Hydrogen Absorbing Material in Carbonaceous-Metal Hydride

One of the most promising materials for storing hydrogen in solid state would be included in metal-carbon composites. In order to obtain nanocrystalline metal particles encapsulated by crystalline or amorphous carbon, mechanosynthesis of zirconium-carbonaceous composites and alkali metal-carbonaceous composites was performed. For zirconium-carbonaceous composites, only zirconium-carbon black composite absorbed more hydrogen than expected for a mere mixture with the same composition. The higher hydrogen capacity on the zirconium-carbon black composite would be due to some specific sites on the carbonaceous material created during the milling. Another effect of the composite formation was stabilization of zirconium, that is, the composites did not ignite in air. On alkali metal-carbonaceous composites, carbon black has superior effect in composite formation compared with graphite in which some cooperative effect was only detected on alkali metal-carbon black composite. The effect of the carbonaceous composite formation was resistance to air and anti-sticking characteristics to balls and the wall of the vial during the ball milling

Composites Prepared from Rice Husk and Recycled/Virgin HDPE with Addition of CouplingAgent

Compositesweremade from recycled HDPE and virgin HDPE as matrix and ricehusk as filler and also added with polyethylene-graft-maleic anhydride (MAPE) as a coupling agent to improve the physical and mechanical properties of composites. Theaim of study is to find the optimum condition of the type of used matrixs and the percentage of added coupling agent on the quality of the producedcomposites. Compositeswere prepared byhot press method. Hot press process was performed at a temperature of 150 oC for 30 minutes.After cooling to room temperature, the product was tested oftensile strength, bending strength, thermal test and FTIR. The results show thatcompositesprepared byvirgin HDPE have much betterphysical and mechanical properties compared to composites prepared by recycled HDPE. The highest tensile strength valueof 5.69 MPawas foundon composite withmatrix of virgin HDPE and addition of 4 wt% MAPE. While the highest bending strength valueof 0.35 Mpa was obtained oncomposite with matrix of recycled HDPE and addition of 2 wt% MAPE. The presence of a number of MAPE concentration in the mixture resulted in increased adhesion properties between rice husk and HDPE thereby increasing the physical mechanical properties of composites

Composites Prepared From Rice Husk and Recycled/Virgin HDPE with Addition of CouplingAgent

Compositesweremade from recycled HDPE and virgin HDPE as matrix and ricehusk as filler and also added with polyethylene-graft-maleic anhydride (MAPE) as a coupling agent to improve the physical and mechanical properties of composites. Theaim of study is to find the optimum condition of the type of used matrixs and the percentage of added coupling agent on the quality of the producedcomposites. Compositeswere prepared byhot press method. Hot press process was performed at a temperature of 150 oC for 30 minutes.After cooling to room temperature, the product was tested oftensile strength, bending strength, thermal test and FTIR. The results show thatcompositesprepared byvirgin HDPE have much betterphysical and mechanical properties compared to composites prepared by recycled HDPE. The highest tensile strength valueof 5.69 MPawas foundon composite withmatrix of virgin HDPE and addition of 4 wt% MAPE. While the highest bending strength valueof 0.35 Mpa was obtained oncomposite with matrix of recycled HDPE and addition of 2 wt% MAPE. The presence of a number of MAPE concentration in the mixture resulted in increased adhesion properties between rice husk and HDPE thereby increasing the physical mechanical properties of composites

The effect of temperature on cr (vi) removal by using guava leaves as a biosorbent

Preliminary research on Cr(IV) removal in a liquid waste using guava leaves (Psidium Guajava) as a bio-sorbent has been done. The experiments were conducted in a stirred batch reactor. The effect of temperature on efficiency and absorption capacity has been studied. Both the efficiency and absorptioncapacity are directly proportional to the temperature under the current experimental conditions. The results showed that optimum absorption capacity and absorption efficiency of Cr(VI) use of guava leaves obtained at stirring time 30 minutes

Adsorption of Heavy Metal Cr (VI) Using BioSorbent of Tea Dregs: Experimental and Modeling

Tea plants have been generally known by most of Indonesian as a refreshing drink. Tea leavesusually contain caffeine of 1-4%, tannins of 7-20% and a little essential oil. Powder of tea dregs has the ability to absorb heavy metal of chromium. The research objective was to study the adsorption kinetics of heavy metal ions of Cr (VI) using powder of tea dregs and to study factors that affect adsorption process of chromium metal. The analysis of sample solution concentration of Cr (VI) in this study was using Atomic Absorption Spectrophotometer (AAS). The effect of various process variables such as initial concentration of the metal solution, stirrer speed and concentration of modifying agent of sulphuric acid has been investigated. The results showed that the optimum adsorption process was obtained at adsorbate concentration of 125 ppm with activation process at sulphuric acid concentration of 0.8 M. The highest efficiency of heavy metal adsorption reached 83.24% with adsorption capacity of 5.202925 mg/g bio-sorbent. This adsorption was in accordance with the Langmuir Isotherm models with R2 value of 0.909. This study was also in accordance with kinetics of a second pseudo order with a R2 value of 0.997 and K of 0.752 g/mg. Minut

Penggunaan Katalis NaOH dalam Proses Transesterifikasi Minyak Kemiri menjadi Biodiesel

Research on biodiesel production from hazelnut oil by transesterification process using NaOH catalyst was one of the efforts for renewable energy research. The purpose of this study was to determine the effect of NaOH catalyst and the ratio of hazelnut oil to methanol on the production of biodiesel via transesterification process. The transesterification process was carried out in a stirred reactor equipped by a condenser with speed of 200 rpm, temperature of 60°C and the operating time of 90 minutes. The results indicated that biodiesel could be produced from hazelnut oil through transesterification process with the highest yield of 81.7% that was obtained on the use of 2% wt. of NaOH catalyst and the mole ratio of oil to methanol of 1:9. Viscosity, density, and acid number of biodiesel obtained in this study met the Indonesia National Standard for biodiesel as SNI 04-7182-2006, therefore hazelnut oil produced biodiesel could potentially be an alternative diesel fuel.Keywords: hazelnut oil, biodiesel, transesterification, NaOH catalys

Studi Pembuatan Cat Tembok Emulsi dengan Menggunakan Kapur sebagai Bahan Pengisi

Studi pembuatan cat tembok emulsi menggunakan bahan pengisi kapur sangat potensial untuk dikembangkan karena ketersediaan kapur yang banyak di alam. Cat tembok emulsi telah dibuat dari campuran bahan pengisi, bahan pengikat, pigmen, pelarut, dan bahan tambahan lainnya. Penelitian ini bertujuan untuk mempelajari apakah cat tembok emulsi dapat dihasilkan dari kapur atau tidak dan untuk mengetahui pengaruh konsentrasi CaO sebagai filler, dan konsentrasi polivinil asetat (PVA) sebagai binder terhadap kualitas cat tembok emulsi yang dihasilkan. Prosedur penelitian dan analisis mutu produk mengacu pada SNI 3564:2009 tentang cat tembok emulsi. Hasil penelitian menunjukkan bahwa kapur dapat digunakan dalam membuat cat tembok emulsi. Baik konsentrasi PVA dan konsentrasi CaO yang divariasikan mempengaruhi semua parameter kualitas cat sebagaimana ditetapkan dalam SNI 3564:2009. Hasil optimum penelitian diperoleh pada perlakuan konsentrasi PVA 20% dan konsentrasi CaO 26% yaitu masing-masing untuk padatan total cat sebesar 76,43%, waktu kering cat 36,00 menit, daya sebar cat 8,4 m2/kg, viskositas cat 110,99 KU, sedangkan daya tutup cat sebesar 8,20 m2/L pada konsentrasi CaO 24%

Adsorption of Pb (II) Heavy Metals from Wastewater Using Modified Rice Husk as Adsorbent

Pb (II) heavy metal from wastewater as by-product of industrial activity often causes problem to environment. In order to minimize the amount of Pb (II), wastewater was treated in various ways, including adsorption process using adsorbent. Rice husks that containing lignin, cellulose, and hemicellulose are one of potential candidates to be utilized as adsorbent. The purpose of this research is to modify rice husk by using sodium hydroxide and citric acid and to know adsorption capacity and adsorption efficiency of modified rice husk adsorbent on Pb (II) metal uptake from wastewater. To identify substituted groups, analysis samples by using Fourier Transform Infrared was performed and to determine adsorbed amount of Pb (II) into adsorbent an Atomic Adsorption Spectroscopy Method was conducted. The result showed that optimum adsorption capacity and adsorption efficiency was 5.08 mg/g and 84.52%, respectively. These results were obtained on 60 ppm of Pb (II) adsorbate concentration and 0.8 M citric acid concentration for 150 minutes of contact tim