Wyniki wyszukiwania - BazTech

1

Domieszkowane katalizatory kobaltowo-molibdenowe do syntezy amoniaku

Nadziejko Marlena, Adamski Paweł, Moszyński Dariusz

Przemysł Chemiczny

|

2020

|

T. 99, nr 10

1454--1458

PL

Zbadano katalizatory kobaltowo-molibdenowe stanowiące alternatywę dla katalizatorów żelazowych do syntezy amoniaku. Określono wpływ stężenia związków cezu, chromu oraz potasu, zastosowanych jako promotory, na zawartość faz krystalicznych azotków kobaltu i molibdenu (Co₂Mo₃N i Co₃Mo₃N) w katalizatorach przed i po procesie syntezy amoniaku. Ustalono także wpływ stężenia promotorów na takie właściwości katalizatorów, jak aktywność katalityczna i wielkość powierzchni.

EN

The Co-Mo oxide catalyst was modified with Ce, Cr and K ions by an impregnation method and treated with NH₃ at 700°C for 5 h. The contents of promoters, phase compn. and sp. surface of catalyst were detd. The catalyst were used for NH₃ synthesis at 400°C and 10 MPa and then subjected to aging at 650°C for 12 h in order to assess their thermal stability. The effect of promoter concn. on the activity, sp. surface and content of cryst. phases of Co₂ Mo₃N and Co₃Mo₃N were detd.

2

Technologia wytwarzania wyrobów tkaninowo--gumowych

Rajkiewicz M., Mikołajska A.

Elastomery

|

2006

|

T. 10, nr 6

43-47

PL

Wyroby tkaninowo-gumowe mają strategiczne znaczenie dla gospodarki. W wyrobach tkaninowo-gumowych, w których tkaniny gumowane stanowią główny element, wykorzystuje się właściwości tkaniny oraz odporność powłoki gumowej na warunki pracy i wpływ środowiska. O trwałości tych wyrobów na równi z właściwościami obu łączonych materiałów decyduje adhezja między nimi. W praktyce produkcyjnej i w pracach badawczych zwiększenie wytrzymałości połączenia włókien chemicznych z elastomerami osiąga się stosując impregnację adhezyjną kordów lub tkanin w kąpielach RFL. Nowszym, mniej kłopotliwym i rozwijanym ostatnio sposobem jest wprowadzenie bezpośrednio do mieszanki kauczukowej specjalnych substancji zwanych promotorami adhezji. Instytut Przemysłu Gumowego w 2004 roku uzyskał patent nr 187854 na "Bezimpregnacyjny sposób łączenia materiałów tekstylnych z gumą".

EN

Textile-rubber goods are of strategic importance for the country economy. The textile-rubber goods, in which textiles are a main constituent, are designed to take advantage of textile reinforcing properties and resistance of rubber coating to operating and environmental conditions. Besides properties of both bonded materials the durability of these goods is determined to the same degree by adhesion between both materials. In production processes and research projects increase of bond strength between synthetic fibres and elastomers is usually achieved by impregnation of cords or textiles in the RFL bath. A modern, less awkward and recently developed way is incorporation into rubber compounds special chemicals called adhesion promoters. In 2004 Instytut Przemysłu Gumowego (Rubber Research Institute) was granted the patent No. 187856 ,,Method of bonding textiles to rubber without impregnation ".

3

The state of studies on iron catalyst for the ammonia synthesis

Arabczyk W.

Polish Journal of Chemical Technology

|

2005

|

Vol. 7, nr 3

8-17

EN

The past and present research of the iron catalyst for ammonia synthesis carried out in the Institute of Chemical and Environment Engineering of Szczecin University of Technology has been described. The role of promoters, especially alkali metals, has been explained. The structure of the surface of active iron catalyst has been proposed. The behavior of iron catalyst during the reaction of nitriding has also been shown.

4

Steam reforming of hydrocarbons - how can it be improved?

Borowiecki T., Ryczkowski J.

Polish Journal of Chemical Technology

|

2005

|

Vol. 7, nr 3

22-26

EN

In the present paper the main directions of improvement towards steam reforming of hydrocarbons are briefly indicated. The mentioned changes of improvement are collected into three leading paths: changes in the process organization (e.g., prereforming, autothermal and integrated reforming), changes in the reactors construction and the catalysts' modifications. The selected examples describing the discussed changes are provided in the text.

5

On the reduction of iron catalyst for ammonia synthesis

Arabczyk W., Moszyński D., Jasińska I.

Polish Journal of Chemical Technology

|

2002

|

Vol. 4, nr 4

1-5

EN

The influence of the potassium concentration change on the surface area and active surface of an iron catalyst for ammonia synthesis was studied. The removal of potassium leads to the increase of the surface area, while potassium addition gives rise to the decrease of the surface area which is accompanied by the fourfold increase of the active area. The mechanism of the reduction of iron catalyst was proposed. A special attention was paid to the role of promoters. First, the reduction of iron oxides leads to the formation of porous structure with a well-developed surface area. It is due to the formation of aluminium and calcium oxides film on the iron surface. This structure thanks to high oxygen content balances the iron surface tension which results in a high surface area. This process is followed by potassium diffusion from the grain boundaries to the crystallite surface. Potassium atoms are more favoured to form stable structure on the iron surface than aluminium and calcium. It leads to the formation of K+O film on the iron surface. Because K+O structure requires less oxygen atoms part of the iron surface is freed. The balance between chemical bonds and surface energy is disturbed and the surface area is lowered. At the same time some number of free adsorption sites are formed giving rise to the increase of active surface and the activation of a catalyst.