Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Modifikasi permukaan boron-doped-diamond (BDD) dengan Ni-Mn, Ni-Co dan Ni-Cu telah dilakukan untuk digunakan sebagai elektroda kerja pada sistem sel bahan bakar berbasis membran polimer elektrolit (Polymer Electrolyte Membrane Fuel Cell, PEMFC). Modifikasi dilakukan dengan rangkaian teknik wet chemical seeding (pembibitan kimia), electrochemical overgrowth of the seeds (penumbuhan kimia), annealing (pemanasan), serta refreshed and activation. Karakterisasi siklikvoltametri dan XPS menunjukkan spesi elekrokatalis Ni(OH)2 pada sampel Ni-Mn/BDD, Ni-Cu/BDD, dan Ni-Co/BDD dapat dideposisi pada potensial +0,32 V, +0,31 V dan +0.33 V berturut-turut, dengan energi ikat sebesar 855,6 eV. Agar dapat mengelektrooksidasi urea, dilakukan perubahan spesi α-NiOOH menjadi β-NiOOH yang lebih stabil dari Ni(OH)2 dengan siklikvoltametri dalam KOH 1 M selama 300 siklus. Poks tertinggi terdapat pada sampel Ni-Cu/BDD yakni 2.75 μA pada +0,59 V. Namun, pada pengaplikasian urea-PEMFC, Ni-Mn/BDD menunjukkan hasil terbaik menggunakan anolit 0,33 M dan KOH 0,1 M di ruang anoda serta katolit H2O2 2 M dan H2SO4 2 M di ruang katoda dengan densitas daya rata-rata 0,061733 mW/cm2, densitas arus rata-rata 0,185242 mA/cm2, potensial rata-rata sebesar 0,34 V vs SHE, dan efisiensi tegangan maksimal sebesar 15.83%. Sedangkan pada PEMFC berbahan bakar urin, densitas daya rata-rata yang dihasilkan 0.0889 mW/cm2, densitas arus rata-rata 0.189 mA/cm2, potensial rata-rata sebesar 0.66 V vs SHE dengan waktu pengoperasian selama 3600 detik ......Surface modification on boron-doped diamond (BDD) using Ni-Mn, Ni-Co dan Ni-Cu have been performed for application as working electrodes in a Polymer Electrolyte Membrane Fuel Cell (PEMFC) system. The series of wet chemical seeding, electrochemical overgrowth of the seeds, annealing, refreshed and activation techniques has been applied to modify the surface area. Characterization using cyclicvoltammetry and XPS indicate that Ni(OH)2 able to be well deposited on Ni-Co/BDD, Ni-Mn/BDD, and Ni-Cu/BDD samples at potential +0,32 V, +0,31 V dan +0.33 V respectively with binding energy as 855,6 eV. To electrooxidize urea, the change of α-NiOOHto β-NiOOH from deposited Ni(OH)2 electrochemicaly can be conducted by giving constant potential for 300 cycles in 1 M KOH. Highest oxidation peak of Ni3+ is belong to Ni-Cu/BDD as high as 2.75 μA at +0,59 V. In contrary, application Ni-Mn/BDD to urea-PEMFC shows best result by using mixture of 0.33 M urea and 0.1 M KOH as anolyte in anodic chamber, while a mixture of 2 M H2O2 and 2 M H2SO4 as chatolyte in cathodic chamber with average power density 0,061733 mW/cm2, current density 0,185242 mA/cm2, and potential of 0,34 V vs SHE with 15,83% of maximum voltage effiency yield. Urine as fuel in PEMFC has been also applied into the system with producing average power density as 0.0889 mW/cm2, 0.189 mA/cm2 for average current density, and 0.66 V vs SHE for open circuit votage for 3600 second of operation time.

Abstrak :
The microbial desalination cell (MDC) is a modification of the microbial fuel cell (MFC) system. The microbial desalination cell is a sustainable technology to desalinate saltwater by directly utilizing the electrical power generated by bacteria during the oxidation process of organic matter. In this study, tempe wastewater will be used as a substrate. Methylene blue (MB) at concentrations of 100 ?M, 200 ?M, and 400 ?M in the anolyte is added as a redox mediator, and the effect on electricity production and desalination performance are evaluated. The average power density increases by 27.30% and 54.54% at MB concentrations of 100 ?M and 200 ?M, respectively. On the other hand, the increase of the MB concentration in the anolyte results in a decrease in the salt removal percentage. The observation made using a scanning electron microscope showed the presence of MB adsorption on the surface of the anion exchange membrane (AEM) and is suspected to be the cause of the disruption of anion transfer between MDC chambers causing a decrease in the salt removal percentage.

Abstrak :
The gas diffusion layer (GDL) is one of the critical components of a proton exchange membrane fuel cell (PEMFC). It is generally made of a fossil-fuel-based carbon material. In this study, carbon composite paper (CCP) for GDL was prepared by using carbon material obtained from coconut coir. To obtain the CCP, 80 wt% carbon material from the coconut coir and 20 wt% polymer binder (ethylene vinyl acetate and polyethylene glycol) were mixed in xylene solvent at 100°C, cast on molded glass, and then rolled. The carbon material consists of a mixture of carbon fibers (length: 2 mm) and powders (size: 74 µm). Subsequently, the CCP was treated with polytetrafluoroethylene solution (10 wt%). The physical properties of the CCPs, such as through-plane electrical conductivity, porosity, density, and hydrophobic properties, were investigated. Scanning electron microscopy and energy-dispersive spectroscopy mapping were used to analyze the morphology and polytetrafluoroethylene (PTFE) distribution in the CCP. The through-plane conductivity test showed that CCP with 70 wt% carbon fiber, 10 wt% carbon powder, and 20 wt% polymer was the optimum sample, and it showed the highest electrical conductivity of 2.22 S cm-1. The physical properties of PTFE-treated CCP, such as porosity, density, and contact angle, were almost similar to that of commercial carbon paper used as a GDL. Therefore, the CCP prepared from coconut coir can be applied as a GDL in a PEMFC.

Abstrak :
Indonesia yang memiliki jumlah kota sebanyak 93 kota yang tersebar di banyak provinsi merupakan konsumen energi terbesar di Asia Tenggara yaitu sebesar 36% dari kebutuhan energi kawasan. Selain tingginya permintaan energi, isu lain yang krusial adalah tingginya produksi limbah di Indonesia, terutama pada daerah perkotaan. Penelitian ini dilakukan untuk memperoleh skema teknologi Waste to Energy (WtE) yang dapat diaplikasikan dan paling optimum dalam menghasilkan LCOE dan emisi GHG yang minimum melalui optimisasi multi objektif. Teknologi yang digunakan di dalam penelitian ini adalah insinerasi, gasifikasi, anaerobic digestion, dan pirolisis dengan teknologi pembangkitan listrik menggunakan gas engine, gas turbin, serta teknologi fuel cell, yakni Solid Oxide Fuel cell (SOFC) dan Molten Carbonate Fuel cell (MCFC). Produksi bahan bakar hidrogen untuk fuel cell menggunakan proses Reforming. Penelitian dilakukan dengan meninjau aspek teknis melalui simulasi produksi listrik dari limbah padat perkotaan di kota Depok dengan menggunakan software ASPEN PLUS. Dari aspek lingkungan, dilakukan analisis faktor emisi yang dihasilkan dari berbagai teknologi proses WtE melalui metode Life Cycle Assessment (LCA). Dari segi ekonomi, dilakukan perhitungan Levelized Cost of Electricity (LCOE) WtE. Emisi total dan LCOE merupakan fungsi objektif pada optimisasi multi objektif yang dilakukan dengan menggunakan software General Algebraic Modelling System (GAMS). Hasil penelitan menunjukkan bahwa teknologi digesti anaerob dengan turbin gas sebagai teknologi pembangkitan merupakan teknologi WtE yang optimum pada tahun 2020-2035. Pada tahun 2035 hingga tahun 2050, teknologi gasifikasi dengan SOFC merupakan teknologi yang optimum dari segi teknis, ekonomi, maupun lingkungan. Penelitian ini diharapkan mampu menjadi inspirasi dan membawa pengaruh terhadap perbaikan sistem konversi limbah menjadi energi yang ada di kota Depok. ......Indonesia, which has a total of 93 cities in many provinces, is the largest energy consumer in Southeast Asia, around 36% of the region`s energy needs. Besides the high demand for energy, another crucial issue is the high production of waste in Indonesia, especially in urban areas. This research was carried out to obtain the Waste to Energy (WtE) technology scheme that can be applied and optimum in producing minimum LCOE and GHG emissions through multi-objective optimization. The technologies used in this study are incineration, gasification, anaerobic digestion, and pyrolysis with power generation technology which using gas engines, gas turbines, and fuel cell technology, namely Solid Oxide Fuel cell (SOFC) and Molten Carbonate Fuel cell (MCFC). The production of hydrogen fuel for fuel cells uses the Reforming process. The study was conducted by reviewing the technical aspects through simulating electricity production from municipal solid waste in Depok using the ASPEN PLUS software. From the environmental aspect, emission factor analysis was produced from various WtE process technologies through the Life Cycle Assessment (LCA) method. From an economic standpoint, Levelized Cost of Electricity (LCOE) of WtE is calculated. Total emissions and LCOE are objective functions in multi-objective optimization that carried out using General Algebraic Modeling System (GAMS) software. The research results show that anaerobic digestion technology with gas turbines as generation technology is the optimum WtE technology in 2020-2035. In 2035 until 2050, gasification technology with SOFC is the optimum technology from the technical, economic and environmental aspects. This research is expected to be able to inspire and influence the improvement of waste conversion into energy systems in the city of Depok.This research is expected to be able to inspire and influence the improvement of the waste conversion into energy systems in Depok.

Abstrak :
Dalam simulasi ini, dilakukan pemodelan dan simulasi Proton Exchange Membrane (PEM) fuel cell dengan pendekatan 3 dimensi 2 fasa, yaitu fasa gas dan fasa padatan dengan bentuk channel serpentine. Persamaan model yang diturunkan meliputi persamaan kontinuitas, persamaan momentum, persamaan energi persamaan transport ion dan persamaan current density. Kesemua persamaan ini dibedakan antara fasa padatan dan fasa gas. Fasa padatan terjadi pada GDL, Catalyst dan membrane baik disisi anode maupun cathode. Scdangkan fasa gas hanya terjadi pada Gas Channel anode dan Gas channel cathode. Penyelesaian numeris model menggunakan perangkat lunak MATLAB™ 6.0. Karena terlalu sulitnya melakukan pemecahan dengan menggunakan MATLABTM pada daerah perhitungan 3 dimensi 2 fasa dan dalam geometri yang komplek, maka model disederhanakan menjadl 2 buah model I dimensi, yaitu model pada sumbu y (lebar) dan model pada sumbu z{ketebalan). Hasil model dari penyederhanaan model kesumbu y dldapat profil kecepatan. konsentrasi, tekanan, temperatur. current density, tegangan ionik. Model 1 dimensi kearah sumbu y ini hanya dapat diselesaikan pada lebar 50 cm, jika melebihi lebar ini model tidak dapat diselesaikan karena menghasilkan sebuah matrik Jacobian dari metoda Newton-Raphson yang singular, hal ini disebabkan karena persamaan current density yang sangat stiff. Sedangkan hasil dari penyederhanaan model kesumbu z...