Use of micropyrolysis and TG to study the thermal catalytic conversion of onshore crude oil using the zeolite catalysts type Y and ferrierite

摘要

The thermal mass conversion of crude oil from the Carmpolis field (19.53 (o)API) was studied by thermal analysis and with an off-line micropyrolysis system. The products of the micropyrolysis experiments were characterized by gas chromatography/mass spectrometry (GC/MS). The effects of the zeolite catalysts ferrierite and type Y on the TG curves for the crude oil were investigated applying different percentages of catalyst [10, 30 and 50 % (w/w)]. The influence of the heating rate (5, 10 and 20 A degrees C min(-1)) on the decomposition profile was also evaluated. The thermal analysis showed that, in general, lower heating rates lead to a better mass conversion. Based on the TG curves obtained at 400 A degrees C, the presence of the catalysts resulted in a reduction in the initial pyrolysis temperature and a gain of 10 % in the mass conversion. A detailed analysis of the hydrocarbons showed that the catalysts are not selective, acting similarly on the decomposition over the entire range of hydrocarbons. Also, the n-alkanes fingerprint shows a bimodal distribution, indicating that this onshore oil is associated with terrigenous higher-plant waxes. From the analysis of the isoprenoids, phytane was present in a higher percentage than pristane which, according to the literature, indicates that the oil was generated in an anoxic environment.