Category Archives: Chemistry

Thermal Decomposition of Sucrose in Nitrogen Atmosphere

2 Replies

Below is a thermogravimetric (TG) scan of commercial grade sucrose. Over the course of the experiment, the compound is quite stable to decomposition to the gas phase under N2 up to the onset temperature of ~226 C. This is indicated by the constant temperature line leading up to the onset.  Above 226 C it begins to evolve gas or aerosols.

The furnace temperature ramp is 10 C/minute, the purge gas is nitrogen, and the crucible is platinum. The software that presents the data determines an onset and offset temperature by intersecting lines extending from the slopes of the lines at points chosen by the operator. In this way, the computer “squares” the broad curves and reports a temperature at that point.

Not shown is the % mass loss; from ambient to 500 C the sample lost 78.55 %. The slope of the curve from the onset to offset temperature is 0.69 %/deg C. Multiplying by 10 deg C/min, the cook off rate is 6.9 wt %  per minute in the temperature ramp. An isothermal run could be performed to look at behaviour under constant temperature.

The value of information presented by this analysis is somewhat limited to the relevance of conditions in the crucible. TGA can be a big help in determining the onset and extent of dehydration or other decomposition transformations. It can easily detect the ability of a material to sublime as well.  And, it can provide information to process chemists and engineers regarding certain aspects of temperature stability and thermal safety.

 

Fire Extinguisher Training

5 Replies

Everyone should have a chance to use a fire extinguisher on a real fire. The trouble with this idea is that the annual discharge of fire extinguishers is expensive, training fires can be problematic, and the discharge from the extinguishers can leave a big mess.

I had the chance recently to undergo annual training with a new controlled fire training system made by BullEx. I’ll admit to being skeptical at first. It seemed awfully contrived and … safe. But watching the tenderfoot office staff line up with their backup buddies to use pressurized water to put down a controlled and “adjustable” fire, I finally came around and had to agree that the system has considerable merit. For us, the system pays for itself in 1 year of training in terms of retiring dry chemical recharge costs.

Most would agree that a fire extinguisher is fairly simple to use. What seems to be the hard part for many is overcoming the uncertainty about whether they should use the extinguisher and under what circumstances. While the simulator does not produce smoke, obnoxious fumes, and there is no dust cloud from a dry chemical extinguisher discharge, the system does a good job of building confidence in people who may be a bit timid.

A Life in Industrial Science

Leave a reply

There are many ways to live a scientific life in chemistry. The obvious examples are the lives of chemistry faculty. A chemistry prof’s time is split between teaching, managing a research group, grant writing, committees, giving seminars, academic advising and, oh yes, a home life. 

In industry, the life of a scientist can be split between several layers of applied research, management of a budget and directly reporting staff, occasional patent work, meetings, writing reports, and if there is a spare minute, leafing through a journal.

I could have never anticipated the job description that I now hold. The specifics aren’t important for the purpose of this essay. What I want to describe is the extent to which I am constantly juggling numerous diverse, often intractable, open-ended tasks. It dawned on me recently that my job description sets me up for a career of dealing with thorny problems that few want and could or would handle.

Is this shameless self-admiration? No, it’s really a kind of lamentation. It would be nice to do something straightforward now and then. I used to do the advertising. Then we got back the C&EN survey results. I don’t do the advertising anymore. I’d like to meet a few of those rotten commenters … \;-)

Because I share office space with the accounting group, I have the chance to lunch and banter with the bean counters. It doesn’t take long to realize that theirs is a life of well defined tasks with built in cross-checks and monthly cycles. These accountants have their work cut to size and funneled to them by highly formalized and structured norms. Their job is to enforce consistency and eliminate surprises. They express discomfort and fear near the boundaries of their knowledge.

In contrast, scientists are people who seek out the boundary waters of knowledge and actually set up camp there. A scientist is someone who finds a way to acclimate to a life of uncertainty. A scientist knows that ignorance and uncertainty can be ground down with hard work and a bit of luck. Luckily for me, dogged persistance can partially make up for the lack of genius.

But despite the high minded platitudes about the endeavor of science, I’ve come to appreciate washing glassware and cobbling together a plumbing solution to a problem with an apparatus exactly because it is so concrete. Unlike molecules, I can actually see the results of my plumbing handiwork of compression fittings, steel tubes, and rubber hose. Sometimes it is nice to leave the abstract behind and make something simple but sturdy.

BASF Offers to Buy Ciba

2 Replies

According to the on-line publication Chemical Engineering, German chemical giant BASF has made an offer to buy Ciba Holdings AG, headquartered in Basel, Switzerland. In the public takeover, BASF has offered CHF 50.00 for each nominal share of Ciba stock.  The agreed upon price represents a 32 % premium above the Sept. 12, 2008, closing price. The acquisition will help BASF strengthen its hold on specialty chemicals, particularly in the area of coatings.

Fast Food Munching Criminals Leave Corrosive Fingerprints

Leave a reply

University of Leicester, UK.  John Bond, a reseacher at the University of Leicester and consultant to the Northamptonshire Police, suggests that criminals who consume fast foods leave fingerprints that are corrosive. Dr. Bond says that enhanced levels of salt in processed foods can lead to sweaty fingerprints that are more corrosive to metals.

Dr Bond said: “On the basis that processed foods tend to be high in salt as a preservative, the body needs to excrete excess salt which comes out as sweat through the pores in our fingers.

“So the sweaty fingerprint impression you leave when you touch a surface will be high in salt if you eat a lot of processed foods -the higher the salt, the better the corrosion of the metal.”

Dr. Bond went on to say that there was an “indirect link” to obesity and the chances of being caught in a crime. Bond says that corrosion due to fingerprints may be helpful in the tracking of terrorists whose bombs are fragmented from the explosion.

PGM Cu-Ni Strike Near Thunder Bay

3 Replies

10 September, 2008. Anglo American has acquired a 12 % stake in the Australian mining firm Magma Metals Limited. Magma Metals had previously announced “spectacular” results August 11, 2008, in its exploratory drilling activities in the Current Lake intrusive complex north of Thunder Bay, Ontario, Canada.

Magma reports a 2.5 kilometer long strike zone with mineralization varying from 5.6 g/ton to 26.5 g/ton of Pt + Pd from one drill hole. The drilling revealed concentrations as high as several percent of Cu and Ni as well. Magma Metals reports that it has been undergoing a 24,000 meter drilling program to map the Thunder Bay claims.

Destroying Munitions with Solvated Electrons

1 Reply

Blundering through the patent literature I took a wrong turn and tripped over a patent that claims an interesting use of ammonia solutions of electrons. The patent, US 6080907, is assigned to Teledyne Commodore and teaches a method that uses ammonia as a fluid metal cutting medium for the safe destruction of bombs and the explosives inside. The inventor claims that ammonia is superior to water as a cutting fluid. Apparently Teledyne employs a few chemists because it dawned on someone that ammonia will also dissolve certain metals and provide a means of conveyance for a reducing agent to enter the bomb casing and reduce the nitro groups on the explosives. It is a clever idea. A new use for the Birch reduction.

 I wonder if it is in operation?

The Chemical Entrepreneur. Part 2.

9 Replies

There are many reasons not to start a business. It’s risky. It inevitably requires many long hours sweating all of the ten thousand details. Building a company from scratch requires wildly diverse skills that are not commonly possessed by a single person. And it usually requires more resources than a typical wage earner can easily muster.

A chemical entrepreneur with an eye on manufacturing faces some unique challenges that, say, a fledgling purveyor of roasted coffee beans could avoid. Most obvious it the issue of a physical plant. Not only must the chemist or engineer have a workable chemical process, but also have a highly specialized facility in which to do the processing. This requires suitably zoned land, local review boards, environmental permits, a local work force, process equipment, a minimum of raw material inventory, and buildings to contain it all.

Then the entrepreneur must provide an infrastructure of chillers, boilers, electrical distribution, liquid nitrogen for inert gas, an analytical facility, an R&D facility, quality control, as well as administration, sales, and technical staff.  There must be a steady stream of cash flow to provide a steady payroll. Taxes must be estimated and paid in advance.

There are many sobering reasons not to go forward with a chemical business plan if one is risk averse or, shall we say, comfortable. Indeed, one of the common character traits of people who are analytically-minded is the tendancy to rattle off all of the reasons why something won’t work. We’ve all experienced this in meetings. A problem arises and meetings are called. After the problem is identified, much of the remaining time is spent in a recital of the additional problems that are expected. Soon, the problem mushrooms into a phantasm with imaginary components of awesome magnitude.

We’re all good at digging up reasons why something won’t work. And chemists suffer no lack of ability here.

But this is where the true entrepreneur stands out from the herd. One mark of a successful entrepreneur is the ability to ignore, or filter out, pessimistic predictions of an outcome. There is a spark within the some people that compels them to go forward. Sometimes it is a special insight. But just as likely the entrepreneur has an inner drive- some might unflatteringly call it “narcissism”- that moves them forward because they are certain of the outcome. It is not uncommon for an entrepreneur to consider him or herself the smartest person in the room.

In Part 3 we’ll look at examples of what kinds of businesses chemical entrepreneurs have started.