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

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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.
Combinatorial Technology as a New Method for Chemical Processes Restu Kartiko Widi; Sharifah bee Abdul Hamid; Looi Mei Hong
Jurnal ILMU DASAR Vol 10 No 1 (2009)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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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.
Pengaruh jenis Spesies Pillaring Agent Logam Si dalam proses Pilarisasi Bentonit Alam Restu Kartiko Widi; Emma Savitri
Keluwih: Jurnal Sains dan Teknologi Vol. 6 No. 1 (2025): Keluwih: Jurnal Sains dan Teknologi (February) - In Progress
Publisher : Direktorat Penerbitan dan Publikasi Ilmiah, Universitas Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24123/saintek.v6i1.6424

Abstract

Abstract—The pillarization process of natural bentonite from Pacitan, East Java has been carried out using the metal species Si in Na-silicate and TEOS. The pillarization process is carried out using direct pillarization and indirect pillarization methods. In this research, the number of moles of metal pillaring agent used was 5 mmol/gram bentonite. The pillarization process is carried out by mixing the natural bentonite suspension and pillaring agent at a temperature of 80oC and stirring for 5 hours using a hot plate stirrer. Pillars were formed in the calcination and oxidation stages at a temperature of 500oC using N2 and O2 gas flows for 1 hour and 5 hours respectively. The resulting material was characterized using the FTIR spectroscopy method, X-ray diffraction and N2 gas adsorption using the BET method. The characterization results show that TEOS species can form better and more homogeneous pore structures compared to silicate species. The direct pillarization method provides better and more homogeneous pillar heights compared to the indirect pillarization method. However, the pore size obtained is still on the micropore size scale observed using the N2 gas adsorption method with the BET method. Keywords: pillarization, si, teos, bentonite Abstrak—Telah dilakukan proses pilarisasi bentonit alam asal Pacitan, Jawa Timur menggunakan spesies logam Si dalam Na-silikat dan TEOS. Proses pilarisasi yang dilakukan menggunakan metode pilarisasi langsung dan pilarisasi tidak langsung. Pada penelitian ini jumlah mol logam pillaring agent yang digunakan adlah 5 mmol/gram bentonit. Proses pilarisasi dilakukan dengan mencampurkan suspensi bentonit alam dan pillaring agent pada suhu 80oC dan diaduk selama 5 jam menggunakan hot plate stirrer. Pilar dibentuk pada tahap kalsinasi dan oksidasi pada suhu 500oC menggunakan aliran gas N2 dan O2 masing-masing selama 1 jam dan 5 jam. Material yang dihasilkan dikarakterisasi menggunakan metode spektroskopi FTIR, difraksi sinar-X dan adsorpsi gas N2 dengan metode BET. Hasil karakterisasi menunjukkan bahwa spesies TEOS dapat membentuk struktur pori lebih baik dan lebih homogen dibandingkan dengan spesies silikat. Metode plarisasi langsung memberikan tinggi pilar lebih baik dan lebih homogen dibandingkan dengan metode pilarisasi tidak langsung. Namun demikian ukuran pori yang diperoleh masih dalam skala ukuran mikropori yang diamati menggunakan metode adsorpsi gas N2 dengan metode BET. Kata kunci: pilarisasi, si, teos, bentonit