Papers by Rochmadi Rochmadi
THE 2ND INTERNATIONAL SYMPOSIUM OF INDONESIAN CHEMICAL ENGINEERING 2021: Enhancing Innovations and Applications of Chemical Engineering for Accelerating Sustainable Development Goals
Methanolysis of epoxidized Tung oil (ETO) with the minimum initial concentration of epoxy of 3.91... more Methanolysis of epoxidized Tung oil (ETO) with the minimum initial concentration of epoxy of 3.9199 mmol/gram was carried out for 4 hours. Sulfuric acid was used as a catalyst. This study aims to evaluate the effect of the mole ratio of methanol to ETO in the synthesis of Tung oil-based polyols and to characterize the resulted polyols. Methanolysis was carried out at a temperature of 60°C and the stirring velocity of 600 rpm. Overall, higher mole ratio accelerates the time required to reach maximum conversion. At the end of the reaction, the OHV was 3.7974 mmol KOH/g (for mole ratio of 10:1). FTIR analysis result shows that a hydroxyl group (-OH) at a wavelength of 3,444.97 cm-1 and a carboxyl group (-COOH) at a wavelength of 1,636.74 cm-1 was present. The simultaneous DSC-TGA analysis resulted T5% loss value of 117.61°C and the decomposition temperature of 396.20°C.
THE 2ND INTERNATIONAL SYMPOSIUM OF INDONESIAN CHEMICAL ENGINEERING 2021: Enhancing Innovations and Applications of Chemical Engineering for Accelerating Sustainable Development Goals
Microalgae is one of source biofuel to substitute the fossil energy. One of the problems of oil e... more Microalgae is one of source biofuel to substitute the fossil energy. One of the problems of oil extraction is the method of extraction which produce higher oil yield. Ultrasound assisted extraction is one of method to extract algae oil from algae biomass. The problem of this method of extraction is solvent. In this paper, the extraction uses mixed solvent between isopropyl alcohol and n-hexane. From the experiment the higher yield of oil is using 40% isopropyl alcohol and 60% n-hexane. While the lowest oil yield is the extraction using 100% n-hexane. From this result, polarity of solvent has the effect to yield of oil.
International Journal of Renewable Energy Research, 2018
In pyrolysis, tar is undesired byproduct because it causes operational problems such as the conta... more In pyrolysis, tar is undesired byproduct because it causes operational problems such as the contamination in the inner wall of a reactor, blockages in pipes, corrosion and formation of tar aerosols and carcinogenic. Therefore, it is necessary to take steps for removing or decomposing tar into fuel gas (bio-syngas) and other compounds that are more useful. In this experiment, catalytic process was selected to decompose tar derived from wood waste pyrolysis. The study was focused on the effect of temperature on catalytic tar decomposition using a fixed bed reactor with using Indonesian iron ore as catalyst. Initially, tar was vaporized inside preheater at temperature of 450°C, and then was passed through the catalyst bed. The variables studied were temperatures between 500-700°C and height of catalyst bed between 0.67-1.34 cm. Yields of gas, bio-oil, char and aqueous and also compositions of gas and liquid product were evaluated. The liquid product are represented in terms of acid compounds, hydrocarbon compounds, ketone compounds, oxygenate compounds, aromatic hydrocarbon-one cyclic (AH-1), poly aromatic hydrocarbon-two cyclic (PAH-2) and poly aromatic hydrocarbon-three cyclic (PAH-3). The results showed that the yields of gas and char increased by increasing temperature from 500 to 700°C, while bio-oil decreased. In addition, increasing temperature resulted new compounds of AH-1, PAH-2 and PAH-3. The yields of PAH-2 and PAH-3 on liquid product and hydrogen and methane on gas product also increased, while yields of acid, ketone, AH-1 decreased.
INTERNATIONAL CONFERENCE ON SCIENCE AND APPLIED SCIENCE (ICSAS) 2021, 2022
The quality of spermatozoa and testicular histology in insulin-injected Rattus norvegicus with di... more The quality of spermatozoa and testicular histology in insulin-injected Rattus norvegicus with diabetes mellitus
4TH INTERNATIONAL SEMINAR ON CHEMISTRY, 2021
Polyol is the main raw material to produce polyurethane which is widely used in the commercial an... more Polyol is the main raw material to produce polyurethane which is widely used in the commercial and industrial fields. The use of candlenut oil to become polyols by epoxidation process is a new alternative method, which has advantages: renewable raw materials and biodegradable polymer. The purpose of this research is to study the rate of reaction of epoxidized candlenut oil with PEG 200, together with the characteristics of the polyols produced. The important of reate reaction is to conclude factors that effect on the reaction. The candlenut oil has iodine number of 109.9 mg I2/g. This experiment was used a three necked flask as batch reactor completed with magnetic stirrrer, thermometer, waterbath, reflux condenser, and heater. In the first process, epoxidation of candlenut oil at 60 o C took 4 hours as the optimal time to produce epoxy of candlenut oil with the oxirane number of 6.092 g/mol. The second process was polymerization of epoxidized candlenut oil and PEG 200-based polyol at 110 o C, 120 o C, 130 o C, and 140 o C, running for 45 minutes to 180 minutes The best reaction temperature takes in 130 o C, with relatively short time, it need 45 minutes, the k1, k2 and k3 were 0.0165, 0.0090, and 0.0577 g/mgek.min respectively. Then, 1:1 mol was the best ratio of polymerization reaction, proven by the k1 0.0006 g/mgek.min, k2 0.0103 g/mgek.min and k3 0.0577 g/mgek.min and small value of error, 3.67%. The results showed that reaction rate of secondary hydroxyl chains is greater than that of primary hydroxyl. The proposed kinetic model with k1, k2 and k3 were 4.69 x 10 2 e-4377.9/T , 4.95 x 10 6 e-7804.9/T , 9.76 x 10 20 e-20433/T respectively fitted well in the early stage of reaction, before the reaction mixture become viscous.
MODIFIKASI NAFION DAN PENGARUHNYA TERHADAP DIFUSI CH 3 OH SEBAGAI ELEKTROLIT PADAT DIRECT METHANO... more MODIFIKASI NAFION DAN PENGARUHNYA TERHADAP DIFUSI CH 3 OH SEBAGAI ELEKTROLIT PADAT DIRECT METHANOL FUEL CELL . Nafion membran dimodifikasi secara fisik dengan menambahkan partikel penyerap air yaitu SiO 2 dan P 2 O 5 pada larutan Nafion dalam berbagai konsentrasi kemudian direcasting kembali. Morfologi permukaan membran dianalisis dengan SEM, dan diketahui bahwa partikel terdistribusi dengan merata dan mempunyai spesifik struktur. Transport CH 3 OH dan air pada membran dianalisis berdasarkan konsentrasi difusi CH 3 OH dan daya serap air. Partikel SiO 2 dan P 2 O 5 menaikkan daya serap air pada membran dan sekaligus mampu menurunkan permeabilitas CH 3 OH. Permeabilitas CH 3 OH pada Nafion termodifikasi rata-rata 10 -6 cm 2 /s. Penambahan larutan elektrolit pendukung (KCl) pada CH 3 OH sebagai bagian dari bahan bakar serta modifikasinya dengan partikel diatas juga mampu menurunkan permeabilitas membran hingga 10 -7 cm 2 /s. Kesimpulan hasil riset ini sangat mendukung penyelesaian prob...
In the last decade, Indonesia intensifies the efforts to reduce pharmaceutical imports. One of th... more In the last decade, Indonesia intensifies the efforts to reduce pharmaceutical imports. One of the initiatives is establishing a paracetamol production facility to start operating in 2024. Kinetics study is needed as a basis to design the paracetamol reactor. This study investigated the optimal temperature, reactant mole ratio, and agitation speed in the reactor for paracetamol production. In this study, aqueous solution of para-aminophenol was reacted with acetic anhydride. The mole ratio of para-aminophenol to acetic anhydride was varied to 1:1, 1:1.2, 1:1.5, and 1:2 while the temperature was varied to 80 °C, 90 °C, and 110 °C. However, due to uncontrolled heat of the reaction and limitation of the mixture’s boiling point, the actual reaction temperatures were 86 °C, 90 °C, and 108 °C. In addition, the agitation speed of 250 RPM and 350 RPM were also studied. Thin layer chromatography (TLC) and densitometry were used to determine the concentration of paracetamol in the reacting mi...
THE INFLUENCE OF MASTICATION TO CURING CHARACTERISTIC OF NATURAL RUBBER AND PHYSICALPROPERTIES OF... more THE INFLUENCE OF MASTICATION TO CURING CHARACTERISTIC OF NATURAL RUBBER AND PHYSICALPROPERTIES OF ITS VULCANIZATES . The research on the mastication that influences the curing characteristic of natural rubber and physical properties of its vulcanizates has been conducted. The research started from rubber mastication with variation of carbon black filler addition into rubber compound. Rubber compound was then measured to identify its curing characteristic using rheometer and tested its viscosity using Mooney viscosity tester. Physical properties of rubber vulcanizates such as abrasion resistance, tear strength, and elongation at break were also measured. The results indicated that curing characteristic tended to decrease, while only scorch time tended to increase from B1, B2, B3 and B4. Elongation at break tended to decrease, while tear resistance and abrasion resistance tended to increase from B1, B2, B3 and B4. Mooney viscosity of the compound also tended to decrease. It can be con...
Journal of Engineering and Technological Sciences, 2021
Indonesia aims to implement large-scale enhanced oil recovery (EOR) to increase the national oil ... more Indonesia aims to implement large-scale enhanced oil recovery (EOR) to increase the national oil production. Chemical EOR is a promising technology to boost the production of old reservoirs with the aid of surfactants and polymers. Thus, the production of low-cost EOR surfactants from local resources with acceptable performance is highly attractive. The objective of the present work was to demonstrate the development of low-cost lignosulfonate surfactant production from kraft black liquor (BL). First, lignin was isolated from black liquor using a novel CO2 bubbling technique, followed by addition of coagulants. Next, sodium lignosulfonate (SLS) was synthesized from the resulting lignin, followed by formulation of SLS with octanol and palm fatty acid distillate (PFAD) soap to obtain an ultralow interfacial tension (IFT) surfactant. The initial IFT value of the SLS solution was already high at 0.7 mN/m. After formulation, the composition SLS:PFAD soap:octanol = 70:22:8 (wt%) improved ...
Jurnal Teknologi, 2021
Epoxides from vegetable oils are currently gaining more attention to replace petroleum-based mono... more Epoxides from vegetable oils are currently gaining more attention to replace petroleum-based monomers for polymer synthesis. As one of unsaturated fatty acids derived from vegetable oil, Oleic acid can be converted into epoxidized oleic acid by chemical epoxidation. Epoxidized oleic acid is a bifunctional monomer that has the potential to be used as raw material for fatty-acid-based polyester synthesis. This paper proposes the Taguchi-based optimization technique for in-situ epoxidation of oleic acid. The combining factors affecting the maximum yield were also determined to obtain a higher quality of epoxidized oleic acid in a relatively short time. Epoxidized oleic acid was characterized and tested for degradation. The characterization result showed the possibility of the polymerization reaction, and the kinetic study showed that the rate of epoxide degradation at room temperature follows second order with a reaction rate constant of2.7235 gr.mmol-1.day-1.
Jurnal Rekayasa Proses, 2020
The application of conventional fertilizer, especially for inorganic fertilizer, has low efficien... more The application of conventional fertilizer, especially for inorganic fertilizer, has low efficiency due to the fast release of its nutrients into the environment. Also, it has a high operating cost caused by multiple fertilization processes in one of the planting periods. One of the possibilities to overcome this limitation is applying organic fertilizer as a slow-release fertilizer (SRF). The objective of this research is to prepare SRF by modifying the formulation of local organic fertilizer with chitosan as a binder. The rate of the nitrogen release was studied and simulated with MATLAB. The result shows that the nitrogen loss by water leaching decreased up to 85% in chitosan/organic fertilizer rather than the fertilizer without chitosan. By MATLAB simulation, the release of nitrogen has followed the proposed mathematical model in which the mass transfer occurred dominated by diffusion mechanism with the diffusivity coefficient of 1.61x10-5 cm2/s.Keywords: chitosan; organic ferti...
Natural Product Communications, 2021
CaCO3 hydrogel incorporation into Plaster of Paris (POP) formulations decreased the resorption ra... more CaCO3 hydrogel incorporation into Plaster of Paris (POP) formulations decreased the resorption rate of the POP after implantation in the body. Although an inflammatory process is required as part of wound healing, the accumulation and activation of inflammatory cells in the POP–hydrogel CaCO3 implant area needs to be controlled. Therefore, cinnamaldehyde, as an anti-inflammatory agent with a unique α, β-unsaturated aldehyde, was incorporated into the CaCO3 hydrogel. During the incorporation, both the lipophilic and hydrophilic sides of the cinnamaldehyde molecule can influence the physical and mechanical properties of the CaCO3 hydrogel, in which mechanical properties of a tissue engineering scaffold are important to fine tune cellular activity during implantation. On the other hand, as a 3-dimensional polymeric structure, crosslinking is needed for the CaCO3 hydrogel to stabilize and increase its molecular weight for better mechanical strength, and more resistance to heat, wear, an...
Bulletin of Chemical Reaction Engineering & Catalysis, 2020
Tung oil with an iodine value (IV) of 99.63 g I2/100 g was epoxidized in-situ with glacial acetic... more Tung oil with an iodine value (IV) of 99.63 g I2/100 g was epoxidized in-situ with glacial acetic acid and hydrogen peroxide (H2O2), in the presence sulfuric acid as catalyst. The objective of this research was to evaluate the effect of mole ratio of H2O2 to unsaturated fatty acids (UFA), reaction time and catalyst concentration in Tung oil epoxidation. The reaction kinetics were also studied. Epoxidation was carried out for 4 h. The reaction rates and side reactions were evaluated based on the IV and the conversion of the epoxidized Tung oil to oxirane. Catalytic reactions resulted in higher reaction rate than did non-catalytic reactions. Increasing the catalyst concentration resulted in a large decrease in the IV and an increase in the conversion to oxirane at the initial reaction stage. However, higher catalyst concentration in the epoxidation reaction caused to a decrease in reaction selectivity. The mole ratio of H2O2 to UFA had an influence identical to the catalyst concentrat...
International Journal on Advanced Science, Engineering and Information Technology, Oct 31, 2017
Chitosan-Alginate micro-particles can serve as coating to the drug through the encapsulation proc... more Chitosan-Alginate micro-particles can serve as coating to the drug through the encapsulation process for controlled release. The addition of Tri Poly Phosphate would change the characterization of Chitosan-Alginate micro-particles because of the process of cross linking. This study aims to determine the characterization of micro-particles of Chitosan-Alginate based on particle size distribution, particle surface morphology and dissolution process in acid medium. The method used to make microparticles of Chitosan-Alginate is using spray drying, thus the micro-particles can be made by mixing Chitosan-Alginate with a weight ratio of 1: 1, 1: 2, 2: 1 then mixed the crosslinking compound Tri Poly Phosphate (TPP) with a concentration of 0.1%, 0.3%, 0.5%, and added emulsifier Tween 80 3% v / v, stirred at a speed of 20,000 rpm for 10 minutes then inserted into the spray dryer to form micro-particles. The powder of micro-particles then analysed by Scanning Electron Microscopy (SEM) and performed in vitro of stomach acid solution using acidic medium for the test of dissolution. Based on the research that has been done, 0.1% TPP concentration of Chitosan-Alginate ratio of 2: 1 can produce the most uniform size distribution with a ratio of 40.54%. The biggest dissolution of micro-particles obtained from the samples with Chitosan-Alginate ratio of 2: 1 with a concentration of 0.1% TPP was 80.8%.
Reaktor, Nov 13, 2010
Pengembunan campuran uap dan gas melibatkan mekanisme perpindahan panas dan massa secara simultan... more Pengembunan campuran uap dan gas melibatkan mekanisme perpindahan panas dan massa secara simultan yang sangat rumit sehingga pendekatan teoritis terhadap peristiwanya belum cukup untuk diterapkan pada perancangan kondensor. Penelitian ini dimaksudkan untuk memperoleh persamaan semi-empirik yang sederhana dan cukup teliti sebagai dasar memperkirakan koefisien perpindahan panas dan massa proses pengembunan campuran metanol(1)-propanol(2)-udara. Percobaan pengembunan dilakukan di dalam kondensor pipa ganda tegak sepanjang 1,7 m. Ukuran pipa luar dan dalam berturut-turut sebesar 50 mm dan 25 mm. Campuran uap dan gas dialirkan dari atas melalui anulus sedangkan air pendingin dialirkan di dalam pipa dari bawah sehingga sistem menjadi berlawanan arah. Data percobaan meliputi kecepatan alir dan suhu air pendingin, komposisi dan suhu campuran uap-gas, kecepatan alir dan suhu kondensat, kecepatan alir udara, dan tekanan sistem. Koefisien perpindahan panas dan massa dievaluasi melalui model matematik yang disusun berdasarkan neraca massa dan panas yang diselesaikan secara simultan. Hasil penelitian dinyatakan dalam bentuk bilangan tak berdimensi yaitu Nu=19,9297(1-yn) 2,9164 Re 0,8142 Pr 1/3. Adapun hubungan fungsional bilangan Sherwood yang merupakan bentuk bilangan tak berdimensi koefisien perpindahan massa dinyatakan dengan persamaan
Reaktor, 2017
ACETYLATED CELLULOSE FROM BETUNG BAMBOO (Dendrocalamus asper) PULP PRODUCTION AND ITS EFFECT ON ... more ACETYLATED CELLULOSE FROM BETUNG BAMBOO (Dendrocalamus asper) PULP PRODUCTION AND ITS EFFECT ON MECHANICAL PROPERTIES OF POLYPROPYLENE COMPOSITES. The utilization of natural fiber as reinforcing agent for biocomposite products have some drawbacks, such as its hydrophilicity that are incompatible with PP. Isolation from bundle fibers into micro fibers could improves the biocomposite properties. However, more moisture absorption of micro fiber makes it difficult to handle. Therefore, modification with acetylation is needed to facilitate good interfacial adhesion between cellulose and PP. The objectives of this research are to obtain acetylated micro fibers from betung bamboo pulp for reinforcing agent and to investigate the effect of acetylated cellulose on mechanical properties of PP biocomposites. Acetate anhydride as acetylating agent and sulfuric acid as a catalyst were used for acetylation process. Acetylated cellulose from betung bamboo pulp with fibrous form, hydrophobic condi...
Indonesian Journal of Chemistry, 2018
In this study, cellulose microfibers were isolated from bagasse fibers in three stages. Initially... more In this study, cellulose microfibers were isolated from bagasse fibers in three stages. Initially, the fibers were treated with 5 wt.% NaOH solution followed by bleaching with 5 wt.% H2O2 in an alkali condition (pH 11) to remove hemicelluloses and lignin. Whole cellulosic fibers were obtained by mechanically separating the fibers using a modified kitchen blender to produce cellulose microfibers. Morphological (Scanning Electron Microscopy (SEM)) and structural analysis of the treated fiber was performed using Fourier Transformed Infrared (FTIR) spectroscopy and X-ray Diffraction (XRD). Morphological characterization identified that the diameter of the fibers varied between 20 nm to 20 µm and the FTIR analysis demonstrated that the treatments resulted in the gradual removal of lignin and hemicelluloses from the fiber. Furthermore, the XRD studies revealed that the combination of the chemical and mechanical treatment is an effective way to increase purity of cellulose (removal of amor...
Jurnal Teknik Industri, 2012
Hard and crunchy are specific characteristics of fried product prefered by consumer. To have text... more Hard and crunchy are specific characteristics of fried product prefered by consumer. To have texture of crunchy product being suitable with consumer taste, it is necessary to observ characteristic change of raw material and frying condition. In frying process, the changes of hardness and crunchiness characteristics of food occur. These changes are predicted caused by free water vaporization and the decrease of starch content in food. The objective of this research is to develop mathematical model of hardness and crunchiness changes as the function of water and extract content degradation. Sample of the research is jack fruit fried in the temperature of 70–100° C, duration of 15–60 minutes, and pressure of 80–90 kPa. The parameters observed are hardness and crunchiness, water and starch content before and after frying. The result showed that hardness and crunciness change as the function of water vaporization and the decrease of starch content can be used to predict hardness and crun...
Indonesian Journal of Chemistry, 2014
Controlled Release Urea Fertilizers-based hydrogels matrices was synthesized by graft copolymeriz... more Controlled Release Urea Fertilizers-based hydrogels matrices was synthesized by graft copolymerization of acrylamide onto the rice straw cellulose backbones in the presence of silica fillers using simultaneous graft copolymerization by gamma irradiation as initiator. Evidence of the silica presence on grafted cellulose was obtained from FTIR. X-ray diffraction analysis showed that the crystalline was reduced through silica fillers added. The effect of silica content on grafting efficiency, gel fraction, Young modulus, swelling degree, and urea loading were examined. It was found that grafting efficiency and gel fraction decrease with increasing silica added inversely with Young modulus. Water swelling and loading urea fertilizers into hydrogels matrices were conducted and the results showed that swelling degree and urea fertilizers loading increased first and then decreased with increasing silica added. The effect of the silica fillers had implications in the mechanism of controlled...
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Papers by Rochmadi Rochmadi