A Simple Technique for Surface Area Determination Through Supercritical Co2 Adsorption

The measurement of specific surface area of porous materials has long been important in physical sciences and iscurrently growing in importance in applied and environmental science. Numerous systems have been developed forsurface area measurement by gas adsorption. Commercial systems are available which can measure a wide range ofabsolute surface area with relative ease. However, their cost is often prohibitive. In this study, an inexpensive apparatusfor surface area measurement has been set up to be used for measuring supercritical adsorption of CO2. The Ono-KondoLattice model was used to represent the adsorption isotherm and to determine the surface area. The results of surfacearea determination using CO2 adsorption combined with OK model have been compared to the numbers obtained fromnitrogen BET method. For surface area determination of zeolites and activated carbons, the new method give reasonableagreement results (within 10% deviation) compared to the results obtained from nitrogen BET method. In addition, thenew method also gives more reasonable results for surface area determination of coals. As known, the nitrogen BETmethod gives almost zero of coals’ surface area. This might due to the characteristic of the coals’ structure that might bechange (the pores are closed) during the cooling process in nitrogen BET method. Moreover, the new method can alsobe used to determine the surface area of porous materials using CO2 adsorption data at various temperatures withoutsacrificing their accuracy

Development of Formaldehyde Adsorption Using Modified Activated Carbon – a Review

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy

Carbon nanotubes shynthesis in fluidized bed reactor equipped with a cyclone

This work aimed to observe the performance of a fluidized bed reactor which was equipped with a cyclone in the synthesis of carbon nanotubes (CNT) by chemical vapor deposition. Liquefied petroleum gas with a constant volumetric flow rate of 1940 cm3/minutes was fed to the reactor as a carbon source, while a combination of metal components of Fe-Co-Mo supported on MgO was used as catalyst. The CNT synthesis was carried out at a reaction temperature which was maintained at around 800 – 850 °C for 1 hour. The CNT yield was decreased sharply when the catalyst feed was increased. The carbon efficiency is directly proportional to the mass of catalyst fed. It was found from the experiment that the mass of as-grown CNT increased in proportion to the increase of the catalyst mass fed. A sharp increase of the mass percentage of carbon nanotubes entrainment happened when the catalyst feed was raised from 3 to 7 grams. Agglomerates of carbon nanotubes have been formed. The agglomerates composed of mutually entangled carbon nanotubes which have an outer diameter range 8 – 14 nm and an inner diameter range 4 – 10 nm, which confirmed that the multi-walled carbon nanotubes were formed in this synthesis. It was found that the mesopores dominate the pore structure of the CNT product and contribute more than 90 % of the total pore volume

REAKSI ESTERIFIKASI ASAM OLEAT DAN GLISEROL MENGGUNAKAN KATALIS ASAM

REAKSI ESTERIFIKASI ASAM OLEAT DAN GLISEROL MENGGUNAKAN KATALIS ASAM. Reaksi esterifikasi antara asam oleat dan glyserol menggunakan katalis asam dilakukan untuk mempelajari kemungkinan terjadinya reaksi polimerisasi antara keduanya. Reaksi berlangsung pada rentang suhu 220 oC hingga 250 oC, dengan harapan setelah reaksi esterifikasi selesai akan berlanjut dengan reaksi polimerisasi. Dengan mempelajari perubahan suhu, dan waktu reaksi pada beberapa parameter seperti bilangan asam, bilangan Iod, densitas produk, viskositas dan berat molekul diharapkan akan diperoleh produk dengan berat molekul yang lebih besar dari reaktan pembentuknya atau terjadi reaksi polimerisasi. Hasil penelitian menunjukkan bahwa keberhasilan reaksi dipengaruhi oleh ratio kedua reaktan dan katalis, pada rasio katalis dan reaktan 1:100 menunjukkan peningkatan berat molekul. Dengan semakin meningkatnya suhu menunjukkan bahwa bilangan asam semakin menurun, mengakibatkan konversi semakin meningkat. Hasil konversi maksimum 93,75% terjadi pada suhu reaksi 240 oC, ratio katalis dan reaktan 1:100 dengan rentang berat molekul sekitar 19,502.06 g/gmol hingga 20,034.94 g/gmol, rentang viskositas sekitar 0.0514 poise hingga 0.0534 poise. Sedangkan densitas produk menunjukkan 0,95 g/cm3 sampai dengan 1,045 g/cm3

High pressure gas flow, storage, and displacement in fractured rock-Experimental setup development and application.

This paper presents the design, development, and application of a laboratory setup for the experimental investigations of gas flow and reactions in a fractured rock. The laboratory facility comprises (i) a high pressure manometric sorption apparatus, where equilibrium and kinetic phenomena of adsorption and desorption can be examined, (ii) a high pressure triaxial core flooding system where the chemical reactive transport properties or processes can be explored, and (iii) an ancillary system including pure and mixed gas supply and analysis units. Underground conditions, in terms of pore pressure, confining pressure, and temperature, can be replicated using the triaxial core flooding system developed for depths up to 2 km. Core flooding experiments can be conducted under a range of gas injection pressures up to 20 MPa and temperatures up to 338 K. Details of the design considerations and the specification for the critical measuring instruments are described. The newly developed laboratory facility has been applied to study the adsorption of N2, CH4, and CO2 relevant to applications in carbon sequestration in coal and enhanced coalbed methane recovery. Under a wide range of pressures, the flow of helium in a core sample was studied and the evolution of absolute permeability at different effective stress conditions has been investigated. A comprehensive set of high resolution data has been produced on anthracite coal samples from the South Wales coalfield, using the developed apparatus. The results of the applications provide improved insight into the high pressure flow and reaction of various gas species in the coal samples from the South Wales coalfield

Development of Formaldehyde Adsorption using Modified Activated Carbon - A Review

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energ

Production of carbon nanotubes: Chemical vapor deposition synthesis from liquefied petroleum gas over Fe-Co-Mo tri-metallic catalyst supported on MgO

Carbon nanotubes were produced by chemical vapor deposition method to meet the specifications for hydrogen storage. So far, the various catalyst had been studied outlining their activities, performances, and efficiencies. In this work, tri-metallic catalyst consist of Fe-Co-Mo supported on MgO was used. The catalyst was prepared by wet-impregnation method. Liquefied Petroleum Gas (LPG) was used as carbon source. The synthesis was conducted in atmospheric fixed bed reactor at reaction temperature range 750 – 850 °C for 30 minutes. The impregnation method applied in this study successfully deposed metal component on the MgO support surface. It found that the deposited metal components might partially replace Mg(OH)2 or MgO molecules in their crystal lattice. Compare to the original MgO powder; it was significant increases in pore volume and surface area has occurred during catalyst preparation stages. The size of obtained carbon nanotubes is ranging from about 10.83 nm OD/4.09 nm ID up to 21.84 nm OD/6.51 nm ID, which means that multiwall carbon nanotubes were formed during the synthesis. Yield as much as 2.35 g.CNT/g.catalyst was obtained during 30 minutes synthesis and correspond to carbon nanotubes growth rate of 0.2 μm/min. The BET surface area of the obtained carbon nanotubes is 181.13 m2/g and around 50 % of which is contributed by mesopores. Micropore with half pore width less than 1 nm contribute about 10% volume of total micro and mesopores volume of the carbon nanotubes. The existence of these micropores is very important to increase the hydrogen storage capacity of the carbon nanotubes