Prarancangan Pabrik Vinil Khlorid Monomer dari Etilen Dikhlorid dengan Kapasitas Produksi 150.000 Ton/Tahun

NABILLA TESTAROSA, Ir. Imam Prasetyo, M.Eng., Ph.D.

2022 | Skripsi | S1 TEKNIK KIMIA

Vinil khlorid monomer merupakan senyawa organik yang tidak berwarna dan berada dalam fase gas pada suhu kamar dan tekanan atmosfer. Pertumbuhan produksi vinil khlorid monomer berhubungan langsung dengan permintaan polyvinyl chloride. Vinil khlorid monomer berperan sebagai produk antara (intermediate product) dalam proses produksi polyvinyl chloride (PVC). Kebutuhan vinil khlorid monomer di Indonesia dari tahun ke tahun mengalami fluktuatif sesuai dengan permintaan pasar. Dalam memenuhi kebutuhan vinil khlorid monomer dalam negeri, Indonesia masih melakukan impor dari beberapa negara seperti Jepang, Singapura dan Amerika Pendirian pabrik vinil khlorid monomer diharapkan dapat membantu terpenuhinya kebutuhan vinil khlorid monomer di dalam negeri serta dapat menambah daya saing Indonesia dalam bidang industri kimia. Di samping itu, pendirian pabrik vinil khlorid monomer dapat membuka peluang lapangan kerja baru bagi masyarakat Indonesia. Pabrik vinil khlorid monomer dari etilen dikhlorid ini dirancang dengan kapasitas 150.000 ton/tahun dan beroperasi secara kontinyu selama 24 jam per hari dan 330 hari per tahun. Bahan baku yang digunakan berupa etilen dikhlorid sebanyak 239.324,2284 ton/tahun. Proses pembuatan vinil khlorid monomer terdiri atas tahap persiapan bahn baku, tahap sintesis dan tahap pemurnian produk. Pada tahap persiapan bahan baku, Campuran bahan baku etilen dikhlorid kemudian diuapkan pada suhu 183oC dan tekanan 20 atm menggunakan vaporizer. Etilen dikhlorid fasa gas lalu dialirkan masuk ke reaktor furnace untuk dilakukan proses pirolisis. Selanjutnya, terjadi proses pirolisis pada reaktor furnace. Reaksi pirolisis etilen dikhlorid merupakan reaksi kesetimbangan dengan konversi reaktan menjadi produk pada 55%. Reaksi pyrolysis tersebut merupakan reaksi endotermis sehingga diperlukan panas yang diperoleh dari pembakaran bahan bakar natural gas dan udara. Selain reaksi pirolisis etilen dikhlorid menjadi vinil khlorid monomer dan asam klorida, terdapat pula dua reaksi samping yaitu vinil khlorid monomer menjadi asetilen dan asam klorida serta etilen dikhlorid menjadi etilen dan klorin. Arus keluaran reaktor yang bersuhu 550°C dan bertekanan 18 atm, kemudian dialirkan ke quenching tower untuk dilakukan pendinginan secara mendadak. Setelah itu, pemurnian dilakukan menggunakan menara distilasi secara bertahap. Pada menara distilasi pertama, dihasilkan sebagian asam klorida, asetilen, etilen, dan klorin sebagai produk distilat dan vinil khlorid monomer, etilen dikhlorid dan sisa asam klorida sebagai produk bottom menara distilasi. Produk distilat yang didominasi oleh asam klorida akan dialirkan menuju absorber. Selanjutnya, pada menara distilasi kedua, dihasilkan vinil khlorid monomer sebagai produk distilat yang kemudian dikondensasikan dan dialirkan ke tangki penyimpanan. Sementara itu, produk bottom berupa etilen dikhlorid di-recycle menjadi umpan reaktor furnace. Pabrik vinil khlorid monomer didirikan di Kawasan Industri Cilegon, Banten. Pabrik ini membutuhkan air sebanyak 124094,8207 kg/jam yang diperoleh dari Laut Utara Jawa. Sedangkan, kebutuhan listrik untuk menjalankan pabrik ini diperkirakan sebanyak 1,2662 MW diperoleh dari PLTU Suralaya. Selain itu, kebutuhan udara yang perlu disediakan unit utilitas sebanyak 33261,2685 kg/jam untuk kebutuhan instrument dan boiler. Pabrik ini dijalankan pada lahan seluas 123.122,47 m2 atau setara dengan 12,3122 hektar dengan jumlah karyawan sebanyak 238 orang. Untuk menjalankan proses produksi pada pabrik, dibutuhkan modal tetap sebesar $ 59.629.327,72 dan modal kerja sebesar $ 67.087.859,01. Berdasarkan prosesnya, pabrik vinil khlorid monomer dari etilen dikhlorid berkapasitas 150.000 ton/tahun ini tergolong low risk dengan nilai ROI before tax 22,96%, ROI after tax 17,22%, POT before tax 3,10 tahun, POT after tax 3,77 tahun, BEP 58,48%, SDP 34,54%, dan DCFRR 17,41%. Berdasarkan nilai-nilai parameter evaluasi ekonomi tersebut, pabrik ini menarik dari segi ekonomi dan layak untuk dikaji lebih lanjut.

Vinyl chloride monomer is a colorless organic compound that exists in the gas phase at room temperature and atmospheric pressure. The growth of vinyl chloride monomer production is directly related to the demand for polyvinyl chloride. Vinyl chloride monomer acts as an intermediate product in the polyvinyl chloride (PVC) production process. The need for vinyl chloride monomer in Indonesia from year to year fluctuates according to market demand. In meeting the domestic demand for vinyl chloride monomer, Indonesia is still importing from several countries such as Japan, Singapore and America. In addition, the establishment of a vinyl chloride monomer plant can open up new job opportunities for the people of Indonesia. The vinyl chloride monomer plant from ethylene dichloride is designed with a capacity of 150,000 tons/year and operates continuously for 24 hours per day and 330 days per year. The raw material used is ethylene dichloride as much as 239,324.2284 tons/year. The process of making vinyl chloride monomer consists of a raw material preparation stage, a synthesis stage and a product purification stage. In the raw material preparation stage, the mixture of ethylene dichloride raw materials is then evaporated at a temperature of 183oC and a pressure of 20 atm using a vaporizer. Ethylene dichloride gas phase is then flowed into the furnace reactor for the pyrolysis process. Furthermore, the pyrolysis process occurs in the furnace reactor. The pyrolysis reaction of ethylene dichloride is an equilibrium reaction with the conversion of reactants to products at 55%. The pyrolysis reaction is an endothermic reaction so that heat is needed from the combustion of natural gas and air fuel. In addition to the pyrolysis reaction of ethylene dichloride into vinyl chloride monomer and hydrochloric acid, there are also two side reactions, namely vinyl chloride monomer to acetylene and hydrochloric acid and ethylene dichloride to ethylene and chlorine. The reactor output stream, which has a temperature of 550°C and a pressure of 18 atm, is then channeled to the quenching tower for sudden cooling. After that, purification is carried out using a distillation tower in stages. In the first distillation tower, some hydrochloric acid, acetylene, ethylene, and chlorine are produced as distillate products and vinyl chloride monomer, ethylene dichloride and residual hydrochloric acid as the bottom product of the distillation tower. The distillate product which is dominated by hydrochloric acid will flow to the absorber. Furthermore, in the second distillation tower, vinyl chloride monomer is produced as a distillate product which is then condensed and sent to a storage tank. Meanwhile, the bottom product in the form of ethylene dichloride is recycled into the furnace reactor feed. A vinyl chloride monomer plant was established in Cilegon Industrial Estate, Banten. This plant requires 124094.8207 kg/hour of water which is obtained from the North Java Sea. Meanwhile, the electricity requirement to run this plant is estimated at 1.2662 MW obtained from the Suralaya PLTU. In addition, the need for air that needs to be provided by the utility unit is 33261.2685 kg/hour for the needs of instruments and boilers. This plant is operated on an area of 123,122.47 m2 or equivalent to 12,3122 hectares with a total of 238 employees. To run the production process in this plant, it takes a fixed capital of $59,629,327.72 and working capital of $67,087,859.01. Based on the process, the vinyl chloride monomer from ethylene dichloride with a capacity of 150,000 tons/year is classified as low risk with an ROI before tax of 22.96%, ROI after tax of 17.22%, POT before tax of 3.10 years, POT after tax of 3, 77 years, BEP 58.48%, SDP 34.54%, and DCFRR 17.41%. Based on the values of these economic evaluation parameters, this plant is attractive from an economic point of view and deserves further study.

Kata Kunci : vinil khlorid monomer, etilen dikhlorid, pyrolysis