|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|6476466||1425385||2017||10 صفحه PDF||سفارش دهید||دانلود رایگان|
- Blending -SVR, ITH, MFI with E-Cat increased LPG yield in VGO cracking at gasoline expense.
- Increasing Si/Al ratio of all zeolites minimized hydrogen transfer reactions and decreased gasoline over-cracking.
- The highest propylene yield was 13.5Â wt% and 12.8Â wt% over E-Cat/MFI-280 and E-Cat/-SVR-120, respectively
- Drop in gasoline yield was due to cracking of isoparaffins and olefins
- Activation energy over MFI increased from 14.2Â kcal/mol to 16.3Â kcal/mol as Si/Al ratio increased from 30 to 2000.
The cracking behaviour of three medium-pore zeolites -SVR, ITH, and MFI, with varying Si/Al molar ratio, was evaluated using an equilibrium FCC catalyst (E-Cat) and a hydrotreated vacuum gasoil (VGO) in a microactivity test unit (MAT). The increase in the yield of light olefins (21-29Â wt% over E-Cat/additive vs. 16Â wt% over E-Cat) was accompanied by a drop in the yield of gasoline (26-39Â wt% over E-Cat/additive vs. 43Â wt% over E-Cat) due to the cracking of reactive species in gasoline fraction (mainly olefins and isoparaffins). With increasing Si/Al ratio in zeolites MFI-280 and -SVR-120, propylene yield passed through maxima reaching 13.5Â wt% and 12.8Â wt%, respectively, compared with 7.0Â wt% over E-Cat. Maximum propylene yield occurred partially due to gasoline over-cracking to light olefins (inverse relation with Si/Al ratio). The effect of MFI crystal size showed that large size crystals enhanced the yield of light olefins as compared to small size crystals due to secondary cracking of gasoline molecules. Results of kinetic study based on 4-lump model showed proportional relation between MFI Si/Al ratio and activation energy for the conversion of gasoline to gases. Activation energy increased from 14.2Â kcal/mol to 16.3Â kcal/mol as Si/Al ratio increased from 30 to 2000.
Journal: Fuel Processing Technology - Volume 161, 15 June 2017, Pages 23-32