Progress in desulfurization technology of aromatic solvent oil

Solvent oil (hydrocarbon solvent) is an important petroleum product. The refining technologies of solvent oil such as dearomatization and desulfurization were introduced. There are four main technologies for dearomatization of solvent oil: hydrogenation, adsorption separation, sulfonation and extraction distillation. Generally, two methods can be used for desulfurization of solvent oil: hydrofining and adsorption refining. Both methods can reduce the sulfur content of solvent oil to less than 0.5 μ g / g. the hydrodesulfurization method is only suitable for the situation with sufficient hydrogen source, and the adsorption method is suitable for various occasions.

Solvent oil (hydrocarbon solvent) is an important petroleum product. With the development of China's national economy and the improvement of people's living standards, on the one hand, the demand for various solvent oil products will be greatly increased, on the other hand, higher and higher requirements are put forward for the quality of solvent oil, especially some properties that affect the environment and health. Therefore, the solvent oil refining technology was developed. Greater development. Solvent oil refining includes aromatics removal, desulfurization and decolorization. Aromatics desulfurization is the key and research focus of solvent oil refining technology. Solvent oil hydrodearomatization technology is widely used in industrial production because of its good dearomatization effect. In particular, catalytic reforming raffinate is used to produce solvent oil. Due to the convenience of hydrogen source, hydrofining is usually used. Some hydrogen source refineries use straight run gasoline as raw material to hydrotreat solvent oil.

At present, the aromatics hydrogenation catalysts at home and abroad are mainly composed of palladium, platinum and nickel. A self-made nickel zinc / A12O3 straight run mixed solvent oil catalyst was studied in Jianghan Oilfield under 120-180 ℃ operation conditions by using a 10 ml fixed bed micro reaction chromatography device. The reaction pressure was 0.5-2.0 MPa, the purity was 1.90%, the content of benzene was 4.21%, the content of toluene was 1.30%, and the content of xylene was 0.90%. Hydrogen Y > 99%, hydrogen oil volume ratio 60-90, space velocity 1.0-3.0h-1. The aromatics removal efficiency of straight run mixed solvent oil with Pd / A12O3 and Ni / A12O3 catalysts was compared. The results show that the catalyst has good catalytic performance for hydrodearomatization of mixed solvent oil. It can be used as catalyst for hydrodearomatization of solvent oil, and its performance is better than that of palladium catalyst. Ni Zn / A12O3 catalyst and Ni / A12O3 catalyst have the same catalytic effect in hydrodearomatization. The presence of zinc makes Ni Zn / A12O3 catalyst have the function of resisting Ni poisoning caused by s in raw material, but it is suitable for low space velocity operation. The hydrogenation process of low aromatics solvent oil developed by Engineering Research Institute of Luoyang Petrochemical Engineering Company has the characteristics of wide distillation range of raw oil and high aromatics content (about 20%). Distillate 130-300 (?) Low aromatics solvent oil was produced from C with A12O3 as the carrier and W-Ni as the main active component. Under different hydrogen partial pressures, the solvent oils with aromatic content less than 1.0%, 0.30% or 0.02%, sulfur and nitrogen content less than 1 μ g / g, colorless, transparent and environmental friendly can be prepared. The solvent oil with low aromatic content can be used as high-quality solvent in fine chemical industry and metal processing field.

The non noble metal rss-1a catalyst developed by Sinopec Petrochemical Research Institute was used in Zhenhai Refining and chemical company. The results show that the optimal process conditions for hydrofining of continuous reforming raffinate with bromine number (Br2: raffinate oil) = 0.165 to solvent oil with bromine number less than 3 * 10-3 are as follows: hydrogenation temperature 240 ℃, high pressure separator pressure 1.5 MPa, space velocity (3-4) H-1. The industrial calibration results show that reducing the dry point and operating space velocity of the feedstock is conducive to reducing the olefin content in solvent oil products.

In addition, aromatics raffinate was hydrotreated at low pressure to prepare high quality solvent oil. Pt / A12O3 showed good activity and stability in low pressure hydrogenation. The experimental results show that space velocity has a great influence on hydrogenation reaction under the conditions of temperature (160-20) C, pressure (0.05-0.25) MPa, space velocity (1.5-3.5) H-1 and hydrogen oil volume ratio (200-300). About 3.0 H-1 is appropriate. After hydrotreating, the olefin conversion and aromatics conversion of raffinate oil reach 90% and 95% respectively. High quality raffinate oil can be obtained by simple distillation and cutting. 6 solvent oil and 120 solvent oil.

The aromatics removal technology developed by Daqing Petroleum Institute can reduce the aromatics content in 6 solvent oil to 500 μ g / g, and the straight run gasoline hydrogenation technology developed by Jianghan Oilfield for the production of solvent oil can reduce the benzene content in straight run gasoline to 200 μ g / g a. The toluene content was reduced to less than 500 μ g / g.

Shanxi Institute of coal chemistry, Chinese Academy of Sciences has developed a supported aromatics extraction and hydrofining catalyst with platinum as the main active component. Compared with the traditional nickel molybdenum.