Chemical engineers who changed the world
Handheld electronics and gadgets – from mobile phones to laptops – have transformed the way we live over the past decade or so. But the revolution led by Steve Jobs and his slightly less famous compatriot, Adam Osborne (the inventor of the laptop), would not have been possible without high-power rechargeable batteries, and they were brought to market thanks to a chemical engineer. Like many engineers, Yoshio Nishi is not a household name but frankly he should be, for he led the team that turned the lithium ion battery from a research concept into practical, commercially viable reality.
Nishi, who studied solid physical chemistry at the engineering department of Keio University in Tokyo, spent a lifetime working for Sony. In the mid-1980s he was appointed general manager of the lithium ion battery development team.
Lithium ion batteries promised to overcome the environmental problems associated with nickel-cadmium batteries, and also had a much greater energy density. Even so in the early stages of development many thought that lithium was too dangerous, the technology too risky and the whole concept premature.
One of the biggest challenges was making the battery safe even when subjected to serious abuse.
The team devised vents to prevent overpressure, introduced a porous membrane separating anode and cathode that would become impermeable in the event of a temperature spike, added elements with a positive temperature coefficient to prevent thermal runaway, and designed a mechanical link that would disconnect the cathode lead if pressure built up inside the battery.
Even so, lithium ion batteries have caused many phones and laptops to spontaneously combust over the years, triggering huge product recalls. Nishi blames price competition putting pressure on engineers to use cheaper materials and other shortcuts, and device designers ignoring the battery’s usage specifications.
His advice: Engineers have a duty to ensure management understands the safety implications of cost cuts, and not to compromise easily on what they believe is important.
The secret of soda
Not all chemical engineers would have called themselves by that name. Indeed, for some that term did not exist. No that that changes the nature of their work.
Take Nicholas Leblanc, for example. Born in 1742 near Orleans, during the reign of Louis XVI, Leblanc’s official profession was that of a surgeon to the Duke of Orleans. That afforded him a laboratory, some spare time, and a reasonable supply of money – enough to indulge his interest in chemistry and crystallisation.
When the French Academy of Sciences in 1783 offered a prize of 2400 livres to whoever might develop an economically viable process for the production of soda ash (sodium carbonate) from sea salt, Leblanc could not resist.
Leblanc, like other researchers looking to solve the challenge, began by heating sea salt in the presence of a source of sulpur (in this case, sulphuric acid) to produce sodium sulphate. His breakthrough was mixing the sodium sulphate with charcoal and adding calcium carbonate, at a temperature of 1000°C. This reaction yields sodium carbonate and sodium sulphate, which are fairly easy to separate.
The king was delighted. The neighbours less so: Leblanc had not just created one of the earliest industrial chemical processes but also one of the first major pollution problems. Per ton of soda ash, the process produces 7 t of calcium sulphate waste and 5.5 t of hydrogen chloride, which was released straight to the atmosphere, killing trees and blighting the landscape for miles around. In the UK, where Leblanc’s process saw widespread use, this resulted in one of the earliest pieces of air pollution regulation – the Alkali Act of 1863.
Leblanc, alas, did not get to enjoy the fruits of his labour. The French revolution intervened, and Leblanc had to reveal the details of his process, which was used to set up competing factories. His own sole soda factory was seized, his paymaster, the Duke of Orleans, executed, and Leblanc and his family evicted from their home. Of the 2400 livres for developing the process he only ever saw 60. Leblanc eventually committed suicide in 1806.
His legacy lives on though: Leblanc soda plants laid the foundation to chemical sites near Glasgow and Liverpool, and the production of soda ash was the key driver of the nascent chemical industry in the mid-19th century.
Getting to the bottom of it
What do you do when your employer, a big consumer goods company, has just acquired several paper mills and now has more paper than it knows what to do with? Well, obviously, you dream up a new and revolutionary product that just so happens to use huge quantities of paper.
For Victor Mills, head of the exploratory products division of Procter & Gamble, the brainwave came courtesy of his family. Mills had just become a grandfather, and was painfully reminded of just how much he detested washing nappies. The idea was born: what if you could create a nappy consisting mostly of shredded absorbent paper which could simply be thrown away after use?
Many hours of experimenting with different types of paper and nappy designs, all with the help of a trusted ‘team’ of Betsy Wetsy toys (a brand of ‘realistic’ urinating doll popular in the 1950s) followed. Further product testing followed on a family holiday, where Mills took his by now three grandchildren on many long drives. The nappies proved to be a full success, now all they needed was a name: Tads? Solos? How about Larks? None seemed right. Eventually, P&G settled on Pampers. And the world’s best-known disposable nappy was born.
Despite questions of the sustainability of the throw-away nappy, the reality is that some 90% of babies in the industrial world wear them. Globally, the market is worth some US$29b/y. Of course today the paper filling of the early nappies has long since been replaced by superabsorbers, making the nappies much thinner while increasingly leak-proof.
And Victor Mills, rather than sinking into the obscurity afforded to most chemical engineers, remains one of P&G’s best-remembered innovators. To this date, the company runs the ‘Victor Mills Society’, an elite club reserved for its most accomplished scientists and innovators.
Full article published in: tce 839, May 2011
The great outdoor revolution
Wilbert and Robert Gore
As everyone knows, polymers are flexible. So much so that in one case, what started out as plumbers’ joint-sealing tape has revolutionsed the world of camping, fishing, hiking and other outdoor pursuits.
The material in question of course is Gore-Tex, developed by a family of chemical engineers-cum-innovators – specifically, the father-and-son team Bill and Bob Gore. Wilbert ‘Bill’ Gore had spent 16 years working for DuPont, during which time he’d become involved with the company’s fluorochemicals business, where he was working on PTFE – commonly known as Teflon. Bill was convinced that Teflon had potential beyond non-stick frying pans.
PTFE has outstanding electrical properties and can withstand extreme temperatures without getting brittle, so Bill, working after hours in his basement, developed it as an electrical wire insulator. The product worked, Bill quit his job, and the resulting Multi-Tet cable was so useful in the early computer industry it even made it to the Moon landings.
PTFE’s transformation from spacefaring insulator to fisherman’s friend came courtesy of Bill’s son Bob, who was trying to stretch extruded polymer to create a material fit for the aforementioned plumbing tape. The material refused to cooperate, no matter how carefully Bob tried to stretch it. The breakthrough came when Bob gave it a fast, hard yank – perhaps out of frustration – and much to his surprise found it had stretched by a factor of 1,000. Quite accidentally, he had created microporous PTFE, a honeycomb-like material which, because it contains 70% air, is a first-rate insulator. Not only that but its fine pores created a fabric that was wind- and waterproof and yet remained breathable.
Once the inevitable teething troubles were straightened out, Gore-Tex was set to become the ubitquitous outdoor material it is today, found in everything from all-weather clothing for skiing, golfing or dogwalking to surgical implants and even dental floss and guitar strings.
Full article published in: tce 840, June 2011
Driving units and progress
Arthur D Little
If chemical engineering is the application of science to industry, then one of its most influential pioneers was Arthur D Little. Founder of the international consultancy that bears his name, Little’s achievements stretch much further: he developed the concept of unit operations – still a cornerstone of the profession – and used it to define the role of chemical engineering in industrial chemistry. He was also one of six founding members of the American Institute of Chemical Engineers and the driving force behind the creation of the chemical engineering practice school at the Massachusetts Institute of Technology in 1920.
Little was far ahead of his time in recognising the importance of long-term industrial research. The turn of the century saw rapid industrial development and process design, but corporate R&D remained an intermittent and hap-hazard affair, stopping and starting on a project-by-project basis. Little was an early and vociferous proponent of organised, longterm R&D, both within companies and at universities, which he lambasted for failing to provide adequate equipment for industrial research.
The consultancy he set up was one way of filling this gap. Little and the people he hired applied themselves tirelessly to improving processes and perfecting products. Their tenacity paid off: within five years of its foundation in 1905, the Arthur D Little consultancy had made a name for itself and ran specialised departments covering fuel engineering, forest products, textiles and more.
To the profession, his most lasting legacy is the concept of unit operations. He explained: “Any chemical process, on whatever scale conducted, may be resolved into a coordinate series of what may be termed ‘unit operations’, as pulverising, dyeing, roasting, crystallising, filtering, evaporation, electrolysing and so on.” He added that the number of different unit operations is quite finite – the great complexity of chemical engineering is the result of the variety of conditions under which these unit operations are carried out.
Almost 100 years later, his analysis remains as accurate as ever.
Charles Edward Howard and Norbert Rillieux
The background of Charles Edward Howard and Norbert Rillieux could have scarcely been more different – Howard the younger brother of the Duke of Norfolk, and Rillieux the son of a slave. Yet both in the early 19th century made crucial improvements to the important process of sugar refining, making important contributions to the pre-history of chemical engineering.
The sugar plantations in North and South America and the Caribbean were a major business at the time, and one that could only be operated with a significant investment in slave labour. Harvested cane had to be processed within two days in a process that was so backbreaking and dangerous that on average it cost one slave life per two tons of sugar.
Juice was extracted from the cut cane by crushing it in a three-roller mill, initially driven by mules and later by steam engines. A wooden gutter would transport the juice into the boiling house, where it entered a series of flat-bottomed copper kettles of decreasing size (the so-called Jamaica train), in which the juice was repeatedly boiled to produce a thick syrup. Milk of lime and ox blood were added to clarify the solution, and slaves would skim off the impurities, before the syrup was poured into pots to set into semi-refined sugar.
Howard’s contribution was to replace the open Jamaica train with a vacuum pan and filter units. Reducing the pressure meant that the sugar juice could be boiled at much lower temperatures, cutting the risk of burns and reducing caramelisation and allowing the evaporation step to continue till the sugar crystallised, resulting in much better, purer sugar.
Rillieux improved Howard’s vacuum pans further by using the hot steam from the first evaporator to heat the second and so on. This improved the energy of the process so drastically that the installation of Rillieux’ improved multi-effect evaporator paid for itself within a year.
Both Howard and Rillieux saw the success of their innovations during their lifetime though Rillieux, because of his colour (he was one quarter black), occasionally found it difficult to enjoy the fruits of his labour. As for slaves, the improvement in their lot was only temporary: while the improved evaporators made processing sugar safer and less arduous, the increased capacity of the processing plants meant that ever-more sugar had to be planted and harvested – equally backbreaking and dangerous work. But vacuum evaporation and multiple-effect evaporators are still very much with us today.
From calculator to flat-screen TV
We owe a greater debt to pocket calculators than we might think – for every flat-screen LCD (liquid crystal display), be it the TV at home, the mobile phone in your pocket or the computer monitor in the office, is essentially the grandchild of a pocket calculator launched by Japan’s Sharp Corporation in 1973. The EL-805 calculator (no prizes for a catchy name) was the first commercial electronic device to use an LCD screen.
The 1960s and 70s saw the so-called ‘calculator wars’ – a period of fierce price competition between manufacturers of early pocket calculators. One of the main problems of early pocket calculators was their power consumption – the fluorescent display tubes or light-emitting diodes they used required a lot of battery power, resulting in a very heavy calculator that worked for little more than an hour before it needed new batteries.
By chance, the Japanese TV channel NHK broadcasted a science documentary featuring an experimental LCD display developed by George Heilmeier at Princeton University. Among those watching it was Tomio Wada, a chemical engineer working for Sharp. Wada instantly realised that LCD displays could be the solution he’d been looking for.
But liquid crystals were a scientific curiosity that had seen very little use outside the science lab. Nobody at Sharp knew anything about them, the scientific literature was sparse to say the least, and it was not even known which compound Heilmeier had used in his display.
Despite this, Sharp decided that LCD screens were the way to go. A 20-strong team was assembled under Wada’s leadership and given the hugely ambitious goal to have a calculator with a working LCD screen on the market within 18 months.
The team tested 3,000 different liquid crystals and 500 mixtures; overcame regulatory hurdles, developed a new photolithographic etching process from scratch, to name but a few of the challenges.
The team succeeded: Within 17 months, the EL-805 was ready for launch. Weighing in at 200 g and only 2.1 cm thick it would fit in any shirt pocket – unlike the competition’s 25 cm alternative, weighing in at a full 25 kg.
Upping the octane
To many an engineer the phrase “It cannot be done” is like a red rag to a bull. Vladimir Haensel, process research coordinator with UOP, was no exception. Haensel was working on petroleum cracking and looking for ways of increasing the octane rating of the resulting fuels – at the time, in 1941, an octane rating of 65 RON was the norm. Such a low octane rating makes a fuel very likely to combust prematurely, causing serious engine knock – which in turn makes it impossible to use efficient high-compression engines.
Haensel was looking for a suitable catalyst for the cracking process and was convinced that platinum would be perfect for the job. Except, of course, that platinum was extremely rare and prohibitively expensive – “it cannot be done” was the received wisdom.
But what, thought Haensel, if he could make do with a vanishingly small quantity of platinum? What if on top of that he could regenerate any fouled catalyst in situ, allowing him to – in theory at least – run the process indefinitely?
His refusal to accept conventional wisdom led to the creation of a heterogeneous alumina-supported platinum catalyst that would very effectively dehydrogenate the hydrocarbons in the C6–C10 paraffins and transform the resulting unsaturated hydrocarbons into nice aromatic rings. By working with a highly-dispersed catalyst with extremely small platinum particles, Haensel managed to reduce the platinum content in the catalyst to as little as 0.01%. The so-called ‘platforming’ (platinum reforming) process was born.
The first platforming unit started up in 1949 and is still very much with us – some minor improvements aside. Today the vast majority of our fuels are produced through a platforming process. Without Haensel’s determination, we could say goodbye to today’s supercars and hello to the backfiring smoke-belching cars of the 1930s.
Reginald Gibson, Eric Fawcett, Michael Perrin and Dermot Manning
Polyethylene (PE) is everywhere. From shopping bags to Tupperware boxes, from plastic toys to water pipes and even hip replacements, it’s PE’s versatility that makes it the world’s most common plastic.
Its commercial success came courtesy of two ICI chemists, Reginald Gibson and Eric Fawcett, who in 1933 experimented with ethylene and benzaldehyde at high pressure. The reaction yielded a mysterious waxy solid but the reaction was fickle – attempts to reproduce it would as often as not result in a very loud bang and a mixture of hydrogen and carbon. Nobody could work out initially why the experiment would result in these quite spectacular failures, and ICI eventually decided to stop the research before someone came to serious grief.
It later transpired that the key to making the experiment work was oxygen: if there’s too little, nothing happens, too much and the mixture explodes. It had been pure luck that some of the ethylene bottles used in the early experiments had been contaminated with just the right amount of oxygen.
With high-pressure chemistry still in its infancy, there was little off-the-shelf equipment, and it fell to the team’s resident engineer, Dermot Manning, to design and build most of the reaction vessels. A key problem was sealing the vessels, as the standard lens ring would not hold gas at pressures above 300 atm – and ICI wase working at well over 1,000 atm here. Manning devised a self-sealing wave ring, which used the rising internal pressure to seal the wavy circumference of the ring into its seat, which overcame the problem.
Full-scale production of PE started the very day Germany invaded Poland, and a polymer that had been destined for telecommunications cable was used to insulate airborne radar instead. This proved to be an important advantage, as it enabled the British forces to create a radar system that was light enough to place on fighter planes, which helped their supply ships avoid German submarines.
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Pfizer’s penicillin pioneers
Jasper Kane and John McKeen
Sometimes it’s not the innovation itself that matters – it’s making it available in quantity and at the right time. Scale-up, in other words.
Ensuring that there was sufficient penicillin to treat the hundreds of thousands of soldiers that took part in the D-Day landings during World War II was not the work of Alexander Fleming; it was chemical engineers who made that happen. While many worked on scaling up production of penicillin, it was Pfizer chemist Jasper Kane and chemical engineer John McKeen who arguably made the biggest contribution.
The two cracked the problem of production via deep-tank fermentation. Since penicillin requires air to grow, the biggest problem was designing an aerated, stirred tank that would reliably and efficiently produce quantities of the notoriously fickle drug.
War-time materials shortages forced Pfizer to take a huge commercial gamble on producing the drug: with no means of acquiring extra reactors, Pfizer had to re-configure units producing tried and tested cash products.
Factory manager John Smith was reluctant. “The mould is as temperamental as an opera singer, the yields are low, the isolation is difficult, the extraction is murder, the purification invites disaster and the assay is unsatisfactory. Think of the risks and then think of the expensive investment in big tanks – think of what it means if you lose a 2000-gallon tank against what you lose if a flask goes bad. Is it worth it?”
It is to the credit of Kane that he did not back down, and convinced his bosses to do the right thing and take the commercial gamble. And it is to the credit of McKeen and his team, who worked sixteen hours a day, seven days a week, to complete the scale-up in just six months. The D-day landings alone saw 150,000 soldiers treated with penicillin, and 90% of the doses supplied were supplied by Pfizer.
Full article published in tce 824, February 2010
Feed the world
Fritz Haber and Carl Bosch
Since the start of the 20th century, the Earth has been experiencing an unprecedented population explosion. Where for the thousands of years of human existence before, global population only crept up very slowly, growth since the late 1800s has been exponential.
Of course many factors have contributed to this. But one of the most fundamental drivers has been our ability to grow more food. Hunger and famine were once commonplace in the western world and a major cause of death. Today, obesity is well on the way to becoming our biggest killer.
This would not have been possible without the advent of modern fertilisers. And that, in turn, is the work of industrial chemist Fritz Haber and chemical engineer Carl Bosch. The Haber-Bosch process, quite possibly the best-known chemical process in the world, captures nitrogen from the air and converts it to ammonia.
Breaking the remarkably stable triple bonds of atmospheric nitrogen in order to make it available for ammonia production was Haber’s work, who developed a high-temperature high-pressure process for the task. It fell to Bosch, chemical engineer at BASF, to scale up the process. Not only did Bosch have to find a cheaper way of producing hydrogen, he also needed t find a practical new catalyst (a task his assistant, Alwin Mittasch, is still fondly remembered for) and he had to develop a reactor that would withstand both the high temperatures and high pressures of the reaction, at a time when high-pressure chemistry was still in its infancy and suitable equipment (reactor vessels, pipes, instrumentation etc) was not readily available.
It is testament to Bosch’s work that over 100 years later, his process is still in use everywhere around the world, and practically unchanged.
Full article published in tce 825, March 2010
Fuelling a way of life
Donald Campbell, Homer Martin, Eger Murphree and Charles Tyson
Modern life runs – quite literally – on the products of a fluid catalytic cracking unit. Our cars run on petrol, the planes on jet fuel, we pick up our food from the supermarket (or bring it from home) wrapped in polyethylene film and wash it down with drinks from a polycarbonate bottle, while standing on a polypropylene carpet.
Yet this ubiquitous feedstock of modern life in all its aspects would be a lot rarer – not to mention a great deal more expensive – if it wasn’t for the workhorse of the refining industry, the fluid catalytic cracking (FCC) unit.
Some 400 FCC units are in operation around the world today. And each and every one of them can trace its ancestry back to one such unit, the Model I FCC, which started up in Baton Rouge, Louisiana, on 25 May 1942.
The 17,000 bbl/d unit was largely the brainchild of four chemical engineers, known as “the four horsemen”, working for the New Jersey company Standard Oil. They were Donald Campbell, Homer Martin, Eger Murphree and Charles Tyson.
The four developed today’s modern FCC process largely because their employer (and several other companies) did not want to pay the hefty $50m licensing fee for another early catalytic cracking process, developed by the French engineer Eugene Houdry and the pharmacist EA Prudhomme. But while the Houdry process was a semi-batch process using a fixed-bed catalyst, the real breakthrough for the “four horsemen” (and their advisors at MIT) was to realise that under certain circumstances, a powdered catalyst could behave like a liquid. This paved the way for the continuous process that was so efficient that it not only rapidly outcompeted the Houdry process, but remains in continuous use 60 years on.
Full article published in tce 826, April 2010
Rubber, PVC and bubblegum
Like so many innovations, the success of PVC – the world’s second most-used plastic, after polyethylene – is down to an accidental discovery. Waldo Semon, a young chemical engineer a few months into his first proper job with rubber producer BF Goodrich, had meant to find an adhesive that would bond rubber to metal. Semon decided to work with polyvinyl chloride, a brittle polymer universally thought to be totally useless. In an attempt to remove the chlorine, Semon solvated the PVC with a high-boiling solvent before treating it with zinc or a strong organic amine. “Imagine my surprise when I found that the solvated PVC was flexible, resilient and would bounce!,” he later said. “When I later found that the plasticised PVC would resist alkaline, strong acids and most solvents it seemed to me that it would have quite a range of commercial possibility.”
Convincing the management of this potential would prove a challenge in its own right, solved through a canny combination of PVC-coated (and therefore waterproofed) curtains, a vice president fond of camping (but tired of leaking tents) and an ad-hoc demonstration involving a bulging in-try and a decanter of water.
Today, PVC is the material of choice for two out of three water pipes and three quarters of the world’s sanitary sewers, with other applications ranging all the way from credit cards and window frames to electrical insulation tape.
Semon, meanwhile, didn’t rest on his laurels: he went on to develop a process and formula for synthetic rubber – a highly sought-after commodity during World War II, considering that the war had cut off supplies of natural rubber from Asia and Germany would not reveal the secret of producing “Buna-S”, the only other known synthetic rubber at the time. Through hard work and determination, Semon and his team developed the Ameripol rubber process, which by 1944 saw the US produce twice as much synthetic rubber as the world’s production of natural rubber had totaled before the war.
Full article published in tce 827, May 2010
Engineering the sexual revolution
George Rosenkranz, Luis Miramontes and Carl Djerassi
Not all of chemical engineering’s contributions revolve around heavy industry, chemicals and refining. In pharmaceuticals, too, they have made their mark – and one of their contributions to the pharma industry has had social consequences that could hardly have been more profound.
If you’re a modern woman, who takes it for granted that women can expect the same sort of career path as men and who revels in the liberty of being able to choose if and when to have children, then you, too, owe a debt to George Rosenkranz, Luis Miramontes and Carl Djerassi. The three – two chemical engineers and one chemist, two Jewish refugees from Europe and one local Mexican – were responsible for synthesising the first synthetic progesterone, which would go on to be used in the contraceptive pill.
Building on a process discovered by the maverick chemist Russel Marker, who synthesised progesterone from sapogenins, natural steroids found in Mexican yams, Rosenkranz, Miramontes and Djerassi created a synthetic variant that not only was a lot more active, but would also survive absorption through the digestive tract.
Not that anyone thought of using it as a contraceptive, at least to begin with; initial target indications were menstrual disorders and, ironically, infertility. Even once its contraceptive effect became known, fear of religiously-motivated boycotts caused companies to veer away from the drug. Rosenkranz says: “I went around Europe and the world offering the contraceptive, but nobody wanted it.”
A sustained campaign by women’s rights campaigners Margaret Sanger and Katharine Dexter McCormick, backed up by deep pockets and research funding, changed all that. Today, the Pill is used by over 100m women ever day. The freedom to choose and time when to have children has allowed women to claim equality in the workplace, and the sharp drop in birth rates in countries wherever the Pill is easy to obtain is arguably chemical engineering’s greatest-ever contribution to sustainability.
Full article published in tce 828, June 2010
From fuel hero to climate zero
Not everyone who changed the world did so in a way we’d celebrate. And sometimes, it takes the benefit of hindsight to realise the true impact of an apparently beneficial innovation. That certainly is the case for Thomas Midgley – mechanical engineer, chemist and chemical engineer – who during his lifetime was celebrated as a prolific inventor with a can-do attitude who had solved the longstanding and damaging problem of engine knock and gifted the world affordable and safe coolants for refrigerators and air conditioning units, as well as a universal safe propellant for aerosols.
Today, he is described, in a much less reverential tones, as the man who “had more impact on the atmosphere than any other single organism in Earth’s history.” Midgley’s innovations? Tetraethyl lead and chlorofluorocarbons (CFCs).
Midgley had, by all accounts, a brilliantly inventive mind, untroubled by received wisdom and undaunted by even the most complex tasks. When his scientific reasoning sent him in the wrong direction, strokes of sheer luck would deliver the unexpected breakthrough, such as in the discovery of TEL. Though his hands-on pragmatic attitude makes for chilling reading for today’s engineers, especially when it comes to the conditions found in the early TEL production plants and Midgley’s cheerful dismissal of the warnings he received about TEL’s poisonous side-effects.
While there were some early indications of the dangers of TEL (even if they were downplayed and dismissed at the time), it would take much longer for the side effects of Midley’s second innovation to become known. For thirty years, CFCs – particularly Midgley’s innovation, Freon – were the workhorse of the refrigeration industry and the propellant of choice in just about any hairspray, deodorant or insecticide spray. Unlike the available alternatives, Freon was neither toxic, flammable nor explosive.
At the time of Midgley’s untimely death at the age of 55, he was highly celebrated and decorated, holder of numerous awards and prestigious offices. His legacy stayed with us for many years more, though perhaps not in the way he and his contemporaries might have anticipated.
Full article published in tce 829/30, July/August 2010
Carl von Linde and William Hampson
The liquefaction and separation of air is one of those processes that many engineers worked on over the years, but only one – or rather two – would succeed at. Two very similar processes for the liquefaction of air were independently developed in Germany and the UK and patented within weeks of each other; the first by the mechanical engineer Carl von Linde, the second by a hitherto unknown, classics graduate and barrister William Hampson.
Both used air itself as a refrigerant, exploiting the Joule Thompson effect, which describes how gas gets colder as it expands. The effect is even more pronounced if the gas was previously compressed and chilled. Harnessing the effect in a virtuous cycle, by allowing compressed cooled air to expand in a counter-current heat exchanger so it cools the incoming compressed air to ever-lower temperatures, both inventors eventually cooled the air to -190ºC: the point at which it turns liquid.
It might have taken von Linde three days of running increasingly cold air through an incredibly long steel tube which he’d packed in wool for insulation, but on 29 May 1895, he eventually got there: “With clouds rising all around it, the pretty bluish liquid was poured into a large metal bucket,” he writes in his autobiography. “The hourly yield was about three litres. For the first time on such a scale air had been liquefied, and using tools of amazing simplicity compared to what had been used before.”
Where von Linde was an engineer, industrialist and already an expert in refrigeration before he started, Hampson was a complete unknown, with no relevant training and no record of what might have perked his interest in sciences and engineering. Nevertheless, his process was both simpler and more efficient than von Linde’s, liquefying air in a mere 20 minutes compared with the three days of von Linde’s early attempts.
The Hampson-Linde cycle gave rise to the modern industrial gases industry, provided pure gases for countless industrial processes and paved the way for the discovery of several rare gases.
Full article published in tce 831, September 2010
Degrees of separation
There are those who have hailed chromatography as one of the most significant developments of the 20th century, and yet few people outside a chemistry lab would have any understanding of what chromatography is, or what it is used for. A classic ‘behind the scenes’ technology, chromatography is the workhorse of analytical chemistry, and finds extensive use in healthcare, quality control, and drug discovery to name but a few fields.
Pharmaceutical companies use it to isolate active ingredients and ensure accurate dosing, hospitals use it to identify poisons or drugs in patients’ blood; environmental laboratories rely on it to check for contaminants; forensic scientists apply it to analyse samples from a crime scene; industrial chemists rely on it to determine the composition of petroleum oil, check the level of additives in foods, monitor pesticide contamination, and so on.
Key to making the process widely applicable was the adaptation of gas chromatography to liquids. This opened up its use for the separation of organic and biological molecules, many of which are involatile and too fragile for vaporization.
That achievement goes to the Hungarian born chemical engineer, Csaba Horváth, the father of modern high performance liquid chromatography. Horwath took an early interest in separation sciences and – unusually for a chemical engineer during the 1960s – in biochemical engineering. Adapting recent advances in gas chromatography to the nascent science of liquid chromatography, Horváth dramatically speeded up throughput and ramped up sensitivity while reducing the size of the equipment.
Today, HPLC is so sensitive that the characteristic patterns of peaks not only identify different molecules in a sample, but – thanks to very subtle differences in production processes and batch chemistry that give chemicals a very unique “fingerprint” also the production plant they came from.
Csaba Horváth may not be a household name, but without him, the world would be a much scarier place.
Full article published in tce 832, October 2010
Man of steel
If the industrial revolution was built on steel, then the father of the industrial revolution was Henry Bessemer. It was the Bessemer process that made steel available in industrial quantities at an affordable price.
Patented in 1855, the Bessemer process reduced the cost of steel from £50–60/t to £6–7/t and was accompanied by vast increases in scale and speed of steel production. Steel girders for bridges, buildings, railroads, skyscrapers – all were unimaginable before Bessemer. The same goes for modern steel ships, steel wire, high-pressure boilers (and with them, the steam engine), not to mention turbines for power generation.
Bessemer was a prolific inventor. Despite no university education, he patented innovations in fields as diverse as pigment production and ship building.
During his experiments with steelmaking, he discovered that contact with hot air would turn pig iron into steel, prompting Bessemer to take the – at the time highly counter-intuitive – step of forcing air directly through the molten iron. He was lucky that the resulting reaction, which was extremely violent, did not permanently damage to his workshop. But at least after just 20 minutes of mild explosions, violent eruptions and showes of red-hot slag, Bessemer was left with a converter full of steel.
Once he had convinced himself that there was no way of toning down the violence of the reaction, Bessemer channelled his efforts into developing a reactor vessel designed to contain the violent inferno with some degree of reliability and safety. The result: the Bessemer Converter.
This in turn prompted the rise of steel as a ubiquitous construction material, driving the second industrial revolution, and made Henry Bessemer a very, very wealthy man indeed.
Full article published in tce 833, November 2010