Natural gas is a cleaner energy source than traditional fuels like coal and oil. In Indonesia, natural gas is mainly used by power plants and industries. Most natural gas is burned to take its heat energy. However, natural gas is also used as feedstock, such as in fertilizer industry. It consists of methane (CH4), the simplest hydrocarbon molecule. As its name suggests, it exists in a gaseous state in room temperature and atmospheric pressure. This makes handling and transporting natural gas more challenging than coal or oil.
The most common way to transport natural gas is by using pipelines. Similar to water pipelines, these systems convey gas from one place to another place. Pipelines can accommodate varying gas volumes, provided they operate within their capacity limits. In Indonesia, natural gas pipeline network currently exists in Sumatra, Java, and Kalimantan.
Another common way to transport natural gas is through LNG (Liquefied Natural Gas) carrier. In order to be transported efficiently, natural gas is liquefied by cooling it to approximately -162°C. This process significantly increases its energy density, reducing the volume required for a given amount of gas. The Liquefied Natural Gas (LNG) is then transported using LNG carrier, a specialized ship to transport LNG, which can be easily identified by having a few large domes.
LNG carriers have substantial capacities, typically transporting between 120,000 and 260,000 cubic meters of LNG. This makes them unsuitable for transporting small quantities of natural gas. Furthermore, their operation is confined to sea routes. LNG ISO-tanks offer a viable solution for transporting natural gas to areas not connected to gas pipelines and distant from coastlines.
ISO tank is a tank whose size is standardized to standard container dimensions. It has a frame surrounding the tank to make it easier to handle and transport the tank. ISO-tank can be handled by common container handling equipment. It can be carried by container ship and trailer truck, just like regular container. They are available in two standard sizes: 20-foot and 40-foot, referring to their overall length.
ISO-tank are designed for transporting various fluids, whether be liquid or gas. There are several types of ISO-tanks based on what they carry. For example, there are food-grade ISO-tanks to transport edible liquid. In the case of transporting natural gas, the natural gas that is filled in to the ISO-tank is in the form of LNG. As stated above, this is to increase efficiency in transporting natural gas. Due to that, the ISO-tanks need to be graded to have ability to carry cryogenic gas, a gas that is cooled to its liquid state. A 40-foot LNG ISO-tank can carry natural gas of approximately 800 MMBtu (million British thermal unit) or 0.8 MMSCF (million standard cubic foot). Both MMBTU and MMSCF are common units to measure amounts of natural gas. For comparison, 800 MMBTU of natural gas can be used to produce 96 MWh of electricity.
LNG itself is not flammable. However, when it evaporates and mixed with air, it become flammable. Because of that, ISO-tank categorized as dangerous goods. According to the International Maritime Dangerous Goods (IMDG) Code, LNG is a dangerous goods class 2.1. This makes handling and transporting LNG require additional attention than regular container cargoes. This is explained in detail in the IMDG Code. Ships and ports are required to have dangerous-goods permits to handle and transport LNG ISO-tank.
Though pipeline and LNG carrier are still the most common ways to transport natural gas, LNG ISO-tank is already used to transport natural gas in Indonesia. An oleochemical plant in Kalimantan and a nickel smelter in Sulawesi have purchased natural gas in the form of LNG ISO-tank, as gas pipelines in Kalimantan and Sulawesi is not as extensive as in Java and Sumatra. LNG ISO-tanks have also been shipped to the export market in China, with gas supplied from Kayan LNG plant.
LNG ISO-tanks present a potential solution to Indonesia’s reliance on LPG imports. They can serve as an alternative fuel source in areas which lack gas pipeline access. However, storing LNG ISO-tanks requires significant space due to their container size. Moreover, the volume of natural gas contained within each tank is relatively large for typical household or commercial consumption. It also requires regasification equipment as LNG itself cannot be burned directly.
While pipelines and LNG carriers remain the dominant methods for transporting natural gas, LNG ISO-tanks offer a valuable alternative, particularly for smaller volumes and remote locations. Continued innovation is necessary to develop more efficient and cost-effective solutions for transporting natural gas on a smaller scale, thereby reducing Indonesia’s dependence on LPG imports.
