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Featured researches published by nan Rochmadi.


PROCEEDINGS OF THE 3RD AUN/SEED-NET REGIONAL CONFERENCE ON ENERGY ENGINEERING AND THE 7TH INTERNATIONAL CONFERENCE ON THERMOFLUIDS (RCEnE/THERMOFLUID 2015) | 2016

Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

Doni Rahmat Wicakso; Sutijan; Rochmadi; Arief Budiman

Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 – 600 °C and catalyst weight between 0 – 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore po...


PROCEEDINGS OF THE 3RD AUN/SEED-NET REGIONAL CONFERENCE ON ENERGY ENGINEERING AND THE 7TH INTERNATIONAL CONFERENCE ON THERMOFLUIDS (RCENE/THERMOFLUID 2015) | 2016

Catalytic cracking of the top phase fraction of bio-oil into upgraded liquid oil

Sunarno; Rochmadi; Panut Mulyono; Arief Budiman

The energy consumption is increasing, while oil reserves as a primary energy resource are decreasing, so that is the reason seeking alternative energy source is inevitable. Biomass especially oil palm empty fruit bunches (EFB) which is abundant in Indonesia can be processed into bio-oil by pyrolysis process. The potential for direct substitution of bio-oil for petroleum may be limited due to the high viscosity, high oxygen content, low heating value, and corrosiveness. Consequently, upgrading of the bio-oil before use is inevitable to give a wider variety of applications of its liquid product. Furthermore, upgrading process to improve the quality of bio-oil by reduction of oxygenates involves process such as catalytic cracking. The objective of this research is to study the effect of operation temperature on yield and composition of upgraded liquid oil and to determine physical properties. Bio-oil derived from EFB was upgraded through catalytic cracking using series tubular reactor under atmospheric press...


ADVANCES OF SCIENCE AND TECHNOLOGY FOR SOCIETY: Proceedings of the 1st International Conference on Science and Technology 2015 (ICST-2015) | 2016

Effect of modification ZSM-5 catalyst in upgrading quality of organic liquid product derived from catalytic cracking of Indonesian nyamplung oil (Calophyllum inophyllum)

Heny Dewajani; Rochmadi; Suryo Purwono; Arief Budiman

The catalytic cracking of nyamplung oil over ZSM-5 catalyst was investigated in a packed bed reactor at the temperature of 450 °C and ratio of catalysts to oils was 1:5. The results show that ZSM-5 has high selectivity for aromatics compounds but low in the paraffin compounds. This aromatic compound has an advantage in increasing the octane number of gasoline even though it should be limited due to environmental regulation. To upgrade the quality of the organic liquid product is done by modification catalyst. One of the method to modify the catalysts by impregnating metal Ni into ZSM-5 with various % weight of Ni (2-7 wt. %). From BET and BJH analysis shows that the modification Ni/ZSM-5 catalysts affected the surface area and pore volume of catalyst. Compared to catalytic cracking of nyamplung oil with ZSM-5 catalysts, the loading of Ni to ZSM-5 could improve the selectivity of paraffin compounds. Increasing on nickel loaded tends to increase the selectivity of paraffin compounds and decrease the aromati...


PROCEEDINGS FROM THE 14TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND | 2017

Synthesis of sodium lignosulphonate from oil palm empty fruit bunches’s lignin

Nurcahyo Iman Prakoso; Suryo Purwono; Rochmadi

Synthesis of sodium lignosulphonate have been done by using batch method. Optimation of synthesis method was achieved through this study. The study was conducted on the optimation of mass ratio of lignin to the NaHSO3 solution, the concentration of NaHSO3 solution, reaction temperature, and reaction time. Of all the treatments, it was found that the optimum mass ratio of lignin to the NaHSO3 solution, concentration of NaHSO3 solution, reaction temperature, and reaction time respectively, 0.3 M, 0.1 M 97 °C, and the reaction was carried out for 4 hours. Excellent yields and selective products were obtained (90-92%)Synthesis of sodium lignosulphonate have been done by using batch method. Optimation of synthesis method was achieved through this study. The study was conducted on the optimation of mass ratio of lignin to the NaHSO3 solution, the concentration of NaHSO3 solution, reaction temperature, and reaction time. Of all the treatments, it was found that the optimum mass ratio of lignin to the NaHSO3 solution, concentration of NaHSO3 solution, reaction temperature, and reaction time respectively, 0.3 M, 0.1 M 97 °C, and the reaction was carried out for 4 hours. Excellent yields and selective products were obtained (90-92%)


PROCEEDINGS FROM THE 14TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND | 2017

Effect of support on catalytic cracking of bio-oil over Ni/silica-alumina

Sunarno; Syamsu Herman; Rochmadi; Panut Mulyono; Arief Budiman

Depletion of petroleum and environmental problem have led to look for an alternative fuel sources In many ways, biomass is a potential renewable source. Among the many forms of biomass, oil palm empty fruit bunch (EFB) is a very attractive feedstock due to its abudance, low price and non-competitiveness with the food chain. EFB can be converted bio-oil by pyrolysis process. but this product can not be used directly as a transportation fuel, so it needs upgrading bio-oil through a catalytic cracking process. The catalyst plays an important role in the catalytic cracking process. The objective of this research is to study the effect of Ni concentrations (1,3,5 and 7 wt.%) on the characteristics of the catalyst Ni / Silica-Alumina and the performance test for the catalytic cracking of bio-oil. Preparation of the catalyst Ni / Silica-Alumina was done by impregnation at 80°C for 3 hours, then done to calcination and reduction at 500°C for 2 hours. The performance test was conducted on catalytic cracking temper...


PROCEEDINGS FROM THE 14TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND | 2017

Study of catalytic upgrading of biomass tars using Indonesian iron ore

Doni Rahmat Wicakso; Sutijan; Rochmadi; Arief Budiman

Catalytic decomposition is a promising way for chemical upgrading process of low quality oil such as biomass tars. In this experiment, catalytic decomposition of biomass tars was performed over Indonesian low grade iron ore catalyst. This process is carried out in a fixed bedreactor which is equipped with preheater to convert the tars into vapor form. The reaction was studied at the temperature range of 500 – 700°C. The kinetic study of catalytic decomposition of biomass tars is represented using first order reaction. The results show that value of constant of chemical reaction is in range 0.2514 – 0.9642 cm3.gr−1.min−1 with value of the frequency factor (A) and the activation energy (E) are 48.98 min−1 and 5724.94 cal.mol−1, respectively.


Carbohydrate Polymers | 2017

Characteristics of glucomannan isolated from fresh tuber of Porang (Amorphophallus muelleri Blume)

Anny Yanuriati; Djagal Wiseso Marseno; Rochmadi; Eni Harmayani

Porang is a potential source of glucomannan. This research objective was to find a direct glucomannan isolation method from fresh porang corm to produce high purity glucomannan. Two isolation methods were performed. In first method, sample was water dissolved using Al2(SO4)3 as flocculant for 15 (AA15) or 30 (AA30) minutes with purification. In second method, sample was repeatedly milled using ethanol as solvent and filtered for 5 (EtOH5) or 7 (EtOH7) times without purification. The characteristics of obtained glucomannan were compared to those of commercial porang flour (CPF) and purified konjac glucomannan (PKG). High purity (90.98%), viscosity (27,940 cps) and transparency (57.74%) of amorphous glucomannan were isolated by EtOH7. Ash and protein level significantly reduced to 0.57% and 0.31%, respectively, with no starch content. Water holding capacity (WHC) of EtOH7 glucomannan significantly enhanced, whereas its solubility was lower than those of PKG due to its ungrounded native granular form.


Key Engineering Materials | 2016

Optimum Conditions for the Formation of Glycidyl Nitrate from 1,3-Dinitroglycerin

Erna Astuti; Supranto; Rochmadi; Agus Prasetya

One of the utilization of glycerol as byproduct of the biodiesel industry is to produce polyglycidyl nitrate, the most energetic polymer. The synthesize of polyglycidil nitrate from glycerol includes three steps: nitration, cyclization and polymerization. The aim of this study is to obtain the optimum conditions of cyclization. The cyclization was carried out in a 5 ml reactor and equipped with Hickman distillation head and nitrogen purge with the variables are mole ratio of sodium hydroxide/glycerol of 1/1 to 1.5/1, reaction temperature of 283.15 to 293.15 K and sodium hydroxide concentration of 15%. Each sample was analyzed by gas chromatography to determine the composition of products. The optimum conditions are temperature of 288.15 K and the mole ratio of sodium hydroxide /glycerol of 1.5.


international conference chemical and material engineering | 2015

Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

Arif Hidayat; Rochmadi; Karna Wijaya; Arief Budiman

Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.


Applied Mechanics and Materials | 2014

Tensile Strength Test of Photo Biocomposites for Application in Biomedical Materials

Joko Triyono; Alva Edy Tontowi; Widowati Siswomihardjo; Rochmadi

The aim of this research is to perform the tensile strength of photo biocomposite materials. This material consist of hydroxyapatite (HA) as a filler, tri [ethylene glycol] dimethacrilate as a matrix, shellac as a coupling agent and camphorquinone as a photoinitiator. Four ingredients then were used to two mixtures. The first mixture was mixing of TEGDMA and camphorquinone and the second was shellac coated HA. Two of mixtures were mixed to be one solution and was stirred in magnetic stirrer for 1 hour. The solution then was poured into the mold of tensile strength (10 x 10 x 3 mm) and was activated with visible blue light 410 – 500 nm for 40 seconds in order to be polimerization processes. The irradiation process was done with a maximum thickness 1 mm so that the irradiation process was done 3 times (layer by layer processing). The results of tensile strength test showed that the tensile strength would decrease with the addition of HA or would increase by the addition of TEGDMA. The highest tensile strength was obtained at HA/TEGDMA ratio of 20/80%. This material could be used as a bone substitute materials.

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Erna Astuti

Universitas Ahmad Dahlan

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