Frequently Asked Questions

Find answers to a wide range of general and technical questions about CHEMCAD's enhanced process simulation capabilities.

What is the best use of simulation software?

This question has different answers if the user works for a chemical company, refinery, engineering firm, pharmaceutical company, etc. In general, the best uses of a simulator are as follows: (1) Investigating a new process by simulating various alternatives to determine the feasibility of each; (2) Simulating an existing process to determine optimal conditions, bottlenecks, or sensitivity to process changes; (3) Simulating an existing process to determine control schemes, dynamic behavior, etc.; (4) Day-to-day engineering work (e.g. bubble/dew points, fluid properties, equipment sizing).

How much financial benefit can I expect to gain from CHEMCAD?

Well, the answer is really up to you! Because CHEMCAD is a productivity tool, it simply allows you to do far more than you can with other tools (honestly, if you had a lifetime or two to solve all the equations that CHEMCAD does, you could get the same answers with a pencil and paper). This means that an engineer can be as much as 100 times more productive with CHEMCAD. Obviously, without computer simulation tools, many shortcut methods are employed to speed up calculations, yet they are limited by their lack of rigor. This is where the additional benefit of simulation comes into play. Once your thermodynamics are verified, you can achieve answers to a far greater degree of accuracy than with other tools. Accuracy of your model allows for more intelligent decision-making, and in turn, greater economic benefit.


What kind of computer do I need to run CHEMCAD?

CHEMCAD can run on nearly any computer or mobile device, on any modern operating system, via a web browser. Licensing for web usage of CHEMCAD enables you to run the software practically anywhere and on any device, provided you have an Internet connection. If this approach is not a good fit for your needs, you can also license CHEMCAD for local installation on a Windows OS laptop or PC.

Can I run CHEMCAD on a network?

Yes, you can run CHEMCAD on a LAN or WAN. In this case, the program is installed locally on all networked systems where users may want to run CHEMCAD. The software licensing is controlled either by a hardware key or with server software that allows licenses to be shared across the network. With network licensing, the number of simultaneous users is limited to the number of licenses you have purchased. To find out more and ensure that your network type is supported, please contact a Chemstations representative.

Is CHEMCAD a client-server type application?

CHEMCAD is a fully integrated software package, in that the graphical interface is completely tied into the calculation engine. There is no lag time created by batch-type communication between the elements of the program.

For CHEMCAD users who access the program through a web browser, the user’s computer or device connects to a multi-core virtual machine that performs very fast calculations. For this reason, even though the user is logging into a remote system, performance can exceed the limitations of the local system or device.

Is it easy to share work with other users?

Yes. CHEMCAD simulation files can be downloaded and then e-mailed, placed on a portable drive, or stored on a shared network drive. They can then be opened on another computer or device by a user with a valid CHEMCAD license.


How long does it take to learn CHEMCAD?

Unfortunately, there is no easy answer to this question. Without training, we find that our users who are simulation literate tend to pick up the basics fairly quickly (1-2 weeks continuous use, 5-6 weeks infrequent use). Those who are new to simulation tend to take significantly longer without training. The interface is extremely easy to pick up for almost anyone; those new to simulation simply need time to understand flowsheeting/thermodynamics selection/convergence issues. With training (our BASIC course), users typically can begin useful modeling as soon as they return to the workplace. The reason for this is that our training course is less "keystroke-oriented" and more "method-oriented."

How many components (chemicals) may I have in a simulation?

You can have up to 2000 components in any given simulation.


Can I add my own unit operations, thermodynamic methods, or other routines to CHEMCAD?

Yes, CHEMCAD allows you to add a new unit operation as an Excel spreadsheet, as a user-programmed C++ .DLL, or as a user inline C program. You can add a thermodynamic method as a C++ .DLL. Other routines, for calculating properties or functions not provided for within CHEMCAD, can be added as Excel spreadsheets, .DLLs, or inline C programs. You can add your own graphical user interface screens using very simple tools distributed with the program.


Can CHEMCAD model dynamic processes?

Yes, CHEMCAD will model dynamic processes with our add-on CC-DYNAMICS package. This product enables generalized dynamic flowsheeting in addition to dynamic distillation/reaction.

Can I add my own chemicals to CHEMCAD?

Yes. You can have CHEMCAD predict physical properties based on chemical structure (if you have no data available), you can enter equation coefficients for temperature dependent data, or you can have CHEMCAD regress these coefficients from your temperature-dependent data.

Does CHEMCAD have equipment costing functions?

Yes, CHEMCAD can perform equipment costing. However, as with most costing algorithms, the answers produced are far more useful as a first-pass or comparison tool than as an actual budgeting tool.

What type of printouts, charts, and reports can I get from CHEMCAD?

CHEMCAD provides its own report and chart displays for onscreen viewing and printing; you can also choose to export your data to WordPad, MS Word, or Excel. You can print out a flowsheet directly from the main CHEMCAD window.

Graphics can be sent to a printer or plotter using Windows print drivers to your particular printer/plotter. In addition, graphics can be sent to a .DXF file (on disk and only available in CHEMCAD 6) or a .WMF file (on the clipboard).

What engineering units does CHEMCAD work in?

You can select from pre-built engineering profiles (ENGLISH, FORMAL SI, COMMON SI, or METRIC), or create your own profile of mixed units. You can save profiles and/or create default profiles to be used with every new simulation.

Can I edit the data in the CHEMCAD physical property database?

To preserve the integrity of our built-in component database, we require that you clone and then edit an existing component, rather than edit the original component.

Will CHEMCAD tell me which thermodynamic option applies to my chemical system?

Yes and no. CHEMCAD has a built-in Thermodynamics Wizard, which follows an algorithm based on your chemical components and your expected temperature and pressure ranges. This algorithm is fallible, and no algorithm can claim to always find the correct method. The CHEMCAD Help system contains both a description of the process you should follow to choose a method and elaborate descriptions of each method (including equations solved). Often you will have to verify your thermodynamic method with field or laboratory data. However, do not think of this as a barrier to using simulation; rather, think of it as an investment in your process. Once it's verified, your model will be infinitely more valuable than an unverified model.

What type of flowsheet convergence does CHEMCAD use?

By default, CHEMCAD is a sequential-modular simulator. This means that given feed streams and unit operation specifications, CHEMCAD will calculate intermediate and outlet streams. CHEMCAD also has a simultaneous modular mode for convergence.

Do I have to run my entire simulation, or can I just run sections?

You can run the entire simulation, certain sections, certain recycle loops, or just individual unit operations if you like.

Can I make a PFD (Process Flow Diagram) in CHEMCAD?

Yes. You can add stream data boxes, unit operation data boxes, text labels and titles, user-created shapes/pictures/lines, and imported .BMP files to your flowsheet.

Can I make a piping and instrumentation (P&I) diagram in CHEMCAD?

In most cases, a CHEMCAD process flow diagram (PFD) can be used as a starting point for a P&I diagram. CHEMCAD is not a drawing program; rather, it is a simulator with drawing features.

Does CHEMCAD use any industry standard for data exchange?

CHEMCAD currently supports OPC, OLE, and COM, when installed locally on a PC. OPC support does not extend to CHEMCAD accessed via a web browser. Chemstations is committed to implementing any future standard adopted for the chemical processing industry.

What language is CHEMCAD programmed in?

CHEMCAD is programmed in Visual C++.

Can CHEMCAD simulate my process?

Almost any chemical process can be simulated in CHEMCAD. We can say this simply because of the flexible foundation that we provide for you. For example, if you are interested in tracking fluid properties that CHEMCAD does not calculate, then you can write a user-added subroutine to calculate those properties. If you have a unit operation that is not in the CHEMCAD unit operation palette, you can either model it from a group of existing unit operations or create it yourself using an Excel spreadsheet or a C program. At the very least, you can employ a "black box" type of unit operation.

Does CHEMCAD have helpful error messages?

CHEMCAD displays all error messages in the Errors and Warnings tab; these error messages are as helpful as we can make them. In most cases, you are prevented from entering conflicting specifications, overspecifying, or underspecifying, but errors can still result from problematic input. For example, if you specify an unreachable composition in a distillation column, you will either get a mathematical error or a message that the column "dried up"-you won't get a warning before you try to run the column, and you won't get a message saying that you specified an unreachable composition. The CHEMCAD Help system offers helpful tips for avoiding such outcomes, especially where distillation columns are concerned.

How is CHEMCAD distributed?

CHEMCAD can be licensed either for on-premises installation or for web access. For on-premises installation, licensed users can download an installer file from the Chemstations website, or request an alternative delivery format for the installer file. For web access, licensed users simply log into the appropriate site using a web browser and their personal login credentials.

How is the software updated?

About once a year, Chemstations releases a major upgrade. Throughout the year, however, we are constantly improving the product and adding functionality. Users who access CHEMCAD via a web browser will automatically have access to the most recent version of the software, simply by signing in. Users who have CHEMCAD installed locally are advised to watch their e-mail and the Chemstations website for announcements about new releases as they become available; installer files for new versions can be downloaded from the User Portal. Lists of new features for each new version can be found on the Chemstations website, as well as in downloadable format on the User Portal.

Does Chemstations do modeling, simulation, or consulting for its customers?

No, and this benefits our clients in the following way: We are never tempted to turn a technical support issue into a money-making opportunity. There is a point at which technical support cannot continue, as we cannot do the work for you, but can only assist you while you do the work. We are happy to recommend consultants who can do the work for you using CHEMCAD, but our technical support department is not a gateway to a consulting business.