Restu Kartiko Widi
Department of Chemical Engineering, Faculty of Engineering, University of Surabaya, TG Building 6th floor, Jl. Raya Kalirungkut Surabaya 60293

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Immobilization of Lipase on Surfactant-Modified Bentonite and Its Application for Biodiesel Production from Simulated Waste Cooking Oil Chrisnasari, Ruth; Yonardi, Angelina; Lie, Hesti; Widi, Restu Kartiko; Purwanto, Maria Goretti Marianti
UNEJ e-Proceeding Indonesian Protein Society (IPS), International Seminar and Workshop 2014
Publisher : UNEJ e-Proceeding

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Abstract

The influence of bentonite modification by cationic surfactant hexadecyl-trimethyl-ammonium bromide (HDTMA-Br) and tetramethyl ammonium hydroxide (TMAOH) on its capability to immobilize lipase was studied. Modification of bentonite was conducted by the adding of 4-6% (v/v) HDTMA-Br and TMAOH respectively. The obtained immobilized lipases then were characterized to observe the optimum pH and temperature as well as their stability during reuse application. The observed results show that there is no significant difference between the variations of HDTMA-Br concentrations to the percentage of immobilized enzyme which can immobilize lipase up to 75-78%. However, the best concentration of TMAOH is 4% (v/v) which can immobilize lipase up to 97.95%. The obtained immobilized lipases on HDTMA-Br-modified bentonite show the optimum catalytic activity on reaction temperature of 35-40 oC and pH of 7.5. In other hand, the optimum catalytic activity of immobilized lipases on TMAOH-modified bentonite is 40oC of incubation temperature and pH of 7. The immobilized lipases on both HDTMA-Br and TMAOH modified bentonite are stable enough so it could be re-used four times before its activity decreased by 48,565% and 46.83 % respectively. Keywords: Lipase, Cationic Surfactant, Bentonite, HDTMA-Br, TMAOH, Biodiesel, Immobilization.
Glucose Oxidase Immobilization on TMAH-Modified Bentonite Chrisnasari, Ruth; Wuisan, Zerlina Gabriela; Budhyantoro, Arief; Widi, Restu Kartiko
Indonesian Journal of Chemistry Vol 15, No 1 (2015)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (365.594 KB) | DOI: 10.22146/ijc.21219

Abstract

The influence of bentonite modification by tetramethyl ammonium hydroxide (TMAH) on its capability to immobilize glucose oxidase (GOX) was studied. Modification of bentonite was conducted by the adding of 0-5% (v/v) TMAH. The observed results show that the different concentrations of TMAH affect the percentage of immobilized enzyme. The results of this study show that the best concentration of TMAH is 5% (v/v) which can immobilize up to 84.71% of GOX. X-ray diffraction (XRD) and Fourier Transforms Infrared Spectroscopy (FTIR) studies have been carried out to observe the structural changes in bentonite due to TMAH modification. The obtained immobilized GOX show the optimum catalytic activity on reaction temperature of 40-50 °C and pH of 7. The immobilized GOX kinetics at the optimum conditions determined the Km and Vmax value to be 4.96x10-2 mM and 4.99x10-3 mM.min-1 respectively. In addition, the immobilized GOX on TMAH-modified bentonite is stable enough so it could be re-used six times before its activity decreased by 39.44%.
KINETIC INVESTIGATION OF PROPANE DISAPPEARANCE AND PROPENE FORMATION IN PROPANE OXIDATION ON DILUTED AND LEACHED MoVTeNb CATALYST Widi, Restu Kartiko
Indonesian Journal of Chemistry Vol 10, No 2 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (211.106 KB) | DOI: 10.22146/ijc.21456

Abstract

Reaction kinetics for the oxidation of propane over diluted-leached MoVTeNb is described. This paper is focused on the study of products selectivity profile and determination of the orders of propane disappearance and propene formation. The result shows that selective oxidation of propane to propene over this catalyst follows the Langmuir-Hinshelwood mechanism. The disappearance of propane is first order with respect to hydrocarbon and partial order (0.21) with respect to oxygen. The propene formation is first order with respect to hydrocarbon and not depending on oxygen concentration.
KINETIC INVESTIGATION OF CARBON DIOXIDE, ACETIC ACID, ACRYLIC ACID FORMATION ON DILUTED AND LEACHED MoVTeNb CATALYST Widi, Restu Kartiko
Indonesian Journal of Chemistry Vol 12, No 2 (2012)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (235.727 KB) | DOI: 10.22146/ijc.21352

Abstract

Reaction kinetics for the oxidation of propane over diluted-leached MoVTeNb is described. This paper is focused on the study of determination of the orders of carbon dioxide, acetic acid and acrylic acid formation. Deep oxidation of propane to carbon dioxide is first order with respect to hydrocarbon, and partial order (0.31) with respect to oxygen. The selective oxidation of propane to acrylic acid is partial order (0.49) with respect to hydrocarbon and partial order (0.09) with respect to oxygen.
Steam Influence and Effect of Oxidant Amount on Propane Oxidation over Multi Metal Oxide Catalyst Using High-Throughput Experiment Widi, Restu Kartiko; Abd Hamid, Sharifah Bee
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (288.055 KB) | DOI: 10.22146/ijc.23959

Abstract

The high-throughput experimentation technique was used to verify the testing conditions due to the effects of catalyst structure modifications and/or due to reaction parameter variation in parallel. In this paper, the design of experiment and catalytic results are discussed in the development of selective oxidation catalyst, to demonstrate the importance and versatility of such technology. It is used for the automated parallel testing of selective oxidation of propane to acrylic acid over some types of multi metal oxide catalysts. The catalysts used for performance test were Mo (molybdenum), cat-1 (unsupported Mo1V0.3Te0.23Nb0.125O), and cat-2 (supported Mo1V0.3Te0.23Nb0.125O). All catalysts were dried using spray drier. The effect of some reaction parameters, such as the amount of oxidant, presence of steam and reaction temperature was also investigated during the test. The configuration of the ‘nanoflow’ is shown to be suitable to screen catalytic performance. The results obtained gave very good reproducibility.
CATALYTIC ACTIVITY TEST OF MO-V-TE-NB-OXIDE IN AMMOXIDATION OF PROPANE TO ACRYLONITRILE Widi, Restu Kartiko
CHEMISTRY PROGRESS Vol 7, No 1 (2014)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.7.1.2014.4846

Abstract

The ammoxidation of propane has been investigated at a multicomponent oxidic, MoVTeNb catalyst in the temperature of 673 K. The catalyst was prepared by sol-gel method, and dried by spray dried method. The activity test of the catalyst has been carried out using micro reactor and showed that it was active for ammoxidation of propane to acrylonitrile.   Keywords : ammoxidation, propane, mixed metal oxide catalyst, acryilonitrile
Screening and Identification of Alkaloid Compounds in Kayu Kuning Stem (Arcangelisia Flava Merr) Kartiko Widi, Restu; Indriati, Titin
Jurnal ILMU DASAR Vol 8 No 1 (2007)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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Abstract

Extraction of kayu kuning stem (Arcangelisia flava Merr) with petroleum ether, chloroform and methanol 80% to screen of alkaloid compound has been carried out. Extract of chloroform was added by 10% of NH3 solution and Al2O3, then put into column chromatography and flowed by chloroform. Eluat was tested by dragendorf reagant to know the present of the alkaloid compound. This eluat was identified by thin layer chromatography with chloroform-methanol (1:4 v/v) as a mobile phase. It gave four spots that had the Rf value of 0.78; 0.64; 0.41; 0.18. After these spots were added by dragendorf reagant, only the first spot gave positive result. Then the chloroform fraction was separated by column chromatography to take the fraction which had Rf value of about 0.78 and thenit was analyzed by spectroscopic method (uv-vis and infra red). The data suggested that the alkaloid compound was the pyridin alkaloids group.
Immobilization of Lipase on Surfactant-Modified Bentonite and Its Application for Biodiesel Production from Simulated Waste Cooking Oil Chrisnasari, Ruth; Yonardi, Angelina; Lie, Hesti; Widi, Restu Kartiko; Purwanto, Maria Goretti Marianti
UNEJ e-Proceeding Indonesian Protein Society (IPS), International Seminar and Workshop 2014
Publisher : UPT Penerbitan Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The influence of bentonite modification by cationic surfactant hexadecyl-trimethyl-ammonium bromide (HDTMA-Br) and tetramethyl ammonium hydroxide (TMAOH) on its capability to immobilize lipase was studied. Modification of bentonite was conducted by the adding of 4-6% (v/v) HDTMA-Br and TMAOH respectively. The obtained immobilized lipases then were characterized to observe the optimum pH and temperature as well as their stability during reuse application. The observed results show that there is no significant difference between the variations of HDTMA-Br concentrations to the percentage of immobilized enzyme which can immobilize lipase up to 75-78%. However, the best concentration of TMAOH is 4% (v/v) which can immobilize lipase up to 97.95%. The obtained immobilized lipases on HDTMA-Br-modified bentonite show the optimum catalytic activity on reaction temperature of 35-40 oC and pH of 7.5. In other hand, the optimum catalytic activity of immobilized lipases on TMAOH-modified bentonite is 40oC of incubation temperature and pH of 7. The immobilized lipases on both HDTMA-Br and TMAOH modified bentonite are stable enough so it could be re-used four times before its activity decreased by 48,565% and 46.83 % respectively. Keywords: Lipase, Cationic Surfactant, Bentonite, HDTMA-Br, TMAOH, Biodiesel, Immobilization.
Combinatorial Technology as a New Method for Chemical Processes Widi, Restu Kartiko; Hamid, Sharifah bee Abdul; Hong, Looi Mei
Jurnal ILMU DASAR Vol 10 No 1 (2009)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (412.412 KB)

Abstract

The ultimate goal approach to combinatorial catalysis taken in this research is from an academic perspective where the main objective is to accelerate the discovery of catalytic phenomena, i.e. new catalytic materials and catalytic processes, constrained by limited equipment and human resources. A commercially synthesis robotic workstation is used for automated parallel preparation of catalyst libraries, which is able to reproduce a conventional catalyst preparation method used routinely in laboratory, thereby increasing significantly the number of catalysts that can be prepared at once. The aim of this work is to produce libraries of catalysts based on this type of system to be tested and optimized by using the high throughput screening reactors and the selected catalysts are characterized to understand the structural properties. The 12 parallel reactors allows a proper catalyst testing, under more realistic conditions than in conventional combinatorial techniques, especially when the catalyst stage is advanced and quantitative data is required.