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"Research and development activities on Liquefied Petroleum Gas (LPG) vehicles have increased LPG engine performance to that of gasoline engines. LPG evaporation in the fuel system also has a potential cooling effect that can be taken advantage of. The results from previous studies, however, do not explain the level of fuel in the tank at the time of data collection. LPG is a mixture of several molecules which have different properties. This paper presents an investigation of LPG composition characteristics in the fuel line during the discharging process. Samples were taken periodically on the fuel line by special gas syringes. Afterwards, the samples were injected into the Gas Chromatography-Mass Spectrometry (GC-MS) device. This series of tests, which was conducted on lengthy LPG tanks, showed that the propane and butane 2-methyl molecules are unevenly dispersed during the discharging of the tank. However, this study found that a change in LPG composition during the discharging process does not have significant influence on the energy delivery and the potential cooling effect."

"Research and development activities on Liquefied Petroleum Gas (LPG) vehicles have increased LPG engine performance to that of gasoline engines. LPG evaporation in the fuel system also has a potential cooling effect that can be taken advantage of. The results from previous studies, however, do not explain the level of fuel in the tank at the time of data collection. LPG is a mixture of several molecules which have different properties. This paper presents an investigation of LPG composition characteristics in the fuel line during the discharging process. Samples were taken periodically on the fuel line by special gas syringes. Afterwards, the samples were injected into the Gas Chromatography-Mass Spectrometry (GC-MS) device. This series of tests, which was conducted on lengthy LPG tanks, showed that the propane and butane 2-methyl molecules are unevenly dispersed during the discharging of the tank. However, this study found that a change in LPG composition during the discharging process does not have significant influence on the energy delivery and the potential cooling effect."

"Model reaktor pembentukan metanol merupakan faktor yang penting untuk menentukan parameter kinetika reaksi pembentukan metanol. Walaupun demikian, model yang digunakan dalam riset-riset mengenai kinetika metanol yang ada masih menggunakan model yang disederhanakan. Graaf et.al (1982) mengevaluasi kinetika percobaanya dengan model CSTRsatu dimensi, sementara Froment dan Bussche (1996) mengevaluasi parameter kinetikanya dengan model reaktor homogen-semu satu dimensi. Penelitian ini bertujuan untuk memodelkan reaksi pembentukan metanol dalam sebuah reaktor unggun diam multitubular tiga dimensidengan menggunakan Computational Fluid Dynamics (CFD) yang dikoplingdengan efek perpindahan panas dan perpindahan massa dalam reaktor multitubular. Evaluasi model berupa karakterisasi pola aliran dalam tube dan shell, karakterisasi temperatur tube dan shell, distribusi konsentrasi dalam tube. Kondisi operasi reaktor suhu inlet tube sebesar 230°C, tekanan 76.89 bar, dan komposisi inlet seperti yang ditentukan darivalidasi penelitian oleh Samimi et.al (2018). Dari hasil simulasi didapat nilai optimal kecepatan aliran pendinginan sebesar 3 m/s dan parameter faktor tumbukkan laju reaksi A1 dan A7 sebesar 1.685 dan 1.6, dengan kesalahan parameter terbesar adalah konsentrasi CO sebesar 33% error.

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The methanol formation reactor model is an important factor for determining the kinetics parameters of the methanol formation reaction. Nonetheless, the model used on existing research in methanol kinetics still uses a simplified model. Graaf et.al (1982) evaluated the experimental kinetics with the one dimensional CSTR model, while Froment and Bussche (1996) evaluated the kinetic parameters with the model of one dimensional pseudo homogeneous reactor. This study aims to model the reaction of methanol formation in a three-dimensional multitubular fixed bed reactor using Computational Fluid Dynamics (CFD) coupled with the effects of heat transfer and mass transfer in multitubular reactors. Evaluation of the model in the form of characterization of flow patterns in the tube and shell, characterization of tube and shell temperature, and characterization of concentration distribution in the tube. The operating conditions of the reactor inlet tube temperature are 230 ℃, pressure 76.89 bar, and the composition of the inlet as determined from the validation of research by Samimi et.al (2018). The simulation results obtained an optimal value of flow velocity 3 m/s and the collision factor of A1 and A7 is 1.6685 and 1.6 respectively, with the biggest error being the CO concentration of 33% error."