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Sri Wahyu Murni
Chemical Engineering UPN "Veteran" Yogyakarta
Chemical Engineering, Chemistry & Bioengineering

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Pembuatan Biodiesel dari Minyak Jelantah dengan Bantuan Gelombang Ultrasonik Sri Wahyu Murni; Latifah Nurrahmaningsih; Punden Fitrianti; Alex Sando; Jefry Roy James
Eksergi Vol 15, No 1 (2018): Vol 15, No 1 (2018)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v15i1.2291

Abstract

In this research, the effect of ultrasonic on the transesterification reaction of waste cooking oil to biodiesel is studied. The biodiesel production from waste cooking oil is conducted in two process stages. All reactions are conducted with the ultrasonic power of 750 watt and frequency of 20 kHz. The first stage is the esterification process that aims to reduce the free fatty acid (FFA) contents using acid catalyst. The esterification reaction is carried out in certain condition. The second stage is the production of biodiesel through transesterification using alkaline catalyst. The parameters being studied are the effect temperature and ultrasonic amplitude to the transesterification reaction. The results shows that the FFA content can be reduced to 0,77% using sulfuric acid catalyst 1% by weight of oil, methanol to oil ratio of 6:1 and a reaction time of 60 minutes. Then, the oil is converted into biodiesel using KOH catalyst. The obtained conversion is 83% with the catalyst amount of 1% by weight of oil, methanol to oil ratio of 6:1, frequency of 20 kHz, amplitude of 50%, temperature of 60oC and reaction time of 40 minutes. The biodiesel has a density of 879 kg /m3 , 5,67 cst of viscosity, flash point of 158oC, pour point of 16oC, water content 0,0642% and caloric value 8521,1 kkal/kg.
Produksi Poli-β-hidroksibutirat (PHB) Menggunakan Bakteri Bulkhoderia cepacia Sri Wahyu Murni; Gunarto Gunarto
Eksergi Vol 9, No 1 (2008): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v9i1.7557

Abstract

Plastics have important roles nowadays. However, its non-biodegradable property potentially makes a great problem because of the accumulation of its waste. Therefore, many researches about biodegradable plastics have been developed. Poly-β-hydroxybutyrate (PHB) is an alternative material to produce biodegradable plastics. The objectives of this research are to study the production of PHB by using Bulkhoderia cepacia bacteria and soluble starch substrate and determine the kinetics parameters including maximum specific growth rate (μmaks), saturation constant (Ks), and yield ratio of product-to-bacterial cell (YP/X). Fermentation was conducted at room temperature by using Ramsay medium with soluble starch at certain concentrations. The starter of Bulkhoderia cepacia incubated for 24 hours was inoculated as many as 10% by volume. The PHB product and dry cell weight were analyzed at certain several time intervals. This experiment was repeated at variation of phosphate concentrations.This research showed that the optimum cell growth and PHB production was obtained at soluble starch concentration of 8 g/100 ml and growth period of 72 hours. At this condition, the results were the dry cell weight of 7.5 mg/ml and PHB concentration of 0.0095 mg/ml. The values of kinetics parameters were μ maks of 0.01292 g/ml. h, Ks of 0.2854 g/ 100ml, YP/X of 0.00143. The accumulation of PHB was optimum at limited phosphate concentration. It could be also concluded that Bulkhoderia cepacia was a non-effective bacteria to produce PHB.
Polymerization Styrene dengan Solven Toluena Sri Wahyu Murni; Wasir Nuri; Indriana Lestari; Ani Saraswati
Eksergi Vol 9, No 1 (2009): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v9i1.7579

Abstract

Polystyrene is the result of free radical-addition polymerization of styrene monomer with the initiator benzoyl peroxide. This research aims to study the effect of variable temperature and ratio of toluene-styrene (T / S) against the conversion and reaction kinetics of polymerization of styrene with toluene solvent and initiator benzoyl peroxide. This research was conducted in two stages, ie preliminary experiments with test FTIR (Fourier Transform Infra-Red) to prove that the manufacture of polystyrene was successful. Manufacture of polystyrene begins with purifying styrene monomer, and then enter a toluene-styrene (5:1 volume ratio, 5:2, 5:3, 5:4) and 0.2 gram of benzoyl peroxide into a three-neck flask and heated to the desired temperature (60, 70, 80, 90 and 100)oC. Samples were taken every 15 minutes. Each sample is added 0.01 grams of hydroquinone in 10 ml of ethanol and shaken gently to precipitate the polystyrene, then wet samples were weighed, put in oven at 200oC for 1.5 hours. Dried sample was cooled in eksikator then weighed to determine the weight of polystyrene formed. From the experimental results at optimum condition of reaction time of 120 minutes, the temperature of 100oC and toluene-styrene ratio of 5:4, obtained by conversion of 58.75%. The global rate reaction according to equation k' = 5963 exp (-8901 / T).
Co-Authors Alex Sando Ani Saraswati Gunarto Gunarto Indriana Lestari Jefry Roy James Latifah Nurrahmaningsih Punden Fitrianti Wasir Nuri