Preliminary Design of Methanol Plant from Natural Gas
The abundance of natural gas reserves in Indonesia so far has not been exploited well. Data from the Ministry show that Indonesia’s natural gas reserves stood at 9826 MMSTB (Million Metric Tons Standard Barrel). During this time natural gas in Indonesia is only used as raw materials and fuels in certain industries, especially the fertilizer industry. In addition, most of Indonesia’s natural gas is also exported as raw material in the form of liquefied natural gas (LNG). This is very detrimental to Indonesia because of the buyers from abroad convert it to other high-value materials and earn benefit from it. Therefore Indonesia needs factories that are able to convert natural gas into other high value materials and generate the income for Indonesia. One of the ways is by establishing the methanol plant, due to the promising prospects of methanol for the next few years. The methanol plant from natural gas is planned to be located in Arun, Nanggroe Aceh Darussalam, with a capacity of 350,000 tons per year. The establishment began in early 2008 and will start operating in early 2009. The process to convert natural gas into methanol in this plant uses the latest technology, namely ICI’s Leading Concept Methanol developed by Synetic Ltd., a company based in the UK. The process of methanol manufacturing can be divided into several stages with four different major processes, i.e the preparation of raw gas, synthesizing of synthetic gas (syngas), methanol synthesis, and distillation units. In the process of synthesizing of synthetic gas (syngas), the reaction takes place in a reformer, which is a combined auto thermal reformer (CAR). In this process there are three forms of chemical reaction, ie partial oxidation, the formation of steam and water gas shift reaction. While in the process of methanol synthesis, there are two kinds of reactions that take place in parallel in a multi-tubular steam raising converter Subsequently methanol produced from the reactor will be purified in the distillation unit to obtain a product (methanol) with a purity of 99.85%. Corporate legal entity is a Limited Liability Company (Perseroan Terbatas / PT), in which the structure used is line and staff. The company is headed by a president director with a number of employees 143 people. This plant uses two types of steam, the saturated steam is 1581 kg/hour and superheated steam at 266,783 kg/hour. The needs of cooling water for the plant are obtained from the river water and sea water as much as 27,658,328 kg/hour. Demand for electricity in this plant is supplied from the PLN of 7000 kWh and a unit of generator as back up with a capacity of 6000 kWh. Fuel used at this plant is diesel as much as 84,279 liters/day. From the results obtained economic analysis of fixed capital investment (FCI) of IDR812,556,377,556, working capital investment (WCI) of IDR187,401,344,345; total capital investment (TCI) of IDR999,957,721,901; with the composition of bank loans by 27% and capital alone by 73%. Break Event Point (BEP) in Third Year at 43.4%, and the Internal Rate of Return (IRR) of 60.3711%.
Keywords: Natural gas, methanol, synthesis gas, reformer
- This undergraduate thesis was conducted as a prerequisite for obtaining bachelor’s degree in Chemical Engineering at Institut Teknologi Indonesia
- Authored by Muhammad Yusuf Firdaus and Besthiary, students of Chemical Engineering Study Program – Institut Teknologi Indonesia
- Examined on the Final Examination Seminar on February 10, 2007 at Chemical Engineering Study Program – Institut Teknologi Indonesia