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mermaid332(金币+10):xiexie 2010-04-19 08:25
sirljz(金币+3):谢谢交流 2010-04-19 15:54
Preparation of novel catalyst and research of new technology for gasoline hydrodesulfurization
Abstract: A novel multi-functional catalyst is prepared and used for hydrodesulphurization of FCC gasoline. The results show that the catalyst with Mo-Co-Ni multi-metal components and additives increase the selectivity of hydrodesulphurization and reduce he amount of the low olefin. Dual purpose, hydrodesulphurization and reduction of octane number loss, are achieved. Sulfur content in FCC gasoline decreases from 1200 μg/g to 115 μg/g and olefin content falls to 20.5 v% from 44.2 v%. The RON loss is 0.5 units. The stability test for 2000 hours indicates that the catalyst is very stable. The catalyst is characterized with strong adaptability concluded from the adaptability test for different raw materials.
Key words: desulfurization; olefin; catalyst; octane number
1. Introduction
Harmful substances such as sulphides and CxHy come from automobile exhaust emissions have caused serious pollutions to the environment. In order to reduce the pollution caused by automobile exhaust, the gasoline has been cleaner and cleaner in recent years. Olefins, aromatics and sulfides are thought as the harmful substances, so their contents in gasoline are limited repeatedly [1-3]. Each standard about the contents is shown in Table 1. Every country has been doing their best to reduce the harmful substances amount.
In China, more than 90% mass fraction of sulfur and more than 98% volume fraction of the olefins in motor gasoline are from the FCC (Fluid Catalytic Cracking) gasoline [4-6]. Conventional hydrodesulphurization (HDS) method is effective to remove organic sulfur form FCC gasoline, but the alkenes hydrogenation easily generate low-octane saturated group that results in a sharp decline of the octane number. New HDS method is that the FCC gasoline is divided into LCN (Light fraction) and HCN (Heavy fraction), HCN is desulfurized and hydrogenated. The method largely avoids the hydrogenation of the high-octane light olefin in LCN. However, in HDS’ process, the high-octane olefin in HCN is saturated which results in the loss of the octane number. Therefore, it is important to develop high selective HDS catalyst for reducing saturation in the hydrogenation process of olefins to control the octane number loss. The foreign new technology of FCC gasoline hydrodesulphurization, such as the technology from Prime-G & Prime-G+(IFP), SCANFining & OCTGAIN (ExxonMobil) and ISAL (UOP), has poor adaptability to the FCC gasoline of high-sulfur (1000~1500 μg/g), high olefins (40~55 v%), low aromatics (13~20 v%) in China. It is necessary to develop new olefin FCC gasoline hydrodesulphurization technology and new catalyst.
In this paper, it is the emphatic to reduce the octane number loss in the process of FCC gasoline hydrodesulphurization. The components in catalyst are determined. Catalyst performance and stability are studied in the hydrodesulphurization of FCC gasoline. The hydrogenation process conditions are optimized.
我也就光改了改时态，还有较少的时态和语法错误。 |
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