Petrochemical processing catalysts

Coke formation is the main reason for catalyst deactivation in catalytic reforming, and also in other refinery and petrochemical processes. Catalyst... 

The behavior of the catalyst is also a consideration. Particularly in high-temperature petrochemical processes, catalysts are deactivated by sintering, coking, and similar processes. 

Eatty alcohols, prepared from fatty acids or via petrochemical processes, aldol or hydroformylation reactions, or the Ziegler process, react with ammonia or a primary or secondary amine in the presence of a catalyst to form amines (10—12). 

Most refinery/petrochemical processes produce ethylene that contains trace amounts of acetylene, which is difficult to remove even with cryogenic distillation. Frequently it is necessary to lower the acetylene concentration from several hundreds ppm to < 10 ppm in order to avoid poisoning catalysts used in subsequent ethylene consuming processes, such as polymeri2ation to polyethylene. This can be accompHshed with catalytic hydrogenation according to the equation. 

Here, we present the high activity and selectivity of an acid Al-containing ITQ-21 catalyst for the production of cumene by alkylation of benzene with propylene, which is an important petrochemical process that employs zeolites [4,5]. 

The weak acidity of the pure OMS materials is disadvantageous for petrochemical processes but for the synthesis of fine chemicals, solids with moderate acidity can be very active catalysts. Table 4.2 gives... 

Zn and used in the metallurgy of this metal. Pure Mo finds applications also as a catalyst in several petrochemical processes. 

In the following decades, researchers in catalysis turned their efforts to controlhng molecular structure as well as size. The catalyst zeolite paved the way. In the late 1960s, researchers at Mobil Oil Co. were able to s)uithesize zeolite by deliberately designing and preparing the structure of catalysts at the atomic and molecular levels. The resulting nanostructured crystalline material (ZSM-5)—with a 10-atom ring and pore size of 0.45-0.6 nm—enabled the control of selectivity in petrochemical processes at the... 

These starting values are used as initial guesses for fitting the model to industrial data and the preexponential factors are changed to obtain the best fit. This is done because the kinetic parameters depend upon the specific characteristics of the catalyst and of the gas oil feedstock. This complexity is caused by the inherent difficulties with accurate modeling of petroleum refining processes in contradistinction to petrochemical processes. These difficulties will be discussed in more details later. They are clearly related to our use of pseudocomponents. But this is the only realistic approach available to-date for such complex mixtures. 

In a number of petrochemical processes, a gas (hydrogen) is present as reactant. In hydrodesulfurization (HDS), hydrocracking (HC), and hydrodenitrogenation (HDN), the reaction products H2S and ammonia, respectively, are known to decrease the catalyst activity, but are partly transferred to the gas phase. Therefore, also these processes profit from reactive stripping. 

Petrochemical processes require smaller reactors than used in refineries. Chemical reactors are sized in the 50 to 250 cu.ft. range. Orders for replacement catalyst usually range from 10,000 to 50,000 lbs, but there are many different process applications. Catalyst quality is becoming more important than in recent years as many industries attempt to reduce the cost of nonconformance and improve the quality of manufactured goods. 

Hydrocarbon Processing s Petrochemical Processes 2005 handbooks reflect the dynamic advancements now available in licensed process technologies, catalysts and equipment. The petrochemical industry continues to apply energy-conserving, environmentally friendly, cost-effective solutions to produce products that improve the quality of everyday life. The global petrochemical industry is innovative—putting knowledge into action to create new products that service the needs of current and future markets. 

Over the past My years there have beat significant developments in the synthesis of zeolites of different pore sizes [6], Many of these developments have resulted in new applications of zeolite catalysts for petrochemical processes. TM is eq>eciaHy so, for exauqile, in the case of catafytic cracking whidi ideally requires the pore sizes to be tailored to cater for reactions involving a wide range of molecular sizes thus leading to the syntheas of catalysts with macro-, meso- and micropores. Table 1 shows the pore aze, dimensionality and structure type of some of the zeolites and molecular aeves which will be discussed in this paper. 

ZSM-5 (Al-MFI) is used as a catalyst in petroleum refining, in the production of synthetic fuels, and in other petrochemical processes, whereas TS-1 (Ti-MFI) is applied as a catalyst in fine chemical processes. The orthorhombic MFI structure exhibits 12 crystallographically unique tetrahedral sites. Calculations have been carried out on substitution preferences using classical as well as quantum models. " In most studies 12 simulations were conducted, and in each run, one or more crystallographically equivalent sites of the subsequently crystallographically unique tetrahedral sites were substituted. Energy minimization and molecular dynamics techniques were employed to calculate... 

Worthy of mention are the numerous catalyzed reactions utilizing highly selective zeolite catalysts tailored to the particular process. However, significantly lower quantities of catalyst are utilized compared with those used in petrochemical processes. 

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