Biomass Utilization: New Approach for The Promising Indonesia Renewable Energy
By: Ghiffari Alfarisy
Tags: Energy, Palm Oil, Indonesia, Renewable Energy, Future

Two noteworthy issues coming out of the news recently are the negative impacts of global warming and the depletion of fossil fuels. We all know, too, that the two issues mentioned both have a correlation. Global warming occurs due to carbon dioxide formed from fossil fuel combustion being accumulated in the atmosphere. As far as mankind consumes coal, natural gas, and petroleum, this accumulating amount of carbon dioxide affecting the atmosphere would always increase.

It is also known that fossil fuel, coal, natural gas, and petroleum are clearly limited. The reserve to production ratio depicts it will run out in about 160 years, 65 years, and 41 years respectively. The depletion of fossil fuel is being issued as the dependence of mankind on those particular resources. As it happens, we are now about to pass the gateway that leads to a new age of fossil fuel-independent humankind and starting to render the utilization of renewable energy widespread. In the years to come, the world should be ready to transform their current energy into renewable energy as the key to suppressing the carbon dioxide emission and maintaining global energy security. Renewable energy comes in various forms which include wind, photovoltaics, geothermal, hydropower, tidal, and wave energy. One of the most used sources of renewable energy is biomass.

In general, biomass means an organic compound that is produced by the activity of the living creatures which can be utilized in the form of energy and material. In tropical countries, biomass reserves exist in enormous amounts — for instance, wood, grass, marine algae, microalgae, agriculture waste, forestry waste, and municipal waste are all biomass reserves.

Biomass differs from other renewable energy. It is renewable and carbon-neutral as well. Additionally, biomass clearly an unlimited source of energy because it comes from living things — as far as the availability is maintained. From the biomass combustion, the concentration of carbon dioxide in the atmosphere remains unchanged, because the amount of carbon dioxide emitted is equal to the amount being absorbed. Moreover, biomass is more storable and transportable in the form of chemical fuels, namely ethanol, methanol, dimethyl ether, and others, compared to other resources. Based on these factors, biomass has a high probability of replacing fossil fuels (or at the very least become a big part of it) and displace the drawback of fossil fuels.

To meet its utilization purpose, biomass should go through the conversion phase. At least, there are three types of available technologies to converting biomass from primary into secondary energy. The conversion process conducted by physical, biological, and chemical.

The physical conversion includes milling, grinding, and steam explosion to decompose the biomass structure for increasing its surface to accelerate the reaction and it also covers densification, drying, and distillation for making biomass more suitable for transportation and storage. Biological conversion mainly composed of fermentation processes such as ethanol fermentation, methane fermentation, acetone-butanol fermentation, hydrogen fermentation, and enzymatic treatment which yeast plays an important role along the whole process. The chemical conversion consists of hydrolysis, partial oxidation, combustion, carbonization, pyrolysis, the hydrothermal reaction for decomposing biomass and also synthesize, polymerization, hydrogenation for constructing new molecules or reforming biomass. Figure 1 shows the illustration of biomass entire conversion process.

Figure 1. Biomass conversion

Providing energy from biomass resource mainly in electricity form. Biomass can be converted into electricity through several methods. The most common method is direct combustion. This method following the principle of the Rankine cycle. Indirect combustion, biomass burned in the combustion chamber or furnace to generate hot gas, and then the heat produced is used to generate steam in the boiler. Next, the steam will be expanded through a steam turbine to obtain mechanical energy, afterwards, it will convert into electricity in the generator.

Figure 2. Diagram of biomass power plant

There are some aspects that need to be considered regarding the utilization of biomass as the future source of energy, i.e. food security and sustainability of agriculture and forestry. Biomass is only permitted for use when it is not classified as a main food source, which, if adhered, to, therefore will not disturb food security. Consequently, there are only certain biomass resources will be included as potential bioenergy.

One of those certain biomass sources that are significant development is biomass from oil palms. Oil palms can typically be raised in places with abundant rainfall and heat such as tropical countries in Southeast Asia. Statistically, Indonesia is the world’s largest producer and exporter of crude palm oil. Thus, palm oil has become one of Indonesia’s most promising sources of biomass. It refers to the fact that Indonesia dominated 60% of the world’s palm oil production when it supplied 36 million tons of palm oil while the world total production was around 58 million tons back then in 2016.

Palm oil is extensively consumed for cooking oil, lubrication, cosmetics, medicine, etc. Hence, it generates a huge quantity of palm oil as well. Furthermore, the biomass generated during the production process also has the potential for an energy source. Surprisingly, in every kilogram of palm oil produced, it generates about four kilograms of waste in the form of empty fruit bunches. In general, palm oil residue comes in various forms such as trunks, fronds, palm shells, and as said before empty fruit bunches. These sources of waste can be converted into more useful products such as transportation fuel, briquettes (blocks of compressed charcoal or coal dust), and gaseous hydrocarbons using solid plant processing.

The theoretical energy that can be obtained from palm oil in Indonesia is estimated to be near 67 million GJ/year. The value seems to keep increasing since the plantation area of the oil palm trees is expected to expand to around 2 million hectares in 2020. Therefore, the utilization of the entire resources from oil palms should be applied to maximize energy production in Indonesia.

Figure 3. Palm oil Plantation in Indonesia

Implementing biomass as the source of energy in Indonesia is not an easy task, but it is worth trying. To achieve, the national energy target of mixed energy in 2025, 23% renewable energy among the others, there are several things to do. For example, the government should provide supportive regulations and proper authorization in order to keep biomass utilization on track. It is also necessary to encourage people who have an interest in this field by arranging some incentive, reward, or other conveniences so more manpower will be able to support the implementation.

Finally, the development of good infrastructure and technology must be enhanced to improve the efficiency of biomass utilization. By taking planned and calculated steps, it is an optimistic projection to make biomass the applicable resource of renewable energy to combat the rocketing energy demand and environmental issues that Indonesia will face in the near future.