Chapter 12 NMR studies of FCC feeds, catalysts and coke

摘要: Abstract NMR has become an indispensable tool for characterizing a variety of complex materials, includingheavy petroleum fractions, catalysts and coke. Determination average molecular parameter by is useful the analysis hydrocarbons like coal liquids, heavy oils, synthetic oils high boiling fractions. This not only gives brief idea molecules present but can also be used prediction crackability coking tendency feedstock under particular condition operation. Although solid state attained resolution as it been proved better technique level characterization particularly in catalysis. because use magic angel spinning, cross polarization (CP) heteronuclear decoupling techniques conjunction with routine sophisticated experiments. In this chapter, to study feeds, coke FCC process refining industries. Fluid catalytic cracking (FCC) feeds from two Indian refineries are structurally characterized inverse gated decoupled 13C distortionless enhancement transfer (DEPT) methods. Detailed structural analyses completely supported range information including chemical shifts 1H 13C, CHn type distributions 1H-13C connectivities 2D HETCOR NMR. The parameters obtained give about nature units. 29Si MAS, 27Al MAS 3QMAS methods employed structure fresh spent catalyst after stripping. Other analytical HPLC, microcalorimetry, XRD, TGA, IR compliment or augment inferences changes described terms framework Si/Al ratio, relative distribution various acid sites (different Si atoms) their populations unit cell sizes. variations correlated quadrupolar coupling constant values at site octahedral tetrahedral Al nuclei MQMAS studies. soluble insoluble concentrates extracted studied different techniques. Conventional derive Quantitative data aromaticity state13C SHPE/MAS protonated non-protonated carbons Dipolar Dephasing (DD) experiments combination SHPE/MAS. compositional variation feed properties explain differences