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"Hampir semua aktifitas industri melibatkan proses pembakaran baik sebagai unit utama maupun sebagai bagian dari unit penyedia energi dalam sistem utilitasnya. Nyala difusi merupakan salah satu proses pembakaran yang memiliki aplikasi sangat luas. Tinggi lifted nyala api difusi sangat menentukan kualitas pembakaran. Laju alir semburan udara mempengaruhi tinggi lifted nyala api difusi. Pada penelitian ini, dilakukan variasi laju alir semburan udara untuk mengetahui tinggi lifted nyala difusi. Pengaruh pemanasan awal bahan bakar LPG pada Bunsen Burner juga diamati. Hasil penelitian menunjukkan bahwa variasi laju alir semburan udara awal menyebabkan tinggi liftedftame akan mengalami penurunan akibat fenomena flame approach. Kecepatan pembakaran maksimum berada pada Q udara 0,25 L/s dan Q bahan bakar 0,0455 Us yaitu dengan kecepatan pembakaran turbulen (ST) 19,15 m/s. Pemanasan awal menyebabkan tinggi lifted nyala api difusi mengalami penurunan.

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Almost all industrial aclivity use combustion process as their energy system supply for Utilities. Dijfusion flame is one type of combustion widely used in industry. Liftedflame distance is one parameter contributing in combustion quality, influenced by air injection flowrate. This research conduct air injection flowrate effect to lifted flame distance from dijfusion type combustion. Fuel (LPG) treatment was carry out to flnd out heating effect on burning characteristics. This research show thal air injection flowrate cattse liftedflame distance tends to decrease at the early combustion. Maximum burning velocity in the range of Qalr 0.25 L/s and Qfuel 0.0455L/s, with turbulence burning velocity (ST) 19,15 m/s. Fuel pr e heating cause liftedflame of burning dijfusion tends t o decreased."

"Telah dilakukan penelitian terhadap karakteristik stabilitas nyala api difusi, apabila bahan bakar gas LPG dipanaskan terlebih dahulu sebelum dibakar didalam bumer. Secara teori dengan meningkatkan temperatur un-burn suatu bahan bakar, maka dapat menyebabkan laju reaksi menjadi lebih cepat, kecepatan pembakaran menjadi lebih cepat, energi minimum menjadi lebih rendah dan starting point menjadi lebih rendah. Pada penelitian ini akan dilakukan pendekatan dengan mencari stabilitas nyala api difusi melalui panjang nyala api dan jarak lifted flame yang terjadi akibat proses pemanasan bahan bakar gas LPG. Hasil yang dapat diperoleh adalah temperature bahan bakar gas LPG yang dapat dicapai setelah dipanaskan adalah 37,5 °C, 38,8 °C, 39,8 °C, 43,1 °C dan 46,6 °C. Lifted flame terjadi lebih awal dan panjang nyala api berkurang dengan meningkatnya temperature bahan bakar gas LPG. Stabilitas nyala api difusi terjadi saat bahan bakar gas LPG dipanaskan pada temperatur 80 °C dan 90 °C.

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This research is about the characteristic of the diffusion flame stability when LPG gases are being preheated before it bums in the bumer. Theoretically by rising unbumed temperature of a certain fuel can cause higher rate of reaction, higher buming velocity, lower minimum energy and lower starting point This research will be approached on buming velocity by length of flame and length of lifted flame which occur because of heaiing LPG fuel gas. The result show that LPG fuel gases buming temperature after heating could be reached 37,5 °C; 38,8 °C; 39,8 °C; 43,1 °C; 46,6 °C. Lifted flame will occur earlier and length of flame will decrease equal to increasingly LPG fuel gas temperature. The diflusion flame stability will occur when the LPG fuel gases are being preheated at temperature 80 °C and 90 °C."

"Tujuan penelitian ini yang pertama adalah untuk mengetahui komposisi campuran biodiesel sawit-jatropha-castor yang terbaik dari segi kualitas dengan cara mengoptimalkan beberapa parameter kunci karakteristik kimia fisik seperti stabilitas oksidasi, viskositas dan bilangan setana. Karena bahan baku biodiesel Indonesia adalah sawit yang merupakan bahan pangan, sehingga perlu dicampur dengan bahan non pangan agar ketersediaannya terjamin. Selain itu juga untuk memperbaiki cold flow properties dari biodiesel sawit.Dan tujuan yang kedua adalah untuk mengetahui pengaruh stabilitas oksidasi biodiesel dan komposisi asam lemak terhadap emisi gas buang yang dihasilkan. Pengujian stabilitas oksidasi dilakukan dengan metode accelerated oxidation stability test dengan bahan baku biodiesel sawit, biodiesel jatropha dan biodiesel castor.Dari hasil penelitian diperoleh komposisi yang terbaik untuk campuran sawit-jatropha adalah untuk 60 - 100% biodiesel sawit. Dimana stabilitas oksidasinya masih memenuhi syarat EN 14214 yaitu minimum 6 jam. Dengan pemakaian biodiesel emisi HC, CO, NOx dan smoke yang dihasilkan menunjukkan kecenderungan untuk turun.

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This research has two goals. The first is study of the blending of palm-jatrophacastor biodiesel to get the best quality key properties characteristics such as oxidation stability, viscosity and cetane number. Due to Indonesian feedstock biodiesel is palm edible oil, so the interest in using jatropha curcas and ricinus communis (castor oil) as feedstock for the production of biodiesel and blend with palm biodiesel. The benefit of jatropha and castor biodiesel to increase cold flow properties of palm biodiesel.The second goal is to study oxidation stability and fatty acid effects chain lenght and number of double bond on emission NOx, Carbon Monoxide, Hydro Carbon and smoke, that produced on biodiesel combustion process. The oxidation test had been controlled by accelerated conditions on palm?jatropha biodiesel blend.The result showed that the optimum quality obtainable at 60% until 100% of palm composition. Compared to the diesel fuel, biodiesel showed lower NOx, smoke and hydrocarbon emission. And the CO emission is slightly reduced."

"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."

"Busway transjakarta telah beroperasi hingga koridor 8 (delapan) saat ini. Jumlah penumpang tiap tahun menunjukkan peningkatan yang tinggi. Pada bulan Agustus 2010 Pemerintah Provinsi DKI Jakarta menerapkan sterilisasi jalur busway. Peningkatan penumpangpun terlihat dari data bulan Agustus 2010. Namun, pelayanan busway belum dapat diandalkan dan ini terlihat dari kekecewaan penumpang terutama yang menggunakan busway pada saat peak hour dan harus menunggu lama. Disisi lain busway belum mampu memaksimalkan perpindahan pengguna kendaraan bermotor pribadi ke busway. Ini menyebabkan emisi kendaraan bermotor di DKI Jakarta makin meningkat. Sehingga dalam pemecahan permasalahan perlu diatur time management busway dan peningkatan pelayanan dalam rangka menurunkan emisi kendaraan di DKI Jakarta.

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Transjakarta busway has been operating up to 8 (eight) corridor at this time. The number of passengers per year increases rapidly. In August 2010, local government of DKI Jakarta apply sterilization busway lane. The Increasing passengers can be observed from the data August 2010. However, level of service busway is not good enough and this can be seen from the disappointment reaction of passengers which using the busway, especially during peak hours which have to wait long time for one bus. On the other side busway still has not be able to maximize the transfer of private motor vehicle users to use the busway. This causes the emissions of motor vehicle in Jakarta increased. Thus, in solving the problem needs to arrange time management busway and improve services in order to reduce vehicle emissions in Jakarta."

"ABSTRAKPemanfaatan biomassa sangat berguna karena merupakan proses re-cycle karbon melalui proses fotosintesis. Salah satu potensi biomassa terbesar di Indonesia adalah sekam padi, yang mencapai 16 juta ton per tahun. Teknologi gasifikasi menjadi teknologi sangat bagus untuk pemanfaatan biomassa menjadi energi lain karena fleksibilitas produk syngas untuk dimanfaatkan. Tar menjadi komponen yang paling membahayakan dalam syngas karena jumlah tar yang sangat besar dibandingkan yang lain. Metode pembersihan tar saat ini ada banyak menggunakan metode sekunder yang lebih ekonomis. Salah satu teknik lama yang masih jarang dikembangkan adalah metode kondensasi. Metode ini dapat memisahkan tar dengan syngas berdasarkan titik embun tar. Selain itu ada metode lain yang sekarang sedang menjadi tren penelitian, yaitu adsorpsi. Adsorpsi bisa menggunakan jerami padi yang mempunyai sifat menarik partikel halus menggunakan silika yang dikandungnya. Pada penelitian ini akan dilakukan investigasi pressure drop pada water condenser, filter, dan kombinasi water condenser-filter yang mempengaruhi karakteristik penurunan temperature dengan variable laju aliran blower sebesar 72 lpm, 96 lpm, 120 lpm, 144 lpm, dan 168 lpm. Efisiensi pengurangan tar juga diteliti pada tiap-tiap variable tersebut dan dilihat karakteristiknya pada water condenser, filter, dan kombinasi water condenser-filter. Pengurangan tar tertinggi terjadi pada moda kombinasi water condenser-filter 120 lpm, yaitu efisiensi pengurangan tar 84,87%.

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ABSTRACT

The use of biomass is very useful because it is a carbon re-cycle process through photosynthesis. One of the biggest biomass potentials in Indonesia is rice husk, which reaches 16 million tons per year. Gasification technology is a very good technology for utilizing biomass into other energy because of the flexibility of syngas products to be utilized. Tar is the most dangerous component in syngas because the number of tar is very large compared to the others. The current tar cleaning method uses many more economical secondary methods. One old technique that is still rarely developed is the method of condensation. This method can separate tar with syngas based on tar dew point. In addition there are other methods that are now becoming a research trend, namely adsorption. Adsorption can use rice straw which has interesting properties of fine particles using silica it contains. In this study, pressure drop investigations on water condensers, filters, and water condenser-filter combinations will be carried out which affect the characteristics of temperature drop with variable blower flowrate of 72 lpm, 96 lpm, 120 lpm, 144 lpm, and 168 lpm . Tar reduction efficiency was also examined in each of these variables and the characteristics of the water condenser, filter, and water condenser-filter combination were observed. The highest tar reduction occurs in the 120 lpm water condenser filter combination, which is the efficiency of tar reduction of 84.87%."

"Gasification is a thermo chemical process for converting solid fuel such as coal, wood and other biomass into fuel gas that consists of the components CO, H2, CH4, CO2 and N2. Gasification technology is increasingly in demand due to oil fuel price is more expensive. And of course gasification technology must also be able to maintain continuity of Producer gas if want to compete in the world of industry. The research objective was to study the characteristics of gasification with coconut shell fuel. Type of gasification reactors that used is a downdraft fixed bed gasifier. This study aimed to obtain the temperature profile in the gasifier during operation, flow rate, flame visualization of combustion of producer gas and calculation aspects thermodynamic. The purpose of the above studies carried out to operating the gasifier for 12 hours with the primary air flow rate and suction blower that optimum. Gasification process use coconut shell with Equivalence ratio 0.423. The best efficiency of the current study scored 78.8 %; LHV from producer gas acquired 1070.49 kcal/m3."