Eugene Houdry

{{short description|French mechanical engineer (1892–1962)}} {{Infobox scientist | name = Eugène Jules Houdry | image = Eugene Houdry Fench Passport photo 1919 98-16 Personal 001.tif | caption = Eugene Houdry, 1919 | birth_date = {{birth date|mf=yes|1892|04|18}} | birth_place = Domont, France | death_date = {{death date and age|mf=yes|1962|07|18|1892|04|18}} | death_place = Upper Darby Township, Pennsylvania | residence = | field = Engineering | known_for = Catalytic cracking | work_institutions = Socony Vacuum, Sun Oil, Oxy-Catalyst | alma_mater = École Nationale Supérieure d'Arts et Métiers in Chalons-sur-Marne |doctoral_advisor = | awards = Croix de Guerre, Chevalier of the Legion of Honor, Perkin Medal }}

'''Eugène Jules Houdry''' (Domont, France, April 18, 1892 – Upper Darby Township, Pennsylvania, July 18, 1962)<ref name="Vassiliou"/> was a mechanical engineer who graduated from École Nationale Supérieure d'Arts et Métiers in 1911.

Houdry served as a lieutenant in a tank company in the French Army during World War One, receiving the French Legion of Honour. He helped innovate catalytic cracking of petroleum feed stocks,<ref name="Landmark"/><ref name="Copp">{{cite book |last1=Copp |first1=Newton |last2=Zanella |first2=Andrew |title=Discovery, innovation, and risk : case studies in science and technology. |date=1993 |publisher=MIT Press |location=Cambridge, Mass. |isbn=978-0262531115 |edition=2. print. |url=https://archive.org/details/discoveryinnovat0000copp |url-access=registration |page=[https://archive.org/details/discoveryinnovat0000copp/page/181 181] |accessdate=11 July 2018}}</ref><ref name="Jewkes">{{cite book |last1=Jewkes |first1=John |last2=Sawers |first2=David |last3=Richard |first3=Richard |title=The sources of invention |date=1969 |publisher=W.W. Norton |location=New York |isbn=9780393005028 |pages=[https://archive.org/details/sourcesofinventi0000jewk_x4v4/page/235 235]–237 |edition=2nd |url=https://archive.org/details/sourcesofinventi0000jewk_x4v4 |url-access=registration |accessdate=11 July 2018}}</ref><ref name="Zecchina">{{cite book |last1=Zecchina |first1=Adriano |last2=Califano |first2=Salvatore |title=The Development of Catalysis: A History of Key Processes and Personas in Catalytic Science and Technology |date=April 3, 2017 |publisher=Wiley |isbn=978-1119181262 |edition=1st |url=https://books.google.com/books?id=mSs8DgAAQBAJ&pg=PA85 |accessdate=11 July 2018}}</ref> for which he received the Perkin Medal among others.<ref name="Landmark"/>

==Life== Eugene Jules Houdry was born on April 18, 1892, at Domont, France near Paris. His parents were Jules Houdry and Émilie Thias Jule Lemaire. His father owned a successful business that manufactured structural steel.<ref name="Encyclopedia">{{cite book |last=Smith|first=John K.|title=Complete Dictionary of Scientific Biography |chapter-url=https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/houdry-eugene-jules |website=Encyclopedia.com|publisher=Charles Scribner's Sons|date=2008|chapter=Houdry, Eugène Jules |accessdate=19 July 2018}}</ref> <ref name="Jewkes"/>

Houdry studied mechanical engineering at the École des arts et métiers in the Paris suburb of Chalons-sur-Marne.<ref name="Landmark"/> He graduated first in his class<ref name="Landmark"/> in 1911,<ref name="Zecchina"/> earning a gold medal from the French government as the highest-ranking scholar in his class.<ref name="Landmark"/> He also captained his school's soccer team, winning the national championship of France in 1910.<ref name="Encyclopedia"/> After graduation, Houdry joined his father's steel-making business as an engineer.<ref name="Encyclopedia"/><ref name="Landmark"/>

===World War I=== During World War I, Houdry served in the French army, first as a lieutenant in the field artillery. He later transferred to the army's new tank corps and took part in the first French battle to use tanks,<ref name="Encyclopedia"/> part of the Nivelle Offensive which began on April 16, 1917.<ref name="Zabecki">{{cite book |last1=Zabecki |first1=David T. |title=Germany at war : 400 years of military history. |date=2014 |publisher=Abc-Clio |location=[S.l.] |isbn=9781598849806 |page=28 |url=https://books.google.com/books?id=rCWMBQAAQBAJ&pg=PA28 |accessdate=19 July 2018}}</ref> Houdry was seriously wounded in the Juvincourt sector during the Second Battle of the Aisne. Most of the French tanks used in this offensive were rendered inoperable and very few reached their objective.<ref name="Observation">{{cite web |title=The Nivelle Offensive: Second Battle of the Aisne (16 April – 9 May 1917) |url=http://www.theobservationpost.com/blog/?p=1897 |website=The Observation Post|date=16 April 2017 |accessdate=19 July 2018}}</ref><ref name="Rieth">{{cite book |last1=Rieth |first1=John K. |title=Imperial Germany's "Iron Regiment" of the First World War |date=2014 |publisher=Badgley Publishing Company |location=Canal Winchester, OH |isbn=978-0692301203 |edition=2nd |url=https://books.google.com/books?id=Ne85DwAAQBAJ&pg=PT202}}</ref><ref name="Gale">{{cite book |last1=Gale |first1=Tim |title=The French army's tank force and armoured warfare in the Great War : the Artillerie Spéciale |date=2013 |publisher=Ashgate |location=Burlington, VT |isbn=978-1409466611}}</ref> Houdry was injured while trying to organize repairs to the damaged tanks under heavy fire.<ref name="Oblad"/> He was later awarded the Croix de Guerre and was made a Chevalier of the Legion of Honor.<ref>{{cite web |title='Visionary Veterans' Exhibit Honors National Inventors Hall Of Fame Inductees Who Served In WWI |url=https://www.warhistoryonline.com/press-releases/visionary-veterans-exhibit-honors-national-inventors-hall-fame-inductees-served-wwi.html |website=War History Online |accessdate=10 July 2018|date=November 7, 2017}}</ref><ref name="Landmark"/>

===Between the wars=== After the war, Houdry returned to his father's company, Houdry et Fils. His hobby was road racing, and he drove a Bugatti racing car.<ref name="Biography">{{cite web|title=Eugene Houdry|url=https://www.sciencehistory.org/historical-profile/eugene-houdry|website=Science History Institute|accessdate=20 March 2018|date=June 2016}}</ref><ref name=Bowden>{{cite book|last1=Bowden|first1=Mary Ellen|title=Chemical achievers : the human face of the chemical sciences|url=https://archive.org/details/chemicalachiever0000bowd|url-access=registration|date=1997|publisher=Chemical Heritage Foundation|location=Philadelphia, PA|isbn=9780941901123|chapter=Eugene Houdry|pages=[https://archive.org/details/chemicalachiever0000bowd/page/122 122–123]}}</ref> Through the family steel company, he met automobile and parts manufacturers, and engineers who were trying to improve engine performance. This sparked Houdry's interest in high-performance fuels. Recognizing that the key to better performance of automobiles and airplanes was the improvement of fuels, he became interested in the catalytic processes used to convert coal and lignite to gasoline.<ref name="Moseley">{{cite journal |last1=Moseley |first1=Charles G. |title=Eugene Houdry, catalytic cracking and World War II aviation gasoline |journal=Journal of Chemical Education |date=August 1984 |volume=61 |issue=8 |pages=655 |doi=10.1021/ed061p655 |bibcode=1984JChEd..61..655M |language=EN |issn=0021-9584}}</ref><ref name="Copp"/><ref name="Jewkes"/><ref name="Encyclopedia"/> In 1922, Houdry visited the United States, where he saw the Indianapolis 500, and toured a Ford Motor plant in Detroit, Michigan.<ref name="Encyclopedia"/>

On July 3, 1922, Eugene Houdry married Geneviève Marie Quilleret.<ref name="Histoire">{{cite web |title=1925 : M.G.R. Eugène Houdry · Histoire de Lucien |url=http://babethhistoires.unblog.fr/2015/07/02/1925-m-g-r-eugene-houdry/ |website=Histoire de Lucien |accessdate=19 July 2018}}</ref><ref name="Encyclopedia"/> The couple were to have two sons, Jacques<ref name="Jacques">{{cite news |title=Jacques H. Houdry |url=http://www.legacy.com/obituaries/mainlinemedianews/obituary.aspx?n=jacques-h-houdry&pid=155931948 |website=Main Line Media News |date=February 18, 2012 |accessdate=19 July 2018}}</ref> and Pierre.<ref name="Pierre">{{cite news |title=Deaths HOUDRY, PIERRE D. |url=https://www.nytimes.com/2004/03/26/classified/paid-notice-deaths-houdry-pierre-d.html |accessdate=19 July 2018 |work=The New York Times |date=March 26, 2004}}</ref>

Following the war, there was an increasing demand for motor fuel. It was feared that petroleum stocks, which were being processed using thermal cracking, would not meet the demand. Scientists sought new ways to produce liquid fuels from bitumen, coal, and lignite. In Italy, a French pharmacist named E. A. Prudhomme was the principal scientist of a group experimenting with promising techniques for water-gas synthesis.<ref name="Brill"/>

In 1920 Houdry had established a manufacturing company for steel springs and chains, the Manufacture Générale des Ressorts (M.G.R.), in Beauchamp, Seine-et-Oise.<ref name="Lucien">{{cite web |title= Vie de Lucien |url=http://babethhistoires.unblog.fr/category/vie-de-lucien/ |website=Histoire de Lucien |accessdate=24 July 2018}}</ref> In 1922, Houdry convinced Prudhomme to join him at Beauchamp and set up a fuel research laboratory under Houdry's management.<ref name="Landmark"/> In 1924 Houdry incorporated the Société Anonyme Française pour la Fabrication d'Essences et Pétroles.<ref name="Encyclopedia"/> By 1927, they had developed a 3-step process for a lignite-based fuel, using desulfurizing and catalysts for cracking.<ref name="Brill"/>

{{blockquote|"During the lignite-to-gasoline process, the solid lignite was initially broken down by heat to produce viscous hydrocarbon oil and tars, then the oil was further converted by an added catalyst to produce lower-boiling hydrocarbons similar to the gasoline fraction derived from petroleum."<ref name="Landmark"/>}}

A major problem with Prudhomme's process was that the catalysts could not be reclaimed.<ref name="Jewkes"/> The surface of the catalyst quickly became coated with a layer of carbon or coke and became less effective.<ref name="Encyclopedia"/> There was already some work in this problem, e. g. in a 1917 patent alumina was suggested as a catalyst for oil cracking.<ref>{{US patent|1330844A}}</ref> By 1927, having tested hundreds of catalysts,<ref name="Biography"/> Houdry had focused on naturally occurring Fuller's earth.<ref name="Brachmann">{{cite news |last1=Brachmann |first1=Steve |title=Evolution of Auto Exhaust Catalysts: Dr. Haren Gandhi invents three-way catalysts for cleaner exhaust |url=http://www.ipwatchdog.com/2017/04/07/evolution-of-auto-exhaust-catalysts-dr-haren-gandhi-invents-three-way-catalysts-for-cleaner-exhaust/id=81668/ |accessdate=24 July 2018 |work=IPWatchdog |date=April 7, 2017}}</ref><ref name="Xiao"/> He determined that it could be processed to obtain a purer aluminosilicate catalyst,<ref name="Xiao">{{cite book |last1=Xiao |first1=Feng-Shou |last2=Meng |first2=Xiangju |title=Zeolites in sustainable chemistry : synthesis, characterization and catalytic applications |date=2016 |publisher=Springer |location=Berlin |isbn=978-3-662-47395-5 |page=273 |url=https://books.google.com/books?id=4AuhCgAAQBAJ&pg=PA273 |accessdate=24 July 2018}}</ref><ref name="Thayer">{{cite journal |last1=Thayer |first1=Ann M. |title=The Catalysis Chronicles |journal=Chemical & Engineering News |date=September 9, 2013 |volume=91 |issue=36 |pages=64–68 |doi=10.1021/cen-09136-cover8 |url=https://cen.acs.org/articles/91/i36/Catalysis-Chronicles.html |accessdate=24 July 2018|url-access=subscription }}</ref> which could be successfully regenerated under certain conditions.<ref name="Zecchina"/>

By 1927 Houdry was able to get initial support from the French government to build a pilot gas plant<ref name="Encyclopedia"/> in Saint-Julien-de-Peyrolas. It began production in June 1929, and ceased production in 1930.<ref>{{cite web |title=Mine et distillerie de lignite de Saint-Julien-de-Peyrolas, usine de produits chimiques (usine de fabrication d'essence synthétique) Houdry |url=http://www.actuacity.com/saint-paulet-de-caisson_30130/monuments/ |website=Saint-Paulet-de-Caisson |accessdate=24 July 2018}}</ref> Although the process was successfully demonstrated, it was expensive and yields were lower than predicted.<ref name="Encyclopedia"/> Houdry was unable to get ongoing support from the French government or from French companies to produce the new fuel.<ref name="Brill">{{cite book |last1=Faragher |first1=W. F. |last2=Noll |first2=H. D. |last3=Bland |first3=R. E. |editor-last=Brill |editor-first=E. J. |title=Third World Petroleum Congress, The Hague, 1951: Proceedings |volume=1-2 |date=1951 |publisher=E. J. Brill |location=Leiden |pages=138–156 |url=https://books.google.com/books?id=S74UAAAAIAAJ&pg=PA139 |accessdate=24 July 2018}}</ref><ref name="Landmark"/> Approaches to the French Saint-Gobain Company and the Anglo-Iranian Oil Company were unsuccessful.<ref name="Zecchina"/>

===Moving to America=== Unable to get backing for new fuels in France, Houdry turned to the United States, where his efforts were more successful. Houdry moved from France to America in 1930. He settled in Paulsboro, New Jersey, where he formed the Houdry Process Corporation in 1931.<ref name="Landmark"/><ref name="NIHF">{{cite web |title=Eugene Houdry |url=http://www.invent.org/honor/inductees/inductee-detail/?IID=82 |website=National Inventor's Hall of Fame |accessdate=10 July 2018}}</ref>

As discussed in more detail below (See ''Inventions''), Houdry worked with the American oil companies, Socony Vacuum and Sun Oil to develop pilot plants for improved fuels.<ref name="Jewkes"/> The first full-scale "Houdry unit" was opened in Marcus Hook in 1937. By 1942, 14 Houdry fixed-bed catalytic units were producing high-octane aviation fuel for the armed forces.<ref name="Moseley"/><ref name="Biography"/><ref name="Copp"/>

===World War II activities=== During World War II, Houdry strongly opposed the government of Vichy France under Marshal Philippe Pétain and its collaboration with Germany. As president of the U.S. chapter of France Forever (where his brother-in-law, Pierre Quilleret,<ref>{{Cite book |last=Jochem |first=Jean |url=https://books.google.com/books?id=fC_xAAAAMAAJ&q=Pierre%20Quilleret |title=Français libre et pétrolier: récit |date=1997 |publisher=Editions La Bruyère |isbn=978-2-84014-309-3 |page=80| language=fr}}</ref> was also one of the founders), Houdry vocally and publicly criticized Petain, stating that he did not speak for the French people.<ref name="NYT1941">{{cite news |title=FRENCH GROUP HERE CHALLENGES PETAIN; His Talk of Collaboration With Nazis Not Voice of the People, E.J. Houdry Says NATION SEEN FOR BRITAIN France Forever Organization Quotes Letter Referring to Marshal as 'Queen Mother' |url=https://www.nytimes.com/1941/01/21/archives/french-group-here-challenges-petain-his-talk-of-collaboration-with.html |accessdate=19 July 2018 |work=The New York Times |date=January 21, 1941}}</ref> Houdry supported General Charles de Gaulle, leader of the provisional French government in exile.<ref name="Landmark"/>

On May 3, 1941, the Vichy government revoked Houdry's French citizenship.<ref name="Zecchina"/><ref name="Landmark"/> In January 1942, Houdry was granted citizenship in the United States.<ref name="Zecchina"/><ref name="Landmark"/> Both of Houdry's sons, Jacques and Pierre, served in World War II as part of the United States Army.<ref name="Jacques"/><ref name="Pierre"/> Pierre served in field artillery and chemical warfare units. Eugene Houdry supported the war effort through the development of industrial processes and fuels.<ref name="Pierre"/>

==Inventions== ===Coal to gasoline=== Houdry originally focused on using lignite (brown coal) as a feedstock, but switched to using heavy liquid tars.<ref name="Jewkes"/> Although others had experimented with catalysts for this purpose, they were stymied by the fact that the catalyst ceased to work after a time. Houdry diagnosed the nature of the problem and developed a method to regenerate the catalyst.<ref name="Xiao"/><ref name="Brachmann"/>

The first Houdry unit was built at Sun Oil's Marcus Hook, PA oil refinery in 1937. Many more units were built by the 1940s and were instrumental for US wartime aviation gasoline production.<ref name="Biography"/><ref name="Carey">{{cite news |last1=Carey |first1=Kathleen E. |title=A look behind the scenes at the Sunoco refinery in Marcus Hook |url=http://www.delcotimes.com/article/DC/20101212/NEWS/312129989 |accessdate=24 July 2018 |work=The Delco Times |date=December 12, 2010}}</ref> Among others at the company who helped Houdry in the development of the catalytic cracking process was Alex Golden Oblad.<ref name="Oblad">{{cite book |last1=Oblad |first1=Alex G. |editor-first=Burtron H. |editor-last=Davis |editor-first2=William P. Jr |editor-last2=Hettinger |chapter=The Contributions of Eugene J. Houdry to the Development of Catalytic Cracking |title=Heterogeneous Catalysis: Selected American Histories |series=ACS Symposium |volume= 222 |date=1983 |pages=61–75 |doi=10.1021/bk-1983-0222.ch006 |isbn=9780841207783}}</ref>

The process was further developed by two MIT engineers, Warren K. Lewis and Edwin R. Gilliland, under contract to Standard Oil of New Jersey, now ExxonMobil. They developed the process into fluid catalytic cracking, which solved the problem of having to shut down the process to burn the coke off the catalyst by using a continuously circulating fluidized catalyst made of a fine zeolite powder. This process is still in widespread use, especially in the US where gasoline is in high demand compared to other refined products.<ref name="Smith">{{cite book |last1=Bowden |first1=Mary Ellen |last2=Smith |first2=John Kenly |title=American chemical enterprise : a perspective on 100 years of innovation to commemorate the centennial of the Society of Chemical Industry (American Section) |date=1994 |publisher=Chemical Heritage Foundation |location=Philadelphia |isbn=978-0941901130 |pages=[https://archive.org/details/americanchemical0000bowd/page/56 56]–58 |url=https://archive.org/details/americanchemical0000bowd|url-access=registration }}</ref><ref name="Zecchina"/>

Houdry later became interested in automotive catalysts, and the catalytic converter was one of approximately 100 patents that he received,<ref name="Encyclopedia"/><ref name="Brachmann"/> but nothing came of it until the 1970s because the tetraethyl lead that was still in use in the 1950s and 1960s poisoned the catalyst.<ref name="Brachmann"/><ref>{{cite web |title=Patent US2674521A: Catalytic converter for exhaust gases |url=https://patents.google.com/patent/US2674521A/en |website=Google Patents |accessdate=24 July 2018}}</ref>

===Butadiene=== Houdry also invented a catalytic process to produce butadiene from butane gas, which was formed during crude oil production. During World War II, butadiene was important to the production of synthetic rubber.<ref name="Landmark"/>

===Oxy-Catalyst=== thumb|upright|Houdry Auto Catalyst Patent 2742437 Following World War II, Houdry started the Oxy-Catalyst Company. Houdry was concerned with possible health risks relating to automobile and industrial air pollution. He built a generic catalytic converter capable of reducing carbon monoxide and unburned hydrocarbons from automobile exhausts. For his design, he received U.S. Patent 2,742,437 in 1956.<ref name="Landmark"/><ref name="Biography"/><ref>{{cite web |title=Catalytic structure and composition |url=https://patents.google.com/patent/US2742437 |website=Google Patents |accessdate=10 July 2018}}</ref> Catalytic converters eventually became standard equipment in American cars, following passage of the Clean Air Act, introduced by Edmund S. Muskie in 1970.<ref name="Weisskopf">{{cite news |last1=Weisskopf |first1=Michael |title=AUTO-POLLUTION DEBATE HAS RING OF THE PAST |url=https://www.washingtonpost.com/archive/politics/1990/03/26/auto-pollution-debate-has-ring-of-the-past/d1650ba3-2896-44fa-ac1b-4e28aca78674/ |accessdate=24 July 2018 |newspaper=The Washington Post |date=March 26, 1990}}</ref>

==Scientific recognition== Houdry's contributions to catalytic technology were recognized by numerous awards, including the Potts Medal of the Franklin Institute in 1948,<ref name="Potts">{{cite journal |title=Eugene J. Houdry |journal=Chemical & Engineering News |date=8 November 1948 |volume=26 |issue=45 |pages=3339 |doi=10.1021/cen-v026n045.p3339 }}</ref><ref>{{cite journal |title=Chemists Honored at Franklin Institute Medal Day |journal=Chemical & Engineering News |date=8 November 1948 |volume=26 |issue=45 |pages=3338–3339 |doi=10.1021/cen-v026n045.p3338 }}</ref> the Perkin Medal of the Society of Chemical Industry (American Section) in 1959,<ref name="Smith"/> the E. V. Murphree Award in Industrial and Engineering Chemistry of the American Chemical Society in 1962,<ref>{{cite web |title=E. V. Murphree Award in Industrial and Engineering Chemistry |url=https://www.acs.org/content/acs/en/funding-and-awards/awards/national/bytopic/e-v-murphree-award-in-industrial-and-engineering-chemistry.html |website=American Chemical Society |accessdate=24 July 2018}}</ref> and posthumous election to the National Inventors Hall of Fame in 1990.<ref>{{cite news |title='Visionary Veterans' Exhibit Honors National Inventors Hall Of Fame Inductees Who Served In WWI |url=https://www.warhistoryonline.com/american-civil-war/mysterious-death-stonewall-jackson-mm.html |accessdate=24 July 2018 |work=War history online |date=November 7, 2017}}</ref>

He was awarded honorary degrees from Pennsylvania Military College (Doctor of Science) in 1940 and Grove City College in 1943.<ref name="Landmark"/> In 1967, the North American Catalysis Society created the Eugene J. Houdry Award in Applied Catalysis, awarded in odd numbered years since 1971, to "recognize and encourage individual contributions in the field of catalysis with emphasis on the development of new and improved catalysts and processes representing outstanding advances in their useful application".<ref>{{cite web |title=Eugene J. Houdry Award in Applied Catalysis |url=http://nacatsoc.org/awards/houdry/8/ |website=North American Catalysis Society |accessdate=24 July 2018}}</ref>

On April 13, 1996, Houdry's work was recognized by the designation of a National Historic Chemical Landmark by the American Chemical Society at the site of the Sun Company (now Sunoco Logistics Partners L.P.) in Marcus Hook, Pennsylvania.<ref name="Landmark">{{Cite web|url=https://www.acs.org/content/dam/acsorg/education/whatischemistry/landmarks/houdry/the-houdry-process-catalytic-conversion-commemorative-booklet.pdf|title=A National Historic Chemical Landmark - The Houdry Process for Catalytic Cracking |date=April 13, 1996 |website=American Chemical Society |access-date=July 9, 2018}}</ref>

==Death== Houdry died on July 18, 1962, at Upper Darby Township, Pennsylvania at the age of 70.<ref name="Vassiliou">{{cite book |last1=Vassiliou |first1=M. S. |title=The A to Z of the petroleum industry |date=2009 |pages=240–241 |publisher=Scarecrow Press |location=Lanham, Md. |isbn=978-0810871533 |url=https://books.google.com/books?id=BdNjTbcB__0C&pg=PA241 |accessdate=10 July 2018}}</ref> He was survived by his sons and his wife, Genevieve Quilleret.<ref name="Landmark"/>

==References== {{reflist}}

==External links== *{{cite web |title=Eugene Houdry |url=http://www.invent.org/honor/inductees/inductee-detail/?IID=82 |website=National Inventor's Hall of Fame}} *{{Cite web|url=https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/houdry.html|title=Houdry Process for Catalytic Cracking - National Historic Chemical Landmark|website=American Chemical Society}}

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{{DEFAULTSORT:Houdry, Eugene}} Category:1892 births Category:1962 deaths Category:People from Domont Category:French mechanical engineers Category:American chemical engineers Category:American mechanical engineers Category:History of the chemical industry Category:Howard N. Potts Medal recipients Category:Arts et Métiers ParisTech alumni Category:French emigrants to the United States Category:20th-century American chemists Category:20th-century American engineers