用^(13)C-NMR自旋回波技术研究减压渣油的平均结构

STUDY ON THE AVERAGE STRUCTURE OF VACUUM RESIDUES WITH SEFT ^(13)C-NMR

对大庆、胜利、孤岛、欢喜岭四种原油的减压渣油及其各组份,用13C-NMR的自旋回波法(常规自旋回波。CSE和门控自旋回波.GASPE)测得其平均结构中—CH,—CH_2,—CH_3各基团的含量.据此计算了平均链长参数C_9,/nCH_3.结果合理,能反映不同样品在这方面的结构特征.将测定结果与DEPT法的数值进行了比较,两种方法的结果有相当好的一致性.自旋回波法较之DEPT法更为简单、易行和准确.

The contents of CH, CH, and CH, groups of the vacuum residues from Daqing Shengli, Gudao and Huanxiling oilfields were determined directly by combining the gated spin echo (GASPE) and the conventional spin echo (CSE) procedures. On the basis of those results, the structural parameter Cp/nCH3 can be obtained to characterize the average chain length of the samples. The results obtained by spin echo Fourier transform (SEFT) are in good agreement with those by the distortionless enhancement by polarization transfer (DEPT) method. However, in comparison with the DEPT, the SEFT is simpler and more accurate in measurement.