Modified Zeolite Hydrocracking for Linear Alkane Steam Cracking

The patent modifies the zeolite catalyst by changing its chemical composition parameters - specifically incorporating Group 4-6 metal atoms (such as Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, or W) bonded to four bridging oxygen atoms in the zeolite framework. This compositional modification transforms the catalyst's selectivity properties, enabling it to produce linear alkanes with >50 wt% selectivity during hydrocracking, thereby improving ethylene yield in subsequent steam cracking without requiring additional isomerization steps

The patent creates a composite catalyst material by combining zeolite framework with Group 4-6 metal atoms. The metal atoms are integrated into the zeolite structure at specific sites, forming a composite catalyst that exhibits enhanced selectivity for linear alkane production. This composite structure synergistically combines the porous framework of zeolite with the catalytic activity of metal atoms, achieving superior product selectivity compared to conventional hydrocracking catalysts

The patent extracts the isomerization function from the separate reverse isomerization process and integrates it directly into the hydrocracking step. By modifying the hydrocracking catalyst with Group 4-6 metal atoms, the catalyst simultaneously performs both hydrocracking and isomerization functions in a single step, producing linear alkane-rich products (>50 wt% linear alkanes) directly without requiring a subsequent reverse isomerization unit

The patent merges two previously separate process steps - hydrocracking and reverse isomerization - into a single integrated hydrocracking step. The modified zeolite catalyst performs both functions concurrently, combining the cracking activity with in-situ isomerization to directly produce linear alkane-rich feedstock suitable for steam cracking, thereby simplifying the overall process flow and reducing equipment requirements