Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  hydrogenolysis
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
PL
Porównano przebieg hydrogenolizy w środowisku rozpuszczalnika protonowego, będącego źródłem wodoru in situ z hydrogenolizą w obecności wodoru cząsteczkowego. Jako źródło wodoru in situ zastosowano 1- i 2-propanol. Hydrogenolizy wodorem in situ wykonywano dwiema metodami: ciśnieniowo – stosując atmosferę gazu obojętnego (azotu) oraz bezciśnieniowo – bez wprowadzania wodoru cząsteczkowego i gazu obojętnego.
EN
The comparison of the course of hydrogenolysis performed in protic solvent as a source of hydrogen in situ with hydrogenolysis carried out in the presence of molecular hydrogen was made. As a donor of hydrogen molecule 1- and 2-propanol were used. Hydrogenolyses with hydrogen generated in situ were conducted using two methods: under inert gas pressure (nitrogen) and pressureless – in the absence of inert gas and molecular hydrogen.
EN
High activity of copper based catalysts for C-O bond hydro-dehydrogenation and their poor activity for C-C bond cleavage1 have prompted an attempt to apply such catalysts in the hydrogenolysis of glycerol to 1,2- and 1,3-propanediol. In the present study the infl uence of hydrogen reduction time of the Cu/ Al2O3 and CuCr2O4 copper catalysts on glycerol conversion and selectivity of transformation to propanediols and by-products was studied. At fi rst a general comparison was made between the commercial catalysts and those prepared by the co-precipitation method. As better results were obtained in the presence of catalysts prepared by co-precipitation, they were selected for further detailed studies of the influence of reduction time. For both prepared catalysts Cu/Al2O3 and CuCr2O4 the reduction time of 8 h was optimal. In the presence of Cu/Al2O3 catalyst the conversion of glycerol was 59.0%, selectivity of transformation to 1,2-propanediol 77.4% and selectivity to 1,3-propanediol 1.9%. In the presence of CuCr2O4 the glycerol conversion was 30.3% and selectivity to 1,2-propanediol 67.3%.
EN
The catalytic properties of supported copper silica prepared by ion-exchange method (denoted as Cu/SiO2-IE) were investigated for the hydrogenolysis of glycerol in a fixed-bed tubular reactor. Compared with the Cu/SiO2 catalyst prepared by wet impregnation and sol-gel methods, Cu/SiO2-IE shows very high activity (99.6 percent conversion of glycerol) and selectivity (86.4 percent to 1,2-propanediol) at 523 K and under hydrogen pressure of 4.0 MPa. The main reason for its good performance in the title reaction may be assigned to the co-existence of two types of active centers, which are the highly dispersed metallic copper and copper ions, on the Cu/SiO2-IE catalysts.
PL
W pracy przedstawiono ocenę DMF jako perspektywicznego biopaliwa drugiej generacji. Omówiono jego właściwości chemiczne oraz możliwości surowcowe do jego wytwarzania. Przedstawiono również technologię wytwarzania DMF wraz z oceną możliwości zastosowania DMF we współczesnych silnikach spalinowych.
EN
The paper presents DMF estimation as a perspective second generation biofuel. There was disscused chemical properties and raw material possibilities. There was also presented a DMF production technology and its estimation of application possibilities in modern combustion engine.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.