PABRIK BIOMETHANE DARI SAMPAH KOTA KAPASITAS BAHAN BAKU 90.000 TON/TAHUN

NANDA PRAWIRA A., Ir. Siti Syamsiah Ph.D.

2010 | Skripsi | TEKNIK KIMIA

Pabrik biomethane dari sampah kota dirancang dengan kapasitas bahan baku sampah kota sebanyak 90.000 ton per tahun dan beroperasi selama 330 hari dalam setahun. Biomethane sebagai produk utama pabrik dapat digunakan sebagai bahan bakar gas untuk kendaraan maupun sebagai bahan bakar pada pembangkit listrik. Proses pembuatannya dengan langkah-langkah sebagai berikut: proses pemisahan sampah kota menjadi sampah organik dan sampah anorganik, lalu sampah organik mengalami proses degradasi secara anaerobik didalam reaktor menghasilkan biogas serta proses upgrading biogas dengan menggunakan proses water scrubbing (penyerapan dengan menggunakan air) sehingga menghasilkan biomethane. Proses degradasi di dalam reaktor berlangsung dalam lingkungan yang anaerobik atau tidak ada kandungan oksigen (udara). Suhu didalam reaktor dijaga pada suhu 40 o C yang masih tergolong pada range suhu mesophilic (30-40 o C), karena reaksi berlangsung secara eksotermis maka dalam reaktor ditambahkan koil pendingin dengan menggunakan pendingin air. Pabrik direncanakan didirikan di daerah Piyungan, Yogyakarta, di atas tanah seluas 15.000 m 2 (1,5 hektar). Utilitas yang diperlukan adalah air sebanyak 64.066,90 kg/jam, listrik 1649.50 kVA dan udara tekan sebesar 431.03 m 3 /jam. Dari perhitungan hasil evaluasi ekonomi diperoleh fixed capital investment, FCI = US$ 4,447,840.91+Rp 22.860.029.406,72, working capital, WC = US$ 1,913,663.48+Rp 9.446.911.588,44, keuntungan sebelum pajak Rp 20.199.495.131,07 per tahun, keuntungan setelah pajak Rp 10.099.747.565,54 per tahun, return on investment before taxes = 32.12%, return on investment after taxes = 16.06%, pay out time before taxes = 2.49 tahun, pay out time after taxes = 4.16 tahun, break even point, BEP = 48.57%, shut down point, SDP = 29.82%, discounted cash flow rate of return, DCFRR = 28,1%. Berdasarkan hasil perhitungan di atas, maka pabrik biomethane dengan kapasitas bahan baku 90.000 ton/tahun perlu dikaji lebih lanjut.

Biomethane plants from municipal solid waste was designed with capacity 90,000 tons solid waste per year and operate for 330 days a year. Biomethane as the main product can be used as fuel gas for vehicles as well as fuel for electricity generation. The manufacturing process by following these steps: separation processes municipal solid waste into organic and inorganic waste, and then organic waste went through anaerobic digestion process inside the reactor to produce biogas and biogas upgrading process using water scrubbing process (absorption by water) to produce biomethane . Degradation process in the reactor takes place in an anaerobic environment or no oxygen exist. The temperature inside the reactor is maintained at 40 o C which is still classified at mesophilic temperature range (30-40 o C), because the exothermic reaction takes place in the reactor cooling coil is added by using cooling water. Factory is planned to be located in areas Piyungan, Yogyakarta, on the land of 15,000 m 2 (1.5 ha). Utilities required are as much as 64066.90 kg / hr water, 1649.50 kVA electricity and 431.03 m 3 /hr of compressed air. From the calculation of economic evaluation results obtained by fixed capital investment, FCI = US $ 4,447,840.91 + Rp 22.860.029.406,72, working capital, WC = US $ 1,913,663.48 + Rp 9,446,911,588.44, profit before tax of Rp 20,199,495,131.07 per year , profit after tax of Rp 10,099,747,565.54 per year, return on investment before taxes = 32.12%, return on investment after taxes = 16.06%, payout time before taxes = 2.49 year, pay out time after taxes = 4.16 years, break even point, the BEP = 48.57%, shut down point, SDP = 29.82%, discounted cash flow rate of return, DCFRR = 28.1%. Based on the calculation above, the biomethane plant with a capacity of 90,000 tons of raw material / year should be studied further.

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