbon dioxide and other environmentally harmful gases and components.

The world currently consumes about 30 billion barrels (or 1.26 trillion gallons) of oil every year or 82 million barrels (or 3.44 billion gallons) of oil every day. Oil experts warn that soon oil production will not keep pace with the world’s increasing demand for oil. Oil experts, such as the former Saudi Aramco geologist Sadad I. Al Husseini, studied more than 200 major oil fields and calculated that the world’s oil production of about 82 million barrels of oil per day started leveling off around 2004. Some oil experts fear that the world has already reached an oil production plateau.

Green algae are low maintenance, easy to grow and very abundant aqueous life forms that use sun light energy to perform photosynthesis. Photosynthesis is a biological process which produces biomass  (sugars or oils), oxygen and the high-energy molecule ATP (adenosine triphosphate) from carbon dioxide (CO₂) and water (see Figure 1). All biomass, whether it is sugars or oils, is convertible into bio-fuels, most commonly bio-ethanol and bio-diesel. Moreover, since algae consume the green house gas CO₂ during photosynthesis, they are an ideal, cheap and “green” option for effective removal of this green house gas from the atmosphere. 

Figure 1:  Photosynthesis & Biomass Production

Green algae are relatives of green plants which perform photosynthesis. They belong to the most primitive forms of plant life and photosynthesis in green algae is very similar to that of green plants. Since many green algae are small organisms and have simple cellular structures, they are more efficient converters of sunlight than green plants and show very rapid growth. Moreover, since algae grow in aqueous environments they have efficient access to the major photosynthesis ingredients, most importantly water and carbon dioxide. 

Green algae are metabolically very versatile and produce important renewable biomass compounds directly from sunlight. They build up the glucose polymer cellulose as part of their cell walls, store starch as food reserve, and more importantly, accumulate significant amounts of oils and fatty acids as energy storage. The oils produced by algae are chemically very similar to the oils produced by oilseed crops and are stored in the form of triacylglycerides (TAGs). 

Algae TAGs are the chemical foundation of the future “green oil” economy. Chemically, TAGs (or triacylglycerols) are molecules comprised of three long chains of fatty acids attached to one glycerol molecule. TAGs (oils and fats) in the presence of simple alcohols and a catalyst can be converted into fatty acid alkyl esters or generally called bio-diesel in a process called “transesterification.” Transesterification is the chemical reaction behind the bio-diesel manufacturing process. It is performed either chemically with the help of alkali hydroxides or biochemically with the help of enzymes called lipases. Since the physico-chemical properties of bio-diesel are very close to those of petroleum diesel, algae oil represent a very attractive alternative source for bio-diesel production. Another important benefit is it does NOT compete with food markets.

Indeed, several algal- and green algae  species, such as Euglena, Chlamydomonas, Spirulina, Neochloris, Scenedesmus, Botryococcus, and Dunaliella, have been found to contain high levels of oils and lipids, some reaching 50% of their dry weight. Because of this, green algae are ideal organisms for sustainable oil production from sunlight and show a series of advantages over the favored terrestrial oilseed plants. They produce more biomass per time on less area of land.  It is these green algae  strains with high oil, or lipid content which gained tremendous interest in the search for sustainable alternative biofuels, such as bio-diesel.  According to a DOE report ([1]), algae are capable of producing 30 times more oil per unit area of land compared to commonly used terrestrial oilseed crops, such as canola or sunflowers (see Table 1).

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[1] A Look Back at the U.S. Department of Energy’s Aquatic Species Program: Biodiesel from Algae: Part I

Algae have a high photosynthesis efficiency due to their small sizes. This leads to higher biomass production compared to agricultural crops, such as palm oil, canola, soybeans and corn. They store much more oil per dry weight than currently used agricultural plants. Some algae store more than 50% of their dry weight as extractable oils; more than double the highest oil content of oil palms.

In recent years, increasing global bio-diesel production from agricultural crop and vegetable oil became more costly, partially due to rising fertilizer and transportation costs. Green algae  oil production from low cost wastes is a very attractive alternative for future biofuel generation. The obvious benefit of using green algae  oils instead of oil derived from food crops is it will not impact the food availability or the food price. Recently there was a dramatic increase in the use of prime quality vegetable oils for bio-diesel production, this reduced the availability of these oils for human consumption triggering social unrest and political instability in many parts of the world.

In the 1980s, research programs at the DOE (1) and other labs focused on establishing large algae farms in the most sun-drenched regions of the U.S.

Several algae farms were tested in the U.S. based on the use of open, shallow ponds using some source of carbon dioxide waste as algae feedstock. However, these “raceway” designed algae ponds had several disadvantages. (A “raceway” is an oval pond that looks like a race track).

1. Limited biomass production due to the limited pond depth

- in these designs the ponds are kept shallow to keep the algae exposed to ample amounts of sunlight

2. High contamination danger with other life forms

- open pond system are prone to contamination with other life form which will eventually compete with the algae for important nutrients, therefore, lowering the desired biomass production

3. Dependency on adequate on-site sources of carbon dioxide to assure high biomass production

- the availability of suitable and high sources of waste CO₂, ideally coal, and other fossil fuel-fired power plants, is limited

4. Difficulty to maintain laboratory organisms and lab-optimized growth and oil production conditions in ponds

We at SGT are developing a novel green algae oil production technology. It is centered around our patent-pending processes that allows us to achieve high and sustainable algal biomass with a high weight per cent of oil. There are four main reasons green algae oil technology must be developed in the U.S.

1. Energy security: Diversification of the U.S. energy portfolio
2. Employment:     Creation of green collar worker jobs
3. Environment:     Algal carbon capturing & Climate protection
4. Social responsibility: Realization of sustainable biofuel     production  from non-food sources