Catalytic Cracking of Light-naphtha Fraction over Zeolite-based Composites for On-purpose Propylene Production
Bibliographic record
Abstract
Catalytic cracking of light-naphtha fraction over zeolite-based composites in fixed-bed mode was investigated to establish an efficient method for on-purpose propylene production. The composite catalysts, consisting of MFI-type zeolites containing iron, gallium and aluminum species (Fe–Ga–Al-MFI) and metal-oxide binder (e.g., silicon oxide, aluminum oxide), were employed for cracking of light-naphtha fraction. Fe–Ga–Al-MFI zeolites as matrix, containing each heteroatom at adequate ratio in the zeolite framework, exhibited both overall acid strength suitable for selective formation of light olefins and enhanced activity for dehydrogenation of light alkanes to alkenes, so that high overall yields of light olefins (ethylene, propylene and butenes) were attained by suppressing aromatics formation compared to cracking of light-naphtha fraction using conventional Al-MFI zeolite (ZSM-5). The unique acidity of the Fe–Ga–Al-MFI zeolite was maintained in the extruded form by using neutral and inactive silicon–oxide binder, which was selected to enhance mechanical strength and/or reduce pressure drop during reaction. The zeolite-based composite (Fe–Ga–Al-MFI/SiO2) selectively converted light-naphtha fraction (n-hexane) into light olefins including propylene with catalyst lifetime longer than 2000 h, suitable for fixed-bed operation, due to its excellent resistance to coke formation. Furthermore, the cracking reactions proceeded in the absence of steam at moderate temperatures below 650 °C, so catalytic cracking using the present zeolite-based composite saved considerable thermal energy required in the reaction unit, and the total amount of hydrocarbon feedstock was reduced by ca. 15 %, compared to conventional thermal cracking at 850 °C. The present review discusses the excellent properties of these zeolite-based catalysts and catalytic cracking of light-naphtha fraction emphasizing the catalytic chemistry and reaction engineering of the catalytic process.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".