Nitrogen as an element that is widely found in nature, can be used as a gas that is absorbed to help characterize materials, especially on the surface of the material. According Brunauer-Emmet-Teller (BET) is a theory where nitrogen is used as a gas characterizing material because of its ability to high purity and can interact with solid elements. So far, BET only produces data in the form of quantitative properties but does not show phenomena that can be seen, because of that, molecular dynamics simulations can be done and modeling it to observe the phenomenon that occurs during nitrogen adsorption in amorphous silica which is a porous material with a large surface area. In this study the molecular dynamics simulations are arranged in a state of isotherm, where the temperature used is 3 variables: 77 K, 100 K and 150 K in the variation of pressure used 1, 3, 5, 7, and 10 atm. Based on the results obtained from the simulation, it was found that on 77 K temperature had the optimal ability to adsorb nitrogen compared to 100 K and 150 K."
Pada industri terutama industri pengolahan minyak bumi, katalis yang banyak digunakan adalah katalis berbasis nikel salah satunya NiO/Al2O3. Di Pertamina Balongan RU VI untuk proses hydrotreating, limbah katalis yang dihasilkan mencapai angka 1000 ton per tahunnya. Padahal limbah katalis ini merupakan salah satu isu lingkungan karena termasuk kedalam golongan limbah B3. Kandungan nikel yang terdapat dalam limbah katalis hydrotreating mencapai angka 72438,59 mg/kg dan hal ini menyebabkan perlunya tindakan perolehan kembali atau recovery. Selain untuk kepentingan lingkungan, logam nikel juga dikategorikan berharga dengan harga per kilogramnya sebesar Rp 239.132. Metode yang dilakukan untuk memperoleh kembali logam nikel dari limbah yaitu dengan proses leaching dan dilanjutkan dengan ekstraksi cair-cair, karena metode ini dikenal sebagai metode yang efektif dalam me-recovery logam. Hasil penelitian menunjukkan bahwa proses leaching mencapai nilai optimum dengan menggunakan asam sitrat 1.5 M dan suhu 80°C selama 2 jam dengan persentase leaching sebesar 82,06%. Sedangkan kondisi optimum yang diperoleh dari proses ekstraksi cair-cair menggunakan 40% LIX 84-ICNS, rasio fasa ekstraktan/fasa internal: 1/1, pH 7 dan kecepatan pengadukan 750 rpm selama 10 menit mampu menghasilkan persentase ekstraksi sebesar 89,29%
In industry, especially in oil and gas industry, catalyst is widely used in order to enhance the process and optimize the production. One of the commonly used catalyst nickel-based catalyst, which is NiO/Al2O3. In Pertamina RU VI Balongan, this catalyst is used for the hydrotreating process, and it annually generates 1000 tons per year. This catalyst is being one issues since nickel is categorized as B3 waste. The nickel contained in hydrotreating spent catalyst is 72438,59 mg/kg and this led us the need to recover nickel metal from catalyst waste. In addition, nickel is also considered as valuable metal with a price per kilogram of Rp 239,132. The effective method used to recover nickel metal from waste is by leaching and continued with liquid-liquid extraction. The results showed that the leaching process reached the optimum value by using 1.5 M citric acid and 80°C for 2 hours resulting a leaching percentage of 82.06%. While the optimum conditions obtained from the liquid-liquid extraction process using 40% LIX 84-ICNS, the extraction phase / internal phase: 1/1, pH 7 and stirring speed of 750 rpm for 10 minutes were able to produce an extraction percentage of 89,29%.
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