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Sir William Ramsay (1852–1916)

Veena Patwardhan
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Sir William Ramsay (1852–1916)

Sir William Ramsay (1852–1916)

Discoverer of the Noble Gases

During his time, Sir William Ramsay was a sort of superstar in the chemistry world. For one, in just five years (from 1894 to 1898), he pulled off the incredible feat of discovering five new elements in quick succession! These were the noble gases – helium, neon, argon, krypton, and xenon. And secondly, since the newly discovered elements could not be fitted into the periodic table as it was structured at that time, his discoveries led to the addition of a new group to it – group 0.

These achievements won him international fame, and a few years later, in 1904, the Nobel Prize in Chemistry “in recognition of his services in the discov­ery of the inert gaseous elements in air, and his deter­mination of their place in the periodic system”.

Early life

William Ramsay was born in Glasgow, Scotland, on 2 October 1852. His family tree included scientists on both the maternal and paternal sides. His paternal grandfather was the founder of Glasgow’s Chemical Society, and his uncle, the well-known geologist Sir Andrew Ramsay. His maternal grandfather and many other relatives from his mother’s side had been physi­cians.

Two years younger than his classmates in school, Ramsay matriculated at the age of 14 from the University of Glasgow where he also completed his science degree. He studied in Germany for his Ph.D. and in 1872, at the age of 19, received his doctorate degree in organic chemistry from the University of Tübingen for his thesis on orthotoluic acid and its derivatives.

Ramsay had multiple interests outside the realm of science. He was fond of dogs and loved to travel and compose and play music. He was a linguist, having studied Latin and Greek at the University of Glasgow and picked up French and German too as a child, delv­ing into the Bible in these languages at the Church his parents went to on Sundays.

Achievements as a pathbreaking chemist

William Ramsay started his academic career on re­turning to Scotland in 1872, progressing from an assis­tant in chemistry at the Anderson College in Glasgow to being appointed as the Chair of Inorganic Chemistry at University College London (UCL), in 1887, a post he held till his retirement in 1913.

Ramsay was an excellent university teacher, much loved and revered by his students who had affection­ately nick-named him ‘The Chief’. His earliest biogra­pher, Sir William A. Tilden had written that his stu­dents and colleagues alike found him to be “cheerful, inspiring, enthusiastic, full of ideas, and ready to give information or discuss any difficulty”.

At UCL, Ramsay had to deal with the peculiar prac­tice of often having to deliver the same lecture thrice – to separate groups of male and female chemistry stu­dents, and medical students as well. A progressive ac­ademic, he suggested the integration of women stu­dents with the mainstream student groups. He also disapproved of examination results being taken as a means of evaluating university students, encouraging original research instead. Accordingly, he played a key role in re-organising the university and transforming it from being just an examining body into a full-fledged centre of learning.

Though his early work was in organic and physi­cal chemistry, it was in inorganic chemistry, the field he chose to focus on from the mid-eighties onwards, that his famous discoveries of noble gases were made.

In April 1894, intrigued by the celebrated physi­cist Lord Rayleigh’s discovery that ‘nitrogen’ in air was around 0.5% denser than nitrogen sourced from nitro­gen compounds, with Rayleigh’s permission, Ramsay too carried out experiments to unravel this intriguing dilemma. In the months that followed, the two scien­tists shared the results of their investigations with each other. On extracting oxygen, carbon dioxide, and nitro­gen from a sample of air, Ramsay realised the remain­ing air contained another gas equivalent to one-eighti­eth of the original volume. He and Rayleigh then stud­ied the gas using spectroscopy, and in 1895 published a joint paper about having discovered a new element that was chemically inert and which they had named argon, after the Greek word ‘argos’ meaning inactive or lazy.

Interestingly, some scientists, including the great Dmitri Mendeleev, creator of the periodic table, dis­agreed with their claim. Mendeleev asserted that what they had found was actually triatomic nitrogen, N3. But the solid evidence, including spectroscopic results, that Ramsay and Rayleigh provided to back their find­ings, convinced the scientific community about their discovery.

Realising that if there was one inert gas, then there ought to be more, perhaps even a whole group of such gases, Ramsay was eager to discover these as well. Thereafter, within just five years, he proved the exis­tence of terrestrial helium, an element already detected in the sun’s chromosphere three decades earlier, and then discovered neon, xenon, and krypton as well.

Soon, Ramsay’s fame as an outstanding researcher made him a much sought-after consultant to industry. In addition to the Nobel Prize, he was also awarded sev­eral other scientific honours by many European coun­tries. The University of Glasgow where he had stud­ied and taught named The Ramsay Chair in Chemistry after him. UCL, where he had carried out almost all of his pathbreaking work, founded the Department of Chemical Engineering in his memory in 1923. The Sir William Ramsay School in Hazlemere, Ramsay grease used for lubricating joints of laboratory glassware (Ramsay was an expert glassblower), and the Ramsay and Shields equation are also named after him.

12 Arundel Gardens, Notting Hill, Ramsay’s family home for fifteen years and where he lived with his wife Margaret Buchanan and two children bears one of the famous Blue Plaques put up by English Heritage for celebrating the links between eminent men and women of the past and their places of residence. In a letter to an aunt soon after moving to this address, Ramsay wrote, “I go to town on a bicycle! Right along the Bayswater Road to Oxford, and to Gower Street. This morning I was at College in eighteen minutes from the house.”

The India connection

As a distinguished scientist, Ramsay was roped in as an adviser for the setting up of the Indian Institute of Science, planned as a tripartite venture between India’s well-known industrialist and philanthropist – Jamshetji N. Tata (who also founded the Tata Group), the then Government of India, and the Maharaja of Mysore. On a special invitation extended to him by J. N. Tata, Ramsay made a long visit to India in 1900 along with his wife, during which he offered valu­able advice for setting up the institute, currently one of India’s finest scientific institutions, even suggesting Bangalore as the most appropriate location.

Sir William Ramsay was among the first scien­tists to appreciate the possibility of radiotherapy, and therefore studied the “curative action of radioactive substances in malignant disease”. Sadly, he himself died of nasal cancer at the age of 63, possibly due to repeated exposure to radioactive substances. He died on 23 July 1916.

This illustrious scientist who took ‘keen pleasure’ in his research work and inspired scores of his stu­dents and other scientists to experience the delights of scientific research was finally laid to rest in his par­ish church, the Holy Trinity Church, at Hazlemere, Buckinghamshire.

References

  1. MLA style: Sir William Ramsay – Biographical – Nobelprize. org, Nobel Media AB 2014, Web: https://www.nobelprize. org/nobel_prizes/chemistry/laureates/1904/ramsay-bio.ht­ml
  2. The University of Glasgow Story: Sir William Ramsay – University of Glasgow, Web: http://www.universitystory. gla.ac.uk/biography/?id=WH0044&type=P
  3. Katherine D. Watson: Sir William Ramsay – Encyclopaedia Britannica
  4. English Heritage: Ramsay, Sir William (1852 – 1916) – Web: http://www.english-heritage.org.uk/visit/blue-plaques/ ramsay-sir-william-1852-1916
  5. Jacqueline Banerjee: William Ramsay – The Victorian Web, September 2015
  6. K. N. Smith: Scientists discovered helium during a total so­lar eclipse – Forbes.com, 18 August 2017
  7. University College London: Sir William Ramsay – UCL, Chemical Engineering, Web: http://www.ucl.ac.uk/ chemeng/about/ramsay.

Helium – The noblest of gases

Veena Patwardhan
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Helium – The noblest of gases

What do party balloons, space shuttles, MRI machines, and the Large Hadron Collider have in common? They all need helium. Whether in the gaseous or liquid form, at room temperature or at temperatures close to absolute zero, the world consumes around 8 billion cubic feet of helium each year for various purposes.

After hydrogen, helium is the second most abundant element in the universe, and having an atom with two protons, two neutrons, and two electrons, is also the second simplest of the chemical elements. It is the lightest of the noble gases and completely inert.

Helium has some fascinating physical properties. Of all the elements, it’s boiling point −452.1°F (−268.9°C) and melting point −458°F (−272.2°C) are the lowest. As is evident from these figures, helium remains a gas even at very low temperatures, and is in the liquid state over a very short temperature range. Just above its melting point, at a temperature of about -271°C (-456°F), it becomes a superfluid, that is, it flows up¬wards out of a container defying the force of gravity. Helium is also the only element that cannot be solidified just by lowering the temperature at ordinary pressures. To solidify it, the pressure too has to be increased. These peculiar properties of helium make it an important element in low-temperature research.

History of the ‘Sun’ element

The most fascinating fact about the history of this noblest of gases is that it was discovered twice. First around 92,900,000 miles away from our planet – in the Sun, and only around three decades later on the Earth.

On a visit to Guntur, India, to observe the solar eclipse on 18th August,1868, the French astronomer Pierre Jules César Janssen studied the spectral lines of the solar prominences and realised they were bright enough to be studied even in normal daylight. So, the next day, he studied the chromosphere of the sun again through his spectroscope and discovered a yellow spectral line close to those of sodium, but distinct from them. He concluded it must be from some unknown element in the Sun. Around two months later, on 20th October, a British astronomer Sir Joseph Norman Lockyer discovered the same spectral line observing the Sun’s spectrum through a more powerful spectroscope and even measured its wavelength (587.49 nanometres). Realising it did not match that of any other known element on earth, he and an English chemist Edward Frankland named the element helium after the Greek word for the Sun and the Sun God – Hēlios. And so, both Janssen and Lockyer are credited with first discovering extra-terrestrial helium.

For quite some time afterwards, it was believed helium only existed in the Sun. Till in 1895, the Scottish chemist Sir William Ramsay discovered trace amounts of helium gas in cleveite, a mineral containing uranium, while trying to produce argon from it. Lockyer confirmed it was indeed helium. Around the same time, Swedish chemist Per Teodor Cleve and his student Nils Abraham Langlet also independently discovered helium in the same mineral. Thus, cleveite became the first known earthly source of helium. Actually, Lockyer had called the new element helium assuming it to be a metal. Later, Ramsay had suggested he re-name it as ‘helion’ to go with the names of the other noble gases. But Lockyer refused and so the name stayed unchanged.

Then, on December 7, 1905, after two years of research in their laboratory in Kansas University’s Bailey Hall, chemistry professors Hamilton P. Cady and David F. McFarland made a significant discovery. They found that the samples of the strange non-flammable gas collected from a natural gas field in Dexter, Kansas, that they had been working on, contained considerable amounts of helium. Their work revealed that natural gas was a much better source for extracting helium as compared to cleveite. Bailey Hall, the site of this significant breakthrough, bears a plaque from the American Chemical Society honoring the building as a National Chemical Historical Landmark. This discovery also led to the detection of a massive reserve of helium below the American Great Plains and to the United States becoming the sole supplier of helium to the rest of the world.

From helping launch rockets to saving lives Helium’s interesting properties have been fully exploited for multiple applications. The earliest use of helium in large quantities was for buoying balloons and airships. Non-flammable helium-filled airships helped win World War II by detecting the presence of German submarines in the Atlantic and guiding US supply and troop ships safely through dangerous waters. Helium was used to support the production of atomic energy and played a significant role in the making of the atomic bomb at Los Alamos, New Mexico.

A major use of helium today is for Magnetic Resonance Imaging (MRI) machines. These machines, used for diagnosing various medical conditions such as cancers, tumours, brain illnesses and heart damage, need liquid helium for cooling the superconducting magnet that provides their magnetic field. Helium also helps create an inert atmosphere for welding processes, facilitating the fabrication of magnesium and other metals. Space shuttles need liquid helium to clean out their liquid hydrogen and oxygen fuel tanks, and also to pressurise the interior of liquid fuel rockets, besides condensing hydrogen and oxygen to make rocket fuel and forcing the fuel into the engines during rocket launches. Being in the liquid state even at -270°C, helium is cold enough to be used in superconducting devices such as sensitive optical devices and detectors of magnetic fields.

Besides, helium is also used in leak-detection systems, for preparing the helium-neon gas lasers used in supermarket check-outs for scanning bar codes, for preparing helium-oxygen mixtures that deep-sea divers can breathe comfortably, and for creating an inert atmosphere for manufacturing fibre optic cables used for internet supply and cable TV and growing ultra-pure crystals for silicon wafers. Now, research is underway for using it as a coolant in next- generation nuclear power plants. An incredible number of applications for an inert gas, one would think.

No longer the disappearing element?

For some time now, scientists have been predicting the world could soon run out of helium, a non-renewable resource. Currently, we have no way of manufacturing it. And once used for as a coolant or for other purposes, we cannot recycle it. Being lighter than air, it immediately rises into the atmosphere and escapes into space. All the helium we have is trapped in the earth’s crust.

And while it’s not possible to estimate the exact amount of helium deep within the earth’s crust, we do know it is formed when radioactive elements like uranium and thorium present in rocks deep beneath the earth’s surface decay, and then it accumulates in pockets in the crust or in reservoirs of natural gas. When wells are dug for collecting the natural gas, helium gas, that also comes to the surface, gets released and escapes into space.

Recently, geologists from the Universities of Oxford and Durham found that volcanic activity releases helium from deep down in the Earth into shallower pockets closer to its surface. Accordingly, they began looking for such helium pockets and found a huge reservoir of the gas in the Tanzanian East African Rift Valley in June last year. Initially estimated to be 54 billion cubic feet (approximately eight times the annual global demand), recent analysis of the helium deposit has revealed it could be much bigger – around 98.6 billion cubic feet.
Many researchers and geologists have referred to the new find as ‘life-saving’ and as a ‘game-changer’, and are of the view that many more massive helium reservoirs could be unearthed in other parts of the world. After the earlier scares, that’s good news indeed. Good enough to lift our spirits!

References
1. John Emsley: Nature’s Building Blocks: An A-Z Guide to the elements – Oxford University Press, August 2011
2. Biman B. Nath: The Story of Helium and the Birth of Astrophysics – Springer Science & Business Media, 10 Nov 2012
3. John H. McCool: High on Helium – University of Kansas, www.kuhistory.com
4. Francie Diep: 8 Surprising High-Tech Uses for Helium – Innovation News Daily, www.nbcnews.com , 18 May 2012
5. Helen Briggs: Helium discovery a ‘game-changer’ – www. bbc.com , 28 June 2016
6. Matthew Gunther: Scientists unearth one of the world’s largest helium deposits – Chemistry World, 30 June 2016
7. Michelle Starr: Massive ‘life-saving’ helium field just turned out to be far bigger than we’d hoped – www.sciencealert. com , 10 October 2017
8. Berganza CJ, Zhang JH: The role of helium gas in medicine – Medical Gas Research, PMC Web, US National Library of Science, 4 August 2013
9. Hobart King: Helium: A byproduct of the natural gas industry – www.geology.com.

Jacobus Henricus van ‘t Hoff (1852–1911)

Veena Patwardhan
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Jacobus Henricus van ‘t Hoff (1852–1911)

Jacobus Henricus van ‘t Hoff (1852–1911)
The Father of Physical Chemistry

The prestigious Nobel Prizes were first awarded in 1901 and the first Nobel Laureate in Chemistry was the well-known Dutch physical chemist with a wealth of pioneering research work to his name – Jacobus Henricus van ‘t Hoff. He won the award “in recognition of the extraordinary services” he had ren­dered “by the discovery of the laws of chemical dynam­ics and osmotic pressure in solutions”. His meticulous research work had shown that very dilute solutions follow laws that are similar to those related to the behaviour of gases.

What’s also noteworthy about van ‘t Hoff is that even before he completed his doctoral disserta­tion, at the young age of 22, he pub­lished at his own cost an 11-page pamphlet titled The Arrangement of the Atoms in Space in which he made an innovative suggestion. He proposed a three-dimension­al structure of an asymmetrical tet­rahedral carbon atom – the carbon atom being at the centre of a regu­lar tetrahedron with each of its four bonds/valence electrons pointed to­wards its corners. His stereochem­ical model of simple carbon com­pounds, he claimed, would explain the baffling cas­es of optical isomerism shown by some chemical com­pounds. However, till he published a German transla­tion of the earlier Dutch pamphlet three years later, his theory was for the most part ignored by the scientif­ic community. A leading chemist, Hermann Kolbe ac­tually wrote: “A Dr. J. H. van ‘t Hoff of the Veterinary School at Utrecht has no liking, apparently, for exact chemical investigation.” The Veterinary School was where van ‘t Hoff first started teaching.

Ironically, van ‘t Hoff’s theory went on to not on­ly emerge as one of the principle concepts of organic chemistry, it also paved the way for the introduction of the new science of stereochemistry.

Early life

Jacobus Henricus van ‘t Hoff was born in Rotterdam on August 30, 1852. His father, a physician, wasn’t too happy about his interest in becoming a chemist, think­ing his son would be better off following in his own footsteps and becoming a medical doctor.

But, going against his father’s wishes, van ‘t Hoff studied chemistry at the Delft Polytechnic Institute, completing the three-year course in two years, at the age of 19. He then studied mathematics for a year at the University of Leiden, and at 22, completed his doc­torate from Utrecht University, before starting work in 1876 as an academic in Utrecht, and later on teaching at the University of Amsterdam and Berlin University.

Besides science, van ‘t Hoff had a deep interest in philosophy and poetry, and was a lover of nature. Passionate about writing till the very end, he had even attempted writing poetry as a young man, his idol be­ing Lord Byron.

Van ‘t Hoff staunchly believed that the power of imagination plays a key role in the engagement of sci­entific work and making new discoveries. In his in­augural address after being appointed Professor of Chemistry, Mineralogy, and Geology at the University of Amsterdam in 1877 he said that his meticulous study of the lives of several outstanding scientists had revealed to him that all of them had a high level of imagination.

Contributions to science

Jacobus Henricus van ‘t Hoff’s postulation of the three-dimensional structure of molecules, led to the discovery of the three-dimensional structure of pro­teins and half a century later to the decod­ing of the double helix structure of the DNA molecule.

Though he started out as an organic chem­ist, later on, van ‘t Hoff’s work was mainly in the areas of theoretical and physical chemis­try. His exhaustive study of the thermody­namic properties of dilute solutions and ap­plication of the laws of thermodynamics to chemical equilibria led him to propose the concept of chemical affinity. Having success­fully used the principles of physics to calcu­late the speed of chemical reactions, he showed that so­lutions obey many of the same laws as gases. His in­novative research earned him not just the first Nobel Prize for chemistry, but also acknowledgement as one of the founders of physical chemistry. One of the rules of chemical thermodynamics that relates temperature changes to changes in equilibrium constant – the Van ‘t Hoff equation – has been named after him.

Elected a member of a number of reputed societ­ies and academies in the world, including the Royal Netherlands Academy of Sciences, van ‘t Hoff soon became famous as one of the outstanding research­ers of his time. He was also awarded honorary doctor­ates by world renowned universities such as Harvard, Yale, Victoria University, Manchester University, and University of Heidelberg. His extensive body of re­search work was published in the form of scientific pa­pers and books too.

Premature death at a productive age

Unfortunately, Jacobus Henricus van ‘t Hoff died on March 1, 1911, at the age of 58 after succumbing to pulmonary tuberculosis at Stiglitz, near Berlin. It was a sad day when death snatched away a great scientist while he was still actively involved in his research and writing work. Soon after his death, in a moving tribute to him, one of his former students, Professor Harry C. Jones of Johns Hopkins University, USA, wrote in the Popular Science Monthly: “The death of Van ‘t Hoff re­moves one of the leading men of science not only of this age, but of all time.”

References

  1. Nobel Media AB 2014: Jacobus H. van ‘t Hoff – Facts – www. nobelprize.org/nobel_prizes/
  2. Harry C. Jones: Jacobus Henricus van’t Hoff – American Philosophical Society, Vol. 50, No. 202, Oct. – Dec., 1911
  3. New World Encyclopaedia: Jacobus Henricus van ‘t Hoff, www.newworldencyclopedia.org

4. G. Nagendrappa: Jacobus Henricus van ‘t Hoff, A short bi­ographical sketch – Resonance, Journal of Science Education, Indian Academy of Sciences, May 2007.

Solving structures from powder diffraction data

Chemical Industry Digest
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Solving structures from powder diffraction data

Properties of materials are directly related to their crystal structure. Traditionally, crystal structures are solved using single crystal X-ray diffraction. However, many materials are only available as powders. The first structure solved from powder diffraction data was LiSbWO6 [Le Bail et al., 1988].

Since then, structure solution from powder data has developed into an established technique suitable for any crystalline material. The two key components for a successful structure solution from powder data are excellent data quality and proven optimized algorithms for data analysis.

Pan Analytical’s instrument portfolio supports a variety of measurement geometries from standard Bragg- Brentano (suitable for most inorganic materials), to the more advanced capillary geometry for compounds with low absorption. For each geometry the optical path is optimized to deliver the best data quality. The HighScore software suite offers a number of tools and algorithms guiding users through all the steps required for structure solution.

Solving structures from powder data can be done using the multi-purpose floorstanding X-ray diffractometer, Empyrean, or our newest addition – the compact X-ray diffractometer, Aeris.

www.panalytical.com/solving-structures

Hydrogen – In a class by itself!

Veena Patwardhan
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Hydrogen – In a class by itself!

Hydrogen. The most abundant and lightest element in the universe. Essential to life on earth as water. An important component of all organic compounds. Clearly, no matter if its atomic number is 1, hydrogen is certainly no inconsequential lightweight.

It’s true, it accounts for just 0.14% of the earth’s crust by weight, and its low density results in it being present in small quantities in the earth’s atmosphere. But, hydrogen covers almost three-fourths of the earth in the form of water. It is also present in countless carbon compounds in vegetable and animal matter and petroleum, and even accounts for two-thirds of the atoms that make up the human body. Coming back to the universe, hydrogen and helium together account for around 99.9% of all known matter in the universe. Hydrogen is the major component of all stars. During their lifetime, they keep fusing hydrogen into helium as they burn. Interestingly, while helium is classified as an unattractive, noble gas, hydrogen on the other hand is highly reactive, forming bonds with all kinds of elements.

Despite being pro­duced for several de­cades, it took a while for scientists to recognise hy­drogen. In 1671, Robert Boyle noted that gas bub­bles were formed when iron filings reacted with acid. Almost a century later, in 1766, Henry Cavendish first identified hydrogen as an element. He called the gas “inflammable air” and showed that unlike other flammable gases, water was formed when it was burned. In 1783, the French scien­tist Lavoisier gave this gas a name – hydrogène (from the Greek words ‘hydro genes’ meaning water forming), from which we have derived the English name hydrogen.

A look at the periodic table shows that hydrogen does not belong to any family of elements. Although a non-metal, it appears on the left side of the table, above the Group I alkali metal family, to which it clearly does not belong. It occupies a position marking it as the No. 1 element, in a class apart from the rest.

Significance of the discovery of hydrogen

In 1800, Nicholson and Carlisle, followed a few months later by Ritter, succeeded in decomposing water into hydrogen gas and oxygen gas through electrolysis. This led to electrolysis of water being used for the production of hydro­gen gas. The fact that we hardly have any natural hydrogen deposits made the production of hydrogen from abundantly available water assume even greater significance. But electrolysis of water being an energy-intensive process, nowadays hydrogen is mostly produced from fossil fu­els like natural gas.

Listed below are a few of the ways hydrogen has significantly impacted our lives.

Industrial applications

Today around two-thirds of the hydrogen produced in the world is used for manufacturing ammonia. Some other major applications include refining of fuels, pro­duction of fertilizers, nitric acid, and methanol, hydro­genation of unsaturated vegetable and animal oils and fats to make margarine and vegetable shortening, re­ducing aldehydes, fatty acids, and esters to the corre­sponding alcohols, reducing aromatic compounds to the corresponding saturated compounds, reducing ni­tro compounds to amines, reducing iron ores to metal­lic iron, and reducing oxides of tungsten and molybde­num to their metal states.

The aviation connection

Its density being lower than that of air and its ready availability made molecular hydrogen a good lifting gas for balloons and then later in the early twentieth century for the first lighter-than-air airships or zeppe­lins for transporting people by air. With this, the world was introduced to the first form of air travel.

The British airship R34 successfully completed the first non-stop trans-Atlantic flight in 1919. However, the airship Hindenburg bursting into flames mid-air while flying over New Jersey, USA in 1937, put an end to commercial air travel in hydrogen-filled air­ships. Soon, the noble gas helium, having the same lift­ing power as hydrogen, came to be used in airships in America, after which further developments in aviation led to the construction of heavier-than-air aircraft like aeroplanes. And the rest is history.

Rocket fuel

By the 1960s, almost two centu­ries after the first hydrogen inflat­ed balloon was launched, liquid hydrogen came to be used for fill­ing the fuel tanks of NASA rockets. Combustion of hydrogen with ox­ygen or fluorine became the pre­ferred choice for propelling nucle­ar-powered rockets into space.

 The Hydrogen bomb

Unlike the atomic bomb that uses the energy re­leased through the splitting or fission of a heavy atomic nucleus, the hydrogen bomb is a thermonuclear bomb that uses the energy released when two light atoms fuse to form a heavier nucleus. In the H-bomb, two at­oms of either of the two isotopes of hydrogen – deu­terium or tritium – fuse to form a heavier helium nu­cleus. The modern design for the hydrogen bomb was developed in America in 1951. But in 1961, the Soviet Union’s hydro­gen bomb – Tsar Bomba be­came the most powerful nu­clear weapon to be ever test­ed when it was dropped over the Mityushikha

Bay nuclear testing range north of the Arctic Circle. The bomb’s explosive power was so im­mense, its mushroom cloud was around 64 km high. That’s sev­en times the height of Mount Everest. And now North Korea is threatening to detonate one too.

Quantum mechanics

The hydrogen atom H and the hydrogen molecule H2 have the simplest structure possible. And so, they have been used for several decades, ever since the birth of quantum mechanics, as the ideal prototype of an atom and molecule respec­tively for critically evaluating various quantum me­chanical models.

Further advances by the first element

From the days when NASA first used hydrogen-ox­ygen fuel cells for firing space capsules and satellites, fuel cells have seen many more applications and un­dergone further development. One of them was the successfully created early form of the rechargeable bat­tery in the 1970s based on electrochemical storage of hydrogen in the form of a metal hydride, resulting in the introduction of nickel – metal hydride batteries for powering vehicles. This in turn led to a renewed inter­est in electric vehicles by almost all the major automo­bile manufacturers.

Also, since the last few decades, scientists and oth­er experts have been discussing ‘the hydrogen econo­my’ that could lead to hydrogen possibly replacing pe­troleum-based fuels. Hydrogen’s probable role in the future as a primary energy carrier for various purpos­es including transportation would certainly have sig­nificant advantages. For one, since hydrogen fuel cells generate electricity and water, they would produce ze­ro pollutants. Secondly, hydro­gen can be produced from mul­tiple sources such as natural gas, oil, other fossil sources, and through electrolysis of water. Hence, the possibility of feed­stock shortages too could be mi­nimised. However, there are a few hurdles to be overcome be­fore the general public can use hydrogen technologies safely and conveniently. For instance, hydrogen being highly flam­mable, safer systems for storing and transporting it would need to be developed. Currently, the industrial production of hydrogen from methane re­leases CO2 into the air. A way out would be develop­ing low-cost methods for splitting water using renew­able electrical resources like solar energy and wind as a clean way of mass producing hydrogen economically.

With even further advances in the applications of hydrogen, it perhaps won’t be too long before what Jules Verne had written in his novel The Mysterious Island way back in 1874 becomes a reality. One of Verne’s characters says, “I believe that water will one day be employed as fuel, that hydrogen and oxygen … will furnish an inexhaustible source of heat and light …” Prophetic words perhaps.

References

  1. Wojciech Grochala: First there was hydrogen – Nature Chemistry, 7, 264, 20 February, 2015
  2. Judith Klinman: Hydrogen – C&EN, Vol 81, Number 36, September 08, 2003
  3. Renewable Energy World: Hydrogen Energy – http://www. renewableenergyworld.com
  4. Science Learning Hub: Hydrogen – the number 1 element, https://www.sciencelearn.org.nz, 28 October 2009
  5. Laura Geggel: Why is hydrogen the most common element in the universe?- www.livescience.com, April 1, 2017
  6. Agata Blaszczak-Boxe: Facts about hydrogen – www.li­vescience.com, January 23, 2015
  7. Ashwin Kumar: Hydrogen Economy – A Future Where Hydrogen Is The Energy Currency, www.techstory.in, December 22, 2016
  8. www.sciencedaily.com : Low cost, scalable water split­ting fuels the future hydrogen economy, Source: Penn State Materials Research Institute, May 31, 2017
  9. Mitch Jacoby: Moving toward a hydrogen economy – C&EN, Vol 81, Number 23, June 9, 2003

Chemingineering | Green Fireworks

K. Sahasranaman (Independent Industry Consultant)
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Chemingineering | Green Fireworks

Fireworks provide that spectacular climax to many celebrations, be it religious, national days or sporting events. And it warms the cockles of many a heart. However, at the same time it releases noxious pollutants into the air, land and water. Recently, for this reason, the Supreme Court ruled against its sale in Delhi and NCR. In India too, like in other countries there is increasing awareness and activism against pollution due to the deleterious consequences of pollution on human health and the environment.

The solution lies in developing alternatives that are benign to the environment and living beings. Such shifts to greener alternatives have taken place in other segments of the chemical industry and in fireworks too, R&D for creating greener fireworks is taking place.

Trust chemistry to solve legacy issues.

No other application in the field of chemistry has such a positive association for the general population as fireworks” – Thomas Klapötke, University of Munich.

Display of fireworks elicits joy and awe among old and young. It cuts across every barrier of caste, colour, creed, race, religion and gender. Be it Deepavali in India, New Year in China, 4th of July in USA, or myriad sporting and religious festivals, fireworks are a spectacular metaphor to herald the new with pomp and grandeur. But like all good things of life, fireworks too come with a flip side. They spew out a cocktail of toxins into our environment, polluting our air, land and water. Only some of these deleterious effects manifest themselves immediately by choking our breath and watering our eyes. Other effects are silent, insidious and long-lasting.

Fireworks have taken the centerstage this Deepavali for the wrong reason, following the Supreme Court decision to ban their sale in Delhi and NCR. Some other states also followed suit. The ban was welcomed by many, especially those vulnerable to respiratory problems. But others saw this as an infringement on the traditional way of celebrating our festivals. The debate rages on social media. But on the day after Deepavali, as I write this, the reports are that Delhi’s air quality was not so different from previous years. So, while the ban may not have worked, it has definitely raised our awareness of a burning problem.

We have a hoary tradition of fireworks, dating back to the medieval period. Ancient kingdoms like Vijaynagara had master pyrotechnicians, whose skills have been recorded by historians. Competitive fireworks are the rule in temple festivals of Kerala, which resulted in the Puttingal tragedy last April killing 111 people. The modern fireworks industry in our country is more than 100 years old and is the second largest in the world with an annual turnover of `7000 crores and providing direct employment to more than 3 lakh people. Another 5 lakh people benefit indirectly through printing, packaging, distribution etc. These are not numbers to be trifled with.

DDT was the most popular insecticide to counter mosquitoes, but it was banned in early 70s, when evidence of its harmful effects on human population started mounting. Pesticide industry quickly introduced Pyrethroids, the mainstay of formulations today. Instead of banning pesticides, a harmful constituent was replaced by a benign one. Chemical industry is replete with such examples of green substitutes. Alternatives to TEL and DOP, for example. Benign substitutes are also available in fireworks industry.

The big initiative for this has come from US military. Militaries use flares for illumination and simulating battlefield explosion. The constituents of flare are very similar to that of fireworks. Flares used during military training leave behind toxic residues in civilian areas and US military spends a considerable amount of money in clean-up operations.

Major constituents of a firecracker are: fuel, oxidiser, ingredients to impart colour and special effects to the display and finally the binder. Once upon a time the oxidiser of choice was Potassium Chlorate, the chemical on the head of a matchstick, but now banned from use in fireworks because of its sensitivity to friction. But it continues to be illegally used because it is powerful and inexpensive. The Puttingal temple tragedy has been attributed to potassium chlorate. Perchlorates of potassium and ammonium are the widely used oxidizers today. But perchlorates are toxic to the human body, impairing the functioning of thyroid gland by interfering with Iodine absorption. Perchlorate contamination of the environment after July 4th celebrations in USA has been widely studied and have raised alarms. Perchlorate levels in water reportedly increase 1000 times after 4th July and it takes up to 90 days for the situation to reach normal. US military had similar experience after carrying out exercises. With authorities imposing stringent limits on allowable perchlorates in potable water, the military had to seek cleaner alternatives or fork out money for cleaning up sites. The quest turned up nitrogen rich cyclic compounds – Tetrazoles and Tetrazines.

Tetrazoles are synthetic heterocyclic compounds having a 5-member ring of four nitrogen atoms and one carbon atom. Tetrazines have 6-member ring with four Nitrogen atoms and two carbon atoms. The main feature of these molecules is their high heat of formation. Di-hydrazinotetrazine (DHT) has a heat of formation of 900 kcal/ kg. Though not releasing oxygen like perchlorates, they do release a large amount of energy when they break down. This kickstarts the combustion process. Also, the combustion product is not carbon dioxide but Nitrogen. Perchlorate free fireworks are a reality, powered by tetrazoles and tetrazines.

Perchlorates are not the only toxic fallout of firecrackers. The colour and special effects of fireworks are contributed by different metals. For example, green is due to barium, blue due to copper, red due to strontium etc. These metals are packed into the firecracker as a salt, usually chlorides or nitrates. While the cations – Ba, Cu, Sr etc contribute to the colour, the anions – chloride, carbonate, nitrate etc influence the flame temperature and hence the brightness and brilliance. Blue light, widely regarded as the most attractive, is also the most difficult to generate in pyrotechnics, since the copper compounds have to be heated to a specific temperature for the optimal shade of blue.

There is more to the chemistry of fireworks than what meets the eye. The colours formed when chlorine combines with various elements were first observed by Chertier in 1836. The blue of copper is not due to cuprous chloride, but cupric monochloride, an unstable molecule that exists only inside the flame. When potassium chlorate was substituted as the oxidiser, a supplemental source of chlorine was introduced into the firecracker. One cheap source is PVC. PVC combustion leads to formation of dioxins and other toxic compounds. So, elimination of chlorine is another important target in the development of “Green Fireworks”. Tests with copper iodide and copper bromide have yielded surprisingly good results. Chlorine-free formulations for emitting blue light are now available, but its widespread adoption is still some years away. Similar benign formulations are under development and trial for other colours too.

Much of today’s research and development of environment friendly fireworks is funded and spearheaded by US and is directed towards military applications. The fallout into civilian domain will take time. Cost will be a serious barrier. Indian fireworks industry has close links with Indian Army and has its own R&D centre in Sivakasi, Tamilnadu. A similar collaboration is thus possible in our country. Through development of “Green Fireworks”, chemistry, considered as the Mother Science, continues to enhance the quality of our lives. From a professional perspective, it is very satisfying to know that Chemical Industry has solutions to the problem of its own creation.

 

Readers’ responses may be sent to k.sahasranaman@gmail.com or chemindigest@gmail.com

Chemical Industry Digest- October 2017

Chemical Industry Digest
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Chemical Industry Digest- October 2017

Articles Covered in this issue:

Overview of Project Management
– A Collaborative Effort – Ashok Adhikary – Consultant
Efficient project management is important for timely completion of projects without cost overruns. This article provides an overview of the fundamentals of project management.

Towards Energy Efficiency in Fertilizer Production
R.G. Rajan, Dilip Deshmukh – Consultants
How the Indian fertiliser industry can become more energy efficient and many of the steps undertaken to make it energy efficient despite the fact that many of the Indian plants are of vintage are described against the backdrop of the latest scenario of the fertiliser industry in India.

Engineering Challenges for a Large Effluent Treatment Plant (ETP)
Nishu Simlote – Aker Solutions India
Large effluent treatment plants throw up many challenges and need to be treated as a project in itself. A case study of how Aker Solutions engineered such a plant and the challenges overcome.

Pipeline Flow Measuring Elements
S. Raghava Chari – Consultant
Orifice plates continue to be one of the common flow measuring elements. Accurate flow measurement saves money. Challenges faced in pipeline flow measurement and solutions provided are described.

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Chemical Industry Digest- September 2017

Chemical Industry Digest
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Chemical Industry Digest- September 2017

Articles covered in this issue:

Pumping Solids
-S L Abhyankar, Designer, Trainer, Consultant for Pumps, Valves, Pumping Systems
The author says that this is one of the most difficult exercises in pumping; the selection of the pumps and systems needs a good understanding of the solids and slurry to be pumped. The article provides important criteria to be considered.

Overview of Membrane Separations with insight on ceramic membranes
– Magan Khakharia, Microfilt India Pvt Ltd; Sachin Jadhav, Arvind Sikarwar, Bhaskar Thorat, ICT-Mumbai
The article provides a quick review of the developments in membrane separations, particularly on membrane materials with a brief on the latest introduction, ceramic membranes.

Centrifugal Pumps Characteristics Curves, System Resistance, Flow Problems and Solutions
-S Raghava Chari, Independent Consultant
While centrifugal pumps and systems are the workhorses of the industry, widely used, due to improper understanding of the problems that come up, many times expensive and ineffective solutions are proposed even by experienced engineers. The author proves this through many case studies and solutions

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Chemingineering | Lessons from Harvey

K. Sahasranaman (Independent Industry Consultant)
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Chemingineering | Lessons from Harvey

Climate patterns are changing all over the world. Severity of rains, droughts, hur­ricanes and typhoons is becoming far unprecedented than before with its occur­rences ominously threatening to hit with regularity, leaving death and destruction in its trail.

When it strikes regions with chemical industry concentrations and when the in­dustry is not geared to face up to it, as happened in Texas when hurricane Harvey stuck, the consequent chemical plant leakages, plant & equipment collapses, fire and explosions, all prove that there is an underestimation of the risk.

With such disasters only set to increase with global warming, Sahasranaman says that it is time to revisit the entire gamut of risk assessment, preparedness and emergency management by the chemical industry.

 

Hurricane Harvey is on course to join the dubi­ous list of disasters – head­ed by Bhopal, Flixbourough and Seveso – in the Chemical Industry. Not only did the category 4 hurri­cane cripple the refining and pet­rochemical hub of the world in Texas, but it also led to unprece­dented spillage and release of tox­ic and carcinogenic chemicals in­to the atmosphere. According to a report in New York Times, more than 2000 additional tonnes of chemicals were released from 46 industrial facilities during the week Aug 23- Aug 30. In addition, 14 sites holding toxic wastes were inundated. It is not that Harvey ar­rived unannounced. It was known for a week and its lethal potential was assessed at least 48 hours be­fore it struck Texas. Yet the chemi­cal plants in arguably the most in­dustrially advanced country of the globe were caught napping and their responses turned out woeful­ly inadequate. How did this hap­pen? A silver lining of every acci­dent is that it mandates us to raise the bar for safe practices. But for Flixbourough we would not be having Hazop; Responsible Care emerged out of Bhopal’s grave­yard. So, what do we learn from Harvey? I can quickly think of fol­lowing three lessons.

Revisiting risk assessment

Hurricanes like Katrina, Harvey and Irma can no longer be con­sidered as “acts of God” or Black Swan events. They are now the new normal and risk matrices need to be reconstructed. Weather ex­perts believe that hurricanes will get more frequent and more pow­erful as a fallout of global warm­ing. Chemical Industry needs to have plans in place to deal with them. Mathematically speaking, risk is a product of severity and likelihood. Likelihood of monster hurricanes like Harvey and Irma need to be ratcheted up by one or even two levels. This will alter our risk perception completely and will call for new safeguards and di­saster management plans.

Hazop is another risk manage­ment tool that needs a serious re­think. While a lot of attention gets lavished on the Inside Battery Limit (ISBL) plant during Hazop study, the Outside Battery Limit (OSBL) plant gets a short shrift. It is the OSBL that has the biggest foot print, usually several multi­ples of the ISBL. Again, it is the OSBL that holds most of the in­ventory in the plant. OSBL comes across as a poor unglamorous cousin of ISBL during design, engi­neering, personnel training, opera­tion and maintenance of a process plant. Even in education curricula it hardly gets the importance it de­serves. This approach and attitude needs to change.

Plants, especially those on sea coasts, can be asked to redo Hazops considering flooding and power outage as a cause. The worst credible consequence and safe­guards for this scenario should be placed in public domain. This will go a long way to improve the trust and confidence of the larger com­munity around the plant.

Revisiting plant inventory

Many chemical plants, especial­ly those built in the last millenni­um, carry far too much inventory. This excess baggage harks back to the pre-computer and pre-Internet era when supply chain manage­ment practices, as we know them today, were not prevalent. Online procurement now has done away with time consuming paperwork and approvals. RFID tracking of shipment has reduced uncertain­ties. Logistics planning, optimised shipping methods and routes, syn­ergy with suppliers etc helps the industry to prune down the inven­tory. Inventory reduction not only brings down the operating expens­es significantly, but is a giant step towards improving plant safety.

Consider what happened dur­ing Harvey. Nearly half a million gallons of gasoline spilled out from just two tanks owned by one of the largest pipeline operators. The ex­act cause of the leak is still under investigation. The pounding rain­fall also reportedly sank floating roofs of at least a dozen large stor­age tanks leading to leaks. At least two dozen storage tanks holding various refinery materials have col­lapsed spewing out carcinogen­ic aromatics – Benzene, Toluene and Xylene. API standards man­date that floating roofs should be designed to withstand a rain­fall of 250 mm in 24 hours. Harvey brought more than double that rain. Perhaps on hindsight, we need to redesign and strength­en floating roof tanks for a high­er rate of rainfall. It will most cer­tainly add to the cost, but would be a small price to pay for protect­ing the environment. Increased fre­quency of inspection, maintenance and structural audit of large stor­age tanks should also help. Clearly storage tanks bore the brunt of the storm surge. The damage would have been less with reduced inven­tory.

It must be mentioned here that some refineries were able to in­crease the levels in their stor­age tanks during the build-up to Harvey. This made the tanks less buoyant and less vulnerable to floating when the water swamped the tank farm.

Revisiting plant siting

Reasons for siting refineries on the coast are obvious. But they are sitting ducks for hurricanes. And if hurricanes and typhoons are like­ly to be more frequent we need a radical rethink. New refineries, not that many new ones are likely to be built, should be located inland. Existing refineries should consider erecting multiple barriers to avoid loss of containment.

One of the most horrific acci­dents in the aftermath of Harvey was the fire and explosion in a per­oxides plant. Peroxides are very unstable compounds and need to be stored under refrigeration. When the hurricane knocked out main power supply to the plant, the backup generators failed to start because they were submerged in water. Locating the generators at grade level was clearly a bad idea. But it appears bad only on hind­sight. The company had refriger­ated trucks to move out the perox­ides to a safer inland location. But by the time they decided to act, the roads were overwhelmed with wa­ter. The accident could have been totally avoided had the backup generators been located at a height beyond reasonable access of flood waters.

Post Script

Seismic zones are taken into ac­count while designing structures in a chemical plant. Now that hurri­canes are expected to become even more frequent than killer earth­quakes, we need an improved sys­tem and response in place from de­sign techniques to disaster man­agement. Ironically, the response to Harvey was hampered by indus­tries taking shelter under the fig-leaf of an anti-terrorism act, un­der which they were not obligat­ed to disclose to authorities the na­ture and quantity of chemicals they stored in their premises.

Readers’ responses may be sent to:  k.sahasranaman@gmail.com or chemindigest@gmail.com

Chemical Industry Digest- August 2017

Chemical Industry Digest
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Chemical Industry Digest- August 2017

Articles covered in this issue:

1. What to do when specialty chemical business gets commoditised ?…..
M.Sriram
Specialty chemicals is a customer focussed, high margin, low volume business. As applications increase it transits to be a commodity chemical – which business management is different to that of specialty chemicals. This article gives very useful tips on how to manage this commoditisation and the transition.

2. Instrumental Methods for estimation of sugars, HMF, furfural and levulinic acid formed during processing of lignocellulosic biomass…….
Sunil Joshi, Kiran V Pandare, CSIR-NCL, Pune
Producing chemicals from biomass or renewables is fast catching up. Processes of manufacture are getting commercialised. Analysis of some of the important platform chemicals produced in such processes is crucial for optimising yields of wanted products.This article details the instrumentation techniques to analyse sugars, furfural, HMF and other products produced in biomass processing.

3. A few latest introductions in Analytical Instrumentation (AI)…
Whether in Raman imaging, mass spectrometry or HPLC systems or in hybrid systems or take any area of AI, there are continuous developments and new Introductions taking place. Few such advances from leading manufacturers are described.

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