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"ABSTRAKGreen diesel merupakan bahan bakar nabati generasi kedua yang memiliki potensi untuk menjawab kebutuhan energi baik dalam negeri maupun dunia. Proses yang digunakan untuk memproduksi green diesel adalah hidrolisis sebagai pre-treatment dan hidrodeoksigenasi menggunakan katalis NiMo/Al2O3. Hidrolisis akan mengubah trigliserida pada bahan baku, yaitu minyak jelantah menjadi free fatty acid FFA yang selanjutnya dikonversi menjadi green diesel melalui hidrodeoksigenasi. Hidrolisis minyak jelantah dilakukan pada suhu 200oC dan tekanan 16 bar dengan rasio volume air dan minyak sebesar 1:1. Waktu reaksi divariasikan dari 1 hingga 3 jam. Kondisi operasi optimum hidrolisis, yaitu pada waktu 3 jam mampu menghasilkan FFA sebanyak 73,89 . Untuk proses hidrodeoksigenasi dilakukan variasi kondisi operasi, yaitu pada suhu 375oC dan tekanan 12 bar yang dapat menghasilkan green diesel dengan konversi 80,24 , selektivitas 53,37 , dan yield 19,26 , serta pada suhu 400oC dan 15 bar yang dapat menghasilkan green diesel dengan konversi 82,15 selektivitas 69,58 , dan yield 68,87 .

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ABSTRACTGreen diesel is a second generation of biofuel that has a potential to answer the energy needs either in Indonesia or in the world. The process used to produce green diesel are hydrolysis as a pre treatment and hydrodeoxygenation by using NiMo Al2O3 catalyst. Hydrolysis will change the triglycerides in the raw material, which is waste cooking oil into free fatty acid FFA and then converted into green diesel through hydrodeoxygenation. Hydrolysis of waste cooking oil carried out at temperature of 200oC and pressure of 16 with water and oil volume ratio of 1 1. Time is varied from 1 to 3 hours. The optimum condition of hydrolysis, which is at 3 hours can produce FFA as much as 73.89 . For hydrodeoxygenation, variations in operating condition used are 375oC with pressure of 12 bar that can produce green diesel with conversion of 80.24 , selectivity of 53.37 , and yield of 19.26 , also 400oC with pressure of 15 bar that can produce green diesel with conversion of 82.15 , selectivity of 69.58 , and yield of 68.87 . "

"Studi Kelayakan Pemanfaatan BBM Sintetik Dari Batubara dan Biomassa Untuk Memenuhi Kebutuhan BBM Dalam Negeri? dilakukan untuk mengatasi kelangkaan bahan bakar di Indonesia karena potensinya sangat besar sedangkan biomassa dipilih dengan alasan dapat diperbaharui. BBM sintetik ini diperoleh melalui beberapa tahapan proses yaitu: gasifikasi, sintesis Fischer-Tropsch dan upgrading produk. Metode yang digunakan adalah metode tekno ekonomi menurut Leland Blank dan Anthony Tarquin dengan pertimbangan kajian teknis dari Borreighter dan Kreutz. Hasil penelitian menunjukkan bahwa kilang BBM sintetik direkomendasikan untuk didirikan di Sumatera dan Kalimantan dengan kapasitas 1 kilang sebesar 104.415 bbl/day dengan harga produk gasoline dan diesel minimal sebesar Rp. 7.500 sehingga modal dapat kembali dalam waktu 6-7 tahun. Dari telaah ini maka dapat disimpulkan bahwa kilang BBM sintetik ini layak untuk segera dibangun di Indonesia.

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The study Feasibility The Use Of Synthetic Fuel From Coal And Biomass In Order To Meet The Need Of Domestic Fuel? was done to overcome the scarcity of fuel in Indonesia because the potential is huge while biomass is selected because it is renewable. Synthetic fuel can be obtained through several stages : gasification, Fischer-Tropsch synthesis and product upgrading. The Method used is Techno Economic method according Leland Blank and Anthony Tarquin using consideration technical review from Borreighter and Kreutz. The result show that synthetic fuel refineries recommended to set up in Sumatera and Kalimantan at capacity 104.415 bbl/day with the gasoline and diesel price at least Rp. 7.500 so that capital can be back at 6-7 years. From this study can be concluded that the synthetic fuel refinery is feasible to be built in Indonesia."

"To fulfill the requirement for synthetic fuel (synfuel) production in Fischer Tropsch process, in which syngas feed to the process has H2/CO mole ratio approaching 2, a lignite coal gasification is needed to satisfy this requirement. In this research, char particles were prepared by pyrolysis of lignite coal at controlled heating rates to obtain the highest possible surface area for gasification. The gasification used char with surface area of 172.5 m2/g, and catalyst K2CO3 in a fixed bed reactor. Steam/char mass ratio used in this research was varied 2.0; 3.0; 4.0 and the gasification temperature was varied 675, 750, 825oC. The result of this research showed that the highest H2/CO mole ratio of 2.07 corresponding to the mole ratio of gas yield/carbon of 1.13 was achieved at gasification temperature of 675oC using catalyst K2CO3 and at steam/char mass ratio of 2.0. However, at the same gasification conditions, but using no catalyst, H2/CO mole ratio and corresponding mole ratio of gas yield/carbon achieved were 3.02 and 0.42 respectively. This research found that the addition of catalyst K2CO3 in lignite coal char gasification adversely reduces mole ratio H2/CO ratio compared to that without catalysis. It is suspected that the high composition of mineral ash in ash reacts with K2CO3 catalyst which renders Boudouard reaction to considerably compete with water-gas reaction. The increases of gasification temperature and steam/carbon ratio both lower the mole ratio of H2/CO in syngas."

"Mikroalga adalah salah satu sumber biofuel yang menjanjikan karena memiliki kapasitas produksi lipid yang dapat dimanfaatkan sebagai bahan baku produksi biodiesel, terutama Nannochloropsis sp. dan Chlorella vulgaris. Lipid yang dihasilkan dapat diolah menjadi biodiesel melalui reaksi transesterifikasi menggunakan katalis homogen atau heterogen. Katalis heterogen memiliki kelebihan dibandingkan katalis homogen karena bentuknya yang padat memudahkan proses pemisahan katalis dari campuran produk. Dalam penelitian ini, digunakan katalis heterogen basa NaOH/zeolit dengan variasi loading Na dalam zeolit untuk melihat pengaruhnya terhadap yield biodiesel yang dihasilkan dari Nannochloropsis sp. dan Chlorella vulgaris. Hasil terbaik didapatkan dengan konsentrasi loading Na sebesar 20,5 . Yield biodiesel terhadap lipid yang didapatkan adalah sebesar 83,5 dari Nannochloropsis sp. dan 98 dari Chlorella vulgaris. Biodiesel yang dihasilkan memiliki kandungan asam lemak jenuh metil ester sebanyak 47,14 dari Nannochloropsis sp. dan 56,41 dari Chlorella vulgaris.

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Microalgae are promising sources of biofuel due to its production capacity of lipid that can be utilized as raw material for biodiesel production, especially Nannochloropsis sp. and Chlorella vulgaris. The lipid produced can be converted into biodiesel through transesterification reaction using homogenous or heterogeneous catalysts. Heterogeneous catalysts are more advantageous than homogeneous catalysts due to its solid form that eases the separation of catalysts from the products. In this research, NaOH zeolite heterogeneous catalyst is utilized with varying Na loadings in the zeolite to observe its effect towards the yield of biodiesel produced from Nannochloropsis sp. and Chlorella vulgaris. The best result was obtained with Na loading concentration of 20.5 . The biodiesel yields obtained from the lipids are 83.5 from Nannochloropsis sp. and 98 from Chlorella vulgaris. The biodiesels contain 47.15 of saturated fatty acid methyl esters from Nannochloropsis sp. and 56.41 from Chlorella vulgaris."

"Penelitian ini bertujuan untuk meningkatkan performa motor otto 4 langkah, menekan kadar emisi dan meminimalkan konsumsi bahan bakar dengan cara menurunkan waktu injeksi pengapian setelah sebelumnya dibuat mixer dengan menggunakan cyclone dll. Alat tersebut digunakan untuk mencampur udara dan LPG (Liquefied Petroleum Gas) sebelum masuk ke dalam karburator. Sebenarnya penelitian ini pernah dilakukan,namun karena adanya perbedaan energi aktivasi antara bensin dengan LPG maka pada penelitian kali ini ignition timing diubah sampai mengahasilkan yang terbaik. Untuk itu pada penelitian kali ini berbagai jenis pengujian serta penambahan alat yaitu CDI ( Capasitor Discharge Ignition) digunakan untuk melakukan remapping ignition timing yang terbaik. Hasil dari penelitian ini membuktikan bahwa setelah dilakukan perubahan ignition timing hasilnya menjadi lebih baik.

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The purposes of this research are to improve the performance of a four stroke motorcycle, reduce the emission level and also minimize the fuel consumption by using a mixing device which has a twelve crossing holes, bluff body, and a cyclone designed to modify the ignition time. The device is applied to mix air and LPG (Liquified Petroleum Gas) before entering the carburator. A similar research has been done in the past however, since there is an activation energy difference between fuel and LPG therefore, in this research the ignition timing is modified until it reaches the maximum performance. In addition, various tests were performed and also adding a CDI ( Capacitor Discharge Ignition) device to re¬mapp the best ignition timing. The results from this research verifies that by modifying the ignition timing, the performance of a motorcycle becomes better. "