Chemical Engineering design of an operation unit paper

Table of Contents

Introduction                                                                                                                            3

Material for the Operation Unit                                                                                              4

Adsorbents Requirements                                                                                                       4

Capacity and Purity of CO₂                                                                                                    5

Choice of Technology (Adsorption)                                                                                       5

Operation Mode                                                                                                                      6

Adsorbent Specification                                                                                                         6

Designing the Operation unit and the Processes                                                                    6

Pressure Aspects                                                                                                                     8

Steps in the Adsorption Process                                                                                             9

Conclusion                                                                                                                              11

 

Bibliography                                                                                                                           12

APPENDICES                                                                                                                       17

Table of Figures

Table 1: Isothermal data                                                                                                         17

Table 2: Technical Data about the Operation Unit                                                                19

Figure 1: The Temperature Swing Adsorption Unit                                                               8

Figure 2: Schematic of the CO₂Adsorption Operation Unit                                       10

Figure 3: Pressure Equalization using Two Modes                                                                10

 

Chemical Engineering design of an operation unit

Introduction

Over the past, adsorption processes have increasingly gained commercial acceptance as effective and energy-saving separation techniques. The process begins with designing and setting up an operation unit for the separation process. After a stipulated start-up time, the unit or system attains a cyclic and steady-state in which all conditions, both at the beginning and at the end of each cycle end up being identical. Adsorption processes work under the application of a determination process, which is direct, using a method that is Newton-based. This happens with accurate sensitivity in order to achieve quick as well as robust cyclic study state coverage. In chemical engineering, a unit operation is the basic step in any separation process. The unit operation involves the initiation of physical changes such as evaporation, crystallization, filtration, and separation among other physical processes. This paper involves a design of one operation unit for CO₂adsorption from flue gas of power plant.

The adsorption process would make use of activated carbon, a source mainly from fuel substances in the mining industry, and it will be based on physical adsorption mechanism. Physical adsorption involves electrostatic attractive interaction of opposite charges and the idea of weak Van der Waals forces. It is chosen over the chemisorption process because it uses lower enthalpy of adsorption, which is between 8-20 kJ mol^-1against 40-800 kJ mol^-1 for chemisorptions. While activation energy in chemisorptions is small, it is zero for the physical process. Another factor considered is the low temperature of occurrence in physical adsorption, which depends on the boiling point. Physical adsorption also allows the application of more than one layer that is adsorbed while chemisorption allows the chance of only one layer.

Flue gas can be obtained from the combustion of a petroleum fuel such as kerosene. The capture of carbon dioxide from power stations has increasingly become a key issue in research. CO₂ separation is a benefit to the chemical industry, where CO₂ is used for many purposes such as the production of methanol, urea, metal bicarbonates and carbonates. The concern on the production of CO₂is enhanced by the issue of global warming. Various capture approaches are typically applicable (Hicks et al. 2008). These approaches include membranes, cryogenic, absorption, and adsorption among other approaches. In this paper, the adsorption process is used as the preferred approach in the gas separation process.

The adsorption process of carbon dioxide gas from flue gas of power plant is critical for various reasons. Carbon dioxide typically affects power consumption. To establish an effective design for the operation unit suitable for this separation, experimental work is important in building a three-bed adsorption plant for carbon dioxide extraction from flue gas of a power plant (Arenillas et al. 2005). Aspects such as temperature, feed concentration, and evacuation pressure are considered. A step-by-step cycle is considered to depict the way each aspect influences the performance of the adsorption process (Arenillas et al. 2005).

In the adsorption process of separating CO₂ from flue gas of a power plant, CO₂ capture is developed and fully employed. Through both experiments and effective analysis, it can be established that feed gas temperatures, feed concentration, and evacuation pressure influence the capture cost and power consumption. The best results could be obtained mainly with 40°Cof feed gas under a relatively deep vacuum condition. Feeding a higher concentration of feed gas to the plant is known to enhance performance according to Chang et al. (2003). The choice of power plant as the carbon dioxide is based on the fact that fossil fuel plants contribute to over 30 per cent of all human practices contributing to global warming (Rinker, Ashour & Sandall 2000). It is thus important to come up with an effective way of capturing and separating carbon dioxide flue gas, which is a post-combustion affluent. This separation could be an effective way of preventing carbon dioxide release to the atmosphere (Himeno et al. 2007).

Material for the Operation Unit

Given that a physical mechanism is used for the adsorption process, activated carbon would be the main requirement for the project. Activated carbon is preferred due to its usage over the past. Besides, it has gained significant commercial applications. Another key requirement would be power supply to run the plant by supporting all chemical and physical processes. Flue gas is another requirement in this case. It can be obtained from sources like the combustion of a flue such as kerosene. Some packing material for the process include rasching ring, pro-pack, and intalox saddle, and they are packed in the absorber. Most of the required materials are obtained from the mining industry where the CO₂constituents can be established. They are dissolved in an HCl solution with a concentration of 37 per cent at room temperature. HCl solution and Tetraethyl orthosilicate are also part of the requirements (Zhao, Chen & Zhao 2009). Besides, adequate and steady power supply is required to maintain the required levels of pressure and temperature.

Adsorbents Requirements 

In order to obtain good results, the adsorbents should be having high selectivity. High selectivity would allow sharp separations in terms of surface and pore shape or size. High capacity of the adsorbents is required for minimizing the amount of sorbent used. Again, there should be favorable kinetic and transport properties to allow rapid adsorption (Lecture14 2013). In order to preserve the sorbent amount and its properties, there need to be thermal and chemical stabilities. This should include low solubility within the contacting fluid. Mechanical strength and hardness are required to avoid crushing and erosion aspects. Resistance to both poison and fouling should be ensured to achieve long life. Again, a free-flowing tendency to ease the emptying or filling of vessels should be ensured (Lecture 14 2013). There should be hardly any tendency for promoting undesirable reactions. Besides, all these requirements should be facilitated with cost considerations.

 Capacity and Purity of CO₂

The adsorption technology is initiated to yield the purest CO₂ product possible. The adsorption technology aims to achieve a CO₂ purity of above 99%, with the target of the final product being 99.5%. This purity level is achievable only with the application of the correct procedures. The use of a modified thermo-gravimetric analysis is initiated in order to determine the adsorption process as well as the adsorption properties of the used adsorbents. This determination could be done with the use of H₂O saturator. For the adsorbent, 10 mg is placed within a sample cell and then heated to a temperature of 373 K (Hiyoshi, Yogo & Yashima 2005). The heating is done under the flow of N₂ at a rate of 50 ml per min.

The flow is maintained at a temperature of 373 K for 30 minutes. This is done until there is hardly any weight loss observed. Subsequent cooling of the sample is then done until the cooling reaches the 348 K. At least 15 percent of dry CO₂ is introduced at the rate of 25 ml per minute (1000). The gas is then switched to nitrogen flow at the rate of 50 ml per minute (Hiyoshi, Yogo & Yashima, 2005). This is done to advance the adsorption processat a constant temperature. Each adsorption cycle requires at least two hours, equivalent to 120 minutes. In this technology, maximizing on the purity of the product is enhanced by determining the accuracy and sensitivity of the thermo-gravimetric analysis. The accuracy and sensitivity are 0.1 percent and 10 μg respectively. The influence of CO₂ adsorption capacity by moisture is likely to occur, which implies that investigation has to be initiated with cyclic measurements in order to access the adsorbents’ stability (Hiyoshi, Yogo & Yashima 2005). The experiment requirements and technical data for the operation unit are tabulated in table 1 and table 2 below respectively.

Choice of Technology (Adsorption)

            The technology chosen in this case is adsorption. The choice of this technology is based on resource availability and ease of application as compared to the material membrane. In the case of the adsorption process, a special vessel is chosen for the purpose of loading air with water in order to get wet air (Reynhardt et al. 2005). Wet air is then combined with the prevailing dry air as well as the start concentration. The results could be measured with the use of hygrometer particularly at the adsorber inlet (Hook 1997).

Adsorption process occurs within the adsorption tower. In this case, absorption of the moisture occurs at the adsorbans. Measurements such as concentration against time are determined mainly for various loadings. The extension operation makes it possible to carry out the adsorption process with flue gas (Siriwardance, Shen & Fisher 2005). With the use of this technology, flue gas is tested among other adsorbans. Again, the determination of isothermal adsorption lines breakdown curves is done at a constant temperature. This curve determination is done for various temperature loadings (Hook 1997).

 

Operation Mode

For this operation unit, a relatively low power plant is used which require a maximum power supply of between 208 and 250 volts. The capacity of carbon dioxide from the power plant is estimated at 1500 liter per hour as per the provided gas flow rate of 25 liters per minute. This occurs under a number of assumptions. One of the assumptions is that the adsorbent has 90 percent of CO₂ working capacity (Siriwardance, Shen&Fisher 2005). Again, 8 percent is considered to be significantly low. The adsorption cycle time for the temperature swing adsorption is two hours of Bed utilization, which results in 90 per cent of the product (Zhao et al. 1998). These assumptions bring about the calculation of the required sorbent.

Adsorbent Specifications

            Activated carbon is chosen for this adsorption process. Adsorption vessel and the carbon storage vessels is pressurized, heated, or put under vacuum. The weight of contaminant to be adsorbed per weight can be absorbed (Erskine & Schuliger 1971). This is based on estimated isothermal data that is supplied by literature or carbon manufacturer. The choice of the activated carbon is based on isotherm aspects, run time between carbon changes, and steady and cheaper carbon source among other aspects. The amount of carbon to be used for the runtime period of 150 days is determined. For this operation unit, two carbon vessels are used in series as indicated in figure 1 above. The flue gas flows from the first vessel to the second vessel and be discharged (Valenzuela & Myers1989).

The flow is directed to the lag vessel after the concentration of the effluent equals that of the influent. The two vessels have equal amounts of carbon. Exhausted carbon is regenerated and put back in the lag vessel. Because it is difficult to know the contaminants in carbon, the exact amount of carbon required may be difficult to establish (Valenzuela & Myers1989). Carbon contaminants are Perchloroethylene (PCE), Trichloroethylene (TCE), Benzene, and Toluene.

The amount of carbon required can be calculated from the following equation with respect to the isothermal data in table 1(Appendix I), whose values are predicted from Freundlich isotherm relationship(U.S. Army Corps of Engineers 2001). From the isothermal data, the weight of each contaminant can be established in order to establish the amount of carbon required for the runtime period (see Appendix I).

Designing the Operation unit and the Processes

In the course of designing the operation unit, aspects like the diameter and depth are considered. The diameter of the tower depends on aspects like liquid flow and vapor. The diameter determination is driven by vapor loads, but the flow rate is mostly critical in the case of acid absorption (Himeno, Komatsu & Fujita 2005). Given that CO₂ is an acidic gas, flow rate is a consideration for the unit dimensions. This aspect is also considered given a case where the product specification is required.

Designing the Operation Unit starts from the vessel choice, in which aspects related to its dimensions are considered as well as adsorbent specifications. In a typical operation unit, since the technology makes use of temperature swing adsorption, CO₂ is adsorbed at a temperature range of 10°C to 60°C. Regeneration is generally conducted at a temperature greater than 100°C (Khatri et al. 2006).  Since with large beds much longer time is taken to heat up due to the regeneration process that uses steam and similarly long time in cooling down, the size of the apparatus has to be considered (Pulido et al. 2009). The rate of carbon usage is evaluated against aspects like initial costs for the larger units as well as the high maintenance and operation cost associated with smaller units. When determining the size of the vessel a bed expansion of between 20% to 50% should be considered to allow backwashing (Reynhardt et al. 2005). The design can have a short vessel with large diameter or it could have a small diameter, but vast in length. The two types would hold the same amount.

Air is used in the process of cooling down (adsorption process) due to possible heat transfer limitations. The steam, which is used for the heating process, is also used to attack some sorbents. This is allowed mainly given that the steam could condense and collect on the surface of the attacked sorbent. Mass transfer as well as diffusion entail a relatively rate-limiting step, which require large beds for CO₂ adsorption (Zheng et al. 2005). This occurs due to the high volume of CO₂ requiring adsorption as well as large granules for the two beds. Another key concern in the operation unit is pressure drop across the two beds.

Designing the operation unit would require an estimation of its dimensions such as the volume, diameter, and depth. The calculations are possibly formulated from some given information (see Appendix III). From table 2 in Appendix IV, which gives a summary of the calculations, it is possible to design the TSA unit as shown in figure 1 below.

Figure 1: The Temperature Swing Adsorption Unit

Pressure Aspects

The pressure drop across the adsorption beds is highly affected by the activated carbon’s particle size. The particle size also affect the diffusion mechanism. These aspects implies that the particle size of the activated carbon affect the entire adsorption process. Typically, pressure drop is inversely proportional to the particle size. Pressure drop is also affected by piping configuration, contact time, as well as surface loading rate (Valenzuela & Myers1989).

Pressure safeguard like rupture disks are used with corrosion allowance being used because wet carbon is very corrosive. The partial pressure for the operation unit is critical in this case. In calculating the partial pressure, it is assumed that the carbon vessel pressure is equal to the discharge pressure. Taking discharge pressure to be 12.7 psia, the partial pressure can be calculated as follows (Valenzuela & Myers1989). For the partial pressure calculations, see Appendix V.

Steps in the Adsorption Process

Adsorption of CO₂  takes place in a determined process. The operation mode for the adsorption process involve four steps in which various processes occur.In designing the operation unit, the application of two beds is considered. The operation unit, in this case, operates mainly in a four step cycle.

The Steps

The four steps of the cycle are explained below:

Step 1

In this step, Bed-1 is set at high pressure. Bed-2 is conversely at relatively low pressure. The feed to be used is first brought to Bed-1 like in the case of distillation (Xu, 2005). This is done at some point along the bed. A portion of the gas obtained from bed-1 is directed to Bed-2 for recycling. The rest of this gas is considered to be the raffinate product. Some of the gas from Bed-2 is directed to Bed-1 for recycling as well. The rest is considered to be the extracted CO₂ product (Zelenák et al. 2008).

Step 2

In this step, pressure levels within the two beds are made equal. The equalization of the pressures is done through a connection of the top ends or even the bottom ends of the two beds. Bed-2 is then pressurized to a high pressure with the gas drawn from Bed-1 (Yue et al. 2008).

Step 3

In this step, the feed is directed to Bed-2. The end streams are then recycles like in the case of Step 1.

Step 4

In this step, the same setting as in step 2 is initiated. This involves the equalization of the two pressures. The entire process could be presented in figure 2 below:

Figure 2: Schematic of the CO₂ Adsorption Operation Unit

Steps 1 to 4 are adequate to complete one cycle. Within the same process, the feed may be introduced to the low pressure bed. This could be initiated in place of the high pressure bed. From the same process, a mathematical model could be developed as a way of stimulating all the four steps of the operation unit. The model would provide a way of assessing the unit performance for the CO₂ adsorption and recovery from flue gas (Xu et al. 2002). In such a case, flue gas in the power plant is considered to be an only a binary mixture of nitrogen and carbon dioxide. This happens because the amount of nitrogen adsorbed within the bed is relatively small as compared to the amount of carbon dioxide (Li &Tezel 2007). Nitrogen is thus considered to be a non-adsorbing component. Again, the process’s theoretical energy, which is required, is calculated. The calculation takes the theoretical energy to be the sum of all energies required to recycle the gas from the lower pressure bed to high pressure bed. It is also considered from the aspect of pressurizing any bed from low pressure to high pressure as well as evacuating one bed from high pressure to low pressure (Lee, Keener & Yang 2009). The simulation results are presented in figure 3 below.

Figure 3: Pressure Equalization using Two Modes

In figure 3 above, pressure equalization as well as pressure resetting is shown for the operation unit. The pressure equalization could be done from the carbon dioxide rich end or from the nitrogen rich end. The CO₂ rich end is represented by mode-1 while the N₂ rich end is represented by mode-2 (Walton, Abney &LeVan 2006).

Conclusion

In the process of conducting the adsorption process, material and requirement consideration is first done. The materials need to be suitable and economical depending on the aspired product quantity and purity. Aspects like power supply, the course, and availability of the flue gas, activated carbon, HCl, and any other requirements need to be established first. This would not only ease the process, but would also enhance accuracy and the purity of the final product. Planning is also good for economical reasons. More importantly, suitable adsorbents for removing CO₂ from flue gas should have a number of attributes. One of the properties is high capacity for CO₂ adsorption. The high capacity is suitable for screening new adsorbents. In this case, considering high skills or adequate knowledge for the adsorption equilibrium is essential. The knowledge helps in the evaluation of potential adsorbents. Another key attribute is fast kinetics since adsorption kinetics influences the working adsorption within the dynamic processes like fix bed column adsorption.

The third attribute to consider is high CO₂ selectivity (Morris and Wheatley 2008). This attribute is critical given that it directly affects the purity degree of the product, which further affects the economy of the entire process. It is also important to consider the regeneration mild conditions. This would ensure the ease of the used adsorbent due to a meaningful selection of the right material for the CO₂ separation. During extensive adsorption, stability need to be maintained throughout the desorption cycle (Pulido 2005). There should also be adequate tolerance to impurities such as moisture within the feed. Besides, the most important parameter to consider is the cost of the entire operation. A consideration of all these parameters would ensure the success of the adsorption process of CO₂ from flue gas in a power plant.

Bibliography

Arenillas, A., Smith, K.M., Drage, T.C., Snape, C.E., 2005. ‘CO2 Capture Using Some Fly ash-   Derived Carbon Materials,’Fuel, vol. 84,pp. 2204-2210.

Chang, A.C.C., Chuang, S.S.C., Gray, M., Soong, Y. 2003. ‘In-Situ Infrared Study of CO2         Adsorption on SBA-15 Grafted with γ-(Aminopropyl)Triethoxysilane,’ Energy Fuels,       vol. 17, pp.468-473.

Erskine, D.B. and W.G. Schuliger, 1971. ‘Activated Carbon Processes for Liquids,’ Chemical

            Engineering Process, Vol. 67, Noll, November.

Figueroa, D., Fout, T., Plasynski, S., Mcllvried, H., Srivastava, R.D. 2008. ‘Advances in CO2      Capture Technology-the US Department of Energy’s Carbon Sequestration Program,’         Inter. J. Greenhouse Gas Control, vol. 2, pp.9-20.

Franchi, R.S., Harlick, P.J.E., Sayari, A. 2005. ‘Applications of Pore-Expanded Mesoporous         Silica: 2. Development of a High-Capacity, Water-Tolerant Adsorbent for CO2,’ Ind.           Eng. Chem. Res., vol. 44, pp. 8007-8013.

Gray, M.L., Soong, Y., Champagne, K.J., Pennline, H.W., Baltrus, J., Stevens, R.W.J., Khatri,     R.A., Chuang, S.S.C., Filburn, T. 2005. ‘Improved Immobilized Carbon Dioxide Capture             Sorbents,’ Fuel Proc. Technol, vol. 86, pp.1449-1455.

Hao, G.P., Li, W.C., Qian, D., Lu, A.H. 2010. ‘Rapid Synthesis of Nitrogen- Doped Porous         Carbon Monolith for CO2 Capture,’Adv. Mater., vol. 22, pp.853-857.

Harlick, P.J.E., Sayari, A. 2007. ‘Applications of Pore-Expanded Mesoporous Silica. 5. Triamine Grafted Material with Exceptional CO2 Dynamic and Equilibrium Adsorption           Performance,’ Ind. Eng. Chem. Res, vol. 46, pp.446-458.

Hicks, J.C., Drese, J.H., Fauth, D.J., Gray, M.L., Qi, G., Jones, C.W. 2008. ‘Designing     Adsorbents for CO2 Capture from Flue Gas-Hyperbranched Aminosilicas Capable of     Capturing CO2 Reversibly,’J. Am. Chem. Soc., vol. 130, pp.2902-2903.

Himeno, S., Komatsu, T., Fujita, S. 2005. ‘High-Pressure Adsorption Equilibria of Methane and   Carbon Dioxide on Several Activated Carbons,’ J. Chem. Eng. Data, vol. 50, pp.369-376.

Himeno, S., Tomita, T., Suzuki, K., Yoshida, S. 2007. ‘Characterization and Selectivity for           Methane and Carbon Dioxide Adsorption on the All- Silica DD3R Zeolite,’Micropor.     Mesopor. Mater,vol.98, pp.62-69.

Hiyoshi, N., Yogo, K., Yashima, T. 2005. ‘Adsorption Characteristics of Carbon Dioxide on        Organically Functionalized SBA-15,’ Micropor. Mesopor. Mater, vol. 86, pp.357-365.

Hook, R.J. 1997. ‘An Investigation of Some Sterically Hindered Amines as Potential Carbon       Dioxide Scrubbing Compounds,’Ind. Eng. Chem. Res., vol. 36, pp.1779-1790.

Khatri, R.A., Chuang, S.S.C., Soong, Y., Gray, M. 2006. ‘Thermal and Chemical Stability of       Regenerable Solid Amine Sorbent for CO2 Capture,’Energy Fuels, vol. 20, pp.1514-   1520.

Kim, S., Ida, J., Guliants, V.V., Lin, J.Y.S. 2005. ‘Tailoring Pore Properties of MCM-48 Silica     for Selective Adsorption of CO2,’ J. Phys. Chem. B, vol.109, pp.6287-6293.

Kleitz, F., Choi, S.H., Ryoo, R. 2003. ‘Cubic Ia3d Large Mesoporous Silica: Synthesis and           Replication to Platinum Nanowires, Carbon Nanorods and Carbon Nanotubes,’ Chem.     Commun, vol. 17, pp.2136-2137.

Knöfel, C., Descarpentries, J., Benzaouia, A., Zelenák, V., Mornet, S., Llewellyn, P.L.,     Hornebecq, V. 2007. ‘Functionalised Micro-/Mesoporous Silica for the Adsorption of      Carbon Dioxide,’ Micropor. Mesopor. Mater, vol. 99, pp.79-85.

Knowles, G.P., Delaney, S.W. 2006. Chaffee, A.L. ‘Diethylenetriamine[Propyl(Silyl)]-     Functionalized (DT) Mesoporous Silicas as CO2 Adsorbents,’ Ind. Eng. Chem. Res, vol.             45, pp.2626-2633.

Lecture 14, 2013, Adsorption Technology,PDF file 26/11/2013, Aston  University, Birmingham.

Lee, J., Sohn, K., Hyeon, T. 2001. ‘Fabrication of Novel Mesocellular Carbon Foams with            Uniform Ultralarge Mesopores’ J. Am. Chem. Soc., vol. 123, pp.5146-5147.

Lee, J.Y., Keener, T.C., Yang, Y.J. 2009. ‘Potential Flue Gas Impurities in Carbon Dioxide          Streams Separated from Coal-Fired Power Plants,’ J. Air & Waste Manage. Assoc, vol.            59,725-732, doi: 10.3155/1047- 3289.59.6.725.

Li, P., Tezel, H. 2007. ‘Adsorption Separation of N2, O2, CO2 and CH4 Gases by Beta-Zeolite,’ Micropor. Mesopor. Mater, vol. 98, 94-101.

Liu, Y., Shi, J.J., Chen, J., Ye, Q., Pan, H., Shao, Z.H., Shi, Y. 2010. ‘Dynamic Performance of   CO2 Adsorption with Tetraethylenepentamine- Loaded KIT-6,’ Micropor. Mesopor.             Mater, vol. 134, pp.16-21.

Liu, X., Tian, B., Yu, C., Gao, F., Xie, S., Tu, B., Che, R., Peng, L., Zhao, D. 2002. ‘Room-         Temperature Synthesis in Acidic Media of Large-Pore Three- Dimensional Bicontinuous            Mesoporous Silica with Ia3d Symmetry,’Angew. Chem. Int. Ed., vol. 41, pp.3876-3878.

Liu, X., Zhou, L., Fu, Z., Sun, Y., Su, W., Zhou, Y. 2007. ‘Adsorption and Regeneration Study of the Mesoporous Adsorbent SBA-15 Adapted to the Capture/ Separation of CO2 and          CH4,’ Chem. Eng. Sci, vol. 62, pp.1101-1110.

Lu, C.S., Bai, H.L., Su, F.S., Chen, W.F., Hwang, J.F., Lee, H.H. 2010. ‘Adsorption of Carbon   Dioxide from Gas Streams via Mesoporous Spherical- Silica Particles,’ J. Air & Waste             Manage. Assoc, vol. 60, pp.489-496, doi: 10.3155/1047-3289.60.4.489.

Maurin, G., Bell, R., Kuchta, B., Poyet, T., Llewellyn, P. 2005.‘Adsorption of Non Polar and      Quadrupolar Gases in Siliceous Faujasite: Molecular Simulations and Experiments,’       Adsorption, vol. 11, 331-336.

Morris, R.E., Wheatley, P.S. 2008. ‘Gas Storage in Nanoporous Materials, Angew,’Chem. Int.      Ed., vol. 47, pp. 4966-4981.

Navarro, J.A.R., Barea, E., Salas, J.M., Masciocchi, N., Galli, S., Sironi, A., Ania, C.O., Parra,      J.B. 2006.‘H2, N2, CO, and CO2 Sorption Properties of a Series of Robust Sodalite-    Type Microporous Coordination Polymers,’ Inorg. Chem., vol. 45, pp.2397-2399.

Pulido, A., Nachtigall, P., Zukal, A., Domínguez, I., Cejka, J. 2009. ‘Adsorption of CO2 on         Sodium-Exchanged Ferrierites: The Bridged CO2 Complexes Formed between Two           Extraframework Cations,’ J. Phys. Chem. C., vol. 113, pp.2928-2935.

Reynhardt, J.P.K., Yang, Y., Sayari, A., Alper, H. 2005. ‘Polyamidoamine Dendrimers Prepared Inside the Channels of Pore-Expanded Periodic Mesoporous Silica,’Adv. Funct. Mater,          vol. 15, pp.1641-1646.

Rinker, E., Ashour, S.S., Sandall, O.C. 2000. ‘Absorption of Carbon Dioxide into Aqueous          Blends of Diethanolamine and Methyldiethanolamine,’ Ind. Eng. Chem. Res., vol. 39, pp.      4346-4356.

Satyapal, S., Filburn, T., Trela, J., Strange, J. 2001. ‘Performance and Properties of a Solid            Amine             Sorbent for Carbon Dioxide Removal in Space Life Support Applications,’            Energy Fuels , vol. 15, pp.250-255.

Serna-Guerrero, R., Da’na, E., Sayari, A. 2008. ‘New Insights into the Interactions of CO2 with   Amine-Functionalized Silica,’ Ind. Eng. Chem. Res., vol. 47, pp.9406-9412.

Serre, C., Bourrelly, S., Vimont, A., Ramsahye, N.A., Maurin, G., Llewellyn, P.L., Daturi, M.,     Filinchuk, Y., Leynaud, O., Barnes, P., Férey, G. 2007. ‘An Explanation for the Very      Large Breathing Effect of a Metal-Organic Framework During CO2 Adsorption,’Adv. Mater, vol. 19, pp.2246-2251.

Serre, C., Millange, F., Thouvenot, C., Nogues, M., Marsolier, G., Louer, D., Férey, G. 2002.        ‘Very Large Breathing Effect in the First Nanoporous Chromium(III)-Based Solids: MIL-        53 or CrIII(OH).{O2C-C6H4- CO2} . {HO2C-C6H4-CO2H}x,’H2Oy, J. Am. Chem.        Soc., vol. 124, pp.13519-13526.

Siriwardance, R.V., Shen, M.S., Fisher, E.P. 2005. ‘Adsorption of CO2 on Zeolites at Moderate             Temperatures,’Energy Fuels, vol. 19, 1153-1159.

Su, F.S., Lu, C.Y., Kuo, S.C., Zeng, W.T. 2010. ‘Adsorption of CO2 on Amine- Functionalized y-Type Zeolites,’ Energy Fuels, vol. 24, pp.1441-1448.

U.S. Army Corps of Engineers, 2001. Engineering and Design, ADSORPTION DESIGN GUIDE, Design Guide No. 1110-1-2, PDF File 1 Mar 2001, DEPARTMENT OF THE       ARMY.

Valenzuela, D.P., and A.L. Myers. 1989. Adsorption Equilibrium Data Handbook. Prentice Hall,

Englewood Cliffs, New Jersey, 07632,. ISBN 0-13-008815-3.

Veawab, A., Tontiwachwuthikul, P., Chakma, A. 1999. ‘Corrosion Behavior of Carbon Steel in the CO2 Absorption Process Using Aqueous Amine Solutions,’Ind. Eng. Chem. Res.,          vol. 38, pp.3917-3924.

Walton, K.S., Abney, M.B., LeVan, M.D. 2006. ‘CO2 Adsorption in Y and X Zeolites Modified by Alkali Metal Cation Exchange,’Mesopor. Mater, vol. 91, 78-84.

Walton, K.S., Millward, A.R., Dubbeldam, D., Frost, H., Low, J.J., Yaghi, O.M., Snurr, R.Q.      2008. ‘Understanding Inflections and Steps in Carbon Dioxide Adsorption Isotherms in             Metal-Organic Frameworks,’ J. Am. Chem. Soc., vol. 130, pp406-407.

Xu, X., Song, C.S., Andresen, J.M., Miller, B.G., Scaroni, A.W. 2002. ‘Novel Polyethylenimine- Modified Mesoporous Molecular Sieve of MCM-41 Type as High-Capacity Adsorbent for CO2 Capture,’ Energy Fuels, vol. 16, pp.1463-1469.

Xu, X., Song, C.S., Miller, B.G., Scaroni, A.W. 2005.‘Adsorption Separation of Carbon Dioxide from Flue Gas of Natural Gas-Fired Boiler by a Novel Nanoporous “Molecular Basket”          Adsorbent, Fuel Proc,’Technol., vol. 86,pp.1457-1472.

Yue, M.B., Chun, Y., Cao, Y., Dong, X., Zhu, J.H. 2006. ‘CO. 2 Capture by as-Prepared SBA-15           with an Occluded Organic Template,’Adv. Funct. Mater, vol. 16,pp.1717-1722.

Yue, M.B., Sun, L.B., Cao, Y., Wang, Y., Wang, Z.J., Zhu, J.H. 2008. ‘Efficient CO2 Capturer   Derived from as-synthesized MCM-41 Modified with Amine,’ Chem. Eur. J., vol. 14,         pp.3442-3451.

Zelenák, V., Badanicová, M., Halamová, D.,Cejka, J., Zukal, A., Murafa, N., Goerigk, G. 2008.   ‘Amine-Modified Ordered Mesoporous Silica: Effect of Pore Size on Carbon Dioxide            Capture,’ Chem. Eng. J., vol. 144, pp.336-342.

Zhao, C.W., Chen, X.P.,  Zhao, C.S. 2009. ‘Effect of Crystal Structure on CO2 Capture   Characteristics of Dry Potassium-Based Sorbents,’Chemosphere, vol. 75, pp. 1401-1404.

Zhao, D., Feng, J., Huo, Q., Melosh, N., Fredrickson, G.H., Chmelka, B.F., Stucky, G.D. 1998.   ‘Triblock Copolymer Syntheses of Mesoporous Silica with Periodic 50 to 300 Angstrom       Pores,’ Science, vol. 279, pp.548-552.

Zheng, F., Tran, D.N., Busche, B.J., Fryxell, G.E., Addlemann, R.S., Zemanian, T.S., Aardahl,    C.L. 2005. Ethylenediamine-Modified SBA-15 as Regenerable CO2 Sorbent. Ind. Eng.          Chem. Res., 44, pp.3099-3105.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

APPENDICES

Appendix I

Table 1: Isothermal data (U.S. Army Corps of Engineers 2001)

The Contaminants	Temperature	K	C (kPa)	1/n	x/m
PCE	298 K	1.0	1.3×10–3	0.144	0.384
TCE	298 K	0.95	1.2×10–3	0.263	0.162
Benzene	298 K	0.388	0.79×10–3	0.131	0.152
Toluene	298 K	0.565	0.44×10–4	0.111	0.240

Table 2: Shows the isothermal data for activated carbon. The K and 1/n values are obtained at a temperature of 77 .

Appendix II

Estimation of Carbon amount for the Runtime Period

An application of safety factor of 100% to the total amount is two times the calculated amount (DEPARTMENT OF THE ARMY, U.S. Army Corps of Engineers 2001).

Appendix III

Estimating the Column Diameter, Depth, and Volume

Useful Information

Flow rate                                             = 1 m3/s.

Temperature of vapor stream              = 305 K.

Run time between carbon changes     = 5 months/vessel.

Number of carbon vessels                   = two (in series).

Atmospheric pressure                          = 87.6 kPa

Temperature of air phase                     = 289 K.

Adsorbent contaminants and the relative concentrations are

Perchloroethylene (PCE)        =15 ppmv.

Trichloroethylene (TCE)         =14 ppmv

Benzene                                  = 9 ppmv.

Toluene                                   = 5 ppmv.

Diameter Estimation

A = Q/V

Where, A         = Vessel cross-sectional area

Q         = Vapor flow rate

V         = Superficial velocity (Assumed to be 25 cm/s)

Thus,

D =

Depth Estimate

H = depth of carbon in the vessel

The Vessel volume (Valenzuela & Myers1989)

Volume is given by:

Thus, volume of each empty vessel is 28.385m³

Appendix IV

Table 2: Technical Data about the Operation Unit

Variable	Description
Carbon source	Carbon Mining Company
CO2 Purity required	99.5%
Column Diameter	2.24m
Column Bed Area	3.942 m2
Column Volume	28.385 m3
Flow Rate	60 m3 /min
Superficial Velocity Rate	25cm/s
Bed Depth	7.2 m
EBCT (each column)	2 min
Weight of Activated carbon per Column per day	76.33 kg
Run Time	150 days

 

Appendix V

Partial Pressure Estimation

Appendix VI

 

---

Get Professional Assignment Help Cheaply

Are you busy and do not have time to handle your assignment? Are you scared that your paper will not make the grade? Do you have responsibilities that may hinder you from turning in your assignment on time? Are you tired and can barely handle your assignment? Are your grades inconsistent?

Whichever your reason is, it is valid! You can get professional academic help from our service at affordable rates. We have a team of professional academic writers who can handle all your assignments.

Why Choose Our Academic Writing Service?

• Plagiarism free papers
• Timely delivery
• Any deadline
• Skilled, Experienced Native English Writers
• Subject-relevant academic writer
• Adherence to paper instructions
• Ability to tackle bulk assignments
• Reasonable prices
• 24/7 Customer Support
• Get superb grades consistently

 

Online Academic Help With Different Subjects

Literature

Students barely have time to read. We got you! Have your literature essay or book review written without having the hassle of reading the book. You can get your literature paper custom-written for you by our literature specialists.

Finance

Do you struggle with finance? No need to torture yourself if finance is not your cup of tea. You can order your finance paper from our academic writing service and get 100% original work from competent finance experts.

Computer science

Computer science is a tough subject. Fortunately, our computer science experts are up to the match. No need to stress and have sleepless nights. Our academic writers will tackle all your computer science assignments and deliver them on time. Let us handle all your python, java, ruby, JavaScript, php , C+ assignments!

Psychology

While psychology may be an interesting subject, you may lack sufficient time to handle your assignments. Don’t despair; by using our academic writing service, you can be assured of perfect grades. Moreover, your grades will be consistent.

Engineering

Engineering is quite a demanding subject. Students face a lot of pressure and barely have enough time to do what they love to do. Our academic writing service got you covered! Our engineering specialists follow the paper instructions and ensure timely delivery of the paper.

Nursing

In the nursing course, you may have difficulties with literature reviews, annotated bibliographies, critical essays, and other assignments. Our nursing assignment writers will offer you professional nursing paper help at low prices.

Sociology

Truth be told, sociology papers can be quite exhausting. Our academic writing service relieves you of fatigue, pressure, and stress. You can relax and have peace of mind as our academic writers handle your sociology assignment.

Business

We take pride in having some of the best business writers in the industry. Our business writers have a lot of experience in the field. They are reliable, and you can be assured of a high-grade paper. They are able to handle business papers of any subject, length, deadline, and difficulty!

Statistics

We boast of having some of the most experienced statistics experts in the industry. Our statistics experts have diverse skills, expertise, and knowledge to handle any kind of assignment. They have access to all kinds of software to get your assignment done.

Law

Writing a law essay may prove to be an insurmountable obstacle, especially when you need to know the peculiarities of the legislative framework. Take advantage of our top-notch law specialists and get superb grades and 100% satisfaction.

What discipline/subjects do you deal in?

We have highlighted some of the most popular subjects we handle above. Those are just a tip of the iceberg. We deal in all academic disciplines since our writers are as diverse. They have been drawn from across all disciplines, and orders are assigned to those writers believed to be the best in the field. In a nutshell, there is no task we cannot handle; all you need to do is place your order with us. As long as your instructions are clear, just trust we shall deliver irrespective of the discipline.

Are your writers competent enough to handle my paper?

Our essay writers are graduates with bachelor's, masters, Ph.D., and doctorate degrees in various subjects. The minimum requirement to be an essay writer with our essay writing service is to have a college degree. All our academic writers have a minimum of two years of academic writing. We have a stringent recruitment process to ensure that we get only the most competent essay writers in the industry. We also ensure that the writers are handsomely compensated for their value. The majority of our writers are native English speakers. As such, the fluency of language and grammar is impeccable.

What if I don’t like the paper?

There is a very low likelihood that you won’t like the paper.

Reasons being:

• When assigning your order, we match the paper’s discipline with the writer’s field/specialization. Since all our writers are graduates, we match the paper’s subject with the field the writer studied. For instance, if it’s a nursing paper, only a nursing graduate and writer will handle it. Furthermore, all our writers have academic writing experience and top-notch research skills.
• We have a quality assurance that reviews the paper before it gets to you. As such, we ensure that you get a paper that meets the required standard and will most definitely make the grade.

In the event that you don’t like your paper:

• The writer will revise the paper up to your pleasing. You have unlimited revisions. You simply need to highlight what specifically you don’t like about the paper, and the writer will make the amendments. The paper will be revised until you are satisfied. Revisions are free of charge
• We will have a different writer write the paper from scratch.
• Last resort, if the above does not work, we will refund your money.

Will the professor find out I didn’t write the paper myself?

Not at all. All papers are written from scratch. There is no way your tutor or instructor will realize that you did not write the paper yourself. In fact, we recommend using our assignment help services for consistent results.

What if the paper is plagiarized?

We check all papers for plagiarism before we submit them. We use powerful plagiarism checking software such as SafeAssign, LopesWrite, and Turnitin. We also upload the plagiarism report so that you can review it. We understand that plagiarism is academic suicide. We would not take the risk of submitting plagiarized work and jeopardize your academic journey. Furthermore, we do not sell or use prewritten papers, and each paper is written from scratch.

When will I get my paper?

You determine when you get the paper by setting the deadline when placing the order. All papers are delivered within the deadline. We are well aware that we operate in a time-sensitive industry. As such, we have laid out strategies to ensure that the client receives the paper on time and they never miss the deadline. We understand that papers that are submitted late have some points deducted. We do not want you to miss any points due to late submission. We work on beating deadlines by huge margins in order to ensure that you have ample time to review the paper before you submit it.

Will anyone find out that I used your services?

We have a privacy and confidentiality policy that guides our work. We NEVER share any customer information with third parties. Noone will ever know that you used our assignment help services. It’s only between you and us. We are bound by our policies to protect the customer’s identity and information. All your information, such as your names, phone number, email, order information, and so on, are protected. We have robust security systems that ensure that your data is protected. Hacking our systems is close to impossible, and it has never happened.

How our Assignment  Help Service Works

1.      Place an order

You fill all the paper instructions in the order form. Make sure you include all the helpful materials so that our academic writers can deliver the perfect paper. It will also help to eliminate unnecessary revisions.

2.      Pay for the order

Proceed to pay for the paper so that it can be assigned to one of our expert academic writers. The paper subject is matched with the writer’s area of specialization.

3.      Track the progress

You communicate with the writer and know about the progress of the paper. The client can ask the writer for drafts of the paper. The client can upload extra material and include additional instructions from the lecturer. Receive a paper.

4.      Download the paper

The paper is sent to your email and uploaded to your personal account. You also get a plagiarism report attached to your paper.

PLACE THIS ORDER OR A SIMILAR ORDER WITH US TODAY AND GET A PERFECT SCORE!!!

---