PRARANCANGAN PABRIK POLISTIREN DARI STIREN MONOMER DENGAN KAPASITAS 90.000 TON/TAHUN

FAJRI ALQODRI, Dr. -Ing. Teguh Ariyanto, S.T., M.Eng.

2020 | Skripsi | S1 TEKNIK KIMIA

Prarancangan pabrik polistiren dari monomer stiren dilakukan untuk mengevaluasi kelayakan pendirian pabrik. Pabrik polistiren dirancang dengan kapasitas 90.000 ton/tahun selama 330 hari/tahun dan 24 jam/hari. Jumlah bahan baku yang dibutuhkan untuk menghasilkan polistiren sesuai kapasitasnya adalah 142.558 ton/tahun monomer stiren, 84.511 ton/tahun etilbenzen, dan 252 ton/tahun benzoil peroksida. Polimerisasi monomer stiren dilakukan dengan metode solution polymerization dengan etilbenzen sebagai pelarut dan benzoil peroksida sebagai inisiator. Reaksi polimerisasi terjadi di reaktor alir tangki berpengaduk pada suhu 900C dan tekanan 1 atm. Hasil reaksi kemudian diolah hingga menghasilkan produk general purpose polystyrene (GPPS) berbentuk granul. Lokasi pendirian pabrik bertempat di Cilegon, Banten, dengan luas tanah 2 ha dan mempekerjakan 135 orang karyawan. Kebutuhan energi untuk menjalankan pabrik ini meliputi kebutuhan listrik sebanyak 4.237 kW . Sedangkan kebutuhan air untuk proses adalah sebanyak 11,2 m3/jam. Proses produksi polistiren membutuhkan modal tetap sebesar $ 20.475.363 + Rp 121.823.377.890 dan modal kerja sebesar $ 33.658.587 + Rp 2.901.672.022 Keuntungan yang didapatkan sebelum pajak yaitu sebesar $ 8.986.647 dan $ 4.493.323 setelah pajak. Hasil perhitungan evaluasi ekonomi untuk pabrik dengan jenis low risk, dapat diketahui nilai ROI sebelum pajak 30,80% dan sesudah pajak 15,40%, PoT sebelum pajak 2,45 tahun dan sesudah pajak 3,94 tahun, BEP 50,83%, SDP 30,08%, dan DCFRR 17,99%. Dapat disimpulkan bahwa pabrik ini menarik secara ekonomi dan layak untuk dikaji lebih lanjut.

The pre-eliminary design of the polystyrene plant from styrene monomer is intended to determine the feasibility study of the plant. This factory is designed to produces polystyrene with a production capacity of 90.000 tons/ year and operates for 330 days / year and 24 hours / day. The process of producing polystyrene uses styrene monomer as much as 142.558 tons / year, 84.511 tons / year ethylbenzene, and 253 tons/year benzoyl peroxide. Poymerization of styrene monomer is conducted by the solution polymerization method with ethylbenzene as solution and benzoyl peroxide as initiator. All raw materials are processed in a continous stirred tank flow reactor which is run at a pressure of 1 atm and a temperature of 90oC. This reaction will produce general purpose polystyrene (GPPS) granules as the product. This factory is planned to be located in Cilegon, Banten with an area of 2 ha and trains 135 workers. The electricity needs of the factory amounted to 4.237 kW. For water process requirements, 11,2 m3/ hour are needed. To establish this factory, it takes a fixed capital of $ 20,475,363 + Rp 121,823,377,890 and working capital of $ 33,658,587 + Rp 2,901,672,022. The profits obtained before being taxed amounted to $ 8,986,647 while the profits obtained after being taxed amounted to $ 4,493,323. After calculating the economic evaluation, it is known that the Return of Investment (RoI) before tax is 30.80% and after tax is 15,40%, Payout Time (POT) before tax is 2,45 years and after tax is 3,94 years, Breakeven Point (BEP) is 50,83%, Shut Down Point (SDP) is 30,08% and Discounted Cash Flow Rate of Return (DCFRR) is 17,99% per year. Based on the results of the economic evaluation, it can be concluded that this polystyrene plant is interesting and deserves further study.

Kata Kunci : Monomer Stiren, Etilbenzen, Benzoil Peroksida, Solution Polymerization