Category Archives: Science

Scale-Up and the Three Pillars of Chemistry

The practice of chemistry rests upon three pillars- Theory, Synthesis, and Analysis.  To bring a chemical product into the market place efficiently, a program of development must evolve that rests upon the three pillars.

Ostensibly, in order to rationally synthesize- that is, conceive of a new substance and design a means to bring it into being- it is advantageous to have some kind of theoretical background in order to take advantage of the orbital formalisms of bond making and bond breaking.  It is certainly possible to do chemical synthesis without even a clear notion of atomic theory.  William Perkin was able to embark on a synthesis of quinine and (end up with a synthesis of Mauve Dye) in 1856 without the benefit of molecular orbital formalism. Of course, if he had the formalisms and the analytical technology, he might have actually come up with quinine and would henceforth been known as the father of pharmaceuticals rather than the father of the synthetic dye industry.

I have been witness to numerous product development cycles in the fabulous commercial world of specialty chemicals. If there has been one underlying theme to all of this product development that I have been a part of, it is that synthesis development is typically years ahead of the analytical devlopment.  Allow me to elaborate. 

[Please note that I am not talking about pharmaceutical product development.  I do not operate in that strange universe and I do not pretend to understand it or even desire to be in it.]

Somewhere a company with lots of R&D money to spend and dash of vision will arrive at a stage-gate in its new product development.  A collection of compounds will be identified as having solid potential for use in a profit making chemical enterprise.  Project managers will have to decide on a molecule to launch the project.  The molecule can be a final product with a specific identity, or it can be a substance used to facilitate a technology platform.

The drivers of the project will invariably be synthesis chemists and engineers.  They may choose to make the molecule of interest in-house.  If the molecule or material is the product to be sold, they will almost aways make it in house to capture the economies of vertical integration and scale.  But if the molecule of interest is a reagent, catalyst, initiator, or specialized intermediate requiring some black art, the developers may choose to farm out the molecule. 

In the latter case of reagent, intermediate, etc., farming out the molecule to a specialist vendor requires that the company disclose the identity of the species and probably a synthetic pathway.  Like dogs sniffing one another, a customer and vendor will circle around each other for a short while trying to assess the merits of the relationship.  Once an agreement to move past the disclosure stage is agreed upon, the vendor will set upon the task of noodling out a process. 

I believe it is axiomatic that analytical culture is different from synthetic culture.  Analytikkers live in a world of validation, significant figures, calibration curves, error analysis, and standard test methods.  Synthetikkers live in a world of space yields, solvent effects, reagents, exotherms, hazmats, filtration, distillation, etc.  Each group looks at product development from a different angle and imperative.

Here is the point I wish to make.  Compounds that have been recently discovered and submitted for scale-up are very often “new species”. That is, molecules that are not fully understood in terms of stability, contaminant profile, and importantly, analytical signature.  It would be best to take the time to fully investigate the compound. But to fill out the data table on a species that may not actually go forward is to commit precious time in a very risky way.  Usually, it seems, a candidate for process development is minimally characterized and put on a frantically short timeline for commercialization. 

Another axiom: If there is a hole, someone will fall in it.  Scale-up is often the beginning of the period I refer to as FMD, or “Failure Mode Discovery”.  During this FMD period up to and including pilot scale processing, it invariably transpires that in-process checks and analyses of intermediates is complicated by the improper choice of analytical method and failure to characterize side products. 

In their frenzy to meet deadlines and goals, synthetikkers may not be able to complete a crucial aspect of their job.  That would be to form a complete understanding of the process.  It includes the identification of side products and the fullest characterization of the product as possible.  It is crucial to find in-process markers that indicate that a reaction is proceeding swimmingly or that it is going afoul.  I believe it is squarely the responsibility of the synthesis chemist to survey the composition of critical intermediates and the final product mixture. 

While the preceeding seems obvious and even pedantic, the cost pressures on new product development are often severe and accordingly, processes are rushed out of R&D without much attention to the analytical issues.  I have seen new products from some of the world’s greatest R&D groups hit with severe quality issues in commercialization because analysts weren’t brought in to help with the characterization.

Analysts frequently need input with the development of quality control test methods for new substrates.  This is where the synthetikker can provide the crucial input.  Synthetic chemists must be well versed in the Three Pillars of Chemistry.  We acquire a theoretical background to support our synthetic activity, but we have the critical responsibility of knowing a variety of analytical techniques to validate our assertions that we have made a particular molecule.

Many times in our haste to get a project wrapped up, we rely on NMR for primary analytical data. Very often, NMR is perfectly satisfactory as a stand alone spec, as long as you do not need reliable data below 0.1 %. 

But NMR doesn’t always tell the whole story.  In fact, I have often seen fellow chemists throw up their hands in a gesture of complete frustration and give up when NMR fails to afford a clue to a process or product problem.  Basically, NMR is fast and affords structural details that are unavailable any other way.  Everything else is a science project.  

Having served in business development and product management, I can testify that unforseen quality issues can become show stoppers. It is not unusual to spend as much R&D time trying to noodle out unanticipated quality issues as it took to develop the product in the first place.

It is good to have two or three ways to quantitate purity. I’ve found it useful to have a good relationship with the analytikkers- one that allows for brainstorming and problem solving. 

Contrarian Views on Corn-Based Ethanol

If you travel through the American midwest, you cannot help but notice that corn-based ethanol is in the news. Over at the Oil Drum blog there is a good post on the merits of corn-derived ethanol (EtOH).  One of the important points that was made is that EtOH will be replacing MTBE as an oxygenating additive. This is an important point. For the near term, as MTBE is phased out EtOH is taking its place.  Therefore, the net effect on imported oil volumes may be nil. 

Then there is the matter of the energy balance for EtOH production.  There is no clear consensus on whether or not corn EtOH production is a net gain in BTU’s.  And then there is the matter of unintended consequences in shunting large mass flows of corn into energy production.

Modern agriculture has been characterized as the process of converting diesel fuel into food. High yield crop production also requires large machinery for efficient cultivation, soil amendments, advanced corn breeding, crop rotation, and specialized pesticides.  And this is just the farming part. Modern grain production requires substantial distribution infrastructure as well as financing for the upfront seed and fuel costs.

By unintended consequences the writer of the Oil Drum post means the possibility of ecological insult resulting from intensification of corn production.  Intensified corn production may result in reduced soybean production in the US, resulting in increased production in Brazil. US farmers may simply choose to grow fewer soybean acres. Increased soybean production in Brazil could result in accelerated deforestation to meet the demand uptick. 

What the writer did not mention is that reduced US soybean production could mean reduced crop rotation, placing increased demand on synthetic ammonia (NH3) production to make up the demand for fixed nitrogen.  Ammonia production uses natural gas (CH4) as the source of hydrogen, and the carbon is lost as CO2.  Increased nitrogen fertilizer use may result in greater run-off into the watershed, placing the aquatic ecosystem under increased stress and polluting drinking water supplies. 

Increased ammonia demand will stress the natural gas market to some extent and result in increased greenhouse gas emissions. 

In addition to ecological insult, there will be a shift of wealth associated with increased diversion of corn to fuels.  If corn yields and acreage cannot be increased to make up for increased fuels demand on corn supplies, the food product chain could be subject to greater scarcity with an increase cost to consumers for everything associated with corn- corn oil, high fructose corn syrup, starch, beer production (!!) with corn starch, cereal products, animal feeds and the associated price uptick that would cause for meat products. 

It is worth remembering that corn is one of the major inputs to our food manufacturing complex. It enters directly as whole corn or as separated corn germ and corn starch, and indirectly as food for hogs, cattle, and poultry.

Many of the choices we have in the supermarket are largely based on what you can do cheaply and on a continuous process basis with grain products.  Stress on this supply will be passed along to the consumer.

One fresh approach is from a start-up company called Zeachem who aims to produce cellulosic ethanol from biomass other than just the corn kernel.  In this process, all fermentable sugars as well as cellulosic hydrolyzates can be converted to acetic acid by fermentation and the lignin sidestream can be processed to yield hydrogen.  Esterification with process ethanol to afford ethyl acetate followed by hydrogenation yields EtOH.  This process is currently in scaleup and may prove to be a major improvement in the otherwise anemic economics of EtOH. 

Manson Impact Structure

Visited the town of Manson, Iowa, today.  This is a farm community nestled in the flat, corn-carpeted central Iowa countryside. Manson is situated over an extraordinary geological formation that is completely invisible from the surface.  Also called the “Manson Anomaly”, this location is the site of a meteor impact ca 74 million years ago. The Manson site was originally thought to be the source of the K-T boundary, but now it is recognized to have been formed ca 9 million years prior to the K-T event. Approximately 130 distinct impact craters have been identified.

The formation contains many of the classic features attributed to an impact crater and it has been studied at length.  Fortunately, the library in Manson has a collection of literature on the formation as well as a collection of core samples from about 10 bore locations. 

The impactor is thought to be a stoney meteor approximately 2 km in diameter.  According to the Iowa Geologic Survey, the crater structure is 37 km in diameter and sits under 20 to 70 m of glacial till.  It is believed that the terrain was covered by seawater at the time of impact and that the crater was filled with water fairly soon after the impact. 

What is interesting for this writer is that the Manson Crater is directly under the place I lived as a child.  Who knew that under the plain, flat, farmland were the remains of a large-scale calamity.  Things are never as they seem.  That’s what I really dig about science.

J.Org. Chem. Git ‘er done!

Citations taken from JOC, 2007, 72, 3981-3987, by Bruce Ganem and Roland R. Franke.

Where observation is concerned, chance favors only the prepared mind.  -Louis Pasteur

Necessity is the mother of invention.  -Anonymous Latin saying

Git ‘er done!  -Southern country male expression (recently popularized by Larry, the Cable Guy)

That’s hilarious!  I’m not sure, but this may be the first reference to a Comedy Central character in an ACS publication.  Well, I’m fairly sure.

Beilstein vs SciFinder? Vote Here!!

OK, it’s time to poll the thundering masses. If you had to make a choice between subscribing to Beilstein or SciFinder for general access to the chemical literature, which would you take?? Let’s say that you needed to find compounds, articles, procedures, or see what the IP picture looked like.  Forget TSCA registry and nomenclature services for purposes of this query.

Obviously, each has strengths.  But if you had to take a side, what service would you take and why??  

Chemical Batch Process Scale-up

A few of us took the course offered by Scientific Update called Secrets of Batch Process Scale-up.  It is a 2 1/2 day whirlwind of slides and class exercises.  In my estimation it is a very worthwhile course for process chemists and I certainly got a lot out of it. It is taught by Francis X. McConville who is a gifted teacher as well as experienced process guy.  He is the author of “The Pilot Plant Real Book“. Th’ Gaussling is pleased to toot this horn because this class is a great example of how such things should be done.

Most chemists know that the changes that occur in scale-up come in large part from differences in heat transfer and mixing.  There are certainly other contributions, but these are the big issues. The parameter that is viewed as most useful in mixing is the mixing energy parameter, Ei, which has units of watts/kg soln. Many of the parameters are subject to large exponents, so one needs to be cautious about how well your intuition works in this non-linear space.  The point is, eyeballing the mixing speed in your benchtop apparatus is almost certainly inadequate in comparing conditions in scaleup.

Ei=(Np*N^3*d^5)/V, where Np = impeller power number (contains density and power units), N = rotational speed (1/sec), d = impeller diameter (m), and V = volume (cubic meters).  Because the mixing energy varies as the 5th power of the impeller diameter and the cube of the rotation speed, small changes in agitator speed or impeller diameter can result in large changes in power demands on the agitator motor.  Obviously,  one should be cautious in hand waving comparisons between your 1 liter kettle and that baffled 500 gallon pot in the plant. 

The latest hiss from Jupiter

The 20.1 MHz radio receiver kit we ordered from Radio Jove arrived last week.  Lots of tiny components to solder onto the PC board.  I seem to have forgotten the color code for resistors. 

The kit comes with conductors and fittings for a dual dipole antenna. I’ll have to go to Home Depot and buy parts for the support structure.  The antenna is going to take a bit of real estate to set up.  Given that Jupiter is low in the sky for a few years, it is desirable to contrive a means for narrowing the antenna beam to help with some noise rejection.  A properly configured dual dipole 15 or 20 ft off the ground helps a bit. 

A powerful station already broadcasts at 20 MHz (WWV), out of Ft. Collins, CO, so the receiver is offset at 20.1 MHz.  Jupiters cyclotron radio emissions are strongest between 18 and 24 MHz.  For locations distant from Ft. Collins, the broadcast at 20 MHz may be irrelevent. The ionosphere is mostly transparent to 20 MHz radiation on the night side of the earth, so transmissions from interfering sources in this band tend to propagate into space at night rather than reflect off the ionosphere and go beyond the horizon.

Th’ Gaussling has been busy studying the basics of antenna theory.  It’s quite interesting, really.  An antenna is basically a transducer, converting energy from one form into another.  The knowledge of antennae is something of a dark art.  I have had to scrounge to find resources that explain without too much forgotten calculus. 

Once you have antennae on your brain, you begin to notice them everywhere. All sorts of them. Yagi’s, dipoles, dishes, mast antennas, and folded dipoles jutting off of every imaginable high spot. I have one bolted to my house. 

The side benefit for yours truly is that it has forced me to have a hard rethink about electromagnetic radiation and the mechanism for its generation. We organikkers generally don’t spend a lot of time thinking about radiation emission and propagation. 

There could be some pedagogical advantages to introducing students to electromagnetic radiation in the radio spectrum rather than the visible range. The acceleration of charges in an antenna element and the subsequent perturbation in the charge field around the charged particle seems to be conceptually easier to reach than the usual abstractions showing the 3-D rendering of a sinusoidal wave in most textbooks. In fact, I have never seen a good representation of visible photon emission beyond arrow pushing on an energy diagram.   Who knows, maybe a student would learn something about electricity as well?

Hey. Check out the Quantum Slacks by Haggar.  The first of their Non-Newtonian line.

Toxic Personalities- The Alpha Male

If you were to look at me, Th’ Gaussling, as a chemist, you might suppose that the biggest obstacle I or other industrielle Ubermenschen faced in our exalted careers related to the transmutation of matter.  Easy conclusion.  To civilians who can barely mix Ovaltine in their 2 % milk, making a metric ton of sensitive, high value-added product to specification from dirt and motor oil would seem daunting.  And to be sure, it is.  But it’s all in a days work. (wink wink, nod nod)

However … (dramatic pause) … chemistry is easy when compared to other issues in the fabulous world of work.  The truly challenging part of work is having to deal with difficult people.  Overexposure to toxic personalities can cause chronic chafing, distress, or worse. 

It is amazing how outrageous some people can be.  A while back we interviewed a swaggering gasbag who proved to be 4 or 5 standard deviations from the mean in his cockiness.  The word that comes to mind is sphincter.  I hadn’t seen this chap in nearly 10 years. But in the first 5 sentences of our brief reunion he had already established his career and organizational superiority. It was only partly in jest.  Then to top it off, he declared after 3 minutes of awkward discussion and glances at the watch that he had no more time to talk. No doubt in his absence there would be utter chaos back at work. 

Afterwards I stood there in awe of the natural phenomenon I had just witnessed.  What do you do with such people? We’re not supposed to shoot them.  This fellow is one of those alpha males who consume all of the air when they walk into a room. If he isn’t able to dominate the situation, he just leaves.  When he walks in, the room lights up due to all of the sunlight shining out of his arse.

When asked about the hardest group of people to manage, this chemical engineer said without hesitation “Ph.D. Chemists”.  He said that he greatly preferred to work with hourly plant people and that Ph.D. chemists tend to pose problems that are more intractable than plant operators. Chemists on salary tend to argue and hourly folk just shrug and do what they are told.  Damned right, bucko!!

If you have ever met a company president, you may notice that they are peculiar sorts who seem to be cut from a certain kind of cloth.  Those who aspire to such elevated status have to rework themselves from mere management soldiers into an executive.  Executives are beings who become organic manifestations of the company.  When the CEO of NewCo visits, later you would say that “NewCo was here”.  And you’d be right.   

It is not enough to be merely competent to be a company executive.  Luck, organizational skill, and a bit of ruthlessness are the stars that have to line up to get to the top.  Ruthlessness by itself usually isn’t enough.

>>>End Rant Subroutine<<<

Wohler’s Urea

Over at A Synthetic Environment you can find an extensive collection of portraits of Friedrich Wohler. It’s pretty cool.  For you historians of chemistry, Wohler was a colleague of Justus von Liebig and a student of great Jons Jakob Berzelius.  After his inadvertant synthesis of urea in 1828 and subsequent realization of its significance, Wohler reportedly told Berzelius

 “I cannot, so to say, hold my chemical water and must tell you that I can make urea without thereby needing to have kidneys, or anyhow, an animal, be it human or dog“.

I do not have a primary reference for this quote, but true or not, it’s a great line.