Dianursanti Dianursanti
Department of Chemical Engineering, Faculty of Engineering, University of Indonesia, Depok 16424, Indonesia

Published : 4 Documents
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Kinetic Model For Triglyceride Hydrolysis Using Lipase:Review

Makara Journal of Technology Vol 11, No 1 (2007)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food and cosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor for utilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil and water, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that the hydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between the interfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reaction mechanism should be considered in the model.

Biomass Production Chlorella Vulgaris Buitenzorg Using Series of Bubble Column Photo Bioreactor with a Periodic Illumination

Makara Journal of Technology Vol 12, No 1 (2008)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy consumption for cellular formation (Ex), and cultural bicarbonate species concentration [HCO3] also give better results on series of reactor.

Effect of Photoperiodicity on Co2 Fixation By Chlorella vulgaris Buitenzorg in Bubble Column Photobioreactor For Food Supplement Production

Makara Journal of Technology Vol 8, No 2 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

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Abstract

To reduce the level of CO2 content in air, effort on converting CO2 to useful products is required. One of the alternatives includes CO2 fixation to produce biomass using Chlorella vulgaris Buitenzorg. Chlorella vulgaris Buitenzorg is applied for production of food supplement. Chlorella vulgaris Buitenzorg is also easy to handle due to its superior adaptation. Currently, Chlorella vulgaris Buitenzorg has been analyzed by some experts for its cellular composition, its ability to produce high quality biomass and the content of essential nutrition. A  series of experiments was conducted by culturing Chlorella vulgaris Buitenzorg using Beneck medium in bubbling column photobioreactor. The main variation in this experiment was photoperiodicity, where growth of Chlorella vulgaris Buitenzorg was examined during photoperiodicity condition. The difference between CO2 gas concentration of inlet and outlet of the reactor during operational period, was compared to the same experiment under continuous illumination. Under photoperiodicity of 8 and 9 h/d, the culture cell densities (N) were approximately 40 % higher than under continuous illumination. Final biomass density of Chlorella vulgaris Buitenzorg at 9 h/d illumination was 1.43 g/dm3, around 46% higher than under continuous illumination. Specific carbon dioxide transfer rate (qCO2) in photoperiodicity was 50-80% higher than under continuous illumination. These experiments showed that photoperiodicity affects the growth of Chlorella vulgaris Buitenzorg The specific  growth rate (μ) by photoperiodicity was higher than that by continuous ilumination while the growth period was two times longer. Based on the experiments, it can be concluded that photoperiodicity might save light energy  consumption. The prediction of kinetic model under continuous illumination as well as under photoperiodicity illumination showed that Haldane model became the fitted kinetic model.

PENGARUH PENGURANGAN AIR TERPRODUKSI TERHADAP FLOW REGIME PADA PIPA PENYALUR DI LAPANGAN PHE-30 PT PHE WMO

Prosiding Seminar Nasional Pakar Prosiding Seminar Nasional Pakar 2019 Buku I
Publisher : Prosiding Seminar Nasional Pakar

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Abstract

PT Pertamina Hulu Energi West Madura Offshore (PHE WMO) berupayameningkatkan produksi minyak, salah satu cara yaitu melakukan optimalisasi pipa penyalur dari PHE-30 menuju fasilitas proses PPP dengan mengurangi slug flow pada pipa penyalur tersebut. Saat ini produksi minyak, gas dan air dari lapangan PHE-30 sebesar 2.070 Bopd, 5,1 MMscfd dan 10.800 Bwpd. Produksi minyak dari lapangan PHE-30 dapat dioptimalkan dengan menjaga gas liquid ratio (GLR) pada pipa penyalur tersebut. Optimalisasi ditujukan untuk menjaga fasilitas proses tetap aman dan terhidar dari kondisi shutdown atau terhenti sementara akibat terjadinya slug flow yang terjadi disepanjang pipa penyalur.Slug flow terjadi karena ketidakseimbangan perbandingan antara distribusi laju alir gas dan laju alir liquid pada pipa penyalur atau dapat disebut dengan gas liquid ratio (GLR).Perbedaan GLR ini disebabkan oleh tingginya air terproduksi dari dalam sumur PHE-30. Analisa dilakukan dengan menggunakan software Pipesim untuk melakukan simulasi flow regime pada pipa penyalur dari PHE-30 menuju PPP. Parameter yang digunakan yaitu laju alir minyak, gas dan air serta kecepatan superficial gas dan liquid. Hasil menunjukkan bahwa dengan pengurangan air terproduksi dari lapangan PHE-30 dengan GLR 2.463 scf/bbl, dapat merubah kondisi flow regime dari yang sebelumnya slug flow menjadi stratified flow.