Flow-sheeting software

Kivisaari, T. Van der Laag, P. C. Ramskold, A. Benchmarking of chemical flow sheeting software in fuel cell application, Journal of Power Sources, 94, (2001), 112-121. 

A wide array of general-purpose distillation packages are available to the engineer. Some of the distillation software is stand-alone, whereas other packages are a part of a general-purpose flow sheet or process-simulation system. Because distillation is so universal, all process simulators have one or more distillation program modules for this unit operation. Often the nature of the distillation modules determines the suitabiUty of or the preference for the use of a specific simulator for an appHcation. 

Complex flow-sheeting programs, that simulate the operation and a complete process, or individual units, have been developed by several commercial software organisations. The names of the principal packages available, and the contact address, are listed in Table 4.1. Many of the commercial programs have been made available by the proprietors to university and college departments for use in teaching, at nominal cost. 

The solution to the problem is obtained by solving mass and energy balances to yield the quantity and state (i.e., composition, temperature, pressure) of all the streams and the utility requirements. Additional parameters for the process equipment, sufficient so that stream specifications are met and the cost of the equipment can be estimated, are calculated. The cost of equipment, raw materials, and utilities is estimated and an economic analysis is carried out. Methods of cost estimation and economic analysis are presented later in this text. This entire procedure may be repeated many times to examine modifications of the process flow sheet or to find optimal values of key process variables. Computer software can greatly simplify these repetitive calculations for the engineer. But even without the need for repetition, the software may simplify the calculations and provide detail and accuracy that would have been impossible otherwise. 

The process flow diagram for the production of 1-40 x 10 kg/s of thiophane is presented below with appropriate tenq) rature, pressure, and heat exchanger duties. The material balance can be developed with the aid of suitable computer software based on the conditions listed on the flow sheet. 

Outline an overall process flow sheet and material balance including solvent recovery and recycle. This should be done with the aid of process simulation software. [See Seider, Seader, and Lewin, Product and Process Design Principles Synthesis, Analysis, and Evaluation, 2d ed. (Wiley, 2004) and Turton et ah. Analysis, Synthesis, and Design of Chemical Processes, 2d ed. (Prentice-Hall, 2002)]. In the flow sheet include methods needed for controlling emissions and managing wastes. Carefully consider the possibility that impurities may accumulate in the recycled solvent, and devise methods for purging these impurities, if needed. 

The third set of tools involves the pharmacist s documentation of interventions and results. If lipids are to be measured and followed, the use of a monitoring flow sheet is extremely useful (Fig. 1). Flow sheets may be on paper files, created on computer spreadsheets, or use special software programs. 

Using available data (technical literature, laboratory data, pilot-scale data, etc.), generate process flow sheets, material and energy balances, and equipment capital costs using ASPEN Plus process simulation computer software. 

The overall lesson from Example 6.2,q is that flow sheets of moderate complexity, with several units and recycle streams, can be solved by hand in a systematic way, as long as the properties of the fluid are known, either from tables or from software applications. The calculation is always reduced to the energy balance around an individual... 

Profiles comprise cross sections that are not a circle, annulus, or wide sheet. Like pipe and tubing lines, profile extrusion lines consist of an extruder, profile die, calibration device, cooling system, puller, and a cut-off saw and stacker or wind-up unit. The main differences are the dies and calibration units. Due to lack of symmetry, obtaining a correct cross section in a profile die is difficult. Differential flow resistance in different parts of the cross section alters the flow rate for these parts of the die. In addition, die swell may vary due to the differences in flow. Consequently, the extrudate may bend as it exits the die. To equalize flow, the die land length is varied or restricting plates are used in channels where the flow is too rapid. Many profile dies are split into sections, with the die sliced perpendicular to the major axis. Thus, sections can be altered in the process of die development. Flow simulation software is particularly useful in profile die design. 

It has many major advantages over other comparable modelling software steady-state and d5mamic modelling within the same environment multi-scale modelling the possibility to create a reactor model that takes into account all phenomena from mass transfer in the catalyst pore to full-scale equipment effects simultaneously the ability to apply such high-fidelity unit models within a full process flow sheet and estimation of equipment or process empirical parameters from experimental-laboratory, pilot or operational-data, with estimates of data uncertainty for risk analysis. 

The design of individual units of a plant and the subsequent combination into a flow sheet is the province of chemical engineering and is dealt with in standard chemical engineering texts. " The optimization of complex integrated plant is done with commercial software that can solve many... 

The application of S88.01 to the development of a batch control system can facilitate the implementation of a project, as it gives engineers a clear set of terms to describe flow sheets and control schemes and can considerably reduce the time required to implement the system, (it) has been very successful in its fundamental task of explaining what batch control is all about, and in cutting the time needed to develop and configure software [10]. 

Let US suppose we have a set of shear-stress/shear-rate data (cr,y) which we want to fit to an appropriate equation. First we plot the data on a linear basis to see if it fits the Bingham equation. If it does, then aU we need to do is to perform a linear regression on the data, using a simple spread-sheet software package, or the software usually provided nowadays with the viscometer/rheometer we have used. Then the values of cto and % can be used to predict flows of the liquid in other geometries, see chapter 10. 

Almost all licensors and contractors use commercial flow sheet simulation software either for primary design or for changes to an existing plant. Various software... 

The process flow sheet the stream table properties obtained using Pro II software is shown in Figure 4.36. Based on the outside area, Uq is 155 Btu/h ft °F. 

Ethyl chloride is produced by the gas-phase reaction of HCI with ethylene over a cop>per chloride catalyst supported on silica. The feed stream is composed of 50% HCI, 48 mol% C2H4, and 2 mol% N2 at 100 kmol/h, 25°C, and 1 atm. Since the reaction achieves only 80 mol% conversion, the ethyl chloride product is separated from the unreacted reagents, and the latter is recycled. The reaction takes place in an adiabatic reactor. The separation is achieved using a distillation column. To prevent accumulation of inerts in the system, a portion of the distillate is withdrawn in a piu-ge stream. Suggest a process flow sheet for this purpose and simulate the process using accessible software package. Compare results with those obtained from Example 9.1. 

Ethylene is produced using ethane in a steam cracking furnace at 800°C. Assume that the reaction takes place in an isothermal conversion reactor where ethane single-pass conversion is 65%. Develop a process flow sheet for the production of ethylene from pure ethane. Use existing software package in your university to perform the material and energy balance of the entire process. 

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