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RECOVERY LOGAM NIKEL DARI SPENT KATALIS NiO/Al2O3 DENGAN TEKNOLOGI LEACHING MENGGUNAKAN AMONIA-AMONIUM KARBONAT Yuliusman, Y
Jurnal MIPA Vol 39, No 2 (2016): October 2016
Publisher : Jurnal MIPA

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Setiap tahun, limbah katalis NiO/Al2O3 dihasilkan oleh unit Hydrogen Plant UP VI Pertamina Balongan sebesar 100 ton mengandung Ni sekitar 10-25%. Melihat jumlah, potensi dan berbahayanya limbah katalis nikel, perlu dilakukan suatu proses memperoleh nikel dari limbah tersebut melalui proses leaching menggunakan amonia-amonium karbonat. Amonia-amonium karbonat dipilih karena memiliki sifat tidak korosif dan ramah lingkungan. Tujuan penelitian ini adalah untuk mendapatkan kondisi optimum proses leaching. Parameter yang akan diuji untuk proses leaching adalah konsentrasi leaching agent, suhu dan waktu proses, serta untuk proses ektraksi cair-cair adalah konsentrasi ekstraktan dan pH. Setiap variasi proses dilakukan secara sekuensial dengan pengujian AAS. Uji EDX dilakukan untuk membuktikan adanya kandungan nikel dalam limbah katalis NiO/Al2O3, hasilnya menunjukkan bahwa untuk logam nikel berada pada tingkat energi 7,477 dan 0,851 keV.Â Hasil analisis AAS untuk konsentrasi logam nikel awal pada katalis adalah sebesar 15,62 %-wt. Dari hasil leaching diketahui bahwa semakin tinggi suhu dan waktu proses, perolehan nikel akan semakin tinggi. Hasil penelitian menunjukkan bahwa kondisi optimum proses leaching adalah pada konsentrasi amonium karbonat 2 M, dengan suhu 60Â°C selama 5 jam, dengan rasio S/L sebesar 20 g/L, menghasilkan persentase leaching sebesar 29,31 % untuk sistem bejana terbuka.Annually, NiO/Al2O3 waste catalyst generated by Hydrogen Plant unit Pertamina at UP VI Balongan in the amount of 100 tonnes with Ni content of about 10-25%. Based on the number and dangerous waste nickel catalyst, it is necessary to do a recovery nickel process from that waste with leaching process using ammonia-ammonium carbonate. Ammonia-ammonium carbonate chosen because it has no corrosive properties and environmentally friendly. The purpose of this study is to obtain the optimum leaching conditions. The tested parameters for leaching processes are leaching agent concentration, temperature and processing time, and for liquid-liquid extraction process are the extractant concentration and pH. Each variation process was performed sequentially with AAS testing. EDX test was done to prove the existence of nickel content in the waste catalyst NiO/Al2O3, the results show that nickel at the level of energy 7.477 and 0.851 keV. AAS analysis results for the initial concentration of nickel metal in the catalyst was 15.62% -wt. From the leaching results was known that the higher temperature and processing time, the recovery of nickel will be higher. The results showed that the optimum conditions leaching process was at a concentration of 2 M ammonium carbonate, with Â temperature was 60Â°C for 5 hours, and the ratio S/L was 20 g/L, resulting leaching percentage of 29.31% for open vessel system.

RECOVERY LOGAM NIKEL DARI SPENT KATALIS NiO/Al2O3 DENGAN TEKNOLOGI LEACHING MENGGUNAKAN AMONIA-AMONIUM KARBONAT Yuliusman, Y
Indonesian Journal of Mathematics and Natural Sciences Vol 39, No 2 (2016): October 2016
Publisher : Universitas Negeri Semarang

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Setiap tahun, limbah katalis NiO/Al2O3 dihasilkan oleh unit Hydrogen Plant UP VI Pertamina Balongan sebesar 100 ton mengandung Ni sekitar 10-25%. Melihat jumlah, potensi dan berbahayanya limbah katalis nikel, perlu dilakukan suatu proses memperoleh nikel dari limbah tersebut melalui proses leaching menggunakan amonia-amonium karbonat. Amonia-amonium karbonat dipilih karena memiliki sifat tidak korosif dan ramah lingkungan. Tujuan penelitian ini adalah untuk mendapatkan kondisi optimum proses leaching. Parameter yang akan diuji untuk proses leaching adalah konsentrasi leaching agent, suhu dan waktu proses, serta untuk proses ektraksi cair-cair adalah konsentrasi ekstraktan dan pH. Setiap variasi proses dilakukan secara sekuensial dengan pengujian AAS. Uji EDX dilakukan untuk membuktikan adanya kandungan nikel dalam limbah katalis NiO/Al2O3, hasilnya menunjukkan bahwa untuk logam nikel berada pada tingkat energi 7,477 dan 0,851 keV.Â Hasil analisis AAS untuk konsentrasi logam nikel awal pada katalis adalah sebesar 15,62 %-wt. Dari hasil leaching diketahui bahwa semakin tinggi suhu dan waktu proses, perolehan nikel akan semakin tinggi. Hasil penelitian menunjukkan bahwa kondisi optimum proses leaching adalah pada konsentrasi amonium karbonat 2 M, dengan suhu 60Â°C selama 5 jam, dengan rasio S/L sebesar 20 g/L, menghasilkan persentase leaching sebesar 29,31 % untuk sistem bejana terbuka.Annually, NiO/Al2O3 waste catalyst generated by Hydrogen Plant unit Pertamina at UP VI Balongan in the amount of 100 tonnes with Ni content of about 10-25%. Based on the number and dangerous waste nickel catalyst, it is necessary to do a recovery nickel process from that waste with leaching process using ammonia-ammonium carbonate. Ammonia-ammonium carbonate chosen because it has no corrosive properties and environmentally friendly. The purpose of this study is to obtain the optimum leaching conditions. The tested parameters for leaching processes are leaching agent concentration, temperature and processing time, and for liquid-liquid extraction process are the extractant concentration and pH. Each variation process was performed sequentially with AAS testing. EDX test was done to prove the existence of nickel content in the waste catalyst NiO/Al2O3, the results show that nickel at the level of energy 7.477 and 0.851 keV. AAS analysis results for the initial concentration of nickel metal in the catalyst was 15.62% -wt. From the leaching results was known that the higher temperature and processing time, the recovery of nickel will be higher. The results showed that the optimum conditions leaching process was at a concentration of 2 M ammonium carbonate, with Â temperature was 60Â°C for 5 hours, and the ratio S/L was 20 g/L, resulting leaching percentage of 29.31% for open vessel system.

Hubungan Good Corporate Governance dengan Nilai Perusahaan yang Dimoderasi Oleh Pengungkapan Corporate Social Responsibility dan Profitabilitas Yuliusman, Yuliusman; Kusuma, Indra Lila
Jurnal Akuntansi dan Pajak Vol 21, No 01 (2020): Jurnal Akuntansi dan Pajak Vol. 21 No. 1, Juli 2020
Publisher : ITB AAS INDONESIA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29040/jap.v21i1.1078

This study aims to examine the effect of Good Corporate Governance on firm value by disclosing Corporate Social Responsibility and profitability as a moderating variable. Good Corporate Governance variables are measured by CGPI scores. Company value variable is measured by Tobins' Q. Corporate Social Responsibility disclosure variables measured by the GRI 4.0 item checklist. The profitability variable is measured by Return on Assets (ROA). This study uses a sample of companies that participated in the IICG on the Indonesia Stock Exchange (IDX) for the period 2014 - 2018. The sampling technique used was purposive sampling. The sample used in this study amounted to 7 companies, a total of 35 data. The data analysis technique in this study is the moderation regression analysis. The software used for data processing is SPSS version 22 for Windows. The results of hypothesis testing are as follows. First, Good Corporate Governance influences company value. Second, disclosure of Corporate Social Responsibility is able to moderate the relationship between Good Corporate Governance and corporate value. Third, profitability is not able to moderate the relationship between Good Corporate Governance and firm value.

Aktivasi Zeolit Alam Lampung sebagai Adsorben Karbon Monoksida Asap Kebakaran Yuliusman Yuliusman
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2016: Prosiding SNTKK 2016
Publisher : Seminar Nasional Teknik Kimia Kejuangan

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This study aims to absorb the carbon monoxide (CO) gas using Lampung natural zeolite as an adsorbent. Natural Zeolite has porous crystal structure, large surface area, high thermal stability, non-toxic, and effective. Natural zeolites contain many impurities, then it must be activated. Activation of natural zeolite was done by soaking in a solution of 2% HF for 10 minutes with stirring. Furthermore, dealumination natural zeolite carried out by soaking in a solution of 6 M HCl for 30 minutes. Zeolite was soaked with a solution of 0.1 M NH4Cl and then was calcined. Then Activated Natural zeolite was tested the adsorption of cabon monoxide gas from burning tissue paper. Variations in particle size of the zeolite is 53-106 μm, 106-150 μm and 150-212 μm. The results showed that activated natural zeolite with a particle size of 53-106 microns can adsorb CO gas at 379 ppm (12.2%) of the initial concentration for 20 minutes.

PEMILIHAN ADSORBEN UNTUK PENJERAPAN KARBON MONOKSIDA MENGGUNAKAN MODEL ADSORPSI ISOTERMIS LANGMUIR Yuliusman Yuliusman; Widodo Wahyu Purwanto; Yulianto Sulistyo Nugroho
Reaktor Volume 14, No. 3, APRIL 2013
Publisher : Dept. of Chemical Engineering, Diponegoro University

ADSORBENT SELECTION FOR CO ADSORPTION USING LANGMUIR ISOTHERMIC ADSORPTION MODEL. The objective of this research is to choose the adsorbent that can be applied to decrease toxicity level and to purify fire smoke. In case of fire, toxicity level is high due to carbon monoxide. Adsorbent is chosen based on its ability to adsorb carbon monoxide using volumetric method in constant temperature. Materials to be tested are natural zeolite, active carbon, TiO2, CuO, MgO. Due to existence of organic and mineral polluters, natural zeolite needs to be activated prior to adsorption test using fluoride acid (HF), chloride acid (HCl), ammonium chloride (NH4Cl) and followed by calcination process. Result shows that activation of natural zeolite can increase Si/Al ratio and surface area. According to Langmuir adsorption model obtained, adsorption capacity of active carbon and natural zeolite are the highest. At 1 atmospheric pressure, adsorption capacity are 0.0682 mmol/g for active carbon, 0.0464 for activated natural zeolite with particle size of 400 nm, and 0.0265 mmol/g for activated natural zeolite with particle size of (37-50) μm. Penelitian ini bertujuan untuk memilih adsorben yang dapat diaplikasikan untuk menurunkan tingkat racun dan menjernihkan asap kebakaran. Pada kasus kebakaran tingkat racun asap disebabkan tingginya kandungan karbon monoksida. Proses pemilihan adsorben dilihat pada kemampuan adsorben mengadsorpsi karbon monoksida, yang dilakukan dengan metode volumetrik pada temperatur konstan. Material yang diuji adalah zeolit alam, karbon aktif, TiO2, CuO, MgO. Zeolit alam banyak terdapat pengotor baik organik maupun mineral, oleh karena itu sebelum dilakukan uji adsorpsi, zeolit alam terlebih dahulu diaktifasi menggunakan larutan asam florida (HF), asam khlorida (HCl) dan larutan amonium khlorida (NH4Cl), dilanjutkan dengan proses kalsinasi. Hasil penelitian menunjukkan bahwa aktifasi zeolit alam dapat meningkatkan rasio Si/Al dan luas permukaan. Semua adsorben yang diuji mempunyai kemampuan mengadsorpsi karbon monoksida. Berdasarkan model adsorpsi Langmuir yang diperoleh, karbon aktif dan zeolit alam mempunyai kapasitas adsorpsi yang paling besar. Dengan menggunakan kondisi tekanan 1 atmosfir, kapasitas adsorpsi adalah 0,0682 mmol/g untuk karbon aktif, 0,0464 mmol/g untuk zeolit alam teraktifasi dengan ukuran partikel 400 nm dan 0,0265 mmol/g untuk zeolit alam teraktifasi dengan ukuran partikel (37-50) μm.

PEMBUATAN KARBON AKTIF DARI BATU BARA TERMODIFIKASI TIO2 UNTUK PENYERAP KARBON MONOKSIDA Yuliusman Yuliusman
Prosiding Semnastek PROSIDING SEMNASTEK 2015
Publisher : Universitas Muhammadiyah Jakarta

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Peristiwa kebakaran dapat menyebabkan kematian karena terpapar CO dari asap kebakaran. Oleh karena itu kandungan CO pada asap kebakaran bisa diadsorpsi menggunakan adsorben seperti karbon aktif. Penelitian ini bertujuan untuk membuat karbon aktif dari batu bara menggunakan aktive agent kalium hidroksida (KOH) dan aktifasi fisika pada suhu tinggi. Karbon aktif yang dihasilkan digunakan untuk menyerap Carbon monoksida (CO). Adapun tahapan batu bara dicampurkan dengan larutan KOH selama 1 jam pada suhu 200oC, kemudian campuran diaktifasi fisika pada suhu 800oC selama 2 jam. Hasil penelitian menunjukkan bahwa proses aktifasi dapat menghasilkan karbon aktif dengan luas permukaan 932 m2/gr, dengan rendemen 40,4%. Hasil karakterisasi X–Ray Fluorescence menunjukkan bahwa proses aktifasi dalam pembuatan karbon aktif dapat mengurangi kandungan pengotor seperti oksida logam yang terdapat dalam batu bara. Dari uji kemampuan penyerapan karbon aktif terhadap karbon monoksida menunjukkan bahwa semakin kecil ukuran partikel semakin meningkat kemampuan karbon aktif menyerap karbon monoksida. Semakin banyak massa karbon aktif yang didispersikan semakin meningkat jumlah karbon monoksida yang terserap. Karbon aktif dengan ukuran partikel 74 μm dan massa 3 gr mampu menyerap karbon monoksida sebesar 5,75%. Penambahan TiO2 pada karbon aktif dapat meningkatkan penyerapan terhadap karbon monoksida, hasil terbaik diperoleh karbon aktif yang termodifikasi logam TiO2 dengan persentase penyerapan karbon monoksida sebesar 6,81%

Kinetic Model For Triglyceride Hydrolysis Using Lipase:Review Hermansyah, Heri; Wijanarko, A.; Dianursanti, Dianursanti; Gozan, Misri; Wulan, Praswasti P. D.K; Arbianti, Rita; Soemantojo, Roekmijati W.; Utami, Tania Surya; Yuliusman, Yuliusman; Kubo, Momoji; Kitakawa, Naomi Shibasaki; Yonemoto, Toshiy
Makara Journal of Technology Vol. 11, No. 1
Publisher : UI Scholars Hub

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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.

CO2 Absorption from Its Mixture with CH4 or N2 through Hollow Fiber Membrane Contactor using Water as Solvent Kartohardjono, Sutrasno; Anggara, Anggara; Subihi, Subihi; Yuliusman, Yuliusman
Makara Journal of Technology Vol. 11, No. 2
Publisher : UI Scholars Hub

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CO2 Absorption from Its Mixture with CH4 or N2 through Hollow Fiber Membrane Contactor using Water as Solvent. Hollow fiber membrane contactors have been widely used as gas-liquid contactors recently such as in the CO2 absorption process from gas stream. This research aims to evaluate the effectiveness of hollow fiber membrane contactor to absorb CO2 from its mixture with CH4 or N2 using water through mass transfer and hydrodynamic tests. There are 3 membrane modules used in this research with shell diameter of 1.9 cm, length of 40 cm, outer fiber diameter of 2.7 mm and fiber number in the contactors of 10, 15 and 20. Liquid flow rates in the hollow fiber membrane contactors are varied in this research. Research results show that mass transfer coefficients in the membrane contactor increase with increasing liquid flow rate and decrease with increasing fiber number in the contactor. Flux of CO2 into water can achieve 1.4x10-9 mol CO2 /m2.s and mass transfer coefficients can achieve 1.23 x 10-7 m/s. Meanwhile, hydrodynamic test results show that water pressure drop in the membrane contactors increase with increasing fiber number in the contactors.

Effects of Ph on Calcium Carbonate Precipitation Under Magnetic Field Saksono, Nelson; Yuliusman, Yuliusman; Bismo, Setijo; Soemantojo, Roekmijati W.; Manaf, Azwar
Makara Journal of Technology Vol. 13, No. 2
Publisher : UI Scholars Hub

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Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In high super-saturated solution, magnetic field strengthens ion interactions, which reduce precipitation during circulation process. However, in low super-saturated CaCO3 solution, magnetic field weakens hydrate ion interaction which indicated by decreasing of the conductivity of solution. It increases the precipitation of CaCO3 after the circulation of magnetization process has completed.

Performance of Hollow Fiber Membrane Gas-Liquid Contactors to Absorb CO2 Using Diethanolamine (Dea) as a Solvent Kartohardjono, Sutrasno; Nata, Pan Ade; Prasetio, Eko; Yuliusman, Yuliusman
Makara Journal of Technology Vol. 13, No. 2
Publisher : UI Scholars Hub

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This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the 0.01 M DEA solution flows in the shell side of membrane contactors. Experimental results show that the mass transfer coefficients and fluxes of CO2 increase with an increase in both water and DEA solution flow rates. Increasing the amount of fibers in the contactors will decrease the mass transfer and fluxes at the same DEA solution flow rate. Mass transfer coefficients and CO2 fluxes using DEA solution can achieve 28,000 and 7.6 million times greater than using water as solvent, respectively. Hydrodynamics studies show that the liquid pressure drops in the contactors increase with increasing liquid flow rate and number of fibers in the contactors. The friction between water and the fibers in the contactor was more pronounced at lower velocities, and therefore, the value of the friction factor is also higher at lower velocities.

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