Claim Missing Document
Check
Articles

Found 8 Documents
Search

Distilasi Azeotrop Campuran Etanol-Air untuk Meningkatkan Kadar Etanol menggunakan Entrainer Etil Asetat Retno Indarti; Rintis Manfaati; Ari Marlina; Keryanti
Fluida Vol 14 No 1 (2021): FLUIDA
Publisher : Jurusan Teknik Kimia, Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/fluida.v14i1.3426

Abstract

Bioetanol yang dapat digunakan sebagai campuran bahan bakar alternatif harus memiliki kadar 99%, sehingga perlu dilakukan proses pemurnian terhadap campuran etanol yang masih mengandung air. Distilasi sederhana campuran etanol-air menggunakan bahan tambahan (entrainer) etil asetat dapat dilakukan untuk meningkatkan kadar etanol. Pada penelitian ini, pemurnian etanol dilakukan dengan proses distilasi azeotrop pada tekanan atmosfer dan suhu penangas air sebesar 70-75oC. Komposisi umpan yang terdiri dari campuran etanol yang mengandung air dan etil asetat sebagai entrainer. Penelitian dilakukan sebanyak 5 run dengan variasi penambahan etil asetat ke dalam umpan sebanyak 10% v/v, 20% v/v, 30% v/v, 40% v/v dan 50% v/v. Hasil penelitian yang diperoleh yaitu penambahan etil asetat ke dalam umpan yang menunjukkan kadar etanol tertinggi dengan waktu yang paling singkat ialah pada penambahan etil asetat sebagai entrainer yaitu sebesar 30% v/v, yang terdiri dari campuran 15 ml etil asetat dan 35 ml etanol 80%. Hasil analisis yang dilakukan dengan kromatografi gas diperoleh konsentrasi etanol sebesar 99.80% dan waktu distilasi selama 90 menit
KARAKTERISASI SIMULATOR SISTEM PROTEKSI KATODIK METODE ANODA KORBAN PADA SISTEM PERPIPAAN YANG TERTANAM DALAM TANAH Retno Indarti; Yunus Tonapa Sarungu; Cut Magesang
Prosiding Industrial Research Workshop and National Seminar Vol 9 (2018): Industrial Research Workshop and National Seminar
Publisher : Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1060.598 KB) | DOI: 10.35313/irwns.v9i0.1039

Abstract

Sistem proteksi katodik anoda korban adalah salah satu metode pengendalian korosi untuk logam dalam sistem perpipaan di dunia industri minyak dan gas bumi yang tertanam dalam tanah, dengan cara menghubungkan anoda korban terhadap material yang diproteksi. Sistem perpipaan terdiri dari jaringan beberapa pipa sesuai dengan standar teknik perpipaan menurut SK Menteri Pertambangan dan Energi Nomor 300.K/38/M-PE/1997. Material yang diproteksi berperan sebagai katoda dan logam yang dikorbankan sebagai anoda. Penelitian ini dilakukan melalui proses perancangan, pembuatan, dan uji karakteristik simulator sistem proteksi katodik metode anoda korban yang berdasarkan acuan pada standar NACE (National Association of Corrosion Engineers). Struktur yang diproteksi berupa pipa seamless dengan luas permukaan 5,7424 m2. Kebutuhan arus proteksi adalah 0,003445 A. Anoda korban yang diterapkan pada simulator ini adalah anoda korban magnesium ( Mg) dengan berat 7 kg dan arus keluaran 0,0328 ampere. Hasil uji karakteristik pipa : potensial proteksi -1400mV/CSE. Anoda korban yang digunakan adalah anoda Magnesium, karena lebih efisien dan efektif daripada anoda Aluminium dan anoda Seng (Zn), sebagai anoda korban di lingkungan tanah. Pengukuran potensial proteksi untuk jarak yang tepat terhadap struktur pipa pada rentang 10-70cm dari punggung pipa.
Pengaruh Laju Alir Terhadap Penurunan Pengotor Limbah Laundry Metode Elektrokoagulasi Kontinyu Berpengaduk Agustinus Ngatin; Adi Rizki Nugraha; Mukhtar Gozali; Ageng Priyambudi; Tri Hariyadi; Rony Pasonang Sihombing; Yusmardhany Yusuf; Retno Dwi Jayanti; Retno Indarti
Fluida Vol 15 No 2 (2022): FLUIDA
Publisher : Jurusan Teknik Kimia, Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/fluida.v15i2.4040

Abstract

Limbah laundry dapat menjadi masalah serius bagi lingkungan jika dibuang tanpa pengolahan. Masalah yang timbul diantaranya nilai Chemical Oxygen Demand (COD), fosfat, dan kekeruhan yang tinggi. Tujuan penelitian yaitu mempelajari pengaruh laju alir terhadap efisiensi penurunan kadar kekeruhan, COD, dan TSS, serta menentukan kondisi optimalnya dengan alat elektrokoagulasi kontinyu berpengaduk. Reaktornya adalah reaktor berkapasitas 10 L dilengkapi pengaduk 180 rpm, pompa peristaltik, rectifier dan 3 pasang elektroda Alumunium dengan ketebalan 0,3x15x15cm yang disusun secara monopolar. Percobaan variasi laju alir (115mL/menit, 170 mL/menit, 340mL/menit) dilakukan dengan rapat arus tetap (70 A/m2), dengan waktu operasi 60 menit untuk setiap variasi. Hasilnya menunjukkan bahwa pada laju tinggi (340 mL/menit) dan laju rendah (115 mL/menit) menghasilkan efisiensi penurunan pengotor yang rendah dan laju alir terbaik ditunjukkan pada 170 mL/menit. Kondisi optimal terjadi pada laju alir 170 mL/menit pada rapat 70 A/m2 menghasilkan efisiensi penurunan kekeruhan, COD, dan TSS berturut-turut 89,35%, 73,33%, dan 99,26%. Laundry waste can be a serious problem for the environment if it is disposed of without treatment. Problems that arise include the value of Chemical Oxygen Demand (COD), phosphate, and high turbidity. The aims of the research were to study the effect of flow rate and current density on the efficiency of reducing turbidity, COD, and TSS levels, and to determine the optimal conditions using a continuous stirred electrocoagulation device. The reaktor used is a reaktor with a capacity of 10 L equipped with a 180 rpm stirrer, a peristaltic pump, a rectifier and 3 pairs of aluminum electrodes with a thickness of 0.3x15x15cm arranged in a monopolar manner. The flow rate variation experiment was carried out with a constant current density (70 A/m2), and the current density variation experiment was carried out with a fixed flow rate (170 ml/minute) with an operating time of 60 minutes for each variation. The results of the flow rate variation showed that at a high rate (340 ml/min) and a low rate (115 ml/min) resulted in a low impurity reduction efficiency, the best flow rate was shown at 170 ml/min. The results of the current density variation show that the increase in impurity reduction efficiency occurs as the current density increases, the best results occur at a current density of 70 A/m2. Optimal conditions occurred at a flow rate of 170 ml/min at a rate of 70 A/m2 resulting in the efficiency of reducing turbidity, COD, and TSS respectively 89.35%, 73.33%, and 99.26%.
Delaminasi Perekat Polivinil Asetat Berbasis Air Satu Komponen untuk Aplikasi Kayu Keras Ulin dan Merbau: Delamination on Polyvinyl Acetate Water Based Adhesive One Component for Ulin and Merbau Hard Wood Working Application Retno Indarti; Agustinus Ngatin; Robby Sudarman; Tifa Paramitha; Rony Pasonang Sihombing
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 2 (2022): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i2.15900

Abstract

Water-based adhesive was one of the most important media for bonding substrates to one another because of their environmental friendly character. Previously, in the application of hardwood adhesives such as Ulin and Merbau, the type of adhesive used was a two-component system. For this reason, a one-component water-based adhesive was introduced in this study. The advantage of these was environmental friendly and high durability. In this application, delamination was one of the important parameters to determine whether the adhesive used was well penetrated or not. For this reason, delamination will be the main parameter in this study. This research includes the preparation of tools and materials, manufacture of PVA (polyvinyl alcohol) solution, polymerization of polyvinyl acetate by mixing the main raw material of vinyl acetate monomer and PVOH solution using APS (ammonium persulfate) initiator. The polymerization process was carried out at 1 atm pressure and 75oC – 80oC temperature accompanied by stirring with ±500 rpm rotation rate. Final product is a homopolymer PVAc (polyvinyl acetate) with PVOH Z-210 with AAEM (acetoacetoxy ethyl methacrylate) content having an acetoxy functional group. A delamination test was carried out on the final product with a modified test based on Japanese Agricultural Standard 1152 where the product was immersed in water for 360 minutes, then placed in an oven at 40oC for 18 hours. Samples using PVOH with AAEM content have an average delamination rate of 0.67-1.67% while existing products on the market have an average delamination rate of 45.83-52.08%.
Sintesis dan Karakterisasi Carbon Nanodots dengan Metode Microwave Assisted Extraction: Synthesis and Characterization of Carbon Nanodots with Microwave Assisted Extraction Mentik Hulupi; Haryadi; Nabila Sofiyani; Rizka Amalia Nuriana; Retno Indarti; Fauzi Abdilah
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 2 (2022): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i2.15910

Abstract

Carbon nanodots (CNDs) is one of the carbon nanoparticles that are environmentally friendly, non-toxic, and have optical properties. The aim of this study was to synthesize CNDs from ascorbic acid as a precursor using the Microwave Assisted Extraction method. method. Best results are obtained at 4 minutes of heating and 500W of power. The synthesized CNDs solution showed a blue color under 365 nm UV light. The measurement results with UV Vis spectrophotometer showed the maximum wavelength at 341.5 nm with an energy gap of 5.57 eV. The results of the Fourier transform infrared spectroscopy (FTIR) analysis show that CNDs have the -OH (hydroxyl) functional group at a wave number of 3354.61 cm-1 and C=O functional group at a wave number of 1633.09 cm-1. Characterization results using High resolution transmission electron microscopy (HRTEM) showed that CNDs were spherical in shape with a particle size range of 2.54-9.48 nm.
Pengaruh Konsentrasi Inhibitor dari Eceng Gondok dalam Air Hujan dan Air Kran terhadap Laju Korosi: Effect of Water Hyacinth Inhibitor Concentration in Rain Water and Tap Water Media on Corrosion Rate Emma Hermawati; Yunus Tonapa Sarungu; Bambang Soeswanto; Rispiandi; Alfiana Adhitasari; Sudrajat Harris Abdulloh; Rony Pasonang Sihombing; Retno Indarti
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 2 (2022): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i2.15931

Abstract

Organic inhibitors in the corrosion process could be obtained from water hyacinth plant. This plant contained antioxidants such as saponins, which could bind to protective metals from corrosion. The objective of this study was to observe the corrosion rate degradation in rainwater and tap water with saponin content of water hyacinth extract with novelty of using methanol in the maceration process. The sample: methanol ratio used in the maceration process was 1 : 9 (w/v). Steel testing was carried out for 5 days in rainwater and tap water. Based on the test results, the saponin content in the water hyacinth extract could be proven by the stability of the foam produced. The experimental results showed a corrosion rate escalation in tap water samples from 47.7% to 94.5% and samples in rainwater from 11.3% to 52.9% at 75 ppm inhibitor concentration. Based on the research, water hyacinth extract using methanol solvent could be used as a corrosion inhibitor.
Ekstraksi Teh Hijau dan Aplikasinya sebagai Pengendali Korosi Pada Pompa di Lingkungan Garam NaCl 3,56%: Green Tea Extraction and Its Application as Corrosion Controller in 3.56% NaCl Retno Indarti
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 3 (2022): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i3.16160

Abstract

Green tea leaves contain antioxidant compounds that can be used as organic inhibitors in a corrosion process. Tea leaves were extracted by maceration method using 70% ethanol solution with a solid:solvent ratio of 1:8 (w/v) for 1 x 24 hours in an atmospheric room. The extract was then concentrated with a rotary evaporator and separated with solvent under vacuum conditions at 852 mbar, temperature of 70oC and rotation of 80 rpm. The results of the qualitative test of extra tea leaves using 10% NaOH and 1% FeCl3 changed the color to brownish orange and blue-black. This indicates the content of flavonoids and tannins. Green tea leaf extract is also applied to control the corrosion rate of brass metal. Variations in the concentration of tea leaves were 200, 400, 600 ppm in 3.56% NaCl solution. The pump circulation is carried out for 40 hours, the weight loss method is carried out every 8 hours. The average corrosion rate without inhibitor is 3.95 mmpy, the corrosion rate with 200 ppm inhibitor is 1.24 mmpy, the corrosion rate with 400 ppm inhibitor is 0.46 mmpy, the corrosion rate with 600 ppm inhibitor is 0.23 mmpy. A significant decrease in the corrosion rate occurred at a concentration of 600 ppm with an efficiency of 92.32%.
Laju Korosi Logam Baja Karbon Rendah di Larutan Garam pada Berbagai Konsentrasi Inhibitor Korosi dari Ekstrak Daun Pepaya: Low Carbon Steel Metal Corrosion Rate in Salt Solution at Various Concentrations of Corrosion Inhibitor from Papaya Leaf Extract Ninik Lintang Edi Wahyuni; Rony Pasonang Sihombing; Nurcahyo; Agustinus Ngatin; Yunus Tonapa Sarungu; Alfiana Adhitasari; Bambang Soeswanto; Emma Hermawati Muhari; retno indarti
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16344

Abstract

Papaya leaf extract could be used as an organic corrosion inhibitor. Corrosion inhibitors were used as a method to reduce corrosion rate. The most corrosive environment was the marine environment. The purpose of this study was to determine the best concentration of papaya (Carica papaya) leaf extract inhibitor which could reduce the corrosion rate of low carbon steel in a 3.56% NaCl solution environment. The maceration process was carried out for 24 hours with 70% ethanol solvent with a solute:solvent ratio of 1:8 (w/v) at room temperature. Inhibitor extracts were analyzed qualitatively with the phytochemical method. The addition of FeCl3 was carried out on the inhibitor extract from papaya leaves. The color change occurred from blackish brown to greenish black which indicated the presence of tannin compounds in the papaya leaf extract. Corrosion testing was carried out with hot stream temperature setting at 45⁰C to 55⁰C and concentrations of inhibitor extracts at 300, 600, and 900 ppm. The test was conducted for 36 hours with a span of metal mass every 6 hours. Corrosion rate calculation is done by weight loss method. The results showed that papaya leaf extract inhibitors positive contained corrosion inhibitor and could reduce the corrosion rate in 3.56% NaCl solution. The corrosion rate without inhibitor is 1.023 mmpy. Corrosion rates with inhibitor concentrations of 300, 600, and 900 ppm were 0.755, 0.585, and 0.438 mmpy, respectively.