Prarancangan Pabrik Asam Adipat dari Sikloheksena dan H2O2 dengan kapasitas 20.000 ton/tahun.

RAMINDA AZKA AULIA, Prof. Ir. I Made Bendiyasa M.Sc Ph.D.

2014 | Skripsi | TEKNIK KIMIA

Pabrik Kristal Asam Adipat 99.7 % dari oksidasi Sikloheksena dengan H2O2 dengan kapasitas 20,000 ton pertahun beroperasi kontinyu 24 jam perhari dan diperkirakan bekerja 330 hari dalam setahun. Asam adipat diproduksi dari oksidasi katalisis sikloheksen dengan H2O2 sebagai oksidator. Karena reaksi oksidasi ini merupakan reaksi pemutusan cincin rantai karbon Sikloheksena menjadi bentuk rantai panjang Asam Adipat, maka reaksi dijalankan didalam reaktor alir tangki berpengaduk berjumlah 4 buah dan dipasang seri. Reaktor ini beroperasi pada suhu 90 °C dan tekanan atmosferis. Asam Adipat yang dihasilkan dipekatkan di evaporator kemudian dikristalkan di unit Crystallizer yang kemudian dipisahkan dari larutannya menggunakan centrifuge sehingga tercapai kemurnian 95%. Setelah itu padatan dihilangkan kadar airnya menggunakan rotary dryer sehingga dihasilkan produk Kristal Asam Adipat dengan kemurnian 99.7 %. Untuk menghasilkan Kristal Asam Adipat sebanyak 20,000 ton/tahun dibutuhkan Sikloheksena 99 % sebanyak 12,507.88 ton/tahun dan H2O2 50% sebanyak 45,638.51 ton/tahun. Sedangkan utilitas yang diperlukan adalah air sebanyak 1,330,824.92 m3/tahun, bahan bakar diesel untuk memenuhi kebutuhan listrik proses sebesar 2,549.134 ton/tahun, bahan bakar gas untuk produksi steam sebesar 2,057.82 ton/tahun dan listrik untuk keperluan selain proses dan utilitas sebesar 462.62 kVA. Pabrik Asam Adipat ini direncanakan didirikan di daerah Cilegon, Banten, Propinsi Jawa Barat, dengan luas tanah 12.000 m2 dan jumlah karyawan 167 orang. Dari perhitungan hasil evaluasi ekonomi diperoleh Fixed Capital Investment, FCI = US$ 17,865,699.29 + Rp 58,676,829,737.49, Working Capital, WC = US$ 13,727,467.35 + Rp 7,124,244,900.42, Keuntungan sebelum pajak Rp 107,801,563,327.96, Keuntungan setelah pajak Rp 53,900,781,663.98, Return On Investment before taxes = 47.20 % , Return On Investment after taxes = 23.6 % , Pay Out Time before taxes = 1.75 tahun , Pay Out Time after taxes = 2.98 tahun, Break Even Point, BEP = 44.64 % , Shut Down Point, SDP = 21.41 % , Discounted Cash Flow Rate of Return, DCFRR = 26,74 %. Berdasarkan hasil perhitungan diatas, maka pabrik Asam Adipat dengan kapasitas 20.000 ton pertahun layak untuk dikaji lebih lanjut.

Adipic Acid (99.7% purity) plant from Cyclohexene and peroxide acid with a capacity of 20,000 tons per year operate continuously 24 hours a day and expected to work for 330 days a year. Adipic Acid produced via catalytic oxidation of cyclohexene with H2O2as oxidant. Since this oxidation is the carbon chain termination reaction of cyclohexene’s ring to form a long carbon chain of Adipic Acid, this reaction operated in 4 continuous stirred tank reactor, installed in series. This reactor operates at a temperature of 90 ° C and atmospheric pressures. Adipic Acid produced by the reactor, concentrated in the evaporator on the next step, and then crystallized to form crystal of adipic acidl, then this crystal is separated from the solution using a centrifuge in order to reach 95% purity. Further more, the crystal of adipic acid is dried from the water content in rotary dryer, and reach 99.7% purity. To produce 20,000 tonnes per year Adipic acid 99.7 %, 12,507.88 tons per year Cyclohexene (99% purity) and 45,638.51 tons per year peroxide acid 50% is needed. It is calculated that 1,330,824.92 m3 of water per year, 2,549.134 tons per year diesel fuel to meet the electricity needs of the process, 2,057.82 tons per year gas oil for boiler to generate steam, 462.62 kVA electricity (except for proscess unit purpose), and 1.2 million m3 (0 ° C, 1 atm ) compressed air per year are required to run the plant. Adipic Acid factory is planned to set up at Cilegon, Banten, West Java Province, with 12.000 m2 land area and 167 employees. From the economic evaluations calculation results, it is obtained Fixed Capital Investment, FCI = US$ 17,865,699.29 + Rp 58,676,829,737.49, Working Capital, WC = US$ 13,727,467.35 + Rp 7,124,244,900.42. Rp 107,801,563,327.96 Profit before tax, Rp 53,900,781,663.98 profit after tax, 47.2 % return on investment before taxes, 23.6 % return on investment after taxes, 1.75 year before taxes Pay Out Time, 2.98 years after taxes Pay Out Time, 44.64 % Break Even Point (BEP), 21.41 % Shut Down Point (SDP), and 26,74 % Discounted Cash Flow Rate of Return (DCFRR). Based on the calculation, Adipic Acid plant with a capacity of 20.000 tons per year deserve to be studied further.

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