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Abstrak :
In the plasma electrolysis process, hydrogen generation around the cathode is affected by the amount of evaporation energy. Utilizing a veil, minimizing the cooling in the liquid phase, and maximizing the cooling in the gas phase become important parameters to improve the process efficiency of hydrogen production. This research aims to obtain an optimum high-efficiency electrolysis plasma reactor based on decreased energy consumption and increased hydrogen gas production. The research method varied the NaOH concentration, voltage, veil length, cathode depth, and the volume of the methanol additive. In characterizing the current and voltage, as the concentration increases, the voltage needed to form the plasma will decrease. As the concentration and voltage increase, the rate of production, hydrogen content percentage, and the hydrogen ratio also increase, while the energy consumption decreases. The optimum condition, based on variations of veil length, is 5 cm when the depth of the cathode is 1 cm below the surface of the solution. Improving the efficiency of the hydrogen production process can be done by adding methanol. The best result was achieved using 15% volumes of methanol additive in 0.01 M NaOH, and higher hydrogen-ratio plasma-electrolysis results were found in comparison with Faraday electrolysis: the hydrogen ratio was 151.88 mol/mol, the lowest energy consumption was 0.89 kJ/mmol, and the highest hydrogen production rate was 31.45 mmol/min. The results show that this method can produce hydrogen 152 times more than Faraday electrolysis.

Abstrak :
Sintesis fatty acid metil ester (FAME) menggunakan reaktor DBD (Dielectric Barrier Discharge) plasma non-termal berhasil diteliti dan memberikan hasil yang menjanjikan. Penelitian ini bertujuan untuk menguji kinerja purwarupa reaktor DBD plasma non-termal serta mendapatkan kondisi operasi optimum untuk sintesis biodiesel. Pada penelitian ini minyak nabati dicampur dengan minyak jelantah, kemudian direaksikan dengan metanol dalam reaktor DBD plasma. Gas Argon digunakan sebagai gas pembawa pada pembentukan pijar plasma. Reaktor dioperasikan pada tekanan atmosfer, laju alir umpan cair 1,33 ml/s, dan laju alir gas pembawa 25,27 ml/s. Hasilnya, reaktor DBD plasma mampu menyintesis biodiesel tanpa katalis, tidak membutuhkan metanol berlebih, membutuhkan energi yang relatif rendah, serta tidak menghasilkan gliserol dan sabun sebagai produk samping. Kondisi optimal sintesis biodiesel adalah menggunakan bahan baku campuran minyak jelantah dan minyak sawit, rasio metanol:minyak 1:1, pelarut Pertamina DEX, temperatur reaksi 40 ^oC, tegangan plasma 10,2 kV, dan frekuensi plasma 25 kHz menghasilkan konversi biodiesel maksimal sebesar 89%. Biodiesel yang dihasilkan sudah sesuai dengan standar yang berlaku. ......Synthesis of fatty acid methyl esters (FAME) using non-thermal DBD plasma (Dielectric Barrier Discharge) reactor has been successfully investigated providing promising results. This study aims to examine the performance of DBD reactor prototypes and obtain optimum operating conditions for biodiesel synthesis. In this study, vegetable oil mixed with waste cooking oil are reacted with methanol in the DBD reactor. Argon gas is used as a gas carrier to generate plasma. The reactor is operated at atmospheric pressure, the liquid feed flow rate of 1.33 ml/s, and carrier gas flow rate of 25.27 ml/s. The results showed that DBD plasma reactor is able to synthesize biodiesel without a catalyst, does not require excess methanol, requires relatively low energy also does not produce glycerol and soap as a by-product. The optimum conditions reaction required to produce biodiesel are using the mixture of waste cooking oil and palm oil as a feedstock, molar ratio of methanol:oil (1:1), Pertamina DEX as a solvent, reaction temperature of 40 ^oC, plasma voltage of 10.2 kV, plasma frequency of 25 kHz, resulting in maximum biodiesel conversion of 89%. Biodiesel resulting from this reaction is suitable with the Indonesian quality standard.

Abstrak :
Carbon dioxide (CO2) as one of the greenhouse gas emissions was decomposed to Carbon Monoxide (CO) and Oxygen (O2) in the three-pass flow Dielectric Barrier Discharge (DBD) plasma reactor, a new designed reactor that having special configuration of its reactant gas flow. This configuration can simultaneously cools the High Voltage Electrode (HVE) during the reaction process; and preheats the gas feed flow before entering plasma zone as well. This article explains the result of a preliminary research which aims to observe the performance of this reactor in utilizing CO2, mixed with CH4 to produce synthesis gas CO and H2, in a CO2 reforming process. This research was conducted using 3 (three) different reactor lengths, they were 36, 24 and 12 cm (Re1, Re2 and Re3), to observe the results of CO2 decomposition performance in the difference reactor lengths, and to observed the occurrence of reverse reaction inside the Re1 reactor. Other parameters were feed flow rates and the reactor voltage. Applied CO2 flow rates were 500, 1000 and 1500 SCCM/minute and applied reactor voltage were 5.4; to 9.5 kV. Results show that the conversion of CO2 was increased with the increasing of reactor voltage and longer reactor. The highest conversion was achieve at the lowest feed flow rate 500 SCCM/minute, this mean in the longest residence time. However, CO2 was only reaching the maximum conversion value on the reaction time of 2.1 minute, and dropped off after that. It is possibly caused by occurring of the reversed reaction due to the high temperature plasma reaction. At that point, the Specific Energy (SE) was 270 kJ/mol. This value is lower compare to the previous research results, as well as compare to its energy bonding, that shows the more energy efficient performance of this reactor.