Gasifikasi Cangkang Sawit dalam Updraft Fixed Bed Gasifier: Pengukuran Laju Gasifikasi Spesifik

Gasification is process conversion solid material into fuel gas. This study were carried on updraft fixed bedgasifier. Commercial application for updraft gasifier is used in Asphalt Mixing Plant at Ngawi with thecapacity 1 ton/hour. Palm shell was used as feedstock in this study with air as gasifying agent. Feedingconducted as batch and intermittent (0.5 kg every 12 minute in certain time). Gasification process alsoproduced an undesirable product called tar. The analysis of tar measurement and gas composition wasperformed by impinger bottle method and GC-TCD respectively. Gasification performance observed includesflare ignition, temperature progress, tar quantity, and specific gasification rate. Biomass with high moisturecontent produces producer gases that will be difficult to burnt because producer gases carried moisturecontent from biomass. Flare ignition on biomass with moisture content 7,01% would be slower 2 minutesthan moisture content 4%. Flammable producer gases when net calorific value more than 3500 kJ/Nm3.Temperature progress with intermittent feeding increase faster than batch feeding. However, temperaturprogress decreases when biomass was fed into the reactor. Tar content with high temperature on intermittentfeeding (4.8 mg/Nm3) was smaller than batch feeding (14 mg/Nm3). In this study, spesific gasification rate(SGR) about 47.7 - 65.4 kg/m2h

PERANCANGAN VIDEO PEMBELAJARAN MATA KULIAH COMMUNICATION SKILLS BERBASIS YOUTUBE

Tujuan penelitian ini adalah mengembangkan video pembelajaran melalui Channel youtube dosen dan menguji kelayakan video baik menurut ahli maupun mahasiswa pengguna. Kegiatan penelitian ini menggunakan channel youtube sebagai media pembelajaran dengan sebelumnya peneliti merancang video materi mata kuliah Communication Skills. Subjek penelitian ini adalah subjek uji pakar dan subjek uji coba adalah 142 mahasiswa STITEK Bontang yang sedang dan akan mengambil mata kuliah Communication Skills. Hasil penelitian ini memberikan output berupa tiga video pembelajaran sebagai sarana pembelajaran visual alternatif melalui media youtube yaitu berupa video pembelajaran powerpoint, aktivitas mengajar, dan gabungan. Responden cenderung memilih video gabungan sebagai video yang paling banyak memberikan ketertarikan mahasiswa terhadap perkuliahan melalui Youtube

Uji Laboratorium Proses Perengkahan Toluen dengan Katalis Reformasi Kukus Ni/a-Al2O3

Tar formation was one of the major problems in the utilization of syngas produced from gasification of biomass and coal. Toluene was used as a model tar and N2 as carrier gas. Laboratory test was performed using a commercial steam reforming catalyst available in our laboratory. The amount of catalyst was 2,5 g and reaction temperature was varied at 500, 600, 700, and 800oC. The gas flow rate was 0,0077 Nm3/h with a toluene concentration of 51 g/Nm3. Our laboratory test revealed that toluene conversion up to 99,6% might be obtained at the reaction temperature of 8000C and molar steam/toluene ratio of 16. Decreases in toluene conversion were observed when reactions were carried out in a condition of stoichiometric steam to toluene ratio of 7. Kinetics parameters toluene steam reforming on catalyst Ni/a-Al2O3 were obtained experimently by laboratory were Ea of 11,6 kJ/mol and k0 of 272 m3/kgcat.hours. Using these kinetics parameters, toluene might be converted almost completely in a plug flow reactor with a resedence time of 0,35 s, under the following condition: steam to toluene ratio of 16 and temperature above 700oC

Simulasi Termodinamika Perengkahan Tar pada Keluaran Fixed Bed Gasifier

Gasification is process to convert solid fuel such as biomass to gaseous fuel. Gasification produces synthetic gas which can be used as fuel, or feedstock for chemical synthesis. Tar production is one of major problem in gasification. Tar can be reduced by steam reforming of producer gas and modification of gasifier’s configuration. Gasifier and tar catalytic cracking reactor configurations and operating conditions are studied by using equilibrium thermodynamic model for steam reforming process. Steam/tar mole ratio and operation temperature must be taken into consideration to minimize tar production and prevent coke formation in catalyst. Simulation result can give guidance about operating condition of steam tar cracking reactor and guidance for gasifier configuration to minimize tar production. Simulation results showed that in order to eliminate tar and prevent coke formation, tar cracking reactor minimum temperature of 500-700oC should be used for downdraft gasifier, 662-756oC for conventional updraft gasifier, and 648-715oC for modified downdraft gasifier depending on steam/tar ratio in tar cracking reactor feed

Influence of Impregnation and Coprecipitation Method in Preparation of Cu/ZnO Catalyst for Methanol Synthesis

Cu/ZnO catalyst was succesfully prepared using a coprecipitation method. The mixing procedure of the Cu(NO3)2, Zn(NO3)2 and Na2CO3 solutions had an important influence on the characteristics of the catalyst. The best catalyst obtained was the one prepared with slow mixing of the salt solutions and a CuO/ZnO molar ratio of 50:50. This raw catalyst had a maximum surface area of about 61.6 m2/g. Increasing the CuO/ZnO molar ratio caused an agglomeration of precipitated particles, reducing the surface area. A much better catalyst was obtained using an impregnation method, in which g-Al2O3 was used as support. The impregnated catalyst had a surface area of about 151 m2/g. Activity tests were carried out in a fixed-bed reactor containing 1 g of catalyst and a flow of syngas at a rate of 60 mL/min. The reaction temperature was 170°C and the pressure was 20 barg. The best coprecipitated catalyst gave a CO conversion of about 10%, while the impregnated catalyst gave a CO conversion of up to 69%

Evaluasi Bejana Rebusan Horizontal dan Vertikal Berdasarkan Kehilangan Potensi Rendemen di Pabrik Kelapa Sawit

Sterilization in palm oil milling is the most important unit process because its will determine the efficiency and effectiveness of the whole process. Fresh fruit bunches (FFB) are cooked in sterilizer using steam as the heating during process sterlization. There is two most common type of sterilizer used in Indonesia that is horizontal and vertical sterilizer. Both of the types have advantages and disadvantages of each other. The performance of horizontal and vertical sterilizer should be investigated comprehensively for achieving satisfactory sterilization and giving minimum loss. This study is conducted to evaluate these sterilizers based on the loss of potential oil extraction rate determined from observation and data processing such as degree of FFB ripeness, laboratory report and sterilization report process. It was found that horizontal sterilizer is generally better than vertical sterilizer

Evaluasi Bejana Rebusan Horizontal dan Vertikal Berdasarkan Kehilangan Potensi Rendemen di Pabrik Kelapa Sawit

Sterilization in palm oil milling is the most important unit process because its will determine the efficiency and effectiveness of the whole process. Fresh fruit bunches (FFB) are cooked in sterilizer using steam as the heating during process sterlization. There is two most common type of sterilizer used in Indonesia that is horizontal and vertical sterilizer. Both of the types have advantages and disadvantages of each other. The performance of horizontal and vertical sterilizer should be investigated comprehensively for achieving satisfactory sterilization and giving minimum loss. This study is conducted to evaluate these sterilizers based on the loss of potential oil extraction rate determined from observation and data processing such as degree of FFB ripeness, laboratory report and sterilization report process. It was found that horizontal sterilizer is generally better than vertical sterilizer

Optimalisasi Perancangan Video Pembelajaran Bahasa Inggris Berbasis Web

The purpose of the study generally is to facilitate high school students preparation for National Test and State/private Entrance Test and specifically the purposes are 1)to increase the activity of English learning videos through website, 2) to increase the learning activity through internet. The stages of this research consists of 5 stages such as; a) capturing English learning videos, b) creating website, c) uploading the videos to the website, d) launching the website to the third year of Bontang State Vocational School 3, and e) evaluating the website content. The results show that video learning designs is the most chosen feature(89%) than other features on the website. Furthermore, the questionaires reaveal that 100% give positive responses to the website given

UNIFAC Model for Liquid-Liquid Phase Equilibrium of Penicillin G and 6-APA System

This study investigated the effect of pH and type of solvent on liquid-liquid phase equilibrium in the system of pure penicillin G and mixed penicillin G with 6-APA. Penicillin G extraction was carried out in a pH range of 2.0–5.0 at 4 oC using several types of solvents. The liquid-liquid phase equilibrium mathematical model is prepared assuming that a single stage of thermodynamic equilibrium occurs in a batch process of liquid-liquid extraction. The coefficient of activity was calculated by the UNIFAC method. From the experiment, it was found that the extraction process of penicillin G was strongly influenced by pH of the solution. The highest yield of extraction was achieved with different solvents in the two types of solution. For pure penicillin G system, the highest yields was obtained in n-butyl acetate solvent (95.51%) while for penicillin G mixture with 6-APA, it was obtained in methyl iso-butyl ketone solvent (92.6%). The UNIFAC model have been tested against five three-component liquid-liquid phase equilibrium systems at pH 2.0 and 2.5. It was able to estimate the concentration of penicillin G in the organic phase with a relatively average error between experiment and calculation of 8.32

Pengaruh Kadar Karbon pada Proses Gasifikasi

Investigasi proses gasifikasi dilakukan dengan pemodelan termodinamik. Kuantifikasi unjuk kerja proses gasifikasi dinyatakan dengan kadar H2 dan kadar CO dalam gas produser, temperatur dan efisiensi termal. Investigasi pengaruh kadar karbon terhadap unjuk kerja proses gasifikasi dilakukan dengan simulasi menggunakan batubara: lignit, bituminus dan antrasit. Ketiga jenis batubara diharapkan mewakili tingkatan kadar karbon. Kajian termodinamika digunakan sebagai piranti prediksi kinerja gasifikasi dan dapat melihat efek berbagai faktor secara cepat. Penyimpangan kinerja gasifier aktual terhadap hasil prediksi termodinamika sering ditemui dan biasanya dianggap sebagai akibat faktor-faktor teknis yang berhubungan dengan laju proses, misalnya pengontakan partikel dengan medium gasifikasi. Pada makalah ini, kajian termodinamika disempurnakan dengan melibatkan pemodelan dekomposisi batubara yang sangat tergantung pada jenis batubara dalam hal ini mewakili kadar karbon. Harapannya, pengabungan model dekomposisi batubara yang diusulkan dalam penelitian ini dan model kesetimbangan reaksi konvensional menghasilkan kajian termodinamika yang lebih rasional. Hasil dari kajian termodinamika digunakan sebagai piranti prediksi kinerja gasifikasi dengan mempertimbangkan kadar karbon batubara. Fraksi mol gas hidrogen maksimum yang dihasilkan lignit lebih tinggi daripada antrasit dan bituminus, berturut-turut 0,43 dan 0,25. Fraksi mol maksimum gas hidrogen dari lignit berada pada laju udara/batubara sekitar 1,2 kg/kg sedangkan antrasit dan bituminus berada pada sekitar 3 kg/kg. Temperatur proses gasifikasi, seperti diduga sangat dipengaruhi oleh jenis batubara. Sesuai dengan kadar H2, temperatur gasifikasi sebaiknya dijaga sekitar 1000 oC (Ru = 2,4 dan 4 berturut-turut untuk batubara lignit, antrasit dan bituminus). Keuntungan pada temperatur sekitar 1000 oC, tar secara praktis sudah terdekomposisi lebih lanjut, sehingga gas produser hanya sedikit mengandung tar