TECHNO-ECONOMIC ANALYSIS OF METHANOL AND ETHANOL PRODUCTION PLANT FROM NATURAL GAS

• Main Author: Laksana Yudharaputra, Dimas
• Format: Theses
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/71766
• Institution: Institut Teknologi Bandung

Indonesia is a net gasoline importer with annual imports of more than 16 million liters in 2020. To reduce carbon dioxide emissions, gasoline can be blended with 3%-v/v methanol and 10%-v/v ethanol. National natural gas with a surplus of 800 billion standard cubic feet (2020) can be partially used to produce methanol and ethanol. An integrated technoeconomic study of methanol and ethanol factories from raw natural gas needs to be carried out to examine the technological and economic aspects of these factories. This study aims to examine the economic feasibility and investment feasibility of an integrated methanol and ethanol manufacturing plant, using natural gas as raw material. The total natural gas consumed was 84.1 MMSCFD, with a composition of 91.64%-mol CH4, 3.35%-mol C2H6, 0.94%-mol C3H8, 0.29%-mol n-C4H10, 0.25 %-mol n-C5H12, 3.28%- mol CO2, 15 ppm H2S, and 0.23%-mol N2. The balance of natural gas consumption for methanol and ethanol plants is 80%-v/v and 20%-v/v. The products produced are 482 thousand tonnes/year of methanol (99.9%-m/m) and 15 thousand tonnes/year of ethanol (99.7%-m/m). Calculations were performed with Aspen Plus V12.1 software. The factory is proposed to be built in Cilegon, Indonesia. The Steam Methane Reforming (SMR) reactor is designed for 25 bar, 1,223 K, with a Nickel (Ni) catalyst. The methanol synthesis reactor is designed for 100 bar, 503 K, with a copper (Cu) catalyst. The ethanol synthesis reactor is designed for 110 bar, 583 K, with cobalt (Co) catalyst. The integrated factory was built with a capital cost of USD 427 million and an annual operational cost of USD 209 million/year. With 8 years of depreciation calculation, the production cost of methanol is USD 297/ton and ethanol is USD 592/ton. Based on the natural gas price of USD 6/MMBTU according to “Kepmen ESDM 134 K Tahun 2021”, the average commercial price in 2017-2022 for methanol is USD 470/ton, and ethanol is USD 542/ton, this plant investment is not profitable because of the Net Present Value (NPV) is -USD 341 million and Internal Rate of Return (IRR) of -1.87%/year. The NPV is USD 243 million, and the IRR is 13.4%/year, if the selling price for methanol is USD 632/ton, ethanol is USD 542/ton, and the purchase price for natural gas is USD 6/MMBTU. The NPV is USD 127 million, and the IRR is 11.0%/year with a purchase price of USD 4/MMBTU for natural gas, USD 470/ton for methanol, and USD 542/ton for ethanol. Pertalite's selling price of Rp. 10,000/liter can be reduced to Rp. 9,562/liter after mixing it with 3%-v/v methanol and 10%-v/v ethanol.