Papers by Johnner Sitompul
The purposes of this paper are two folds. The first purpose is to improve system performance of P... more The purposes of this paper are two folds. The first purpose is to improve system performance of PID environment system by incorporating a fuzzy high-level controller. The second is to present an online genetic algorithm for learning the parameters of the fuzzy controller. The case study is employed to a nonlinear process consisting of three input variables, three output variables, and four disturbance variables. From the simulation it is shown that the output performance can be improved while maintaining the robustness.
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Nusantara Bioscience
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Malaysian Journal of Fundamental and Applied Sciences
Nanocomposites were prepared by melt extrusion technique using single screw extruder and subseque... more Nanocomposites were prepared by melt extrusion technique using single screw extruder and subsequent hot compression. In this work, poly lactic acid-clay nanocomposites were obtained using two types of clays, namely commercial montmorillonite (Cloisite 30B) and commercial bentonite. Nanocomposites were prepared at low clay composition of 0.5, 1, 3, and 5 wt.% of clays. From XRD spectra, the partially exfoliation of nanoclay layers were occurred during melting extrusion. It resulted in improvement of mechanical properties, such as Young’s modulus, tensile strength, and elongation at break. The highest tensile strength was obtained by the addition of 0.5 wt.% commercial bentonite increasing about 23.25% compared to the neat PLA. The increasing composition of clays revealed a decrease in mechanical properties due to filler-filler interaction. Furthermore, water absorption of nanocomposites up to `1 wt.% of clays better than the neat PLA. Biodegradability was enhanced in the presence of ...
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KOVALEN: Jurnal Riset Kimia
Development of renewable resource-based polymers attracts attention to solve environmental proble... more Development of renewable resource-based polymers attracts attention to solve environmental problems due to the build up of polymer (plastic). Poly(lactic acid) (PLA) is one of the most widely used polymers which have good biodegradability and processability. The addition of fillers to the PLA matrix aims to improve the characteristics of the PLA, such as mechanical properties of nanocomposites of PLA. Thus, PLA can be use as substitution of fossil fuel-based polymer. Spent Bleaching Earth (SBE) can be used as a filler after regeneration process. SBE was extracted and oxidized to take its oil content. Then, SBE was modified with urea solution to increase the interlayer distance. In this study, structure of nanocomposites was characterized using X-Ray Diffraction and mechanical properties of nanocomposites were characterized using Universal Testing Machines. X-Ray Diffraction characterization results show that PLA-SBE nanocomposite and PLA-modified regenerated SBE nanocomposites do no...
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Malaysian Journal of Fundamental and Applied Sciences
In this study, the effect of fermentation substrate and its concentration on cell growth and dode... more In this study, the effect of fermentation substrate and its concentration on cell growth and dodecanedioic acid (3DA) production by wild type Candida tropicalis isolated from Ambarella fruit shells in Indonesia was studied. The types of substrate (lauric acid and methyl laurate) and their concentrations (1, 3, 5 g/L) were varied. The addition of 1.67%-v/v of surfactant Tween-80 increased the solubility of lauric acid and methyl laurate by 13% and 91%, respectively, as measured by gas chromatography. The added substrates were then utilized by C. tropicalis for its growth, whereby the maximum biomass concentration measured by spectrophotometry was attained in methyl laurate system on the last day of experiment (day 5 of bioconversion phase). The cell growth was followed by 3DA production in which the maximum yield was obtained on the fourth day after substrate addition. The maximum 3DA yield of 0.247 g-3DA/g-dissolved substrate was obtained with lauric acid while the maximum 3DA yield...
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Indo. J. Chem. Res.
In this study, bentonite was used as a filler in the synthesis of polylactic acid (PLA) nanocompo... more In this study, bentonite was used as a filler in the synthesis of polylactic acid (PLA) nanocomposite. The mechanical property of PLA-Bentonite nanocomposite was treated using two different surfactants, namely octadecyl amine (ODA) and trimethyl stearyl ammonium chloride (TSC) at two different concentration (20 mmol and 40 mmol). The treatments of ODA and TSC in the matrix with regards to the basal spacing of bentonite stacks measured by X-Ray Diffraction (XRD) analysis. The results showed a significant increase in basal spacing was obtained when TSC 40 was applied for treatment. Data of Fourier Transform Infrared Spectroscopy (FTIR) suggested that this increase was caused by the incorporation of surfactant into the bentonite stacks. Most of the PLA-Bentonite nanocomposite can form intercalation structure, while a sample containing TSC 40 formed exfoliation structure. This exfoliation structure resulted in a film with the best tensile strength and water vapor permeability compared ...
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Jurnal Teknik Kimia Indonesia
Marine vegetation anaerobic biodegradation and biogas production in a mini-pilot digesterThis pap... more Marine vegetation anaerobic biodegradation and biogas production in a mini-pilot digesterThis paper describes the productivity of biogas from anaerobic biodegradation of macroalgae Ulva lactuca and Padina sp. Marine biomasses especially macroalgae contain less lignin, thus the anaerobic biodegradability of these biomasses was higher than terrestrial biomass. Banana stem waste was used as comparison for the feedstock. Initial inoculums were prepared from cow manure and water. The inoculums and substrates were fed into a mini-pilot digester, operating semi-continuously. Volume of biogas was measured daily while methane content was measured every 3 days using gas chromatograph. Biogas productivity from the mini-pilot digester for feedstock Padina sp., U. lactuca, and banana stem waste was 5.22, 4.88, and 3.06 L respectively, after 28 days operation, with methane content 64.85, 49.90, and 34.76 %-v/v, respectively. The study also shows that lignin content in Padina sp., U. lactuca, and ...
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Jurnal Teknik Kimia Indonesia
bstrak. Minyak jarak kaliki (Ricinus communis L.) merupakan salah satu bahan baku terbarukan yang... more bstrak. Minyak jarak kaliki (Ricinus communis L.) merupakan salah satu bahan baku terbarukan yang banyak diaplikasikan di berbagai industri kimia. Salah satu dari turunan minyak jarak kaliki yaitu metil 12-hidroksistearat merupakan metil ester yang memiliki manfaat dalam berbagai jenis industri, khususnya industri pelumas. Makalah ini membahas produksi metil 12-hidroksistearat via hidrogenasi ester minyak jarak dalam reaktor mini-pilot. Makalah ini membahas kondisi optimum proses hidrogenasi dari metil ester risinoleat dengan melakukan variasi terhadap tekanan dan temperatur operasi. Tekanan dan temperatur operasi proses hidrogenasi divariasikan pada rentang 2-4 bar dan 150-210℃. Diperoleh produk hidrogenasi metil ester risinoleat dengan konsentrasi massa metil 12-hidroksistearat mencapai 61,28% dan angka iodin 23,84. Peningkatan temperatur dan tekanan operasi meningkatkan konversi metil 12-hidroksistearat dan menurunkan angka iodin. Pada rentang variasi kondisi, kondisi operasi opt...
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Jurnal Rekayasa Proses
Lactic acid is a platform chemical that is usually used to form various chemical products. Nowada... more Lactic acid is a platform chemical that is usually used to form various chemical products. Nowadays, the need of lactic acid is increasingly high especially for bio-based chemical as a substitute for petroleum-based one. Catalytic chemical conversion is seemingly potential to substitute the bioconversion pathway. This research aims to determine the best operating condition for separating lactic acid from its mixture (the catalytic conversion product of oil palm empty fruit bunch) by esterification-hydrolysis in order to produce the highest yield and purity. The esterification of the mixture was carried out by using n-butanol as a solvent and wet Amberlyst-15 as a catalyst. The esterification process was conducted by reacting n-butanol and lactic acid for 6 hours in a batch reactor. Hydrolysis was then followed by reacting organic phase as an esterification product and water in batch reactor system for 4 hours. The result showed that the higher reactant volume ratio, temperature, and...
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MATEC Web of Conferences
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MATEC Web of Conferences
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International Journal of Oil Palm
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Journal of Engineering and Technological Sciences
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International Journal of Renewable Energy Development
This paper concerns on process evaluation and modification for bioethanol separation and producti... more This paper concerns on process evaluation and modification for bioethanol separation and production by applying pinch technology. Further, the paper is also focused on obtaining a most energy-efficient process among several processes. Three basic process configurations of bioethanol separation and production were selected for this study. The three separations and production systems are Othmer process, Barbet process and a separation process that operates under vacuum condition. Basically, each process is combination of Danish Distilleries process with a separation system yielding 95% (v/v) bioethanol. The production capacity of the plant is estimated about 4 x 107 litre of bioethanol 95% (v/v) per year. The result of the studies shows that the most energy efficient process among the three processes evaluated is the Othmer process, followed by the Barbet process and the process involving vacuum operation. The evaluation also shows that further energy saving can be carried for Barbet ...
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Journal of Engineering and Technological Sciences
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International Journal of Engineering & Technology
This paper concerns on synthesis of nanocomposites consisting of Poly(lactic acid) (PLA) and clay... more This paper concerns on synthesis of nanocomposites consisting of Poly(lactic acid) (PLA) and clays. Two types of clays were regenerated organobentonite and commercial organobentonite. PLA and clays were melt extruded using single-screw extruder. The extruded compound was pelletized, then hot pressed using compression molding machine. Regenerated organobentonite was obtained from regeneration of spent bleaching earth (SBE) using solvent extraction and oxidation method. Afterwards, regenerated SBE modified by organic compound. While, commercial organobentonite was directly modified of commercial bentonite using organic compound. In this study, nanocomposites were prepared with varying compositions of clays from 0% to 5% (by weight). Experimental results show that partially exfoliated nanocomposites structure was shown by X-ray diffraction analyses. In addition, the effect of clays on morphology structure, mechanical, barrier, and biodegradable properties were analyzed. The utilization...
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Journal of Engineering and Technological Sciences, 2016
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REAKTOR, 2012
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... akan diulas. 2 Metodologi penelitian. Skema rangkaian peralatan percobaan yang dipakai dalam ... more ... akan diulas. 2 Metodologi penelitian. Skema rangkaian peralatan percobaan yang dipakai dalam penelitian ini ditampilkan pada Gambar 1. Gambar 1 Skema rangkaian alat spouted-bed sistem padat-cair. Kolom spouted-bed ...
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Papers by Johnner Sitompul