Catalytic aspects of industrial hydrogenations of nitriles

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F18%3A43916865" target="_blank" >RIV/60461373:22310/18:43916865 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.icct.cz/predchozi-konference/2018" target="_blank" >https://www.icct.cz/predchozi-konference/2018</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Catalytic aspects of industrial hydrogenations of nitriles

Popis výsledku v původním jazyce

Part: The possibilities of producing lower aliphatic dialkylamines and trialkylamines by nitrile hydrogenation in CSTR. The possibilities of producing lower aliphatic trialkylamines &amp; dialkylamines by nitrile hydrogenation are discussed and potential problems of such a production method are described and summarized. The paper is focused mainly on the possibility of manufacturing in continuous slurry stirred-tank reactors. Lower aliphatic dialkylamines can be produced commercially by hydrogenation of nitriles in these reactors, but it is not possible to produce trialkylamines, if sponge metal catalysts (Raney catalysts), incl. the modified types, are used. Trialkylamines are formed in significant quantities only if supported palladium catalysts are used. Nevertheless, this reaction path is unsuitable and inscrutable for the trialkylamine industrial production. In addition, the CSTR mode cannot be applicable for the nitrile hydrogenation catalyzed with Pd. Opposite to Raney-Ni, where nitrile hydrogenation follows the zero-order kinetics respect to the nitrile conversion, the kinetics of hydrogenation of nitriles on Pd is of an order higher than one. The reaction rate decreases progressively with the nitrile concentration in the reaction mixture and at nitrile concentrations lower than 1% it is in principle at zero. In many cases, the reaction stops before the 100% nitrile conversion is achieved. The steep decrease in the reaction rate along the nitrile conversion is caused by strong chemisorption of hydrogenation products to the Pd catalyst surface. This sorption is so strong that it causes complete deactivation of the catalyst. The loss of activity is not permanent, by washing the catalyst with a suitable solvent, it is possible to remove the strongly absorbed amines from its surface and renew partially its hydrogenation activity. Although the supported Pd catalysts are highly active for hydrogenation of unsaturated hydrocarbons at low temperatures already, their specific activity to nitrile hydrogenation is, by contrast, very low. In the nitrile hydrogenation, Pd is far less active than Ni.

Název v anglickém jazyce

Catalytic aspects of industrial hydrogenations of nitriles

Popis výsledku anglicky

Part: The possibilities of producing lower aliphatic dialkylamines and trialkylamines by nitrile hydrogenation in CSTR. The possibilities of producing lower aliphatic trialkylamines &amp; dialkylamines by nitrile hydrogenation are discussed and potential problems of such a production method are described and summarized. The paper is focused mainly on the possibility of manufacturing in continuous slurry stirred-tank reactors. Lower aliphatic dialkylamines can be produced commercially by hydrogenation of nitriles in these reactors, but it is not possible to produce trialkylamines, if sponge metal catalysts (Raney catalysts), incl. the modified types, are used. Trialkylamines are formed in significant quantities only if supported palladium catalysts are used. Nevertheless, this reaction path is unsuitable and inscrutable for the trialkylamine industrial production. In addition, the CSTR mode cannot be applicable for the nitrile hydrogenation catalyzed with Pd. Opposite to Raney-Ni, where nitrile hydrogenation follows the zero-order kinetics respect to the nitrile conversion, the kinetics of hydrogenation of nitriles on Pd is of an order higher than one. The reaction rate decreases progressively with the nitrile concentration in the reaction mixture and at nitrile concentrations lower than 1% it is in principle at zero. In many cases, the reaction stops before the 100% nitrile conversion is achieved. The steep decrease in the reaction rate along the nitrile conversion is caused by strong chemisorption of hydrogenation products to the Pd catalyst surface. This sorption is so strong that it causes complete deactivation of the catalyst. The loss of activity is not permanent, by washing the catalyst with a suitable solvent, it is possible to remove the strongly absorbed amines from its surface and renew partially its hydrogenation activity. Although the supported Pd catalysts are highly active for hydrogenation of unsaturated hydrocarbons at low temperatures already, their specific activity to nitrile hydrogenation is, by contrast, very low. In the nitrile hydrogenation, Pd is far less active than Ni.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20402 - Chemical process engineering

Projekt

<a href="/cs/project/LO1613" target="_blank" >LO1613: Výzkum nových materiálů pro chemický průmysl</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

PROCEEDINGS of the 6th International Conference on Chemical Technology

ISBN

978-80-86238-77-7

ISSN

2336-8128

e-ISSN

neuvedeno

Počet stran výsledku

5

Strana od-do

314-318

Název nakladatele

Česká společnost průmyslové chemie (ČSPCH)

Místo vydání

Praha

Místo konání akce

Mikulov

Datum konání akce

16. 4. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000461293800058