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"Gamma Valerolactone (GVL) merupakan senyawa organik turunan dari asam levulinat yang memiliki banyak kegunaan, salah satunya adalah sebagai aditif bahan bakar. Penelitian ini difokuskan pada perancangan reaktor unggkun trickle skala komersial untuk sintesis GVL dari asam levulinat pada katalis Ru/C. Pemodelan matematis yang digunakan adalah model reaktor unggun trickle aksisimetri dua dimensi untuk perpindahan massa dan momentum di celah unggun, aksisimetri dua dimensi untuk perpindahan energi di dalam unggun, dan satu dimensi untuk perpindahan massa dan di partikel katalis. Tujuan dari penelitian ini adalah mendapatkan desain reaktor dengan volume paling kecil untuk produksi GVL sebanyak 1.239 ton. Desain reaktor dilakukan melalui simulasi pada COMSOL Multiphysics 5.5, dengan mengubah parameter operasi berupa suhu, tekanan, GHSV, LHSV, dan diameter katalis, sehingga didapatkan kondisi optimal pada masing-masing parameter. Hasilnya, didapatkan parameter operasi optimal dengan suhu 423 K, tekanan 25 bar, GHSV 0.065 s-1, LHSV 0.00117 s-1, diameter katalis 3 mm, diameter reaktor 5 cm, dan panjang reaktor 5 m. Laju alir yang dihasilkan dari reaktor skala komersial dengan kondisi optimal adalah 7.06 kg/hari, sehingga diperlukan 536 buah tube untuk memperoleh kapasitas produksi sebanyak 1.239 ton.

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Gamma Valerolactone (GVL) is an organic compound derived from levulinic acid that has many uses, one of which is as a fuel additive. This research is focused on designing a commercial scale trickle bed reactor for the synthesis of GVL from levulinic acid on a Ru/C catalyst. The mathematical modelling used is a two-dimensional axisymmetric trickle bed reactor model for mass and momentum transfer in the bed gap, two-dimensional axisymmetric for energy transfer in the bed, and one-dimensional for mass transfer and in the catalyst particles. The objective of this research is to obtain a reactor design with the smallest volume to produce 1,239 tons of GVL. The reactor design was carried out through simulations on COMSOL Multiphysics 5.5, by changing the operating parameters such as temperature, pressure, GHSV, LHSV, and catalyst diameter, so that optimal conditions were obtained for each parameter. As a result, the optimal operating parameters were obtained with temperature 423 K, pressure 25 bar, GHSV 0.065 s-1, LHSV 0.00117 s-1, catalyst diameter 3 mm, reactor diameter 5 cm, and reactor length 5 m. The flow rate produced from a commercial scale reactor with optimal conditions is 7,06 kg/day, so 536 tubes are needed to obtain a production capacity of 1,239 tons."

"Gamma-valerolakton (GVL) adalah senyawa organik turunan dari asam levulinat yang memiliki banyak manfaat di berbagai sektor. Penelitian ini dilakukan untuk mengetahui pengaruh tekanan dan suhu gas umpan terhadap kinerja reaktor trickle bed untuk produksi GVL dari segi konversi asam levulinat, yield GVL, dan selektivitas GVL. Mekanisme yang terjadi adalah asam levulinat yang sudah dilarutkan dengan air deionisasi akan melalui proses hidrogenasi menghasilkan senyawa intermediet yaitu 4-HPA. Kemudian, terjadi proses esterifikasi intermolekul untuk menghasilkan GVL. Katalis yang digunakan adalah Ru/C dengan muatan Ru sebesar 5 wt%. Eksperimen diawali dengan persiapan bahan baku, lalu dilakukan karakterisasi katalis. Kemudian digunakan reaktor berdiameter 2,01 cm den gan unggun katalis setinggi 24 cm. Reaktan cair (asam levulinat) dan gas hidrogen direaksikan dengan kondisi operasi temperatur 90 °C – 150 °C, dan tekanan 5 dan 10 bar. Penelitian pada tekanan rendah dilakukan untuk mengurangi penggunaan hidrogen berlebih sehingga proses menjadi lebih ekonomis. Setelah reaksi berlangsung, asam levulinat sebagai bahan baku terkonversi menjadi dua senyawa yaitu 4-HPA dan GVL. Produk kemudian dianalisis dengan High-Performance Liquid Chromatography. Setelah berlangsungnya reaksi, asam levulinat sebagai bahan baku terkonversi menjadi dua jenis produk, yaitu senyawa intermediate 4-HPA dan produk utama GVL. Pada penelitian ini, kondisi terbaik untuk memproduksi GVL adalah pada tekanan 10 bar dan suhu 150 °C dengan yield GVL 72%, selektivitas GVL 73%, dan konversi asam levulinat 97%. Berdasarkan tren yang diamati, semakin meningkatnya tekanan dan suhu yang digunakan, maka hasil yang diperoleh semakin optimal.

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Gamma-valerolactone (GVL) is an organic compound derived from levulinic acid which has many benefits in various sectors. This research was conducted to determine the effect of feed gas pressure and temperature on the performance of trickle bed reactors for GVL production in terms of levulinic acid conversion, GVL yield, and GVL selectivity. The mechanism that occurs is that levulinic acid which has been dissolved in deionized water will go through a hydrogenation process to produce an intermediate compound, namely 4-HPA. Then, an intermolecular esterification process occurs to produce GVL. The catalyst used was Ru/C with a 5 wt% Ru. The experiment started with raw material preparation, and catalyst characterization, then a 2.01 cm diameter reactor with a 24 cm high catalyst bed was used. Liquid reactants (levulinic acid) and hydrogen gas were reacted under operating conditions of temperature 90 °C – 150 °C, and pressures of 5 and 10 bar. Research at low pressure is carried out to reduce the use of excess hydrogen so that the process becomes more economical. After the reaction takes place, levulinic acid as a raw material is converted into several compounds including levulinic acid, 4-HPA, and GVL. Products were analyzed with High-Performance Liquid Chromatography. After the reaction takes place, levulinic acid as a raw material is converted into two types of products, namely the intermediate compound 4-HPA and the main product GVL. In this study, the best conditions for producing GVL were at a pressure of 10 bar and a temperature of 150 °C with a yield of 72% GVL, 73% selectivity of GVL, and 97% conversion of levulinic acid. Based on the observed trend, the higher the pressure and temperature used, the more optimal the results obtained."

"The Fukushima accident resulted in the melting of the reactor core due to loss of supply of coolant when the reactor stopped from operating conditions. The earthquake and tsunami caused loss of electricity due to the flooding that occurred in the reactor. The absence of the coolant supply after reactor shutdown resulted in heat accumulation, causing the temperature of the fuel to rise beyond its melting point. In the early stages of the accident, operator could not determine the severity of the accident and the percentage of the reactor core damaged. The available data was based on the radiation exposure in the environment that was reported by the authorities. The aim of this paper is to determine the severity of the conditions in the reactor core based on the radiation doses measured in the environment. The method is performed by backward counting based on the measuring radiation exposure and radionuclides releases source term. The calculation was performed by using the PC-COSYMA code. The results showed that the core damage fraction at Dai-ichi Unit 1 was 70%, and the resulting individual effective dose in the exclusion area is 401 mSv, while the core damage fraction at Unit 2 was 30%, and the resulting individual effective dose was 99.1 mSv, while for Unit 3, the core damage fraction was 25% for an individual effective dose of 92.2 mSv. The differences between the results of the calculation for estimation of core damage proposed in this paper with the previously reported results is probably caused by the applied model for assessment, differences in postulations and assumptions, and the incompleteness of the input data. This difference could be reduced by performing calculations and simulations for more varied assumptions and postulations."

"Minyak nabati terozonasi (Oleozon) telah terbukti memiliki kemampuan anti bakteri. Oleozon belum diproduksi untuk umum karena penelitian selama ini hanya berfokus pada produk dan belum meninjau sisi efektivitas pada reaktor untuk mensintesis oleozon. Pada penelitian ini digunakan minyak kedelai sebagai bahan baku dan diozonasi dengan menggunakan reaktor berpengaduk turbin yang terbuat dari stainless steel sehingga dapat digunakan pada tekanan diatas 1 atm dan reaktor kaca yang digunakan untuk ozonolisis pada tekanan atmosferik. Ozonator yang digunakan memiliki produktivitas ozon sebesar 0.589 g/jam untuk atmosferik dan 0,754 mg/jam. Kondisi operasi yang paling efektif untuk membuat oleozon adalah pada tekanan diatas atmosferik (1,2 bar) yang memiliki nilai bilangan asam sebesar 3,005 𝒎𝒈 𝑲𝑶𝑯 𝒎𝒈 𝒔𝒂𝒎𝒑𝒆𝒍 dan bilangan peroksida 12,353 𝒎𝒆𝒒 𝒌𝒈 𝒍𝒆𝒎𝒂𝒌. Pada variasi suhu, suhu rendah (15 ° C -19 °C) memiliki kualitas minyak terbaik dengan bilangan asam sebesar 0,84 𝒎𝒈 𝑲𝑶𝑯 𝒎𝒈 𝒔𝒂𝒎𝒑𝒆𝒍 dan bilangan peroksida 0,748 𝒎𝒆𝒒 𝒌𝒈 𝒍𝒆𝒎𝒂𝒌 serta dengan kecapatan pengaduk 150 RPM.

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Ozonated vegetable oil (Oleozon) has proven having a function as anti bacteria. Oleozon has not produced to the public because the research about oleozon still focused on the products only and never research about the effectiveness of reactor for oleozon synthesize. On this research, soybean oil is used as raw material and been ozonized in two stirred reactor which using turbine impeller that can be used on pressure above 1 atm and the glass reactor that used for atmospheric pressure. Ozone productiom from ozonator are 0,589 mg/h for atmospheric condition and 0,754mg/r for pressurized condition. The most effective operating conditions to produce oleozon is on pressure above atmospheric (1,2 bar) that has acid value about 3,005 𝒎𝒈 𝑲𝑶𝑯 𝒎𝒈 𝒔𝒂𝒎𝒑𝒍𝒆 and peroxide value about 12,353 𝒎𝒆𝒒 𝒌𝒈 𝒇𝒂𝒕 ; low temperature (15 °C-19 °C) that has acid value about 0,84 𝒎𝒈 𝑲𝑶𝑯 𝒎𝒈 𝒔𝒂𝒎𝒑𝒍𝒆 and peroxide value about 0,748 𝒎𝒆𝒒 𝒌𝒈 𝒇𝒂𝒕 ; and speed of impeller is 150 RPM."

"[Dalam penelitian ini dilakukan sintesis minyak terozonasi dari minyak bungamatahari dengan reaksi ozonolisis secara semi-kontinu selama 12 – 72 jam.Ozonolisis dilakukan pada tiga variasi tekanan operasi (atmosferik, bertekanan,dan vakum) menggunakan reaktor semi-batch khusus berbahan stainless steelberpengaduk turbin dan berjaket pendingin. Ozonator yang digunakan adalahrancangan sendiri dengan laju alir udara masukan sebesar 540 L/jam dankonsentrasi ozon keluaran sebesar 520 mg/jam. Kondisi reaksi dijaga pada suhu15 – 22 °C. Pengujian kualitas hasil ozonasi dilakukan dengan metode bilanganasam, bilangan peroksida, bilangan iod, analisis viskositas, dan analisis FT-IR.Berdasarkan hasil penelitian, kecepatan pengadukan terbaik adalah 150 RPMdengan pola aliran transisi dan tekanan operasi terbaik untuk sintesis minyakterozonasi dari minyak bunga matahari adalah tekanan atmosferik (1 atm)., In this study, synthesis of ozonated vegetable oil was made ftom sunflower oilwith semi-continue ozonolysis for 12 – 72 hours. Ozonolysis was done in threevariation of operation pressure (atmospheric, pressurized, and vacuum) by usingparticular strirred semi-batch reactor from stainless steel with cooling jacket.Ozonator used was self-designed with input air flowrate of 540 L/h and ozoneconcentration output of 520 mg/h. The reaction condition maintained attemperature of 15 – 22 oC. Minyak terozonasi product testing was done withseveral methods such as analysis of acidic value, peroxide value, iodin value,viscosity, and FT-IR. Based on this research, the best stirrer speed is 150 RPMand the best pressure condition for minyak terozonasi synthesis from sunfloweroil is atmospheric pressure (1 atm).]"