An interesting presentation at 2011 AIChE National meeting

I’m privileged to be able to regularly attend the AIChE Spring and National (fall) meetings. I attend presentations, meet with customers and prospects, and attend division dinners. Chemstations has been a long-time exhibitor at these meetings, and often sponsors the meeting. I’m vice-chair of the admin committee for DIPPR (www.aiche.org/dippr/), which often meets during the National meeting.

One of my favorite papers at the 2011 National meeting in Minneapolis was a presentation by Dr. Becky Toghiani titled Group Contribution Methods in Undergraduate Chemical Engineering Thermodynamics. Dr Toghiani is a professor at Mississippi State; we’ve known her for years and admired the way she teaches her students the fundamentals. In her presentation, Dr Toghiani discussed one way she has her students use computer programs (CHEMCAD and Cranium*) to learn about the limitations of predicting chemical properties.

Several of the exercises involve predicting well-known chemicals and comparing the results to database values. The students start by comparing predicted pure component properties to experimental data, noticing that if Tc, Pc, and Tb are not well predicted, other properties that are correlated from these values (VP, Cp, HOV) will not be well predicted either. This shows students some of the limits of correlations.

The students then move on to mixture behavior, where they model the separation of binary mixtures using UNIFAC to predict non-ideal VLE. After modeling with predicted chemicals, they look at experimental VLE data to see how well the predicted behavior matches the system. One of the systems is a mixture of o-xylene and p-xylene. Use of a first-order subgroup model (such as Joback) to predict these chemicals will lead to these predicted isomers having the same properties and UNIFAC subgroups, which means they cannot be separated. Use of a second, order model will create slight differences in critical properties and allow for (very difficult!) separation. Naturally, the students are not warned that “cannot be separated” is the wrong answer; this is a process to help them learn to think.

These problems teach Dr Toghiani's students to remember “what is behind the curtain” when they are using modern tools and methods. The students also learn to inspect and think about their results, and ask “Should I try to approach this problem in a different way?” These are the types of lessons we really like; they show the power of a process simulator, and they also teach that a simulator is a tool, not a magical device. It’s important to understand the engineering concepts and the models underneath, even if you don’t have to do the math yourself.

* I should note that I was sitting next to a long-time friend of Chemstations during this presentation: Dr. Kevin Joback, President of Molknow (http://www.molknow.com/) and author of Cranium.

Chemical Engineering Hero: Ben Horwitz

You’ve probably caught on to the fact that we here at Chemstations are pretty proud of the chemical engineering profession. Well, I’d like to take this opportunity to recognize someone who has made some serious contributions to chemical engineering practice everywhere he’s been.

Those of you who have met Ben Horwitz know that he’s one of a kind. He’s sort of a force of nature that sweeps in and makes an impression. I’ve worked with Ben since 1995, and I owe a lot of what I know about practical process engineering to him.

Ben made a career at HK Ferguson (and then MK Ferguson) before going out on his own. He’s designed, troubleshot, de-bottlenecked, and optimized more processes that most of us will ever see; his hands-on, in-the-field techniques have made plants run when others had given up. In my experience, he doesn’t brag about the financial impact of his efforts, but I’d wager that he’s easily saved millions of dollars for his clients. Along the way, he’s educated future engineers in college process design classes and trained hundreds of engineers (and chemists!) in the use of simulation tools with his irreverent yet effective style. Ben is NOT a “click here” and “click there” instructor (as you know if you’ve taken a class!); he is a problem solver of the highest order, and he never lets you forget that process engineering is about solving problems.

If you’re interested in learning more about Ben and his myriad of engineering (and life) experiences, I invite you to take a look at his web site (www.benjaminhorwitz.com). You will very likely find his book, Portrait of a Chemical Engineer, to be a fascinating read. It spans his university years, his time in the Peace Corps, and through to his professional work; it’s told in a fast pace through a series of vignettes that capture the highlights of the events that molded and shaped him into the professional, the chemical engineer, and the hero that we’ve come to know. You can read an excerpt online, and even order your own copy.

I’m incredibly lucky to count Ben as a colleague, and I’m proud to count him as a friend.

OK, so if you’ve read this far, I’m going to tell you about Ben’s influence on me. 1994. I was pretty green (ok, very green) and just out of undergrad when Ben began teaching at our seminars. I think the first thing he said to me was, “Who are you?” I said I was the new guy; he looked me up and down and walked away. He spoke quickly. He was to the point. I had no bona fides yet, and I was unproven. I sat in the back of the seminar room and watched in amazement as Ben began by telling stories. Telling stories to teach simulation? This was an amazing sight, to be sure.

So there he is, telling stories. Setting up scenes in chemical plants. Describing characters. Replicating dialogue from other engineers, from plant managers, and from operations staff. Focusing our attention on the challenge at hand. And then he led us all down the chemical engineering, problem solving path. He often asked questions of the attendees—questions that forced us to think and really got to the heart of the challenges. He also gave quizzes. He used a flip chart to describe a problem, and he just let the class run with potential solutions. I don’t remember which quiz it was, or which day it was, but I do remember that I answered one of the quizzes in a way that caused Ben to leap up and say “YES! THAT’S RIGHT! STEVE IS EXACTLY RIGHT!” In that instant, I saw how passionate this guy was about both the challenge of process engineering and the objective of teaching its principles to the class. He cared more than anyone I have ever seen in the chemical engineering world, and with that answer, I was suddenly on Ben’s radar.

We probably worked together five or six times a year for several years after that, and I was always impressed by Ben’s ability to quickly learn every attendee’s name and background. Ben’s style is to engage everyone, keep your attention, and make it fun. He puts every ounce of his energy into the courses, and everyone comes out tired, but with new perspectives.

I don’t get to work directly with Ben as much these days, but when I get the chance I love to wander into our training room and see the class react to Ben’s stories. I know most of them by heart now, but they still sound as fresh and important as they ever did. This is because he loves what he does (and does what he loves), and that makes him a hero to me and the rest of us at Chemstations.

Great article on Heat Integration in CEP

The December 2010 issue of CEP (Chemical Engineering Progress) has a good article on heat integration. Disclaimer, I am a friend of the author (Alan Rossiter). Rossiter's article is a very understandable explanation of pinch analysis, a topic that is confusing to the uninitiated.

The concept of pinch analysis is that you don't need to use steam for all your heating needs, or cooling water for all your cooling needs. You might have 'hot' process streams that need to be cooled, and 'cold' process streams that need to be heated. Pinch analysis suggests that you will save energy if you use the 'cold' process stream as a utility for the 'hot' process stream, rather than purchasing steam and cooling water. While that may sound simple…most people find the next steps, performing the pinch analysis, difficult to understand.

Rossiter does a wonderful job showing us how to perform pinch analysis, and shows that the use of this method is not as difficult as we think. He explains how to understand the composite curve for 'heat sinks' and 'heat sources. He shows how you can perform a retrofit study, to see the potential benefits to integrating heat on an existing crude column.

Some of our customers have done pinch analysis before, some are interested in it.

Want to do it in CHEMCAD? We have the ability to generate a composite curve (fig 1, in Rossiter's article). You can specify the value for deltaTmin, the distance between the hot and cold curves. You can specify that some of the streams on the flowsheet should be ignored when you generate the composite curve; you wouldn't want to include a steam flow rate on the theoretical composite curve. When you're ready to explore alternate configurations, draw out a flowsheet with heat exchangers and match streams (Fig 3, Rossiter). We don't automatically match streams for you; we feel that an engineer needs to make that decision.

I suggest that anyone involved with utilities (or crude columns) and process simulators take the time to read Rossiter's article; it might give you money saving ideas.

PS While you are looking at recent issues of CEP, you could also take a look at page 59 of the Nov '10 issue, for a picture of the CHEMCAD Technical support team at AIChE's Process Technology Conference. Better yet, check out the back cover of January '11 CEP.

Chemstations Lectureship Award

Our own Fred Justice attended the recent (ASEE) American Society for Engineering Education 2010 Annual Conference and Exposition to help present the 2010 Chemstations Lectureship Award. Fred had a chance to catch up with longtime friends and to make some new ones in Louisville. The winner this year was Dr. Frank Doyle from the University of California, Santa Barbara for his work, "Research at the Interface of Control and Biology."

Last year's winner was Dr. Antonios Mikos from Rice University for his efforts, "Building a Better Biomaterial." The 2008 Winner was Dr. Jennifer Sinclair Curtis from University of Florida for her work, "Simulation of Particulate Flow Processes." Our belated congratulations to them both, also!

We've been fortunate and proud to be a part of the good work done by the ASEE, especially in advancing research and teaching in the field of chemical engineering. We wish our winners well and look forward to hearing more good things from them in the future.

Chemical Engineers are Heroes

A couple of years ago, the phrase above came to me as I listened to yet another anti-“chemistry” rant in the media. The phrase struck me as one that would communicate the positive impact that chemical engineers have on their regional, national, and even global societies and economies. I don’t think I’m alone in saying that the process industries haven’t done a very good job of telling the world about the good we do. “Chemical” has become, somewhere along the line, a dirty word.

So if top-down campaigns are having limited impact, what about a bottom-up, grassroots message? A simple one like “Chemical Engineers are Heroes.”

We have probably all had the experience of having to quickly educate someone as to the number of products in their daily lives that would not (indeed, could not) exist without chemistry and the refining/chemical industry. Shoes, clothing, personal care products, makeup, perfumes, automobiles, paper products…the list is endless. Take a step further and think about all the advances in materials chemistry that make computing/electronics what they are today. And yet, “chemical engineer” represents something nefarious to many.

But it is chemical engineers who will be called upon to design and build new energy sources, new battery technologies, and processes to better clean effluent streams from chemical and power plants. We will be a part of plans to help bring food and fresh water to the planet’s growing population. We will continue to help improve the standard of living across the globe. We will increase the efficiency of today’s chemical processes, and we will help develop tomorrow’s processes.

So I considered a campaign to tell the world that you, as chemical engineers, are heroes. Something simple that wouldn’t be about anything other than bringing some positive attention to our education and careers. It isn’t always why we chose chemical engineering to start with, but it is why many of us are dedicated to the profession. It is why, up and down the halls of Chemstations, we’re all members of the American Institute of Chemical Engineers. It is why we support the activities of the AIChE. We’re proud of chemical engineering and we’re proud of you, the world’s chemical engineers.

Come visit us at the AIChE Spring Meeting in San Antonio, TX, March 21-25, 2010. Of course our sales staff will be happy to talk to you about the latest features in CHEMCAD, but come by and spend some time with our customer support engineers and our development staff…and we’ll have a free “ChemE’s are Heroes” wristband waiting for you.

CHEMCAD around the world—and some useful shortcuts

This blog entry is being written on a plane, somewhere between Mumbai/Bombay and Newark. Did you know that CHEMCAD is a global program? At last count, the software is being used in more than 70 countries around the world. I frequently visit our distributors, to help ensure that they can give the same level of support to their customers that we demand from our own employees.

While presenting some case studies of CHEMCAD use, I recently showed a roomful of engineers a hidden feature of CHEMCAD which is very useful. We sometimes hear, “Learning this feature alone was almost worth the cost of training!” So, I decided to share this trick—and a few others that I like—with our blog readers.

Engineering units are a constant frustration when you work across international borders. The default engineering units of CHEMCAD are English units, because the program was written by engineers in the USA. You probably know that the Format > Engineering Units command enables you to select different units (you can even specify local gauge pressure and reference temperature for standard vapor volume flow rate). But did you know that CHEMCAD has a handy units converter?

To use this feature, open any Edit Streams dialog and click the mouse in the temperature field. Now press the [F6] key on your keyboard. The Temperature units converter will appear, as shown at left. Type a number and then press [ENTER] to convert it. Better yet, click OK to send the converted value back to the flowsheet!

Any dialog box field that has an engineering units label should display the correct units conversion tool when you press [F6]. When you use [F6] with the cursor in a field without units, or when you don’t have a dialog open at all, CHEMCAD displays the Engineering Units Converter, shown below. Here, you can choose the type of units to convert. (Users who have been with us since the DOS version of CHEMCAD may remember that there was once a European-to-US clothing size converter, as an Easter egg.)

Since I’m talking about one overlooked but useful feature, I might as well mention a few others that I rely upon:

• Look at the Palette pane on the right side of the CHEMCAD screen. See the capital T symbol near the top? You can use this tool to add a text box to the flowsheet. I like to use this for simulation notes, but you can also dress up your text with the other drawing tools seen here—rectangles, lines, polygons—or even an imported graphics file.
  
  
• For text that will not be displayed on the flowsheet, just click the Notes tab at the bottom of the workspace and start typing. This is another convenient way to keep notes with the simulation.
  
  
• If you make a plot from the Plot menu, you can then use the Chart menu to export the plot’s data points to a table in MS Excel.
  
  
• Using a wheel mouse? Hold the wheel button down to click and drag the view of your flowsheet. You can also scroll the center wheel forward or back to zoom in or out, respectively.
  
  
• Find the section of the CHEMCAD toolbar that contains the various ‘zoom’ items. One of them is Zoom to fit. This resizes your view of the flowsheet to fit everything in the window.

Informex 2010 and Green Engineering

The show

I visited the most recent Informex show put on by UBM and SOCMA in San Francisco last week. I was very interested in seeing the messaging that manufacturers were using to communicate their products and services to each other. Has the messaging changed since the global downturn?

It appears that for the majority of the exhibitors, the booths and brochures are still focused on the basics: Here is our product list, inquire for prices and delivery. However, I saw a significant number of exhibitors that were aggressively touting their companies' value-add: quality, post-deal service, speed, and custom products/services. It was good to see these companies really setting themselves apart in what's obviously a very competitive landscape. I'll be visiting with our staff here to see how best to position Chemstations to be a part of our customers' plans to remain competitive and successful.

Seeing green

I attended the "Green Chemistry Breakfast Briefing" on Friday morning and listened to three presentations by representatives from industrial companies regarding their implementations of Green Chemistry and Green Engineering. The meeting was produced by the ACS Green Chemistry Institute. I learned a little about the initiatives in place to create an ANSI standard, a "Greener Chemicals Product and Process Standard." I'm interested to hear whether this will end up as a self-certifying procedure or whether it will follow the ISO standard certification path and require third-party labs to be involved. I'm sure all the stakeholders have strong opinions!

All the presenters emphasized that there have been strong economic drivers to using these Green methodologies: lower energy usage, less waste, less recycle of solvents, and so forth. Following the presentations, I was left with a question that always comes up when discussing this type of optimization (Green or not): How do you manage the tradeoffs between optimization/efficiency/Green and operating flexibility?

In today's dynamic, global market, a manufacturer needs single-product flexibility (make more or less to suit market demand), as well as multi-product flexibility (make a product slate using existing facilities to suit market demand). If you optimize a single product or process, you may lose both types of flexibility. The panel tolerated my question with varying degrees of enthusiasm, but the message I came away with is that in the short term, the tradeoffs are more severe, but with long-term planning of products, processes, equipment, and facilities, there will be fewer tradeoffs.

Finally, I'd like to post the "12 Principles of Green Engineering" as described by Anastas & Zimmerman ("Design through the Twelve Principles of Green Engineering", Env. Sci. and Tech., 37, 5, 95, 101, 2003.):

The Twelve Principles of Green Engineering

1. Inherent Rather Than Circumstantial
   Designers need to strive to ensure that all materials and energy inputs and outputs are as inherently nonhazardous as possible.
2. Prevention Instead of Treatment
   It is better to prevent waste than to treat or clean up waste after it is formed.
3. Design for Separation
   Separation and purification operations should be designed to minimize energy consumption and materials use.
4. Maximize Efficiency
   Products, processes, and systems should be designed to maximize mass, energy, space, and time efficiency.
5. Output-Pulled Versus Input-Pushed
   Products, processes, and systems should be "output pulled" rather than "input pushed" through the use of energy and materials.
6. Conserve Complexity
   Embedded entropy and complexity must be viewed as an investment when making design choices on recycle, reuse, or beneficial disposition.
7. Durability Rather Than Immortality
   Targeted durability, not immortality, should be a design goal.
8. Meet Need, Minimize Excess
   Design for unnecessary capacity or capability (e.g., "one size fits all") solutions should be considered a design flaw.
9. Minimize Material Diversity
   Material diversity in multicomponent products should be minimized to promote disassembly and value retention.
10. Integrate Material and Energy Flows
    Design of products, processes, and systems must include integration and interconnectivity with available energy and materials flows.
11. Design for Commercial "Afterlife"
    Products, processes, and systems should be designed for performance in a commercial "afterlife."
12. Renewable Rather Than Depleting
    Material and energy inputs should be renewable rather than depleting.

What do you think of these? Are you already approaching business using these principles or something similar? Are there marketing benefits to promoting Green engineering in your organization? Are there drawbacks to competing with companies who do not subscribe to these principles?

Talk back

I'd really like your feedback and thoughts on these topics. I can envision a spreadsheet-scorecard for a process flowsheet generated in CHEMCAD to give qualitative comparisons of processes, and maybe even some quantitative analysis for the future ANSI standard. Who knows, maybe some of you are already doing just that. Let us know!