Category Archives: Chemistry

Respecting liquid hydrocarbons as a natural wonder

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I just had a conversation with a colleague who is somewhat mainstream in his/her thinking. The question came up as to why can’t we be energy independent.  What is taking so long with the electric cars and natural gas powered … everything? When can we break away from middle eastern petroleum?

In the public sphere, all I hear are the questioners seeking reassurance that there are energy forms out there that will allow us to maintain our current level of consumption. They rarely put it exactly that way, but that is the heart of the issue.

I think multiple generations of people have failed to appreciate the natural wonder of liquid hydrocarbons. The C7-C10 fractions of petroleum, whether directly from the ground or from a cat cracker or reformer, are the motive basis for most of our ground transportation. These liquid hydrocarbons are of a reasonably low vapor pressure and high enough boiling point to allow their use in everything from go-carts and lawn mowers to automobiles and caterpillars.  Teenagers and grandmothers can pump hydrocarbons into an inexpensive and simple tank for use at ambient pressure and temperature. This liquid has a melting point low enough to make it flowable under nearly all earthly conditions.

The high energy density and the liquid state of gasoline is what makes it nearly perfect for propulsion. The energy density of gasoline is 34.8 mega-Joules per liter (MJ/L), as opposed to 21.2 MJ/L for ethanol.

Yeah, gasoline is cheaper per liter than the bottled water inside the convenience store. That perversion is just a temporary historical aberration. This will change.

Cosmically, hydrocarbons in the C7-C10 range suitable for automotive use are quite scarce in the local stellar neighborhood.  Some small hydrocarbon molecules like methane have been spotted in the gas giant planets and on Titan. But for the most part, the only supply of hydrocarbons we have are found in porous deposits below the surface of the only place we can get to- Earth.

We should appreciate our hydrocarbon resources for the true natural wonder that it is and be a bit more reluctant to squander it.  I doubt we’ll ever find a source of energy that is as cheap and convenient to use with such a high energy density.  Battery technology may get close, but innovation there is a highly specialized art that is beyond the scope of most shade tree mechanics. Common lead acid batteries require material and energy inputs, like everything else, and have somewhat low energy density and a high weight penalty.

Lithium batteries, with their higher energy density require a variety of manufactured and relatively exotic substances. And, they require lithium which is fairly scarce, both cosmically and on earth. We really should be recycling lithium scrap.  Seriously, we need to have great respect and appreciation for lithium as well. There really isn’t enough lithium to support everyone’s high energy density lifestyle.

Pinch Predicted in the Uranium Market

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According to an article in Mineweb, the remaining cold war era uranium will be consumed in the next few years, leaving the nuclear industry with inadequate supply streams from mining.  Thomas Drolet of Drolet & Associates Energy Services, said that in 2010 mining produced 118 million pounds of uranium against a demand of 190 million pounds. Obviously, the balance was made up from decomissioned nuclear weapons stockpiles. The article did not say whether the numbers represented lbs of U or of U3O8. The oxide is commonly cited in relation to uranium mine production.

Drolet suggests that Japan will have to restart ca 30 of its 50 or so reactors in order to meet power demand.

It is my sense that the Fukushima disaster will not be the stake in the heart of nuclear power. The location of the Fukushima plant and a list of easily identifiable design features allowed the initiation and propagation of the incident. While the future of reactor operation in Japan may be stunted, most reactors elsewhere in the world are not located in tsunami flood zones. Regrettably, some are located in fault zones. But the insatiable demand for kilowatt hours will override everything. Commercial fission will continue into the indefinite future.

Return to fundamentals

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As we labor away on our extractive metallurgy project, I continue to marvel at how even complex extraction schemes reduce to the application of fundamental chemistry and basic unit operations. It is crucial to have a comprehensive understanding of the composition of your ore and the fate of the components as they are exposed to unit operations. The extraction of desired metals from your ore requires extensive use of analytical resources in order to keep the process economics in line.

Extractive metallurgy also requires an extensive knowledge of descriptive inorganic chemistry- something that was glossed over when I was in college. When I took undergraduate inorganic chemistry the emphasis was on ligand field theory, group theory application to symmetry and vibrational modes, coordination complex chemistry, etc. Lots of content that took many lecture hours to cover. Basic reaction chemistry was neglected in favor of admittedly elegant theory.

The fun for me (an organikker) has been in learning lots of descriptive inorganic chemistry and inorganic synthesis.

Extractive metallurgy in practice comes down to a relatively short list of operations. Roasting or calcining, comminution & classification, extraction, dissolution, flocculation, frothing, dewatering and filtration, redox transformations, precipitation, and drying.  Since most of the solution work is water based, the main handles you have to pull are temperature, selective solubility, and pH.

My undergrad coursework in inorganic qualitative analysis, specifically the separation schemes, has been very valuable both in terms of benchwork as well as descriptive chemistry.

Vannoccio Biringuccio. Sixteenth Century Chronicler of Metallurgy.

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By the early 16th century in Europe, metallurgy had become an established cottage industry in numerous locales. Artisans were sourcing copper, tin, zinc, antimony and iron ores for reduction, refinement and alloy production for cannon and bells among other products.  While there was no systematic science of chemistry in a form recognizable today, the necessity of constant proportions was understood and exploited to maximize the efficient use of scarce materials. Metallurgists of the 16th century would no doubt share the enthusiasm of developing technology with the same fervor as the technologists of today. 

Unfortunately for these 16th century technologists, the contribution of centuries of alchemy produced a confusing array of occult-based practices. These alchemical practices were based on Aristotelian notions of material “qualities” rather than a system of quantitative relationships of and between substances. It is thought that alchemy began with Grecian metalworker’s practical knowledge of metal preparation. Inevitably, this practical art was overprinted with a thick layer of theological mysticsm by the end of the first millenium. By the end of the alchemical age, any systematic theories of matter were blended into a Mulligan stew of early Roman Catholic mysticism,  incomprehensible nomenclature, and the false choices set forth by Aristotle in his theory of matter.

Fortunately for 16th century practitioners of the metallurgical arts, several encyclopedic works were published detailing the practical art of smelting and casting of metals and what we now know to be alloys.  A prominent early work published in 1540 was the Pirotechnia by Vannoccio Biringuccio (1480-1539). Born in Siena, Italy, over the course of his life Biringuccio traveled extensvely throughout Italy and Germany. His Pirotechnia is a series of books and chapters detailing foundry techniques that he witnessed first hand throughout his travels. He made every attempt to describe methods and techniques in enough detail to accurately capture the technique in question. Above all, he completely drops all the alchemical mysticism and bases his comments on process oriented details such as measured proportions and processing conditions.

Up to this point, what was missing from this very early form of chemistry was a systematic collection of facts and measurements and an accurate chemical model in which to give the facts meaning and predictive value.  Biringuccio, and later Agricola, would begin the disengagement of alchemical mysticism and provide a basis of metallurgical technology upon what might be called science. In a real sense, this helps to set into motion the western industrial revolution. Metallic goods would be produced by very pragmatic artisans who would continue to improve their art through the application of rudimentary measurement.  While it would be four centuries before atomic theory would be developed to make sense of the manner in which definite proportions operated, systematic methods of assay would begin to appear well before atomic theory. The ability to identify value in ores and quantitate it allowed the mass industrialzation of metals.

Thorium and Rare Earths. A Possible Market Synergy.

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If one studies the economic geology of Rare Earth Elements (REE), it becomes clear that REE’s are frequently (usually?) found in deposits rich in other elements.  Deposits of zirconium, tantalum and niobium, for instance, are frequently co-located with REE’s.

The REE’s are found in ore bodies that are naturally enriched in either heavies (yttric or HREE’s) or lights, (ceric or LREE’s). The LREE’s seem to be the most common spread of the REE’s.  Molycorp’s Mountain Pass bastnasite deposit is a good example of this.

What is not so widely known is that thorium and/or uranium are nearly always found in these deposits.  This might be regarded as a good thing except that companies in the REE business seem to be less interested in actinides than lanthanides. The actinide business is fraught with complications related to the natural radioactivity of Th and U. If one is interested in rare metal production, the matter of radioactivity is unwelcome.

However, there is opportunity here if certain institutional thinking is allowed to expand. I refer to the global preference for uranium and plutonium in the nuclear fuel cycle. Nearly the entire world’s nuclear materials infrastructure was directed to the production of yellowcake and separation of U235 from U238 post WWII. While there has been some experimentation with thorium 232 in the US, and there are some limited initiatives in motion, it has been largely neglected in reactor design and the fuel cycle in favor of uranium and plutonium.

Rare earth element mining and processing naturally produces thorium and uranium. At present, those practicing REE extractive metallurgy have every incentive to avoid concentrating the actinide components owing to the radioactivity. However, if there were a coherent program for the development of an efficient thorium fuel program, this natural resource could be efficiently taken from the REE product streams now or in the future.

Our reliance on energy will trend substantially towards electricity. The greater absolute abundance of Th over U, as well as the ability to use 100 % of the predominant isotope makes thorium a good candidate for energy exploitation. The recent boom in REE exploration has uncovered new sources of thorium. The nuclear genie was let out of the bottle nearly 70 years ago. By now we should be a little smarter about how we use it.

Re-thinking start-up opportunities

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It is interesting how ones perception of opportunities in the world depend on your context. I have academic colleagues who are in nanotechnology, for instance. When I have spoken of the apparent dearth of entrepreneurialism in chemistry, the sincere feedback I get is that there are nanotech-related startups out there. You know, I don’t doubt this.

What I was unable to articulate to my friends was that we need people willing to start companies for the manufacture of starting materials and intermediates for less cutting edge applications. I’m afraid that the word “start-up” has come to mean “bleeding edge technology”.

Have you ever tried to source specialty silanes or halogenated hydrocarbons for instance? The choices of manufacturers in North America are very slim. There are companies in the USA and Canada who manufacture pharma related materials. But believe it or not, not everyone needs costly cGMP manufactured feedstocks. You can find suppliers of thousands of varieties of boronic acids, esters, and difluorides. But what if you want an alkyl chloride?  In my experience there has been a mass extinction of North American halogenators in the last 10 years.

In the previous 5 decades US taxpayers have heavily subsidized US industry by the establishment of a university research complex residing at many dozens of public and private universities. Several generations of faculty at these institutions have written and been awarded a large number of grants over the decades that have produced the scientific talent. Some of the graduates have been the children of those whose combined support via taxed income paid for the complex. Others, in the form of foreign undergraduates, graduate students, and post-docs have been invited to come to the US and take advantage of this rich resource.

I, for one, am in support of sharing the scientific knowledge that has been so expensive in time and money. But what we find is that over the decades, the unstoppable advance of civilization has come to apply the inventions of technology to increase industrial efficiency by reducing the need for labor. Thus, as technology has advanced, the man-hours needed for any given item of commerce has generally declined.

When you combine this natural consequence of invention with a cultural inclination to export industrial production, what you get is a post-industrial civilization that becomes unable to support its previous level of comfort.

The US has been exporting its industrial magic faster than it can adapt to deindustrialization.  Whereas in previous times whole cities have grown around manufacturing plants, today we have whole cities substantially abandoned and blighted (like parts of Detroit). Public corporation shareholders who have taken full advantage of the rich infrastructure of the USA have pulled up stakes and moved to Mexico or Asia.  This article in Forbes is telling.

The combination of automation plus outsourcing overseas with the absentee landlord management of public corporations has triggered a basic instability in our culture. No one really knows how this will play out.

This is what leads me to urge my colleagues out there to consider starting out on your own. It will be hellishly difficult and will consume 5-15 years of your life. I have been a part of several failed startups myself. It is really hard to do. But let me say this: Avoid starting with a one-act pony, and find a way to have something to sell right away.  Not all start-ups have to bring single item, new technology on stream. Find a niche selling high value added, low volume products. Don’t be intimidated by environmental complications and zoning. You have to put your head down and plow through it.  Showing up and some hard-headed persistance counts for a lot.

Euphemisms and similes to avoid in 2012

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I propose a 20 year ban on the following overused and often mangled euphemisms and similes-

Rocket scientist–  “it doesn’t take rocket scientist to …”.  This one is really tiresome. I propose that it be banned indefinitely and that repeat offenders be tatooed with some humiliating symbol on their noses.

Holy Grail–  “… It’s like the Holy Grail of …”.  This was overused centuries ago and abusers should be called down on the carpet forcefully and publically. A good swatting with a rolled newspaper may be called for.

American taxpayers–  “… The American taxpayers are tired of …”.  You mean, American citizens. To play to the taxpayer’s emotional conflicts over taxes is a ham fisted rhetorical manipulation that bypasses the greater good of citizenship and responsible stewardship over our civilization. I am a citizen who pays taxes and I insist on being addressed as a citizen.

Perhaps the dear readers have even better examples of rhetorical ditties that should be retired.

 

Mercury Processing at the New Idria Smelter

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A few Andreas Feninger photos found at the Library of Congress are shown below.  The New Idria mine was a productive mine and smelting operation in central California. Note the fellow at the tilted sorting table, physically agitating the mercury from the solid soot and allowing it to run down the table for collection.  This is a gravity sorting process. Hard to know what kind of occupational exposure the poor fellow is into.

Worker collecting mercury from soot from smelter at New Idria mine, ca 1942. Library of Congress.

Since the early days of Spanish mercury trade, mercury has been packaged in iron flasks. According to my sources, the 76 lb sizing of the flask was based what laborers and pack animals could plausibly carry all day. In the picture below, a flask is being filled with mercury at the New Idria smelter.

Mercury Filling Station at New Idria Mercury Smelter, 1942. Photo by Andreas Feninger, Library of Congress.

Cinnabar ore was crushed and then roasted in a rotary kiln. This process not only released the sulfur from the cinnabar (HgS), but also decomposed the oxide and volatized the mercury. The mercury vapor was knocked down from the exhaust gas in condensers.

Rotary Kiln at the New Idria Mine and Smelter, 1942. Photo by Andreas Feninger, Library of Congress.

Process development with calorimetry

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I’ve turned my attention to reaction calorimetry recently. A reaction calorimeter (i.e.,  Mettler-Toledo RC1) is an apparatus so constructed as to allow the reaction of chemical substances with the benefit of measuring the heat flux evolved. Reaction masses may absorb heat energy from the surroundings (endothermic) or may evolve heat energy into the surroundings (exothermic).

Calorimetry has been around for a very long time. What is relatively recent is the development of instrumentation, sensor, and automation packages that are sufficiently user friendly that RC can be plausibly used by people like me: chemists who are assigned to implement a technique new to the organization.  What I mean by “user friendly” is not this: an instrument that requires the full time attention of a specialist to operate and maintain it.

A user friendly instrument is one engineered and automated to the extent that as many adjustments as possible are performed by the automation and that the resulting sysem is robust enough that operational errors and conflicting settings are flagged prior to commencing a run.  A dandy graphic user interface is nice too. Click and drag has become a normal expectation of users.

An instrument that can be operated on demand by existing staff is an instrument that nullifies the need for specialists. Not good for the employment of chemists, but normal in the eternal march of progress. My impression is that RC is largely performed by dedicated staff in safety departments. What the MT RC1 facilitates is the possibility for R&D groups to absorb this function and bring the chemists closer to the thermal reality of their processes. Administratively, it might make more sense for an outside group to do focus on process safety, however.

In industrial chemical manufacture the imperative is the same as for other capitalistic ventures- manufacture the goods with minimal cost inputs to provide acceptable quality. Reactions that are highly exothermic or are prone to initiation difficulties are reactions that may pose operational hazards stemming from the release of hazardous energy.  A highly exothermic reaction that initiates with difficulty- or at temperatures that shrink the margin of safe control- is a reaction that should be closely studied by RC, ARC, and DSC.

It is generally desirable for a reaction to initiate and propagate under positive administrative and engineeering controls. Obviously, it is desirable for a reaction to be halted by the application of such controls. Halting or slowing a reaction by adjustment of feed rate or temperature is a common approach.  For second order reactions, the careful metering of one reactant to the other (semi-batch) is the most common approach to control of heat evolution.

For first order reactions, control of heat evolution is had by control of the concentration of unreacted compound or by brute force management of heating and cooling.

Safe operation of chemical processing is about controlling the accumulated energy in the reactor. The accumulated energy is the result of accumulated unreacted compounds. Some reactions can be safely conducted in batch form, meaning that all of the reactants are charged to the reactor at once. At t=0, the accumulation of energy is 100 %. A reliable and properly designed heat exchange system is required for safe operation (see CSB report on T2). In light of T2, a backup cooling system or properly designed venting is advised.

The issue I take with the designers of the process performed at T2 is this: They chose to concentrate the accumulated energy by running the reaction as a batch process. This is a philosphical choice. The reaction could have been run as a semibatch process by feeding the MeCp to the Na with a condenser on the vessel. Control of the exotherm could have been had by control of the feed rate and clever use of the evaporative endotherm. A properly sized vent with rupture disc should always be used. These are three layers of protection. 

Instead, they chose on a batchwise process relying on a now obviously inadequate pressure relief system, and the proper functioning of water to the jacket.

No doubt the operators of the facility were under price and schedule pressure. The MeCp manganese carbonyl compound they were making is an anti-knock additive for automotive fuels and therefore a commodity product. I have no doubt at all that their margins may have been thin and that resources may not have been there to properly engineer the process. This process has “expedient” written all over it in my view.

Reactions that have a latent period prior to noticeable reaction are especially tricky. Often such reactions can be rendered more reliable by operation at higher temperatures. Running exothermic reactions at elevated temperatures is somewhat counter-intuitive, but the issue of accumulation may be solved.  

Disclaimer: The opinions expressed by Th’ Gaussling are his own and do not necessarily represent those of employers past or present (or future).