Primary Study On Catalytic Cracking Of Crude Oil With High-Neutralization Number By TSRFCC Technology

In recent years, a lot of inferior crude oil with high-sulfur content and high density was processed in our country, and we had already gained mature experience in this domain. However, the development of technology in processing crude oil with high-neutralization number wasn't emphasized enough in recent years. All over the world, the crude oil with high-neutralization number is still in the aspect which supply exceeds demand, and its price is relatively low. In addition, processing crude oil with high-neutralization number will enlarge our country's resource supply of crude oil, and this will agree with the national strategy for decreasing the risk of crude oil import. This research subject was based on the new technology of Two-Stage Riser Fluid Catalytic Cracking (TSRFCC) developed indepen- dently by the State Key Laboratory of Heavy Oil Processing of China University of Petroleum (East China). The crude oil with high-neutralization number was directly used as the FCC feedstock, and characteristics of catalytic cracking at different conditions were investigated.The experiments were mainly conducted at the continuous flow Riser pilot unit in the State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China). Crude oil with high-neutralization number was heated up to 210℃before it entered the Riser reactor. At the temperatures of 500~540℃, catalytic decomposing reaction of the naphthenic acid and catalytic cracking reaction of the hydrocarbon compound were took place. The removal of the acidic compounds is above 99%, and the most of heavy metals and carbon residue is removed effectively. In the experiments, crude oil with high-neutralization number was firstly pretreated over a catalyst with low activity, and then the heavy oil and gasoline obtained were reacted again over the fresh catalyst according to TSRFCC technology. Moreover, crude oil with high-neutralization number was directly processed over catalyst with high heavy oil converting ability such as ZC-7300 produced by Zhoucun catalyst factory and the equilibrium catalyst obtained from Karamayi factory.The Sudanese crude oil with high-neutralization number as feedstock was directly converted in the pilot unit over the LTB-2 catalyst with lower activity at the reaction temperature of 520℃, with the catalyst to oil ratio of 15, and the residence time of 1.26s. The reaction results showed that the yield of light oil is over 38%, the yield of propylene 11.64% and the yield of butene 11.66%. Then, with the mixture of gasoline and heavy oil obtained from the above experiment as feedstock, catalytic conversion reaction was conducted over the fresh LTB-2 catalyst at the temperature of 540℃, with the catalyst to oil ratio of 18, and the resident time of 1.57s. The total result of the two-stage reactions showed that the yield of diesel oil is 30% , the yield of propylene 18.3% and the yield of butane 16.1%, and the fractional conversion of crude oil is 94%, the overall yield of liquid products 71.6%.In addition, with the Sudanese crude oil with high-neutralization number as feedstock, catalytic conversion reactions were conducted over ZC-7300 and Karamayi equilibrium catalyst respectively. The results of the two reactions both showed that the one-through conversion of heavy oil is over 97%, and the yield of light oil 52%, the yield of propylene 11%.