The ponchonsavarit graphical construction allows the rigorous computation of the number of equilibrium stages in the case of the separation of a binary mixture composed of hexane and octane. However, most of the applications are limited to problems where extreme top and bottom compositions and reflux ratio are specified and the objective is to determinate the number of stages. A mccabethiele diagram can be obtained by clicking on the mccabethiele icon on the button bar. Constant molaloverflow no heat loss from column not suitable if. In addition, you will also learn about specification and selection of the appropriate distillation hardware. It plots the classic mccabethiele diagram and evaluates the minimum and actual reflux ratio, and the thermodynamic state of the feed. It uses the fact that the composition at each theoretical tray or equilibrium stage is completely determined by the mole fraction of one of the two components and is based on the assumption of constant molar overflow which requires that. The mccabe thiele method is a graphical procedure to solve alternately the equilibrium relation and the material. Mccabe thiele method for an ideal binary mixture in matlab. Eventually the scope of the application will include other types of chemical process separations which use the mccabethiele method as well as nonideal separation equipment. This excel spreadsheet for mccabethiele method is awesome. By the use of the mccabethiele method and the advantage of a solvepackage mathcad, a procedure is proposed to solve problems with different.
A unit operation is one step in a process to convert a raw material into some useful chemical product. Mccabethiele method revisited solving binary distillation problems with nonconventional specifications article pdf available in journal of chemical engineering of japan 419. Plotting mccabethiele diagrams in microsoft excel for non. Once all the balances are developed, mccabethiele method is the most widely way to find the number of equilibrium stages for a given feed. The following matlab project contains the source code and matlab examples used for mccabe thiele method for an ideal binary mixture. Unit operations of chemical engineering, 5th ed, mccabe. Review and extension of the mccabethiele method covering multiple feeds, products and heat transfer stages a.
Calculate the number of theoretical trays by the mccabethiele method for binary mixtures. This application calculates the required number of theoretical stages for a set of specified operating parameters via the mccabethiele method. Problem solving approach problem solving approach to. Thiele in 1925 and is mainly used to calculate the total number of stages required in the column section n, the minimum reflux ratio r min, and the minimum number of stages n min.
A graphic mccabe thiele method is developed for application to fully reactive column configuration. The mccabethiele method is considered to be the simplest and perhaps most instructive method for the analysis of binary distillation. It is started by plotting the vapourliquid equilibrium. Includes mass transfer analysis, third edition book. 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. Relative volatility is 5 reflux ratio method presentation by. We may also elect to select the mccabethiele panel. We draw the mccabe and thiele diagram and get the number of theoretical plates equal to 9. Distillation column with one feed, total condenser, and partial reboiler. The method follows the here below sequence of steps.
Mccabethiele method of distillation design the mccabethiele method of distillation design is a graphical method of design that dates back to the early 20 th century. You can manipulate some of the data and see the immediate graphical changes, which kinda puts the method into perspective a bit more clearly. It is used as an introductory method to teach the design of distillation and is still in use today by engineers who design distillation columns. The mccabethiele method allows full control over reboiler duty, and it is not uncommon to first solve a problem assuming minimum reflux ratio. Separation methods, system diagrams, nonideal mixtures, solving an page 610. Its one of the blackboxes which appeared in process and performs some physical as opposed to chemical change.
The extended method takes in to account several aspects as classic mccabe thiele method under. Solved problems in chemical engineering thermodynamics. Absorption and stripping in addition to the distillation, there are other unit operations used for separating substances absorption is the unit operation in which one or more components of a gas stream are removed from the gas mixture by being absorbed onto a nonvolatile liquid called a solvent in this case, the solvent is the separating. Effect of relative volatility on number of stages 100 kgmolehr of a mixture containing 50 mole percent a and 50 mole percent b is to be fractionated to a distillate containing 90 mole percent a and a residue containing 90 mole percent b using a total condenser and feed at its saturated liquid condition. Results can be scaled to actual reflux ratio, typically r 1. Ethanol distillation mccabethiele diagram and murphee. This application also highlights several maple concepts. Ponchonsavarit method the overall balances for a distillation column with one feed see fig. The distillate, feed and bottom mole fractions are 0. This graphical method uses both material and energy balances to determine the number of theoretical stages required to achieve a specific separation. The feed is a two phase mixture with a feed quality is equal to 0. The condition of the feed determines the difference in vapour and liquid flow rates.
Mccabethiele method revisitedsolving binary distillation. The drawback to mccabethiele diagrams is that they are difficult to draw freehand, and this difficulty is aggravated when the vaporliquid equilibrium data for the system is represented not by a constant relative volatility but rather by a set of equilibrium data points, as then the necessary first step is to fit the equilibrium curve to the data. Learn essential distillation concepts likely to be faced by process support, operations and process design engineering personnel. As this is a binary system, the mccabethiele method described in section 11. Distillation principles chemical engineering, 200711, rvce. By the use of the mccabethiele method and the advantage of a solvepackage mathead tm, a procedure is proposed to solve problems with different specifications. Where qr is the total energy input btu per hour or kj per hour to the reboiler and qc is the total energy removed btu per hour kj per hour by the condenser. First, the rectifying and stripping operating lines are plotted using a reflux ratio equal to 1. Mccabethiele method gui for binary column distillation. Vs mccabethiele method assumes that molar vapor and liquid flow rates are constant in each section of the column constant molar overflow eliminates the need to make an energy balance around each stage for nonideal binary mixtures, such an assumption may not be valid and the mccabethiele method may not be accurate. 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. A friend suggested i publish the initial version and get community feedback before continuing as progress has somewhat stagnated.
The computer solution of a binary distillation problem by the mccabethiele method utilizes the equations of lewis and sorel which when drawn upon the y x diagram of vaporliquid concentrations, are the. Reyeslabarta abstract the mccabethiele method is a classical approximate graphical method for the conceptual design of binary distillation columns which is still widely used, mainly for. Mccabethiele method when constant molar overflow does. The method, we are going to illustrate in this section, is known under the name of fenskeunderwoodgilliland fug, from the three guys which developed the three different parts of the method in order to get the ideal number of stages of a multicomponent distillation column. Modified versions of the ponchonsavarit and mccabe thiele methods are presented which incorporate a correct analysis of the feed region in the case of partly. Chemical software free download chemical page 2 top.
Unit operations of chemical engineering, 5th ed, mccabe and smith 0070448442. Mccabethiele method for an ideal binary mixture file. 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. Modified ponchonsavarit and mccabe thiele methods for download as pdf file. Ethanol distillation mccabethiele diagram and murphee efficiency. Reflections on the use of the mccabe and thiele method. 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. Binary distillation with the mccabethiele method binary fractional distillation is a means of separating two liquid components via a distillation column which contains a number of trays, or stages.741 461 607 1399 1231 672 711 1051 599 1111 1520 269 1517 200 299 880 204 1234 1009 683 573 1226 1238 1425 608 388 1255 64 415 845 796 818 1299