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Abstrak :
Adanya perkembangan teknologi dan infrastruktur maupun sektor lainnya menyebabkan menaiknya tingkat kebutuhan energi, terkhusus energi listrik. Salah satu sumber daya alam yang dapat menghasilkan energi listrik adalah batubara. Indonesia termasuk negara penghasil batubara terbesar di dunia. Namun, pada umumnya batubara hasil tambang Indonesia adalah batubara dengan peringkat rendah atau dikenal sebagai batubara lignit. Batubara lignit baik digunakan sebagai bahan bakar dalam industri PLTU karena memiliki kandungan sulfur yang rendah sehingga dapat menghasilkan efisiensi pembakaran yang tinggi. Namun, sebelum dijadikan sumber bahan bakar untuk PLTU, batubara lignit harus melalui proses peningkatan kualitas. Peningkatan kualitas yang dimaksud adalah dengan cara dikeringkan. Pengeringan dilakukan untuk mengurangi kadar air yang tinggi di dalam batubara lignit sekitar 40-70 dari massa aslinya. Penelitian pengeringan batubara lignite berlangsung menggunakan sistem refrigerasi dan pemanas heater serta desain ruang pemanas menggunakan tambahan desain Fixed-Bed Reactor. Pengeringan dilakukan dengan menggunakan variasi humidity ratio dan suhu pemanas. Pada penelitian ini, data yang didapat kemudian diolah sehingga diketahui pengaruh humidity ratio dan suhu pemanas terhadap nilai k konstanta laju pengeringan. Nilai k akan digunakan untuk desain pengeringan batubara di masa yang akan datang.

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The existence of technological and infrastructure developments increases energy needs, especially electrical energy. Commonly, electrical energy can be obtained from natural resources such as coal. Indonesia is one of the largest coal producers in the world. However, most of coal that Indonesia can produce are low rank coal. There are two types of low rank coal, they are sub bituminous and lignite coal. Lignite coal can be used as a fuel in Electric Steam Power Plant Industries because it has low sulfur content which can produce high combustion efficiency. On the other hand, lignite coal must be upgraded with a drying process to reduce its moisture content the lignite coals moisture is about 40 70 from its total mass. Lignite Coal drying enhances the heating value. In this study, the dryer uses a refrigeration system and heater. The drying chamber is designed with an additional Fixed Bed Reactor. Lignite Coal drying is operated in two variations of air condition. The variations are humidity ratio and heating temperature of dryers air condition. Based on this research, all the data resulted will be used to find the influence of humidity ratio and the heating temperature on the drying rate and activation energy of low rank. The drying rate constant and activation energy value will be used for future drainage design of low rank coal.

Abstrak :
Hidrogenasi katalitik CO2 menjadi CH3OH memiliki prospek yang cerah seiring dengan permintaan pasar yang tinggi. Metanol CH3OH dibutuhkan sebagai bahan baku di industri petrokimia untuk memproduksi formaldehida, klorometana, amina asetat dan juga sebagai alternatif energi baru yang ramah lingkungan. Penelitian ini bertujuan untuk mendapatkan pengaruh katalis CuO/ZnO/Al2O3 dan pengaruh temperatur umpan dalam bentuk konversi CO2, selektivitas CH3OH, dan yield CH3OH. Preparasi katalis CuO/ZnO/Al2O3 dilakukan dengan metode kopresipitasi menghasilkan persentase rasio komposisi logam Cu-Zn-Al yaitu 66,7: 27,4: 4,29 dan luas permukaan katalis sebesar 98,3411 m2/g. Komposisi perbadingan gas umpan H2 : CO2 yaitu sebesar 3 : 1. Reaktor unggun tetap dengan diameter dalam 1,5 cm; panjang 19 cm bed katalis 5 cm, dan furnace 5 cm. Reaksi dilakukan pada tekanan 30 bar dan laju alir dijaga konstan. Variasi yang dilakukan dalam reaksi yaitu variasi temperatur umpan pada 220, 250, 280 oC. Didapatkan nilai konversi CO2 yang tertinggi terjadi pada saat temperatur umpan 250 oC dengan waktu reaksi hingga mencapai kondisi stabil yaitu selama 240 menit. Sehingga kondisi reaksi pada temperatur 250 oC dikatakan sebagai kondisi optimal dengan didapatkan nilai konversi CO2 sebesar 21,8, selektivitas CH3OH sebesar 82,76, dan yield CH3OH sebesar 18,04.

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The catalytic hydrogenation of CO2 to CH3OH has a bright prospect along with high market demand. Methanol CH3OH is needed as raw material in the petrochemical industry to produce formaldehyde, chloromethane, amine acetate and also as an alternative new environmentally friendly energy. This study aims to obtain the effect of CuO ZnO Al2O3 catalyst and the influence of feed temperature in the form of CO2 conversion, CH3OH selectivity, and yield of CH3OH. Preparation of CuO ZnO Al2O3 catalysts by coprecipitation method resulted in percentage ratio of Cu Zn Al metal composition of 66,7 27,4 4,29 and catalyst surface area of catalyst 98,3411 m2 g. H2 CO2 gas ratio composition of 3 1. Fixed bed reactor with 1.5 cm inner diameter length of 19 cm bed catalyst 5 cm, and furnace 5 cm. The reaction is carried out at a pressure of 30 bar and the flow rate is kept constant. Variations made in the reaction are variation of feed temperature at 220, 250, 280 oC. The highest CO2 conversion value occurs when the 250 oC feed temperature with reaction time reaches a stable condition of 240 minutes. So that the reaction condition at 250 oC is said to be the optimal condition with a CO2 conversion value of 21.8, CH3OH selectivity of 82.76, and CH3OH yield of 18.04.

Abstrak :
The effect of precipitant and ultrasonic over Ni7CeO,-MgO-La,0/A503 catalyst was studied in an atmospheric fixed-bed reactor for partial oxidation of methane. Two types of precipitant used in this work were Na2C)3 and NH4OH2 and the length of ultrasonic iradiation was 60 minutes (1 hour). The bulk surface area, nickel particle diameter, nickel dispersion and morphology of the catalysts were investigated by various characterization techniques, including BET] XRD, H; chemisorption and SEM The partial oxidation of methane to syngas was done at 800 ?C atmospheric pressure and the feed ratio (CH/01) was 2 : 1.2. It was found that catalysts prepared by using NH4OH2 precipitant have pore size that larger than those of catalysts prepared using Na,CO, precipitant. The effect of ultrasonic on the catalysts showed that ultrasonic irradiation enhanced the surface area of the catalyst and the nickel dispersion. SEM analyses shown changes of the catalyst morphology, i.e. the particle of the catalyst became smaller and more uniform because of the ultrasonic irradiation. Catalyst prepared using NH,0H precipitant and irradiated shown the best performance with 96% methane conversion.