Category Archives: Chemistry

et Al. A Gathering in Memory of Albert I. Meyers.

Colorado State University has announced “a gathering in memory of a remarkable life” in honor of University Distinguished Professor Albert I. Meyers. It will be held Friday, February 22, 2008, at 10:30 a.m. in the Arizona Room at the Hilton Fort Collins. You may recall that this hotel is 2 blocks south of the Chemistry Building.

RSVP:       csn (at) lamar dot colostate dot edu

This event is being managed by the Director of Development at the College of Natural Sciences at CSU. (I am hesitant to post names and phone numbers that can be collated by web crawlers)

I’ll definitely be there.

Bicarbonate Vulcanism

I’m taking thursday off to judge a middle school science fair. Should be a hoot.  I don’t know what I’ll say if I see an 8th grader with a volcano experiment. Hopefully we’ll see some hypotheses, measurement, data reduction, and conclusions rather than just demonstrations. I’ll try not to make anyone cry.

Update:  By my estimation, the science fair was a success. I was impressed by the number of students who obtained results that did not align with their hypotheses. I made a point of suggesting to them that experiments which give results that are unexpected are the most interesting of all.  We talked about what success really means in experimentation. Most seemed relieved to hear that their efforts weren’t wasted.

After we discussed this, I placed an epistemological time bomb in their consciousness. I asked the question “When people speak with great certainty but never do experiments, what are you going to think about their assertions?”

There were no volcano displays. That is elementary school stuff. But there were several Mentos/Coke Cola research studies. One kid built a potato cannon that used hairspray and a lantern igniter to launch the spuds. I predict that this kid will eventually lose body parts.

Bis, Tris, Tetrakis

For many seasons, Th’ Gaussling was the keeper of part numbers and nomenclature in his village.  Fellow peasants would stumble out from the dark and dank mines to plead for new part numbers and names for the new products. As always, outsiders are surprised to learn that this is an actual “job”, but in fact it is. When you make new stuff, eventually you have to call it something. And what you call it has to be recognizable to the barbarian tribes outside the walls.

Peasants and grandees alike would take the names in gratitude for the everpresent fear was that they themselves would be called to toil in the muck of nomenclature as I have.

The dark world of nomenclature is split into two hemispheres- IUPAC and CAS. I don’t know what the deal is with Beilstein. It seems to be a sinking ship with a few deckhands polishing the brass knobs as the bow submerges.  Arguably, CAS has become the default system for nomenclature and identification in much of the world. The CASRN is increasingly the standard for unambiguous substance identification. The US EPA relies upon CAS to keep track of the TSCA inventory. Chemical sellers all over the world rely on the CASRN system to identify products and as a search term to attract internet search engines to their websites.

The major problem that I have encountered is that nomenclature from the 9th collective index (9CI) is often incompatible with our accounting system. The system does not accomodate Greek letters (kappa and eta) and the numbering system leads to sorting and format problems with list generation and subsequent retrieval. The complex system of numbering schemes and nested hierarchies plays havoc with the system as well, if for no other reason than the character count exceeds what is permissable in the data field.

Even more troublesome, the complex names are largely inaccessable to non-chemists. It is very hard for administrative assistants and temps to comprehend accounting data when they are fundamentally unsure of what the identity of the product is and why various materials show up in the bill of materials. To non-technical folks on the business side, chemical names are often just a complicated character string that is prone to data entry errors.

I’ll have to admit that nomenclature from earlier indices (6CI to 8CI) is often more user friendly in this regard. So when it is time to choose a name, 9CI doesn’t always win. This is a propagation step in the retention of obsolete nomenclature and I am guilty as hell of keeping it going.

Unhappy Chemicals

We all have experiences with chemicals that stick in our memory. Experiences where we have witnessed just what chemical potential really means.  Proton or electron transfer can be downright frightening sometimes. Rude and abrupt phase changes or angry exotherms. Sometimes nature rages back at our feeble attempts to take the dragon out for a walk on a short leash.

I can name many exciting materials, but I think that chlorosulfonic acid is one of the more exciting and obnoxious substances that isn’t explosive or neurotoxic.  What are your favorites?

Skeptical of Hydrogen as a Mass Market Fuel

If one examines the composition of propellants and explosives, what you find is that the successful and desirable compositions are those substances that decompose to produce many more moles of decomposition products than moles of starting materials.  As a result, modern propellant compositions have not just a preponderance of nitrogen atoms, but also more skeletal C-N or N-N linkages that replace C-C linkages. Dinitrogen as a decomposition product is more atom efficient in producing PV work than is CO2 or H2O if only because a molar volume of N2 contains only 2 moles of atoms as opposed to 3. 

Designers of explosives and propellants are principally concerned with doing work (W=Fd=PV) against the environment. It could be moving soil, forming a shock wave, or a accelerating a projectile out of a tube. Some particular mass needs to be accelerated over a distance and extracting the last bit of work from the expanding gases is desirable.

PV work is performed by evolving lots of -kJ/mol from heat of formation and arranging for the expanding gas to do something useful. In the case of propellants, dinitrogen formation yields a healthy heat of formation produced from making a triple bond. Hot gases want to expand and move whatever they are in contact with. The more molar volumes of gas generated, the more work that can be done. 

Some of the above line of thinking applies to the combustion of hydrocarbons as well, though the necessary formation of triatomic gases lowers the atom efficiency. The combination of C=O and H-O bonds being formed leads to a net evolution of heat compared to heat absorbed in breaking C-C, C-H, and O-O bonds. Properly chosen fuels and oxidizers provide a net increase in moles of gaseous products leading to an increase in molar gas volume.

Now, consider the case of the combustion of hydrogen and oxygen to produce water: 2 H2 + O2 –> 2 HOH.   In this reaction three moles of gas react to produce only 2 moles of  gas. There is a net loss in molar volume of 1/3 at constant presssure.  Obviously H2 reacts violently with O2 to produce PV work.  Hydrogen can be used to power an Otto cycle engine. But the net loss of molar volume across the reaction would appear to be a drawback to this system compared to others. The question I have is, how does this figure into the overall efficiency of H2 as a fuel?? 

Hydrogen is known to be problematic in engines due to what is called a cooling effect.

One of the key issues to consider with hydrogen economics is the fact that every last molecule has to be manufactured from hydrogen rich feedstocks using energy input. Hydrocarbons have to be cracked in some way, water has to be electrolyzed, or metals have to be oxidized with acid to produce dihydrogen. 

Given that H2 has to be manufactured by cracking hydrocarbon resources or electrolysis of water, does it make sense to use H2 as an automotive fuel? Why not just combust the hydrocarbon that was cracked to give up the H2 in the first place? Better yet, combust H2 at a centrally located gas turbine power plant and distribute the energy as electricity.

Hydrogen isn’t easily liquified (like propane) and the compressed gas requires heavy containment. 

With xtal ball in hand, the more I peer into the next 50 years, the more the future appears to be electrically powered. Todays hydrogen and ethanol schemes found in the popular media result from our collective unwillingness to address the real problem: How do we modify our behaviour to consume fewer kilowatt-hours (or BTU’s) per capita?

The answer is that we need to live closer to work, drive fewer miles, divert fewer hydrocarbons into disposable products, and generally consume fewer kg of resources per capita. Hydrocarbons are a very valuable resource- we’re fighting in the middle east over access to oil output in that part of the world. 

Petroleum distillates have a wonderful combination of attributes that make them valuable. Petroleum distillates have high energy density, they are liquid in ordinary conditions and hence can be pumped and atomized, they offer a choice of flash points, and are reasonably safe for people to handle. This is a splendid set of properties! We should be more appreciative and take better care of how we use it.

For Americans, a glimse of the future can be had for the price of a plane ticket to Japan or Europe. Higher population density, smaller portions of most things, and a larger fraction of income spent on energy.

Archaic Chemical Terms

There are interesting sites out there that list antiquated chemical terms. One apparently authoritative site lists 18th Century chemical terms (compiled by Jon Eklund of Smithsonian Studies in History and Technology). 

Some terms seem to remain quite useful, some are hopelessly irrelevant, and others are just odd.  Naturally, I am attracted to the odd words. Have a look for yourself. Here are a few good ones copied verbatum from early in the alphabet-

Cohobation –Repeated distillations, or any cyclic process in which a liquid is vaporized and condensed as, for example, in refluxing.
Cucurbit – The lower part of an alembic. Shorter, more squat and ovoid than a matrass.
Decrepitation – Rapid physical decomposition of some crystals when heated. Characterized by a crackling noise.
Dephlegmation – To remove water from a solution, usually one of an acid or alcohol. There is a sense of purifying about the term, as opposed to simple concentration.
Desquamation – The process of removing scaly crusts which form on a surface.
Dulcification – Any process in which a caustic substance is rendered less corrosive.
Empyreumatic – Tasting or smelling or burnt organic matter.
Exalt – To make more spiritous, volatile, or generally more active; activate.

I wonder if any of these would get through the peer review process if one were to try to use them in a procedure submitted for publication? Perhaps if Roald Hoffmann used them, I suppose.

Boiling the Frog. US Export of “Chemical Problematics”.

Recent announcements by some of the big players in chemical manufacturing are stunning in their magnitude and implication for our western hemisphere. Like the movement of tectonic plates, business landmasses are shifting and grinding their way to other parts of the world.

Last summer AstraZeneca announced that it will leave manufacturing all together. According to C&EN, Merck is downsizing its staff by 7000 jobs and reducing its number of sites by 20 %. Pfizer is reportedly closing or otherwise trimming off 29 sites.

Recently, Dow announced its departure from commodity chemicals with the upcoming US$9.5 billion joint venture with Petroleum Industrial Chemicals (PIC) of Kuwait.

Some of this migration to the far side of the world will place the companies in a better market position to compete with rising demand in the distant corners of the world. Many of the players are already multinational in structure and have existing units elsewhere, so changes amount to consolidation.

What concerns me is the extent to which R&D and product development is being transferred off-shore. Like the frog in slowly warming water, no alarm is noted because from moment to moment the comfort level changes only slightly. But eventually, the warm water becomes hot and the inattentive frog gets cooked.  It is hard to escape the notion the US and EU are the frog in a warming pot of water.

Outsourcing is a choice, not a law.  A company has to choose to outsource rather than find other options. But to be fair, a company has its hands tied in many ways by regulatory or competitive constraints that are hard to contend with economically. 

Compliance with the confusing web of overlapping jurisdictions and increasingly harsh regulations pertaining to the manufacture, transport, and consumption of chemicals is wearing down the willingness of US companies to continue to manufacture in North America. Instead, we export “Chemical Problematics”.

A chemical product can become problematic in several ways- 1) commoditization, 2) patent expiration, 3) liability blooming, 4) raw material scarcity, and 5) regulatory compliance costs. 

In the life cycle of a successful product, it is inevitable that competition will discover the market and find a way to supply competing goods and services. This is commoditization. Eventually, you will lose control of your market exclusivity and others will set up their lemonade stand next to yours and sell for a nickel cheaper.

A major issue for pharma is the near term expiration of patents protecting highly profitable products. High cost manufacturing can be sustained by suitably profitable products. Exclusivity is the keystone that keeps the entry from collapsing. But when the patents expire, the Huns storm the gate and take over with lower priced generics.

What I call liability blooming is a circumstance wherein an existing product suddenly becomes the focus of some liability problem. It can be a drug that suddenly starts showing bad side effects, or it can be a product that has come into the  radar of the regulatory agencies.  Materials that carry a penalty for their use in terms of liability exposure are difficult or impossible to continue using. If an end product carries a legal liability, it is probably dead as a product. But if materials used in its manufacture- but not final composition- develop liability issues, manufacturing under the current regulatory environment can become prohibitively expensive.

Raw material scarcity is becoming a widespread problem for US manufacturers. As outsourcing becomes more prevalent, key raw materials for a given product may become unavailable in the US. As long as one can source the materials, this is not such a bad problem. But what about strateging substances needed for national defense? I have spoken with government procurement people who are increasingly having to resort to off-shore vendors for defense-related products and materials. Electronic products have a high reliance on some rather exotic substances and national defense is increasingly reliant on such technology. Indium and neodymium are examples of elements that are becoming quite scarce and whose loss from the market would have a high impact on many products. 

For any growing chemical company, the first real expense of regulatory compliance is for staffing. Increasingly, regulatory compliance requires a staff of specialists who serve as internal watchdogs for non-compliance and manage compliance programs that trail documentation much like a cable ship pays out cable into the murky ocean deep. 

Chemical products vary in their regulatory compliance paperwork according to type. Chemicals that are not used by the public out in the open like pesticides may be generally less complex to manage. TSCA is for materials that do not meet the criteria for food, drug, or pesticide use. Compounds that are used in B2B markets and will never be darkened by the shadow of consumers are still subject to complex TSCA regulations. But TSCA registry is not forever.  The ever shifting sands of TSCA registry may place a product into further examination by EPA if a new application is contemplated.  The all-seeing-eye of compliance managers may be strained as SNUR’s affecting product use can show up in the Federal Register at any time.

There are lots of good reasons not to start a chemical business in the US these days. Public or private companies are increasingly in competition with nationalized business entities abroad. Petroleum, petroleum products, and defense in particular are markets where western companies are having to compete with nationalized organizations that can swing a big money stick as well as influence national policy.

The US and EU are sliding into a Nanny State mentality microgoverned by those schooled in the Precautionary Principle.  Timid acolytes shuffling along the hallways of regulatory agencies and cock-sure MBA’s strutting like roosters in their corporate headquarters are independently guiding US culture to an epoch of de-industrialization. 

Catalyst Recovery. Gaussling’s 6th Epistle to the Bohemians.

In catalyst development literature it is often stated that the particular catalyst under study can be recovered for re-use with full or nearly full activity.  I have heard this proclamation at meetings and in conversation as well.  Having spent a bit of my adult life analyzing process economics, I would like to comment on this matter. 

The world of chemical processing can be coarsely divided into two regimes- continuous and batch processing.  Since my hands-on continuous processing experience amounts to less than a year of time, I’ll limit my comments to batch processing. 

In this post I’ll define catalyst recycling as an operation wherein a catalytically active substance is recovered from a process stream and made available for another run. There are a great many catalysts and a great many applications, so generalizations are hazardous.  Nonetheless, there are a few generalizations to be made.

For a batch liquid-phase process performed in a multipurpose reactor, there are operations that are common to all processes.  Charging the reactor with raw materials, heating or cooling, agitation, reflux/distillation, discharging the contents, and cleaning. All of these operations consume resources and plant time. Generally speaking, any change that reduces consumption without harming the product could be considered a process improvement.

For catalyst recycling to qualify as a process improvement, some kind of consumption would have to be reduced over the useful lifetime of the material: i.e., reduction of time and/or materials. Obviously, reuse of a catalyst holds the potential to reduce the consumption expense of the catalyst over the course of the campaign. 

Before we draw any conclusions, it is useful to review the requirements put upon any material that might be used in a process. In bulk processing, raw materials are obtained from suppliers who have the necessary experience to provide the material.  But of equal importance, the vendor must have the necessary quality control mechanisms in place to warrant that the delivered product meets the promised specifications.

For instance, if you use butyllithium, you must be assured that all of the raw materials going into the process- reagents, solvents, etc.- meet a low water specification.  You have to know that the aryl bromide you are using isn’t contaminated with HBr or a polybrominated side product. There has to be assurance that all raw materials going into the pot meet some minimum purity.  A chemical processing company must know how to manage change.

Bulk processing is all about stability and predictability. You can’t rely simply on having ordered the proper grade of raw material. You need a certificate of analysis showing that the composition of the lot meets your in-house spec. When a vendor issues a cert, they are warranting the purity and accepting some risk as a result of sending bad product.

Management of change is a business methodology compelling an organization to adopt a standard procedure for the evaluation and approval of chemical process changes.  For instance, just because the chemists say that a change should be made to a scaled-up process doesn’t mean that it has to happen tomorrow if ever. The proposed change has to go through a protocol that exposes it to safety and economic scrutiny.  Frankly, it also spreads the potential blame for mishaps and economic disasters, so others have motivation to evaluate the process from a fresh view and sign-off.

The re-use of a catalyst brings forth the possibility that the activity of the catalyst could be altered in some way from one run to the next. There could be a downward trend in activity or some kind of variability. This means that a reused catalyst charged into the reactor could be a different catalyst from one run to the next. Potentially, what you saved in catalyst costs you might lose in extra plant hours or lower yield due to degraded performance or from outright process upsets.

Naturally, any kind of catalyst recycle has to be researched and understood by the R&D group and by the cost accountants.  Catalyst recycling will involve an operation to retrieve the material from the product or raffinate streams and to prepare it for the next run. Stable activity will have to be demonstrated, preferably under the influence of a variety of off-normal conditions.

Someone- a chemist or engineer- will have to sit down and do the calculations to see if there is a net benefit to the re-use of the catalyst against the backdrop of diminished performance, variability, or added operation costs. 

The point is that catalyst recycling isn’t automatically desirable. A recycling scheme that requires many labor hours to purify the catalyst may sour the benefit of the action. Another issue that may arise is the matter of validation of the re-used catalyst.  The company will have to decide if or when activity validation is necessary.  For a pot full of expensive precursor, a wink and a grin from the analysts may not be enough. A qualification run at the bench may be needed.

Here are my favorite catalyst attributes for batch processing- 1) high turnover number, 2) selective, 3) cheap enough to use once and send to waste disposal, 4) not a PGM (Platinum Group Metal)- PGM’s are subject to large market price variations, and 5) doesn’t contain one of the bad actors that trigger EPA thuggery or public protests- Hg, Cd, Cr(VI), etc. Metals are forever.

Catalyst recycle makes no sense, of course, in a one-time process run. A wise operator will calculate a price to cover the catalyst cost. But it may make sense if a plant is to start an extended run of batches, or if the catalyst is rare or expensive. Sometimes recycle has merit.  The point is that a sober cost calculation should be made prior to the implementation of recycle schemes.

At the beginning of the article I stated that some generalizations were possible. I will modify that in saying that PGM’s in the catalyst may necessitate the recovery, though not necessarily the re-use, of the metal for return credit to the supplier.

The Flame of Innovation

It is amazing how delicate the innovative impulse is.  Like most brain related activities, innovation is a use-it-or-lose-it kind of affair.  Innovative folk can be inspired by management to go forth and devise products that will keep the company afloat 5 years from now. They can also be contradicted or neglected by management and as a result the innovative flame can extinguish.

It is not unusual for organizations to go to the considerable expense of hiring research chemists yet not let them do what, ostensibly, they are best at- developing new art.  New art can lead to new goods and services, or it can lead to more cost efficient approaches to existing product.  Research chemists can also capture the nuance of a given process, leading to a better understanding of quirks and diagnostic signals.

Or not.

It is quite possible for a company to be run by people who have no interest or ability to use a research chemist in a broadly productive way. In my experience, it is not uncommon for chemists to be hired on to perform a very narrow range of activities. A wise chemist in the job market should be alert to the possibility that their creativity will not actually be sought by the employer. Rather, the chemist might become just a mechanical arm for some character whose ambitions may not include you.

Research is very expensive and the wary R&D chemist should always have an ear to the ground to listen for the galloping horse of the axeman.  Some organizations have a policy of spending a certain fraction of the proceeds on R&D every year. Others are more project or product line oriented and staff-up or staff-down as the circumstance requires.  R&D resources may get re-jiggered when a project changes. It is always best to be on a winning project that management is enthusiastic about.  Dark horse projects are prone to being jettisoned at the first sign of trouble.