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All Journal Eksergi: Chemical Engineering Journal Seminar Nasional Teknik Kimia Kejuangan Jurnal Rekayasa Proses
Perwitasari Perwitasari
Universitas Pembangunan Nasional "Veteran" Yogyakarta
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Control & Systems Engineering Education Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Social Sciences

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Ekstraksi Ultrasonik Karotenoid pada Kulit Waluh Menggunakan Pelarut Virgin Coconut Oil Susanti Rina Nugraheni; Perwitasari Perwitasari; Heni Anggorowati
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2020: PROSIDING SNTKK 2020
Publisher : Seminar Nasional Teknik Kimia "Kejuangan"

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Abstract

Model Dispersi Gas dan Vapor Cloud Explosion pada Kebocoran Outlet Pigtail Tubes Primary Reformer Perwitasari Perwitasari; Sumardi Sumardi; Indra Perdana
Jurnal Rekayasa Proses Vol 12, No 1 (2018)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.33802

Abstract

Outlet pigtail tubes, one of the components in primary reformer, have a function to carry the reformed gas from the catalyst tubes to the collection manifold. Moreover, it also has a function to provide the required flexibility within the system to avoid overstress at the end of connections of the pigtail to the manifold and to the bottom of the catalyst tube. It operates in an extreme condition with temperature range of 825-850 oC and pressure 36.2 kg/cm2 which is possible to initiate a failure. The consequences of outlet pigtail tubes failure are a dispersion of synthesis gas and vapor cloud explosion. This research aimed to make a model of those consequences with an assumption that the leakage hole was the same as the diameter of outlet pigtail tubes. The gas dispersion model used in this research was dense gas dispersion continuous release model. The results showed that the highest ratio of synthesis gas-air concentration was 0.1 at 17.4 m distance from leaking point. Whereas the lowest ratio of synthesis gas-air concentration was 0.002 at 163.4 m distance from leaking point. The highest ratio of the concentration of gas dispersion gave vapor cloud explosion energy of about 11.67 x 105 kJ with an overpressure of about 8.41 kPa. The overpressure caused a partial demolition of the building (for example control room), panels blow in, and fastening fails of equipment or machines around the area. A B S T R A KOutlet pigtail tubes adalah salah satu komponen pada primary reformer yang berfungsi untuk membawa gas hasil reforming dari tube katalis ke manifold. Selain itu outlet pigtail tubes juga berfungsi untuk memberikan fleksibilitas yang diperlukan di dalam sistem sehingga terhindar dari overstress di bagian akhir sambungan antara pigtail dengan manifold dan bagian bawah dari tube katalis. Outlet pigtail tubes beroperasi pada kondisi ekstrim yaitu suhu 825-850 oC dan tekanan 36,2 kg/cm2 yang mana memungkinkan untuk terjadinya kegagalan. Konsekuensi dari kegagalan outlet pigtail tubes adalah dispersi gas sintesis dan ledakan awan uap. Penelitian ini bertujuan untuk membuat model dari konsekuensi tersebut dengan asumsi bahwa lubang kebocoran sama dengan diameter outlet pigtail tubes. Model dispersi gas yang digunakan dalam penelitian ini adalah model dispersi dense gas untuk pengeluaran yang kontinu. Hasil menunjukkan bahwa rasio konsentrasi gas sintesis-udara tertinggi adalah 0,1 pada jarak 17,4 meter, sedangkan rasio konsentrasi terendah adalah 0,002 pada jarak 163,4 meter. Konsentrasi tertinggi dari gas terdispersi memberikan energi untuk ledakan awan uap sebesar 11,67 x 105 kJ dengan overpressure sebesar 8,41 kPa. Overpressure tersebut menyebabkan kerusakan pada sebagian dari bangunan (sebagai contoh ruang kontrol), terlemparnya papan, dan mempercepat kegagalan dari peralatan atau mesin di sekitar area.
Fly Ash – Alginate Composites Beads for Rhodamine B Removal Heni Anggorowati; Perwitasari Perwitasari; Indriana Lestari
Eksergi Vol 19, No 3 (2022)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v19i3.8199

Abstract

Dyes are a very serious problem for the environment. Composite beads consisting of fly ash and sodium alginate proved to be an adsorbent to reduce rhodamine b from dye waste. In this study, the effect of the mass of beads (5-45 grams), the pH of the solution (2-11) and the stirring time (0-360 min) was studied. Determination of concentration after adsorption was carried out by UV-Vis spectrophotometer. The maximum reduction in rhodamine b concentration of 31.15% was obtained after the adsorption process for 300 minutes with a mass of 35 grams of beads. The adsorption of rhodamine b is quite sensitive to the pH of the solution and shows the optimum adsorption value at pH 2. Based on the characterization with BET, fly ash – alginate beads include mesopores with a pore diameter of 10 nm, a total pore volume of 5,332 x 10-3 cc/g and a pore surface area. 2,133 m2/g
Utilization of Papaya Seed Powder as a Bioadsorben to Reduce Total Iron (Fe) in Wastewater Munira Munira; Andi Aladin; Perwitasari Perwitasari; Nur Aulia Hamza; St Umrah Tulzhaliza
Eksergi Vol 19, No 3 (2022)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v19i3.8007

Abstract

Papaya is a tropical plant that is widely cultivated in Indonesia. Papaya seeds have a high cellulose content, so that papaya seeds can be used as raw material for adsorbents (biosorbents). Biosorbent is used to reduce environmental pollution through the absorption of various types of liquid waste including heavy metals. Fe is an essential heavy metal if in excess amounts can cause toxic effects. One of the methodes to reduce  of iron ion in wastewater is  the adsorption method is using papaya seed biosorbents. The aim of study was to determine the effectivness of using papaya seedd as bioadsorbent  to reduce of iron ion in the wastewater. Papaya seed as the adsorbent agent activated ones was used in five particle size and contact time variations in order to determine the optimum particle size and contact time of papaya seed powder to absorb the heavy metals. The results show that the optimum adsorbent particle size was 100 mesh and the optimum contact time was 60 minute. The adsorption efficiency of (Fe) metal ions in wastewater was 60%, the adsorption capacity value was 0.365 mg/g.  Kinetic modelling of adsorption process is  pseudo second order.
Edible Oil sebagai Pelarut Ekstraksi Karotenoid dari Kulit Labu Kuning (Cucurbita moschata) Perwitasari Perwitasari; Heni Anggorowati; Susanti Rina Nugraheni; Indriana Lestari
Eksergi Vol 20, No 2 (2023)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v20i2.10003

Abstract

Carotenoids are pigments found in various types of fruits and vegetables that provide yellow, orange, and red colors. This study aimed to extract yellow pumpkin skin using edible oil solvents. The extraction process was carried out using ultrasound-assisted extraction (UAE) method with virgin coconut oil (VCO) and palm kernel oil (PKO). Yellow pumpkin peel powder with sizes of 40 mesh and 100 mesh were extracted with variations in extraction time (30 minutes, 60 minutes, and 90 minutes) and variations in solid-to-solvent ratio (1:10, 1:20, 1:30, 1:40, and 1:50). UV-Vis spectrophotometer analysis was used to determine the concentration of the extraction results. According to the research results, the best carotenoid concentration of 2513.44 ppm was obtained using PKO solvent with a powder size of 100 mesh, extraction time of 30 minutes, and powder-to-solvent ratio of 1:10.
Co-Authors Andi Aladin Indra Perdana Indriana Lestari Indriana Lestari Munira Munira Nur Aulia Hamza St Umrah Tulzhaliza Sumardi Sumardi Susanti Rina Nugraheni Susanti Rina Nugraheni