C2h2 was only found in very small quantities 1 to

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: gher temperatures the reaction was first started at the lower temperature and than increased. This procedure was chosen to avoid possible early reduction of the catalyst by the reaction. 4. Results and discussion - catalytic partial oxidation of propane 118 ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp After the maximum reaction temperature was reached, the temperature was decreased to see if any indications of such a reduction process at higher reaction temperatures were visible. No signs of reduction of the unreduced Ni containing catalyst were observed in its temperature cycle, as the catalyst performance was almost unchanged. 4.2.2. The active catalyst (reduced Ni10C900) Over the reduced catalyst Ni10C900 very different results were observed compared to the other cases. Here regardless the reaction temperature the O2 conversion was always complete ( •   ZKHUHDV WKH & H 3 8 conversion decreased with decreasing temperature, but was always high (> 60%) (Fig. 38). Only CO and H2 were at all temperatures main products. Their yields decreased with decreasing reaction temperature from 84% to 44% and from 72% to 31%, respectively. The opposite trend was observed for H2O and CO2, their yields increased with decreasing reaction temperature from 14% to 28% for H2O and from 3% to 15% for CO2. CH4 was the only considerable hydrocarbon product its yield was between 2-3% independently of the temperature. At 800°C also traces of alkenes (C2H4 and C3H6) were observed (Y < 1%). To see if Ni10C900 after previous reduction was oxidised or deactivated at lower reaction temperatures the reaction temperature was first decreased after starting at the highest temperature and increased again after the lowest reaction temperature was reached. Upon the increase of the reaction temperature the catalyst’s performance was worse with regard to the C3H8 conversion and yields of CO and H2 but fully recovered at 800°C. 119 4. Results and discussion - catalytic partial oxidation of propane conversion [%] 100 O2 C3H8 75 Full sybols: empty reactor Hollow symbols: SiO2 wo...
View Full Document

This document was uploaded on 10/07/2013.

Ask a homework question - tutors are online