常压渣油在高温接触剂上化学组成和结构的变化

CHANGE IN COMPOSITION AND STRUCTURE OF REDUCED CRUDES DURING CONVERSION ON CONTACT AGENT

用固定流化床反应器进行了常压渣油在高温接触剂上转化的实验,反应温度为480～540℃。为了研究在反应中的化学组成和结构的变化,采用正戊烷沉淀沥青质和氧化铝吸附色谱法,将原料和重油产物分离成八个组分,并用改进的Brown-Ladner法计算原料和产物的结构参数。所得结果表明,常压渣油各组分在高温接触下反应的转化率是很不相同的,沥青质和胶质的转化率大大高于饱和分和芳香分。结构参数计算结果表明,350℃以上加重质产物的CH_2/CH_3值以及芳碳率、芳环、环烷环和总环数等参数明显地低于常压渣油原料的参数。实验中也考察了反应温度对脱硫、脱氮、脱金属的影响;数据表明,弱极性组分中镍的脱除率高于中极性和强极性组分中镍的脱除率。

Experiments for the conversion of reduced cruder on a contact agent at 480～540℃ were carried out with a fixed fluidized bed reactor. In order to study the changes in composition and structure during conversion, the feedstocks and heavy producis were subdivided into eight fractions by using normal pentane precipitation and alumina adsorption chromatography. The average molecular parameters were calculated with the modified Brown-Ladner's method. The results showed that the conversion of various fractions of the reduced crudes was quite different. The conversion of asphaltic substances was much higher than those of saturates and aromatics, It was shown that the CH_2/CH_3 ratio, aromaticity and the numbers of aromatic, naphthenic and total rings of heavy products were obviously lower than those of seduced crudes. The effect of temperature on metal, sulfur, and nitrogen removal was also investegated. The data indicated that the removal of weak polar nonporphyrin nickel was greater than that of medium and strong polar nickel complex.