The Sun is the great mother. All life on Earth might be considered as a transient materialisation of the exhaustless flood of radiance which the sun pours on the planet’s surface. This enables green plants to synthesise sugars and starches from water in the soil and carbon di oxide in the atmosphere, thus making possible the emergence of all other forms of life on earth by providing the essential foods. We eat sunshine in sugar, bread and meat and burn sunshine of millions of years ago in coal and oil, wear sunshine in wool and cotton. Sunshine makes the wind and the rain, the summers and winters of years and of ages. Inextricably woven are the threads of life and light – Thomas R Henry, National Geographic, September 1948

Green Fuel

The recent report that an Indian-origin scientist at the University of Texas, Arlington, USA, has developed new high-performing materials for cells that harness sunlight to split carbon di oxide and water into usable fuels, such as methanol and hydrogen gas, has kindled great interest, once again, in “green fuels”.

Technologies that simultaneously permit us to remove green house gases (GHGs), such as carbon di oxide, while harnessing and storing the energy of sunlight as fuel are at the forefront of current research. The new material could improve the safety, efficiency and cost-effectiveness of solar fuel generation, which is still not economically viable for many countries, like India, though a country like Germany has made dramatic advances in this sector owing to superior technology.  

It is in this context, suddenly, the question arises: can one tap the great energy source of the sun locked up in the widely growing algae, which pose a great environmental threat in many areas, like ponds, rivers, marshes and wet paddy fields? This article explores the opportunity in this hitherto untapped energy source. 

The Value Proposition

1.      Using non arable land, low rainfall, sunshine, carbon di oxide and sea water to produce cost-effective, renewable commercial commodity product with existing market need.

2.     Feed stock conversion, so other biomass including waste viz., bio-solids from effluent treatment units, human and animal solid waste can be converted.

3.     Potential for remote deployment at rural, mining sites and other off-grid sites.

4.     Licensing and purchasing for global expansion.  

Why Algae as an Important Bio-source for Green Fuel manufacture?

1.      Algae produces 70-100 dry tons of biomass/ha/year compared to just 12-25 tons from conventional terrestrial bioenergy crops like Jatropha.

2.     Need only very unproductive land and poor quality water (for example sea water) for production.

3.     Has very high bio-remediation potential.

4.     Can be harvested daily and throughout the year.

5.     Has simple composition and contains no lignin, like in Jatropha (the popular bio energy plant source, to manufacture bio diesel, which many in India are talking about) 

The Innovation

An Indo-Australian company, Muradel, has developed a technique whose main features are:

-         Low energy harvest and concentration technology with hyper-saline micro-algal strain.

-         Conversion of total biomass to green crude via continuous process (involving four patent  or PCT applications).

-         Fully integrated  recycle (nutrients, substrate and carbon di oxide), minimising inputs and competition with traditional agriculture.

The technique is the first of its kind in the world and shows tremendous potential in the production of green fuel.

In this connection, one has to understand the primary difference between bio-diesel and green fuel.

Bio-diesel properties, such as energy density, boiling temperature, viscosity and oxidation stability differ significantly, depending on feed stock. Ultra low sulphur containing diesel derived from fossil crude (now the most sought after fuel in automobiles because of its price advantage compared to petrol) has an unsustainable negative ERoEI (ratio of Energy Returned on Energy Invested) = 0.74 MJ/MJ).

Production of biodiesel from trans-esterification of halophytic micro-algal lipids is energetically an unsustainable proposition because the total amount of energy input far exceeds the energy output, because of the energy required for growing algae, harvesting algae, drying the algae, algal cell lysis, lipid extraction and trans-esterification.

The bio-crude produced from algae is nearly identical to fossil crude obtained from the earth – it can be fractionally distilled to produce gasoline, diesel, kerosene, aviation turbine fuel, naphtha, bitumen etc.

When does biomass carbon gain competitiveness?

Crude oil extraction from the bowels of the earth is becoming increasingly energy-intensive. In the 1930s it was possible to produce 100 barrels of crude oil with the energy available in one barrel of crude oil; by 2011 it was only possible to produce 14 barrels with the energy available in one barrel of crude oil; and by 2013 this had fallen to less than 6 barrels. These figures show that while on equivalent energy basis, the amount of energy expended on extracting fossil crude oil has increased significantly over the decades, the global energy requirement has correspondingly exponentially increased.

This is the reason there is a scramble for renewable energy sources, like solar or wind energy. As long as the primary energy source continues to be either fossil fuel or coal, it is a safe bet that the world will head towards more environmental pollution. This is the context in which green fuels come to the fore, and algae, as a bio-source for green fuel, is at the forefront on this score.

Some basic facts on energy and what end users want:

1.      Whatever the energy source, it should be Energy Positive i.e., Energy Returned on Energy Invested (ERoE1) must be more than 1.

2.     GHGs (Green House Gases) emissions from novel energy sources should be less than that of fossil fuel equivalents.

3.     Novel energy sources must have cost parity with fossil fuel equivalents

The average ERoEI for US oil production has declined from roughly 20 during the early 1970s (beginning of the energy crisis) to 11 today. Global average ERoEI was roughly 30 in 2000 which has declined to 17 today (almost 50 per cent, meaning that on average there is a 5 per cent reduction of ERoEI per annum). The ERoEI of oil production from ultra-deep water sources (about 2 km deep) is estimated to be less than 10. The ERoEI of producing oil from shale is as low as about 1.5.

The above scenario clearly shows that if the world, or India, in particular, has to move forward on the energy equation one has to look at alternative sustainable sources of energy before it becomes energetically unsustainable to extract fossil crude to make liquid fuels. In this context, algae seems to be a good bet.

Benefits from algae as a “green fuel”

-         First and foremost is job creation potential because of regional development.

-         There is a need for sustainable source (both for fuels and plastic manufacture), based on market pull and carbon economy.

-         Integrated production/concentration/conversion/extraction/fractionation processes with guaranteed supply of feedstock can provide the solution to India’s energy crisis economically and sustainably, if not entirely, but substantially. In sum, algae is the future on the energy front for India.

Acknowledgments:  

The authors wish to acknowledge the input for this article from The Australian Renewable Energy Agency (ARENA), Muradel Team, University of Adelaide, Australia.

Sailendra Bhaskar is President, Aban Group, Chennai