Distillation optimal design

Spreadsheet Applications. The types of appHcations handled with spreadsheets are a microcosm of the types of problems and situations handled with fuU-blown appHcation programs that are mn on microcomputers, minis, and mainframes and include engineering computations, process simulation, equipment design and rating, process optimization, reactor kinetics—design, cost estimation, feedback control, data analysis, and unsteady-state simulation (eg, batch distillation optimization). 

Diwekar UM (1995) Batch Distillation - Simulation, Optimal Design and Control, Taylor Francis. 

Pressure-relieving systems are unique compared with other systems within a chemical plant hopefully they will never need to operate, but when they do, they must do so flawlessly. Other systems, such as extraction and distillation systems, usually evolve to their optimum performance and reliability. This evolution requires creativity, practical knowledge, hard work, time, and the cooperative efforts of the plant, design, and process engineers. This same effort and creativity is essential when developing relief systems however, in this case the relief system development must be optimally designed and demonstrated within a research environment before the plant start-up. 

EXAMPLE 12.1 OPTIMAL DESIGN AND OPERATION OF A CONVENTIONAL STAGED-DISTILLATION COLUMN... 

Example 12.1 Optimal Design and Operation of a Conventional Staged-Distillation Column... 

G. Diinnebier and C. Pantelides. Optimal design of thermally coupled distillation columns. Ind. Eng. Chem. Res., 38 162-176, 1999. 

Logsdon, J. S., Diwekar, U. M., and Biegler, L. T., On jhe simultaneous optimal design and operation of batch distillation columns, Trans. IChE 68A, 1134 (1990). 

M. A. Is la and J. Cerda. A general algorithmic approach to the optimal synthesis of energy-efficient distillation train designs. Chem. Eng. Comm., 54 353, 1987. 

Yeomans H, Grossmann IE. Disjunctive programming models for the optimal design of distillation columns and separation sequences. Ind Eng Chem Res 2000 39 1637. 

Petlyuk, Distillation Theory and its Applications to Optimal Design of Separation Units Rao and Nott, An Introduction to Granular Flow... 

In this problem, there are 3 outer loop decision variables, N and the recovery of component 1 from each mixture (Re1 D1B0, Re D2,BO)- Two time intervals for reflux ratio were used for each distillation task giving 4 optimisation variables in each inner loop optimisation making a total of 8 inner loop optimisation variables. A series of problems was solved using different allocation time to each mixture, to show that the optimal design and operation are indeed affected by such allocation. A simple dynamic model (Type III) was used based on constant relative volatilities but incorporating detailed plate-to-plate calculations (Mujtaba and Macchietto, 1993 Mujtaba, 1997). The input data are given in Table 7.3. 

State-of-the-art methods for achieving optimal design of distillation processes... 

This book deals with control strategies for integrated plants. In most cases the plant consists of a separate reaction section followed by a refining section with recycles between the two. Optimal designs usually call for tight integration of the unit operations, as we mentioned in Chaps. 2 and 5. What if we could take the ultimate step in integration and combine the reaction and separation sections "We would then have reactive distillation. 

If the product of the reactor goes to a separating unit such as extractor or distillation column, we may take v to be the value of the product after separation minus the costs of separation. If an optimal policy is used for the separating unit, then the principle of optimality shows that the optimal policy using this objective function will give the optimal design for the reactor and separating unit as a whole. 

F.B. Petlyuk, 2004, Distillation Theory and Its Applieation of Optimal Design of Separation units, Cambridge series in ehemical engineering... 

In previous work (Filipe et al. 2007) the multi-objective optimization of a distillation column was performed and the Pareto front relating the total number of stages, reactive holdup and cost, identified. In this work a study on how the Pareto optimal designs could be adapted for real implementation is presented. Different design details, such as reactive holdup and feed quality, are investigated and the sensitivity of the solutions assessed to quantify the effect on the column expected performance. 

Optimal Design and Operation of Multivessel Batch Distillation Column with Fixed Product Demand and Strict Product Specifications... 

Unlike the past work, this work focuses on optimal design and operation of multivessel batch distillation column with fixed product demand and strict product specifications. Both the vapour load and number of stages in each column section are optimised to maximise a profit function. For a ternary mixture, the performance of the multivessel column is also evaluated against that of a conventional batch distillation column. Although the profitability and the annual capitalised cost (investment) of the multivessel column is within 2-3% compared to those of conventional column, the operating cost (an indirect measure of the energy cost and environmental impact) is more than 30% lower for multivessel column. Thus, for a given separation task, multivessel column is more environment friendly. 

Low and Sorenson (2003) presented the optimal design and operation of MultiVBD column. A profit function based on revenue, capital cost and operating cost was maximized while optimising the number of stages in different column sections, reflux ratio, etc. They compared the performance of MultiVBD with that of conventional batch distillation column for a number of different mixtures and claimed that MultiVBD operation is more profitable. However, for all cases considered in their work, the products specifications and amounts were not matched exactly and therefore the... 

---