24 research outputs found
A Simple Technique for Surface Area Determination Through Supercritical Co2 Adsorption
Get PDFThe 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
Improved Methods for Phase Density Prediction : Cob2s + Hydrocarbons�
No full textImproved methods for mixture phase density predictions were developed. First. scaling-law theory was introduced in the volume translation concept which results in simpler form and better representation for saturation densities of COz-hydrocarbon mixtures than that given by Peneloux's volume translation. Second. the scaled-variable-reducedcoordinate (SVRC) method was extended to the prediction of mixture densities. Using the extended SVRC correlation, mixture density predictions may be performed based on pure-fluid properties. or more precisely based on some mixture data. Both treatments gave comparable results with the existing methods in the literature with the added advantage of covering the full saturation range and obeying scaling-law behavior in the near-critical region. Generalized SVRC correlations provide adequate liquid and vapor density predictions (2 and 7% AAD. respectively). The quality of these predictions. however. is enhanced by the flexibility offered by one system-specific parameter.Chemical Engineerin
Production of antipollutant mask with bamboo based carbon activated using H3PO4 and K2CO3
No full textThe increase of developing countries’ economic level has led to increase in air pollution problem. This research aims to make activated carbon based gas mask filter that was prepared from bamboo scraps by the combined activation using H3PO4 and K2CO3.Bamboo was selected as raw material because of its abundant availability and high cellulose content (42.4-53.6%).Dip coating was conducted to coat activated carbon on the surface layer of mask by adding TEOS compound.Furthermore, adsorption capacity of activated carbon was tested using compartment by flowing air containing CO and CO2 for one hour. The results of the characterization shows that the iodine number of the activated carbon produced reaches 916.3 mg/g with BET surface area of 465.2 m2/g. SEM-EDX analysis shows that the carbon content is 74.83%wt.Adsorption capacity of activated carbon was tested using compartment by flowing air containing pollutant gas and compressed air for one hour. The results indicate that the maximum number of moles CO2 adsorbed is 4.8 mmol/g with 7 hour saturated time,while adsorption capacity of CO measured in 1 hour test is 0.103 mmol/g. Therefore, activated carbon has met the standards and can be applied for gas mask filter to eliminate CO and CO2 until below safety limit concentration
Hydrogen Recovery from Hydrogen-Methane Gas Mixture Using Coffee Grounds Based Activated Carbon Bioadsorbent
No full textHydrogen recovery from off-gas of hydrocracking unit by adsorption is one of the process that could increase the efficiency processes of refinery unit. The purpose of this research is to make coffee grounds based activated carbon bioadsorbent that will be used in hydrogen recovery proses. The carbon was prepared by chemical activation using ZnCl2 at temperature 600°C. The surface area of produced activated carbon was measured using BET and Iodine number, while its surface morphology and composition were characterized using SEM-EDX. The adsorption capacity of activated carbon and its selectivity will be tested using hydrogen-methane gas mixture. The test was carried out on pure methane and hydrogen gas at 20°C and a mixture of CH4/H2 (mole ratio: 4:1) at 10°C, 20°C and 30°C and pressures from 1 to 6 bars. The results of this study show that the activated carbon can be successfully produced having the specific surface area of 728.07 m2/g and the iodine number of 2160 mg/g. The result shows that the adsorption of pure CH4 gas at the same pressure was 2.4 times greater than pure H2. The adsorption test indicates that the produced activated carbon might be used for hydrogen/methane separation
Production of antipollutan mask based activated carbon from wasted coconut shell
Get PDFIndonesia is one of the countries with the highest levels of air pollution in the world. Air pollution in Indonesia, especially in Jakarta due to the number of private vehicles increased at least 10% every year. This air pollution can have an impact on public health. One effort to do as a protection of people health is to use a mask. Activated carbon can be coated to mask in order to improve the effectiveness in reducing the pollutants. One good material used as material for activated carbon is coconut shell. Selection of coconut shell as the raw material of activated carbon is also based on cellulose content of 26.06%, hemicellulose content 27.07% and a lignin content of 29.40% in the dry state. This research was done in some variation such as activation methods, activated carbon mass, and adhesive material types. Based on pollutants adsorption test, mask with 6 grams of activated carbon, chemically activated, and used TEOS as adhesive is the best variation that able to adsorb as much 76,25% of CO2 Pollutants. Mask made in this research, has saturation time as long as 4 hours under high CO2 concentration
Betung bamboo-based activated carbon bioadsorbent for the separation of hydrogen-methane gas mixture
No full textHydrogen recovery from off gas of hydrocracking and hydrotreating unit is one of the crucial processes in an oil and gas refinery unit as this process helps in lowering the expenses for operations. This study aims to obtain activated carbon that is made from Betung bamboo which can be used as the adsorbent in this process. The activated agents used are H3PO4 and K2CO3, respectively. Each activation lasts for 30 minutes. The results of the characterization test shows that the Iodine number of the activated carbon produced reaches 916.4 mg/g with BET surface area of 465.2 m2/g. SEM-EDX analysis shows that the carbon content is 74.83%. The activated carbon obtained is used to separate Hydrogen and Methane from its mixture at 10, 20 and 30oC with pressure variations of 1 - 6 bar. The results indicate that the maximum number of moles adsorbed from CH4(21.5%)/H2 gas mixture is 0.247 mmol/g, that has been carried out at 6 bar with temperature of 10oC. Methane has 2.2 times higher adsorption capacity than hydrogen, therefore, the Betung bamboo based activated carbon produced from this research can be applied as the adsorbent in the separation process of CH4/H2 mixture and it fits the Langmuir model
Betung bamboo-based activated carbon bioadsorbent for the separation of hydrogen-methane gas mixture
No full textHydrogen recovery from off gas of hydrocracking and hydrotreating unit is one of the crucial processes in an oil and gas refinery unit as this process helps in lowering the expenses for operations. This study aims to obtain activated carbon that is made from Betung bamboo which can be used as the adsorbent in this process. The activated agents used are H3PO4 and K2CO3, respectively. Each activation lasts for 30 minutes. The results of the characterization test shows that the Iodine number of the activated carbon produced reaches 916.4 mg/g with BET surface area of 465.2 m2/g. SEM-EDX analysis shows that the carbon content is 74.83%. The activated carbon obtained is used to separate Hydrogen and Methane from its mixture at 10, 20 and 30oC with pressure variations of 1 - 6 bar. The results indicate that the maximum number of moles adsorbed from CH4(21.5%)/H2 gas mixture is 0.247 mmol/g, that has been carried out at 6 bar with temperature of 10oC. Methane has 2.2 times higher adsorption capacity than hydrogen, therefore, the Betung bamboo based activated carbon produced from this research can be applied as the adsorbent in the separation process of CH4/H2 mixture and it fits the Langmuir model
Production of antipollutant mask with bamboo based carbon activated using H
No full textThe increase of developing countries’ economic level has led to increase in air pollution problem. This research aims to make activated carbon based gas mask filter that was prepared from bamboo scraps by the combined activation using H3PO4 and K2CO3.Bamboo was selected as raw material because of its abundant availability and high cellulose content (42.4-53.6%).Dip coating was conducted to coat activated carbon on the surface layer of mask by adding TEOS compound.Furthermore, adsorption capacity of activated carbon was tested using compartment by flowing air containing CO and CO2 for one hour. The results of the characterization shows that the iodine number of the activated carbon produced reaches 916.3 mg/g with BET surface area of 465.2 m2/g. SEM-EDX analysis shows that the carbon content is 74.83%wt.Adsorption capacity of activated carbon was tested using compartment by flowing air containing pollutant gas and compressed air for one hour. The results indicate that the maximum number of moles CO2 adsorbed is 4.8 mmol/g with 7 hour saturated time,while adsorption capacity of CO measured in 1 hour test is 0.103 mmol/g. Therefore, activated carbon has met the standards and can be applied for gas mask filter to eliminate CO and CO2 until below safety limit concentration
The Effect of Various Zeolites as an Adsorbent for Bioethanol Purification using a Fixed Bed Adsorption Column
Get PDFThe
depletion of fossil energy sources has increased the demand for renewable
energy. Bioethanol, which is a type of biofuel, can be used as a gasoline
mixture, resulting in cleaner combustion with higher octane values as compared
to conventional fuels. For bioethanol to be used as a gasoline mixture, two purification
steps are required. Difficulties in the ethanol purification process are caused
by the azeotrope condition of the ethanol-water mixture. To remove water from
the mixture in azeotropic conditions, advanced technology is necessary. One
method for separating ethanol and water that is both economical and effective
is the adsorption process. This study observed adsorbent performance during a
continuous adsorption process through a fixed bed column with different ethanol
influent concentrations. Synthetic zeolites 3A and 4A will be examined as
potential adsorbents because they have properties that result in a high
adsorption capacity, they are not easily saturated, they have high selectivity,
and they are easy to regenerate. This study was carried out under the
bed operation condition of atmospheric temperature and
pressure (20°C and 1 atm), with a 50% v/v and 10% v/v ethanol inlet
concentration, which has a 10 ml/min flow rate. The results of this study
are presented with a breakthrough curve, which is used to analyze adsorption
performance by determining the highest ethanol effluent
concentration, the adsorption capacity, and the effective adsorption time. The zeolite 3A
adsorbent, which has a larger surface area and a pore diameter that is closest in
size to that of water molecules, was found to have better adsorption
performance, resulting in higher ethanol purity, higher adsorption
capacity, and a longer saturation time as compared with the adsorption process
of zeolite 4A
