• • Zeolite type dictates dodecane conversion: SAPO-34 (0.38 nm pores) yields only 24.33% conversion, whereas ZSM-5-38 and USY achieve near-complete conversion, underscoring pore size as a primary selectivity filter.
• • ZSM-5-38, with moderate acidity, delivers the highest light olefin yield (18.40%) among different zeolite types, while minimizing coke (0.18%), indicating an optimal balance between cracking and hydrogen transfer.
• • USY, with higher acid density, over-promotes hydrogen transfer and coking, producing light alkanes and 12.90% coke, demonstrating that excessive acidity is detrimental to olefin yield.
• • Reducing acid site density in ZSM-5 (ZSM-5-200) boosts total light olefin yield to 41.93% (ethylene 11.11%, propylene 20.33%, butenes 10.49%) at 97.79% conversion, with coke remaining low at 0.43%, offering a clear strategy for process optimization.