This method relies on representing the material balances equation 49 and the equilibrium relation equation 51 graphically and counting the number of theoretical stages and feed location based on simplifying assumptions. Similar a binary distillation column, in reactive distillation column. For instance, a user should have some idea of the column behavior before attempting to use aspen. The mccabe thiele method allows full control over reboiler duty, and it is not uncommon to first solve a problem assuming minimum reflux ratio. An example of the mccabe thiele is shown in figure 77. Describe the distillation process determine the vapour liquid equilibrium vle data for a binary mixture determine the number of stages required to achieve a specified separation using the mccabe. A graphic mccabe thiele method is developed for application to fully reactive column configuration. Equilibrium separation column jordan university of. By the use of the mccabe thiele method and the advantage of a solve. The mccabethiele method is considered to be the simplest and perhaps most instructive method for the analysis of binary distillation.
The mccabe thiele method is less rigorous as it doesnt enthalpy data. Pdf mccabethiele method revisitedsolving binary distillation. This information could come from an approximate method, such as the mccabe thiele approach, general modeling of the txy behavior, or residue curve maps. Mccabethiele method revisitedsolving binary distillation problems with nonconventional specifications. Flow rates in the intermediate section are constant, but change when feed 2 is introduced.
The mccabe thiele method sometimes predicts negative minimum reflux ratio which is physically meaningless. Notes, videos, mcqs and ppts engineering is created by the best chemical engineering teachers for mass transfer preparation. The mccabethiele method is valid when we have constant molal overflow in both the rectifying and stripping sections of the distillation column. The separation of a binary waterethanol solution via a. The simplest example of a mccabethiele analysis involves the special case of no material being removed from the top or the bottom, so that the lvlv and. Binary distillation with mccabethiele method this excel spreadsheet uses the mccabe thiele method to calculate the number of theoretical stages needed for binary distillation. The use of the method is illustrated in the case studies.
The mccabe thiele method is considered to be the simplest and perhaps most instructive method for the analysis of binary distillation. Stepping off stages course description learncheme features faculty prepared engineering education resources for students and instructors produced by the department of chemical and biological engineering at the university of colorado boulder and funded by the national science foundation, shell, and the engineering excellence fund. The mccabe thiele graphical design method school of electrical. This excel spreadsheet for mccabethiele method is awesome. Aspen tutorial chemical engineering and materials science. Fractional distillation ponchon savarit and mccabe thiele. For the mccabe thiele method as well as for the simpli ed mass transfer calculation it is assumed that the phase ows are constant over the whole column. One quick method of estimation for number of plates and feed stage can be obtained from the graphical mccabe thiele method from the. Apply the mccabe thiele graphical design method to determine the number of equilibrium stages in a column. This approach is sometimes called the ponchonsavarit method. As this is a binary system, the mccabe thiele method described in section 11. Multiple feeds total condenser feed 1 overhead vapor boilup distillation column multiple feeds reflux drum bottoms partial reboiler reflux distillate feed 2 the mccabe thiele method for cascades can be applied to systems with more than two sections.
Constant molaloverflow no heat loss from column not suitable if. Several contributions of reactive mccabethiele method have been reported for reactive systems. Summary redrawn in inkscape from png image by user. Reflections on the use of the mccabe and thiele method. Mccabethiele graphical method example part 1 youtube. Mccabe thiele method developed in 1925 suitable for binary mixtures in continuous columns can be used as a preliminary study for multi component combination of vle data and operating lines assumes. Mccabethiele method and stage efficiency in binary distillation alex ali academia. Working on the hx diagram is more general than a mccabe thiele construction, because it takes direct account of the thermal effects and does not require an assumption of equimolal overflow. Calculation of the finite reflux the further step is the calculation of the finite reflux. A mccabe thiele diagram for the absorption operation from separation process engineering by wankat, 2007 note that the operating line in the mccabe thiele diagram for absorption is. The mccabe thiele method is a graphical procedure to solve alternately the equilibrium relation and the material balance for binary distillation. I think this spreadsheet is stunningly helpful for understanding the mccabe thiele method for the analysis of binary distillation. Apply the mccabe thiele graphical design method to determine the number of equilibrium stages in a column describe column internals trays and packing define tray efficiency explain the height of packing equivalent to a theoretical plate thanks to ming thamswebsite for pictures and information. This application calculates the required number of theoretical.
Relative volatility is 5 reflux ratio mccabethiele method, the total number of necessary plates, as well as the feed plate location can bidd if i lbbe estimated, and some information can also be determined about the enthalpic condition of the feed andrefluxratio. This implies constant molar ow rates of both apvor and liquid leaving every stage. For example, according to figure 3c, for the more volatile component in a binary mixture, the concentrations of feed, bottom product and overhead product are, respectively, xf0. Welcome to the sixth lecture of module 5, module 5, we are discussing distillation. The following example is particularly useful in order to assess the applicability of the mccabe and thiele method, especially when compared with other analytical methods, such as fenske 10 and kirkbridge 11 methods.
This method is based on the assumption of equimolar overflow, meaning that for every mole of liquid that is vaporized, a mole of vapor condenses. Made by faculty at the university of colorado boulder. The mccabethiele method is considered to be the simplest and perhaps most instructive. Uses the mccabethiele graphical method to determine the number of equilibrium stages in a distillation column. Ali mansoori2 abstract the mccabe thiele graphical method is considered as a basic and simple technique to determine the number of theoretical stages in a distillation column. Binary distillation with open steam heating youtube. Binary distillation example involving open steam direct steam heating instead of a reboiler. The mccabethiele method is a graphical separations procedure that exploits the fact that a separation stage involves interaction between the mass balance and vaporliquid equilibrium. It uses the fact that the composition at each theoretical tray or equilibrium stage is completely determined by the mole fraction of. Pdf at undergraduate level, the separation of binary mixtures is studied using, mainly, the mccabe thiele method because of the advantage to present.
Below only the method applying the mccabe thiele diagram is discussed. A revision of the distillation theory jinlun wang1 and g. The flow rates above feed 1 are constant due to constant molar overflow cmo. Derive the top operating line equation in terms of the reflux ratio r. During the laboratory a short introduction to the method using the ternary diagram will be given and can be found in 1. Aspen cannot tell you how many stages to use for a given separation.
Mccabethiele method when constant molar overflow does. The feed changes the slope depending on the feed condition. Ponchon savarit method pdf this approach is sometimes called the ponchonsavarit method. It is an edited student report and contains some incorrect statements and formatting, and describes questionable experimental procedures. Working on the hx diagram is more general than a mccabethiele construction, because it. Pdf the mccabe thiele graphical design method sikandar. You can manipulate some of the data and see the immediate graphical changes, which kinda puts the method into perspective a bit more clearly. Sample formal report b chemical engineering 4903 and 4905 the following sample laboratory formal report is not intended to represent the scope and depth of the projects assigned to students.
This simplification can often be made when the amount of the nonkey components is small, or where the components form nearideal mixtures. Constant molar overflow cmo, which means that for every mole of vapor condensed, one. Calculate the number of theoretical trays by the mccabe thiele method for binary mixtures. The number of stages can then be calculated using a mccabe thiele diagram, or the other methods developed for binary systems. Pdf at undergraduate level, the separation of binary mixtures is studied using, mainly, the mccabethiele method because of the advantage. Binary distillation with mccabethiele method excel. Batch distillation is highly preferable to continuous distillation when highvalueadded, lowvolume chemicals must be separated. The extended method takes in to account several aspects as classic mccabe thiele method under. The mccabethiele method is a classical approximate graphical method for the conceptual design of. By mccabe thiele method, total 8 numbers of stages are required for desired separation. Shortcut method binary system mccabe thiele indicates. However, it is demonstrated that there are a number of weaknesses in this method when it is.
An example of the mccabe thiele diagram for absorption is illustrated in figure 8. Consider the distillation column shown in figure 4. Results can be scaled to actual reflux ratio, typically r 1. Binary distillation using mccabe thiele diagram calculates total number of stages, feed point required to separate a binary mixture with given relative volatility, reflux ratio, feed, bottom, distillate mol. The mccabe thiele graphical solution method for binary distillation is used to determine the number of equilibrium stages needed to achieve a specified separation in a distillation column.
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