In view of the forecasted shortages and increasing prices of fossil fuels, climate change, the need for new income, and employment opportunities in rural areas, biofuels have taken center stage in policy debates. The use of biofuels as sustainable energy source is developing favorably worldwide. Brazil, the United States, many European countries, and a growing number of countries in Southeast Asia, including Indonesia, are now pinning their hopes on biofuels. Microalgae, as the source of oil used for biofuel, have promising prospect for Indonesia biofuel industry for its superiority in oil yield per area.

In 2007, Indonesia imported 116,4 million barrels crude oil and 129 million barrels fuel. The government of Indonesia subsidizes diesel and gasoline but with the increase in fuel prices on the world market, continuing the subsidy has placed extra pressure on the national budget. Indonesia, and all countries, oil reserves are declining. In the other hand, the consumption of diesel is increasing as the population is increasing. If we continue using petro-diesel oil, one day we will use wood to run our vehicles. According to the Jakarta Post, a report compiled by Indonesia’s State Minister for the Environment states that the natural environment is deteriorating on all fronts. The slash and burn tactic used to make palm plantation exacerbate already high levels of emissions from industry and motor vehicles, leading to levels of smog and air pollution that have affected neighboring countries. To solve those problems, we need alternative energy sources.

Biofuel as an alternative sustainable energy source seems to be promising for Indonesia. Beside solve fuel problems, plants, as the source of biofuels, will solve environment problem. Biodiesel, a biofuel made from vegetable oil, has the same characteristic with diesel oil but it contains no sulfur. This will make the exhaust gas is cleaner compared to diesel oil.

The major problem associated with the use of pure vegetable oils as well as oil from algae as fuels for diesel engines is caused by high fuel viscosity in compression ignition. Microalgae oil, as well as vegetable oils, is all highly viscous. Due to their high viscosity and low volatility, they do not burn completely and form deposits in the fuel injector of diesel engines. Furthermore, acrolein (a highly toxic substance) is formed through thermal decomposition of glycerol.

Dilution, micro-emulsification, pyrolysis, and transesterification are the four techniques applied to solve the problems encountered with the high fuel viscosity. Amongst the four techniques, chemical conversion of the oil to its corresponding fatty ester is the most promising solution to the high viscosity problem. This process, chemical conversion of the oil to its corresponding fatty ester, and thus biodiesel, is called transesterification.

Transesterification refers to a reaction between an ester of one alcohol and a second alcohol to form an ester of the second alcohol and an alcohol from the original ester, as that of methyl acetate and ethyl alcohol to form ethyl acetate and methyl alcohol. Chemically, transesterification means taking a triglyceride molecule or a complex fatty acid, neutralizing the free fatty acids, removing the glycerin and creating an alcohol ester. Transesterification is not a new process. Scientists E. Duy and J. Patrick conducted it as early as 1853.

Other than transesterification, the other methods that have been considered to reduce the high viscosity of vegetable oils or algae oil are dilution, microemulsions with short chain alcohols (e.g. ethanol or methanol), thermal decomposition, which produces alkanes, alkenes, carboxylic acids, and aromatic compounds, and catalytic cracking, which produces alkanes, cycloalkanes, and alkylbenzenes. However, when compared with others, the transesterification process appears to be the best choice, as the physical characteristics of fatty acid esters (biodiesel) are very close to those of diesel fuel, and the process is relatively simple. Furthermore, the methyl or ethyl esters of fatty acids can be burned directly in unmodified diesel engines, with very low deposit.

Microalgae contain lipids and fatty acids as membrane components, storage products, metabolites, and sources of energy. Algae strains, diatoms, and cyanobacteria (categorized collectively as “Microalgae”) have been found to contain proportionally high levels of lipids (over 30%). These microalgae strains with high oil or lipid content are of great interest in the search for a sustainable feedstock for the production of biodiesel.

The biodiesel from algae in itself is not any different from biodiesel produced from vegetable or plant oils. All biodiesel essentially are produced using triglycerides (commonly called fats) from the plant or algae oils. The difference is however in the yield of oil, and hence biodiesel. Feedstock yield efficiency per acre affects the feasibility of ramping up production to the huge industrial levels required to power a significant percentage of national or world vehicles. The highest yield feedstock for biodiesel is algae which can produce 16-32 times the amount of oil per acre as palm oil (http://en.wikipedia.org/wiki/Biodiesel).

The flakes left over from biodiesel squeezing can be processed into ethanol. It can also be used as livestock feed, such as chicken feed. Algae biomass has other potential on- and off-farm uses. Although it has primarily been considered as an alternative high-grade protein source in animal feed, algae biomass with a balanced N:P ratio is a potentially valuable organic fertilizer. It may also have some biocontrol properties. Algae biomass is also reported to be particularly suitable for pisciculture (fish pond).

Biodiesel produced from microalgae appears to be the only feasible solution today for replacing petro-diesel in Indonesia completely. No other feedstock has the oil yield high enough for it to be in a position to produce such large volumes of oil. To elaborate, it has been calculated that in order for a crop such as palm to yield enough oil capable of replacing petro-diesel completely, a very large percentage of the current land or forest available needs to be utilized only for biodiesel crop production, which is quite infeasible. However, if the feedstock were to be algae, owing to its very high yield of oil per acre of cultivation. Clearly, algae are a superior alternative as a feedstock for large-scale biodiesel production.

Indonesia has the longest coastal line in the world. Combine with its tropical weather, Indonesia will enjoy being the biggest algae oil and biodiesel producer. By producing biodiesel from algae oil, Indonesia can save a lot of its national budget that used to import crude oil and fuel, and will secure its energy source. Algaeculture and biodiesel industries will absorb many workers and reduce unemployment or underemployment rate. Algae, like other plants, will absorb CO₂ gas and produce O₂ in photosynthesis. As we know, CO₂ gas is the main gas that causes greenhouse effect and climate change. Algae grow in water, so we can save our land and preserve our forest for future generation. Biodiesel production from microalgae oil will not only solve Indonesia energy problem, but also its environment and employment problems.

By : Kemal Argha Y