Potensi Energi Arus Laut Pada Berbagai Kedalaman Untuk Pembangkit Listrik Di Selat Badung, Bali

Selat Badung merupakan percabangan outlet dari Selat Lombok yang berada di antara Pulau Bali dan Pulau Nusa Penida. Kecepatan arus di Selat Badung berkisar dari 0,2 cm/s - 204,3 cm/s. Kajian arus di lokasi ini diperlukan untuk mengetahui potensinya sebagai pembangkit listrik mengingat kebutuhan akan listrik setiap tahun terus meningkat sekitar 9%.Pengukuran data di perairan lokasi penelitian dilaksanakan pada tanggal 20 Juni 2014 - 5 Juli 2014 dengan interval perekaman 30 menit. Metode yang digunakan dalam penelitian ini menggunakan software Matlab dengan toolbox t_tide yang dapat memisahkan data arus perekaman menjadi data arus harmonik dan non-harmonik dengan mengeluarkan komponen yang berpengaruh nyata menghasilkan energi. Ketiga data arus ini akan dianalisis untuk dikonversi. Konversi energi menggunakan persamaan Fraenkel dengan asumsi-asumsi.Potensi daya terbesar yang dapat dihasilkan pada lokasi penelitian adalah 43.701,76 W yang berada pada kedalaman 13 m sedangkan potensi daya rata-rata terbesarnya adalah 71,52 W berada di kedalaman 3 m dari permukaan. Akumulasi potensi daya yang didapat berada pada kedalaman 13 meter dengan besar daya 95.125,32 W

The Influence of Pt Atomic Ratio in the Activity PtNi/C Nanocatalysts for the PEMFC

Pt-Ni/C alloy nanocatalysts synthesized by polyol method with different atomic ratio are investigated to enhance activity of the oxygen reduction reaction (ORR) for fuel cell applications. Prepared catalysts are characterized by various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM-EDX), and cyclic voltammetry (CV). XRD analysis shows that all prepared catalysts with different atomic ratio exhibit face centered cubic and have smaller lattice parameters than pure Pt catalyst. The mean particle size of the catalysts are between 4.3 to 6.3 nm. Cyclic voltammograms with scan rate 5 mV s-1 at 25oC obtain range the electrochemical active surface (EAS) between 40 to 164 cm2/mgPt, mass activity (MA) and specific activity (SA) of nanocatalysts PtNi/C in the potential range 900 mV versus RHE between 3.61 to 8.42 mA/mgPt, and 0.05 to 0.09

Natural Gas as Petroleum Fuel Substitution: Analysis of Supply-demand Projections, Infrastructures, Investments and End-user Prices

The petroleum fuels (PF) subsidy has long burdens the government spending, and discourages less expensive energy USAge such as natural gas (NG). Exporting NG and importing the more expensive PF products cause financial losses to Indonesia. The lack of NG infrastructure is the main hurdle in maximizing domestic NG USAge and so does the perception of its high investment costs burdening government spending and pushing the NG transportation cost up. This study calculates the required NG infrastructure and its investments for several levels of PF substitutions up to 2030. To balance the NG demands, the supply from each field and its corresponding infrastructures needed was calculated and optimized using non-linear programming with generalized reduced gradient  method to calculate the lowest transportation cost for the consumers. The study shows with a favorable return on investments attractive to private investors, the NG prices can still be put much lower than PF prices, allowing subsidy, import and production cost savings in many sectors. Furthermore, the highest level of substitution scenario needs only US$2.07 billion a year investment, very low compare to the current US$ 14.17 billion a year PF and electricity subsidy. &nbsp

Production Hydrogen and Nanocarbon Via Methane Decomposition Using Ni-based Catalysts. Effect of Acidity and Catalyst Diameter

Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loadingAl-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reactionperformances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts wereprepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation andsol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressureand 500-700°C. The main results showed that the Al content of catalyst increases with the increasing amount ofprecipitant. The activity of catalyst increases with the increasing of catalyst\u27s acidity to the best possible point, and thenincreasing of acidity will reduce the activity of catalyst. Ni-Cu/4Al and Ni-Cu/11Al deactivated in a very short timehence produced fewer amount of nanocarbon, while Ni-Cu/15Al was active in a very long period. The most effectivecatalyst is Ni-Cu/22Al, which produced the biggest amount of nanocarbon (4.15 g C/g catalyst). Ni catalyst diameterhas significant effect on reaction performances mainly methane conversion and product yield. A small Ni crystal sizegave a high methane conversion, a fast deactivation and a low carbon yield. Large Ni particle diameter yielded a slowdecomposition and low methane conversion. The highest methane conversion was produced by catalyst diameter of 4nm and maximum yield of carbon of 4.08 g C/ g catalyst was achieved by 15.5 nm diameter of Ni catalyst

Preparasi Membran Elektrolit Berbasis Poliaromatik Untukaplikasi Sel Bahan Bakar Metanol Langsung Suhu Tinggi

PREPARASI MEMBRAN ELEKTROLIT BERBASIS POLIAROMATIK UNTUKAPLIKASI SEL BAHAN BAKAR METANOL LANGSUNG SUHU TINGGI. Operasi sel bahan bakar metanol langsung (Direct Methanol Fuel Cell / DMFC) suhu tinggi (>120 oC) mempunyai keuntungan yaitu meningkatkan reaksi baik di anoda maupun di katoda. Saat ini membran yang banyak digunakan untuk aplikasi DMFC adalah Nafion. Kelebihan dari membran Nafion memiliki konduktivitas ionik yang tinggi tetapi kelemahannya adalah permeabilitas metanol yang tinggi, termasuk membran yang mahal dan kinerja membran menurun jika digunakan pada suhu >80 oC. Untuk hal tersebut perlu pengembangan polimer pengganti Nafion diantaranya adalah polimer aromatik yaitu polisulfon (PSf) dan polieter-eterketon (PEEK). PEEK dan PSf adalah polimer yang bersifat hidrofobik, untuk menjadi elektrolit perlu diberikan gugus sulfonat melalui proses sulfonasi. Sulfonasi PSf dilakukan setelah membuat membran terlebih dahulu, dengan memvariasikan konsentrasi asam sulfat (0,5 M dan 1 M) dan waktu sulfonasi (2 jam, 3 jam dan 4 jam) pada suhu tetap 80 oC. Sedangkan sulfonasi PEEK menggunakan asam sulfat pekat dengan variasi suhu (50 oC , 60 oC dan 70 oC) pada waktu tetap 3 jam, yang kemudian dibuat membran. Karakteristik membran elektrolit polisulfon yang tersulfonasi (sPSf) menghasilkan swelling air pada membran 10 % hingga 25 %, konduktivitas ionik sebesar 10-4 S/cm hingga 10-3 S/cm, permeabilitas metanol sebesar 10-7 cm2/detik hingga 10-6 cm2/detik dan suhu transisi glass membran PSf dan sPSf sebesar 220 oC dan 237 oC. Karakteristik membran elektrolit polieter eter keton yang tersulfonasi (sPEEK) menghasilkan swelling air pada membran 8 % hingga 28 %, konduktivitas ionik sebesar 10-2 S/cm, permeabilitas metanol sebesar 10-7 cm2/detik hingga 10-6 cm2/detik dan suhu transisi glass membran PEEK dan sPEEK sebesar 187 oC dan 266 oC. Kedua polimer tersebut berpeluang untuk aplikasi DMFC suhu tinggi, walaupun konduktivitas ionik dari sPSf perlu ditingkatkan

Pemodelan Sistem Dinamik Ketercapaian Kontribusi Biodiesel Dalam Bauran Energi Indonesia 2025

Biodiesel industry in Indonesia commercially emerged in 2005 driven by concerns on energy security triggered by high oil price, increasing environmental demand to reduce CO2 emission, while leveraging on Crude Palm Oil feed stock availability. The Government of Indonesia mandated biodiesel to contribute 10.22 million kilo litre in 2025 energy mix target, beside current weak industry performance of 27% low utilization ratio of biodiesel plant installed capacity of 4.2 million ton per annum. A system dynamic model, called Indonesia Biodiesel Industry Dynamic Model, has been developed as a platform to study the structure and behaviour of the biodiesel industry enriched with inputs from biodiesel related experts panel discussion and interview and to simulate the impact of energy policy interventions, such as biodiesel subsidy, diesel subsidy reduction and removal, blending mandate, and diesel environmental tax to the performance of biodiesel production, industry profitability EBITDA and Carbon Emission Reduction (CER) during simulation period of 2005-2030. Based on the scenario 1 of MDIBI, targeted 10.22 million tones per annum contribution of biodiesel in 2025 Indonesia\u27s energy mix would not be achieved with current structure and condition, mainly due to three factors, which are (i) low mixture of biodiesel-diesel mandate, (ii) a relatively limited supply of CPO raw materials which must be allocated for competing demand from cooking oil, oleofoods, oleochemicals and biodiesel industries, and (iii) currently available limited public service obligation (PSO) market

The Influence of Tio2 Morphology and Doped PT on Hidrogen Production From Water with Photocatalytic Method

The influence of TiO2 morphology and doped Pt on hydrogen production has been investigated. TiO2 nanotubes (TiO2 NT) were obtained by using combination of sonication and hydrothermal methods. Pt was doped on the surface of TiO2 NT by using photo-deposition method. TiO2 Degussa P25 nanoparticle was employed as comparison. Sonication was performed using ultrasonic cleaner for 60min then followed by hydrothermal treatment in a teflon lined stainless steel autoclave for 12 hours at 13 °C. TiO2 nanotubes were characterized by means of X-Ray Powder Diffractometer (XRD), Scanning Electron Microscope (SEM), UV-Vis Diffuse Reflectane Spectroscopy (UV-Vis DRS) and Brunauer-Emmet-Teller (BET) technique. A pyrex reactor was employed to conduct hydrogen production while methanol was used as sacrificial agent. The result shows by using Pt/TiO2 NT increased hydrogen production about 18 times than that of TiO2 NT without Pt doped

PRODUCTION HYDROGEN AND NANOCARBON VIA METHANE DECOMPOSITION USING Ni-BASED CATALYSTS. EFFECT OF ACIDITY AND CATALYST DIAMETER

Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loadingAl-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reactionperformances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts wereprepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation andsol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressureand 500-700°C. The main results showed that the Al content of catalyst increases with the increasing amount ofprecipitant. The activity of catalyst increases with the increasing of catalyst's acidity to the best possible point, and thenincreasing of acidity will reduce the activity of catalyst. Ni-Cu/4Al and Ni-Cu/11Al deactivated in a very short timehence produced fewer amount of nanocarbon, while Ni-Cu/15Al was active in a very long period. The most effectivecatalyst is Ni-Cu/22Al, which produced the biggest amount of nanocarbon (4.15 g C/g catalyst). Ni catalyst diameterhas significant effect on reaction performances mainly methane conversion and product yield. A small Ni crystal sizegave a high methane conversion, a fast deactivation and a low carbon yield. Large Ni particle diameter yielded a slowdecomposition and low methane conversion. The highest methane conversion was produced by catalyst diameter of 4nm and maximum yield of carbon of 4.08 g C/ g catalyst was achieved by 15.5 nm diameter of Ni catalyst.Keywords: carbon nanotube, hydrogen, methane decomposition, nickel based catalys