Algae : An Oil Crop of Future

A New Source of Energy for Alcohol Distilleries : Most of Ethanol distilleries in India process Cane Sugar Molasses as raw Material. In the manufacture, large amount of CO₂ is released in the process, which is in highly concentrated form. It can be more profitably converted in Algae containing oil. This also fixes the CO₂ which is released into atmosphere.
For a 50 KiloLiters per day distillery :

Process	Raw Material	Product	CO2 Produced	Algae oil that can be Produced
Fermentation	Cane Molasses	50 KL Ethanol	15 KL CO2	15 KL
BioGas Plant	Spent Wash	Methane	15 KL CO2	15 KL
Power Generators	Methane		20 KL CO2	20 KL

Latest developments : The subject is studied, in last few years, with fairly specific aspect of algae, their ability to produce natural oils, finding algae that produced a lot of oil, but also with algae that grow under severe conditions, extremes of temperature, pH and salinity. There are around 300 species, mostly green algae and diatoms. Nutrient deficiency was the major factor. The common thread among the studies showing increased oil production under stress seems to be the observed cessation of cell division. While the rate of production of all cell components is lower under nutrient starvation, oil production seems to remain higher, leading to an accumulation of oil in the cells. The increased oil content of the algae does not to lead to increased overall productivity of oil. In fact, overall rates of oil production are lower during periods of nutrient deficiency. Higher levels of oil in the cells are more than offset by lower rates of cell growth. The main aim is to isolate the enzyme Acetyl CoA Carboxylase (ACCase) from a diatom. This enzyme was found to catalyze a key metabolic step in the synthesis of oils in algae.
Companies in Europe have made tremendous advances in the science of algae and the engineering of microalgae production systems. They have established a Germplasm on Algae with 91% Hydrocarbon using open Pond and Photo bioreactor systems. The record production is 120 million tons of Algae Oil per Hectare per annum and the biggest strength is One million ton of Algae biomass will consume 1.6 million ton of Carbon dioxide and release 1.2 million ton of Oxygen. Also CO₂ is converted into Biomass, and these company is aiming to produce in the near future Biofuels out of Algae crude.
Microalgae : These can build a global oil supply chain that is sustainable and delivers fuel. It will be the supplier to the biodiesel business.
Why microalgae technology? : There are a number of benefits that serve as driving forces for developing and deploying algae technology.
Energy security is the number one driving force behind Biofuels Program. There is a dismal picture of growing dependence on foreign oil.
Algae Oils : Algae oils, need research and development of algae cultivation as an energy source in the of biofuels, which is an economically feasible and eco-friendly alternative to petroleum-based transportation fuels.
Cultivating Algae for Biodiesel Production : With the increasing interest in biodiesel as an alternative to petro-diesel, many have looked at the possibility of growing more oilseed crops as a solution to the problem of peak oil. There are two problems with the approach: first, growing more oilseed crops would displace the food crops grown to feed mankind. Second, traditional oilseed crops are not the most productive or efficient source of vegetable oil. Micro-algae is, 8 to 25 times productive than palm and 40 to 120 times than rapeseed, the highest potential energy yield temperate vegetable oil crop.
Algae as Oil bearing plant :

1. Micro-algae are single celled microscopic organisms which, like plants, use photosynthesis to convert the sun’s energy into chemical energy.

Micro-algae can be grown in large bioreactors that provide the algae with all the needs to maximize growth and oil production.

2. Micro-algae are much more efficient converters of solar energy than any known plant, because they grow in suspension where they have unlimited access to water and more efficient access to CO₂ and dissolved nutrients.

3. The total oil content in algae can be up to 70% of their dry weight.

4. Micro-algae are capable of producing more than 30 times the amount of oil (per year per unit area of land) when compared to oil seed crops.

5. Some algae can grow in saline water. It is worth exploring the possible economic production of oils from algae using saline ground water in the growing ponds. Once the water becomes too salty for the algae to grow, it could be drained to evaporation ponds to recover the salts for use by the chemical industry.

6. Micro-algae are the fastest growing photosynthesizing organisms. They can complete an entire growing cycle every few days.

7. 120 tons of oil/hectare/year can be produced from algae.

8. Algae production can be increased by increasing the carbon dioxide concentration in the water.

9. One of the problems with growing algae in any kind of pond is that only in the top 6 mm or so of the water does the algae receive enough solar radiation. So the ability of a pond to grow algae is limited by its surface area, not by its volume.

Cultivation of Algae Strains for oil : The ponds in which the algae are cultivated are usually what are called the raceway ponds. In these ponds, the algae, water & nutrients circulate around a racetrack. With paddle wheels providing the flow, algae are kept suspended in water, and are circulated back to the surface on a regular frequency. The ponds are usually kept shallow because the algae need to be exposed to sunlight, and sunlight can only penetrate the pond water to a limited depth. The ponds are operated in a continuous manner, with CO₂ and nutrients being constantly fed to the ponds, while algae-containing water is removed at the other end.
Open Algae Pond : In case of a large algae pond, the pond depth is 20 cm corresponding to a volume of 200 m³ or 200,000 liters, it is unlined and powered entirely by electricity. Many ponds of this size fit into a small area along with larger settling ponds and a pumping centrifuge station in order to produce algae on a large scale. The pond surface area corresponding to a volume of 200 m³ or 200,000 liters is 1,000 m².
Pond Operation : Algae pond operations are very simple. The algae are introduced into the pond and allowed to grow until they occupy 1% of the volume of the pond. Very high growth rates are achieved because the pond is constantly mixed by the paddle wheel and it is infused with an ample amount of CO₂ and fertilizer. The paddle wheel rotates providing a current of 20 cm/s around the pond. The mixing is required to ensure that all of the algae receive the necessary amounts of solar radiation, CO₂, and fertilizer required for optimal growth. The CO₂ is injected into the algae pond in the form of flume gas from a nearby coal fired electric plant. The bubblers are spaced around the pond so that the CO₂ is evenly dispersed throughout the pond.
Algae Oil Extraction : There are three well-known methods to extract the oil from oilseeds, and these methods should apply equally well for algae too. These are Expeller or Press and Solvent extraction.

Photo BioReactors : In case of Photo Bioreactors made of Flat glass fixed in steel frame, the depth is 10 cm corresponding to a volume of 0.1440 m³ or 140 liters. Many such BioReactors of this size would fit into a small area along with settling tanks and a pumping centrifuge station in order to produce algae on a large scale. The surface area of each is 2.42 m².
Producing biodiesel from algae has been touted as the most efficient way to make biodiesel fuel. The advantage being that the land requirement for growing the biodiesel is very small. Independent studies have demonstrated that algae is capable of producing 30 times more oil per acre than the current crops now utilized for the production of biofuels. Algae biofuel contains no sulfur, is non-toxic and highly biodegradable. Some species of algae are ideally suited to biodiesel production due to their high oil content, in excess of 50%, and extremely rapid growth rates.
These photosynthetic organisms are far from monolithic. Biologists have categorized microalgae in a variety of classes, mainly distinguished by their pigmentation, life cycle and basic cellular structure. The four most important (at least in terms of abundance) are:

1. The diatoms (Bacillariophyceae) : These algae dominate the phytoplankton of the oceans, but are also found in fresh and brackish water.

2. The green algae (Chlorophyceae) : These are also quite abundant, especially in freshwater.

3. The blue-green algae (Cyanophyceae) : Much closer to bacteria in structure and organization, these algae play an important role in fixing nitrogen from the atmosphere.

4. The golden algae (Chrysophyceae) : This group of algae is similar to the diatoms. They have more complex pigment systems, and can appear yellow, brown or orange in color.

The bulk of the organisms for oil, fall in the first two classes, the diatoms and the green algae.
The unique ability of algae to grow in saline water means that we can target areas of the country in which saline groundwater supplies prevent any other useful application of water or land resources. In a world of ever more limited natural resources, algae technology offers the opportunity to utilize land and water resources that are, today, unsuited for any other use. Land use needs for microalgae complement, rather than compete, with other biomass-based fuel technologies.