Liquid Fuel (Oil) from Halophilic Algae: A Renewable Source of Non-Polluting Energy

Abstract

A system was developed for producing high yields of a biomass rich in proteins and low in polymeric carbohydrates from the halophilic alga Dunaliella grown in saline water. It was found that the major nutrients (C, N) could be recycled. On a global scale the use of fuel obtained from biomass need not lead to an increase of CO₂ in the atmosphere. For the efficient conversion of biomass into hydrocarbon by pyrolysis, the most important component is protein. Pyrolysis of biomass was shown to be exothermic, thus enabling the recycling of an important fraction of the thermal energy.

Liquid fuel in the form of a mixture of hydrocarbons has been produced from a renewable source of the green microalga Dunaliella [1]. Many of the constituent processes have been tested, at least in the laboratory, and a start was made at upscaling some of them. The project is now inactive, for lack of funds.

Oil is the only form of liquid fuel. Its use has spread over the entire globe and it has been the most important factor in shaping the affluent life-style of the 20th century. It has also made possible the fighting of wars on a world-wide scale. One of the reasons that oil has such power is because it was - and still is - very cheap. Technologically, it is unrivalled among other forms of energy (including nuclear energy). It is a very densely stored form of energy per unit of volume (Table 1 [2]). It is the most readily available form of energy for mobile transport (cars, aeroplanes, etc.). It is easily and relatively cleanly, cheaply and safely transported over long distances. Sociologically, its production requires high skill, and does not demand a large unskilled labour force, and/or dangerous working conditions. It can be one of the least polluting forms of energy if used judiciously.