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"The use of Waste Cooking Oil (WCO) as feedstock, and microwave heating technology are favored to reduce the cost of biodiesel. In order to identify the effect of using biodiesel from WCO Methyl Ester (WCOME) blends on diesel engine emissions and performance, WCOME blends were tested in a single-cylinder Direct Injection (DI) diesel engine at a constant speed of 2500 rpm and with five loads. For comparison, commercial diesel fuel, Petron Diesel Max (PDM), and biodiesel mixture from palm oil (POME) were also used. The performance and emission test results of the five test fuels: PDM, BP10, BP20, BW10, and BW20 were then compared with simulation results created by using GT-Power software. The experimental results indicated that using POME and WCOME blends led to increments in Brake Specific Fuel Consumption (BSFC) of up to 5.9% and reduction in Brake Thermal Efficiency (BTE) of up to 29.3% compare to PDM. These biodiesel blends also increased nitrogen oxide emissions and decreased carbon dioxide, carbon monoxide and hydrocarbon emissions for all engine loads at a constant speed of 2500 rpm. The experimental testing of the cylinder peak pressure demonstrates significant increase with the increase of engine load for the four test fuels. All the simulation graphs show similar trends."

"Mesin diesel silinder tunggal banyak digunakan pada bidang pertanian dan perikanan dimana sistem injeksi bahan bakarnya masih menggunakan Direct injection. Saat ini sistem injeksi bahan bakar tersebut telah digantikan CommonRail Direct Injection yang pada otomotif tekenal mesin menjadi lebih efisien dan ramah lingkungan. Sistem injeksi bahan bakar dengan kendali open loop pada mesin diesel silinder tunggal telah dikembangkan pada penelitian ini.Pada penerapannya mengganti seluruh komponen sistem injeksi pada mesin diesel silinder tunggal Kubota RD 85 dan telah dipetakan tekanan injeksi, timming injection dan durasi untuk mendapatkan daya yang optimal dari mesin tersebut. Pada paper ini akan di perkenalkan disain perangkat sistem injeksi bahan bakar, metode pemetaan karakteristik mesin dan metode uji yang digunakan untuk mengetahui unjuk kerja mesin diesel silinder tunggal. Dari penelitian ini dengan memodifikasi sistem injeksi bahan bakar didapatkan penurunan unjuk kerja mesin <<23%. Dengan menambahkan biodiesel B10 dan B20 pada bahan bakar dengan mesin yang menggunakan teknologi CommonRail Direct Injection didapatkan hasil penurunan unjuk kerja <<3% untuk campuran 10% Biodiesel dan <<5 % untuk campuran 20 % biodiesel.

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Single cylinder diesel engines are widely used in the fields of agriculture and fisheries which is the fuel injection system still uses Direct injection . Currently the fuel injection system has been replaced by commonrail Direct Injection which already applied for automotive engines that becoming more efficient and environmentally friendly . Fuel injection system with an open loop control in single cylinder diesel engine has been developed in this research.In its application to replace all components of the injection system on a single -cylinder Kubota diesel engine RD 85 has been mapped injection pressure , injection timming and duration to obtain optimal power from the engine . In this paper introduced the design of the fuel injection system , a method of mapping the characteristics of the engine and the test method used to determine the performance of a single -cylinder diesel engine . From this research by modifying the fuel injection system obtained a decrease in engine performance << 23 % . By adding B10 and B20 biodiesel fuel engine technology that uses commonrail Direct Injection showed a decrease in performance << 3 % for 10 % of biodiesel and << 5 % for 20 % of biodiesel."

"The demand for high-speed data transmission has increased significantly in the last decades. Terahertz (THz) frequency, which lies between 100 GHz to 10 THz, has been considered as the solution to the demand. However, the low gain and low efficiency of a THz antenna remain to be issues that hinder reasonable performance for various applications. This paper proposes the design of a high-gain and high-efficiency planar bow-tie antenna for applications in the THz frequency. A planar bow-tie on a high-resistivity silicon substrate is considered to obtain the broadband characteristics. To increase the gain and efficiency, a dielectric silicon lens and a matching layer based on the quarter-wavelength are applied in the design. From simulations using Computer Simulation Technology (CST) Microwave Studio, gain and radiation efficiency of up to 32.69 dB and 90.4% are obtained, respectively. This proposed design has shown high radiation performance suitable for high-speed transmission systems."

"Penelitian ini mengkaji satu karakteristik biodiesel dan campuran biodiesel-solar yakni stabilitas oksidasi, bahan bakar dengan stabilitas oksidasi rendah dapat dengan mudah teroksidasi dengan udara, bila telah rancid atau tengik dapat mengakibatkan korosi dan kerusakan pada injektor, tangki dan elemen mesin lain. Metode 743 Rancimat (modified) round robin test khusus untuk menguji stabilitas oksidasi biodiesel, campuran biodiesel-solar dan solar melalui determinasi waktu induksi/induction time, hasilnya B100-UFO atau biodiesel minyak jelantah murni (Used Frying Oil/UFO) memiliki stabilitas oksidasi 1,6 jam (pada 110oC), B95-UFO 2,95 jam, B90-UFO 3,56 jam, B80-UFO 17,13 jam dan B30-UFO 98,24 jam. Dengan standar minimal stablilitas oksidasi 6 jam (EN 14112), Stabilitas oksidasi yang aman bagi mesin diesel dimulai B80 dan grafik trendline meperlihatkan B85 masih aman di kisaran 10 jam. Adapun kinerja mesin diperoleh hasil dibandingkan dengan solar, minyak jelantah sebagai campuran mengakibatkan kenaikan konsumsi bahan bakar untuk daya yang sama, mengakibatkan penurunan Brake Horse Power/BHP untuk semua campuran. Terdapat keunikan pada B15-UFO dibandingkan campuran biodiesel jelantah-solar yang lain yakni memiliki efisiensi thermal yang naik (0,26%) sedangkan campuran yang lain turun, pada kondisi putaran poros tetap memiliki kenaikan SFC yang paling rendah (2,34%) dan memiliki penurunan BHP yang paling rendah (9,38%).

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This research is studying oxidation stability of biodiesel and biodiesel-petrodiesel blends, fuel with low oxidative stability will be oxidized by atmosphere air easily, rancid fuel is corrosive and will damage the injector, tank and other elements. 743 Rancimat Method (modified) round robin test is only for determining the oxidative stability of biodiesel, biodiesel-petrodiesel and petrodiesel by determining induction time. The result : B100-UFO or the neat Used Frying Oil (UFO) Biodiesel has oxidation stability 1,6 hours (at 110oC), B95-UFO 2,95 hours, B90-UFO 3,56 hours, B80-UFO 17,13 hours and B30-UFO 98,24 hours. the minimum standard of oxidation stability is 6 hours (EN 14112), B80 is safe for diesel engine and graph trendline shows B85 is still safe as around 7 hours. The Diesel engine performance results are : w The Diesel engine performance results are : With petrodiesel as the standard, Used Frying Oil as blender make an increase of fuel consumption for the same power, make a decrease of Brake Horse Power/BHP for all blends. There are some uniqueness of the B15-UFO compared with other UFO biodiesel-petrodiesel such as it has an increase thermal efficiency (0,26%)as the other blends are decrease, at constant rotational speed (rpm) it has the lowest increase of SFC (2,34%) and the lowest decrease of BHP (9,38%). ith petrodiesel as the standard, Used Frying Oil as blender make an increase of fuel consumption for the same power, make a decrease of Brake Horse Power/BHP for all blends. There are some uniqueness of the B15-UFO compared with other UFO biodiesel-petrodiesel such as it has an increase thermal efficiency (0,26%)as the other blends are decrease, at constant rotational speed (rpm) it has the lowest increase of SFC (2,34%) and the lowest decrease of BHP (9,38%).;This research is studying oxidation stability of biodiesel and biodiesel-petrodiesel blends, fuel with low oxidative stability will be oxidized by atmosphere air easily, rancid fuel is corrosive and will damage the injector, tank and other elements. 743 Rancimat Method (modified) round robin test is only for determining the oxidative stability of biodiesel, biodiesel-petrodiesel and petrodiesel by determining induction time. The result : B100-UFO or the neat Used Frying Oil (UFO) Biodiesel has oxidation stability 1,6 hours (at 110oC), B95-UFO 2,95 hours, B90-UFO 3,56 hours, B80-UFO 17,13 hours and B30-UFO 98,24 hours. the minimum standard of oxidation stability is 6 hours (EN 14112), B80 is safe for diesel engine and graph trendline shows B85 is still safe as around 7 hours. The Diesel engine performance results are : w The Diesel engine performance results are : With petrodiesel as the standard, Used Frying Oil as blender make an increase of fuel consumption for the same power, make a decrease of Brake Horse Power/BHP for all blends. There are some uniqueness of the B15-UFO compared with other UFO biodiesel-petrodiesel such as it has an increase thermal efficiency (0,26%)as the other blends are decrease, at constant rotational speed (rpm) it has the lowest increase of SFC (2,34%) and the lowest decrease of BHP (9,38%). ith petrodiesel as the standard, Used Frying Oil as blender make an increase of fuel consumption for the same power, make a decrease of Brake Horse Power/BHP for all blends. There are some uniqueness of the B15-UFO compared with other UFO biodiesel-petrodiesel such as it has an increase thermal efficiency (0,26%)as the other blends are decrease, at constant rotational speed (rpm) it has the lowest increase of SFC (2,34%) and the lowest decrease of BHP (9,38%)."

"ABSTRAKPolusi telah menjadi masalah serius, salah satu penyebabnya penggunaan bahan bakar fosil yang terus meningkat khususnya oleh sektor transportasi. Pemanfaatan bahan bakar alternatif bisa mengurangi dampak tersebut. Biodiesel merupakan bahan bakar alternatif yang sangat potensial, karena memiliki sifat yang mirip dengan Solar. Untuk itu diperlukan suatu penelitian dengan pendekatan simulasi khususnya pada proses injeksi bahan bakar, pencampuran dan pembakaran. Tujuan penelitian ini, adalah untuk melakukan simulasi injeksi bahan bakar dengan variasi bahan bakar yang berbeda dan menyelidiki proses pembentukan semprotan dan campuran. Simulasi dilakukan dengan menggunakan software AVL FIRE. Hasil simulasi menunjukan bahwa campuran Solar dengan Biodiesel menunjukan kualitas pembakaran yang baik.

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ABSTRACT

Pollution has become a serious problems, one of the cause is the rapid fossil fuels consumption, especially in transportation sector. Utilization of alternative fuels can reduce these impacts. Biodiesel is an alternative fuel with huge potential, because it has similar properties to diesel fuel. For that we need a study with a simulation approach, especially in the process of fuel injection, mixing and combustion. The purpose of this study is to simulate injection process with different variations of fuel by investigating spray and mixture formation process. The simulation is conducted by using AVL FIRE software. The output from the simulation using mixture between diesel and biodiesel shown a good combustion quality."

"The performance test of CI engine which uses biodiesel fuel from vegetable oils and its blends with diesel fuel is essential to be carried out. This research investigates the quality of rubber seed oil methyl ester (RSOME) which is produced via catalytic method dry wash system which uses magnesol (magnesium silicate) as absorbent based on Indonesian Biodiesel Forum (FBI) standard in 2005 and the performance of CI engine, which uses its blends with diesel fuel (B-10, B-20, and B-30). The best engine performance is then compared with RSOME which is produced via non-catalytic method, namely, superheated methanol high temperature atmospheric pressure and diesel fuel (B-0). The engine test shows that B-20 produces the best engine performance at 2550 rpm. Compared to RSOME non-catalytic method and diesel fuel, RSOME catalytic method and non-catalytic method yield the same effective power, whereas diesel fuel is lower than both methods. The engine which uses RSOME non-catalytic method needs the same specific fuel consumption as diesel fuel, but a bit more than catalytic method. The thermal efficiency of RSOME non-catalytic method is higher than catalytic method and diesel fuel, but catalytic method has lower efficiency than diesel fuel. The emission of non-catalytic method is the most eco-friendly, catalytic method is the next, and diesel fuel is the one with the highest emission levels."

"Penelitian ini bertujuan untuk mempelajari proses produksi biodiesel dari minyak goreng bekas menggunakan peralatan kavitasi hidrodinamik. Proses produksi biodiesel dilakukan dalam 2 (dua) tahap. Tahap pertama adalah proses esterifikasi menggunakan katalis asam yang bertujuan untuk menurunkan kandungan asam lemak bebas dalam minyak goreng bekas. Pada tahap kedua dilakukan proses transesterifikasi menggunakan katalis basa untuk mengkonversi minyak menjadi biodiesel. Hasil penelitian proses esterifikasi dengan perbandingan molar metanol terhadap minyak 5:1 dan temperatur 60°C menunjukkan bilangan asam awal minyak goreng bekas sebesar 3,9 mg KOH/g dapat diturunkan menjadi 1,81 mg KOH/g dalam waktu 120 menit. Pada proses transesterifikasi, rendemen biodiesel tertinggi sebesar 89,4% diperoleh pada waktu reaksi 150 menit dengan rasio molar metanol terhadap minyak 6:1. Analisis komponen biodiesel menggunakan kromatografi gas-spektrometer massa (GC-MS) menunjukkan biodiesel terdiri dari 5 (lima) metil ester asam lemak dominan yaitu metil oleat, metil palmitat, metil linoleat, metil stearat dan metil miristat. Selain itu, beberapa parameter biodiesel yang diuji telah memenuhi persyaratan SNI No. 04-7182-2006.

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The aim of this research was to study biodiesel production from low cost feedstock of waste cooking oil (WCO) using hydrodynamic cavitation apparatus. A two-step processes esterification process and transesterification process using hydrodynamic cavitation for the production of biodiesel from WCO is presented. The first step is acid-catalyzed esteri-fication process for reducing free fatty acid (FFA) content of WCO and followed by base-catalyzed transesterification process for converting WCO to biodiesel as the second step.

The result of esterification process with methanol to oil molar ratio of 5 and temperature of 60°C showed that the initial acid value of WCO of 3.9 mg KOH/g can be decreased to 1.81 mg KOH/g in 120 minutes. The highest yield of biodiesel in transesterification process of 89.4% obtained at reaction time of 150 minutes with methanol to oil molar ratio of 6. The biodiesel produced in the experiment was analyzed by gas chromatography-mass spectrometry (GC-MS), which showed that it mainly contained five fatty acid methyl esters. In addition, the properties of biodiesel showed that all of the fuel properties met the Indonesian National Standard (INS) No. 04-7182-2006 for biodiesel."

"Nanokomposit CaO−Fe3O4/Al2O3 berhasil disintesis untuk pembuatan biodiesel menggunakan limbah minyak goreng yang didukung dengan karakterisasi menggunakan instrumen FTIR, XRD, SEM, BET, dan TEM pada nanokomposit CaO−Fe3O4/Al2O3. Persentase produk optimum sebesar 91,17% menggunakan nanokomposit CaO−Fe3O4/Al2O3 dengan CaO yang dikalsinasi pada suhu 900 °C, rasio massa CaO/Fe3O4 2:1, dan rasio massa CaO/Fe3O4 : Al2O3 (1:1) dengan waktu reaksi 2 jam, jumlah katalis 3%, rasio methanol terhadap minyak (9:1). Kandungan asam lemak pada biodiesel dianalisa menggunakan GC-MS dan sifat fisik biodiesel hasil sintesis sesuai standar SNI dan ASTM dengan massa jenis 0,8852 g/mL, kadar asam lemak bebas 0,0346%, dan angka asam sebesar 0,6885 mg/KOH/g. Studi kinetika reaksi mengikuti pseudo orde pertama dengan hukum laju reaksi v =k[TGA]=0,0117 menit^(-1) (TGA)dengan nilai konstanta laju reaksi 0,0117 menit-1.

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CaO−Fe3O4/Al2O3 nanocomposites were successfully synthesized for biodiesel production using waste cooking oil supported by characterization using FTIR, XRD, SEM, BET, and TEM instruments on CaO−Fe3O4/Al2O3 nanocomposites. The optimum product percentage was 91.17% using CaO−Fe3O4/Al2O3 nanocomposite with CaO calcined at 900°C, CaO/Fe3O4 mass ratio of 2:1, and CaO/Fe3O4 mass ratio: Al2O3 (1:1) with reaction time of 2 hours, catalyst amount of 3%, methanol to oil ratio (9:1). The physical properties of the synthesized biodiesel were in accordance with SNI and ASTM standards with a density of 0.8852 g/mL, a free fatty acid content of 0.0346%, and an acid number of 0.6885 mg/KOH/g. The reaction kinetics study follows the first-order pseudo with the reaction rate law v =k[TGA]=0,0117 menit^(-1) with a reaction rate constant value of 0.0117 min-1."