Pressure continuous catalyst regeneration

Since the first catalytic reformers were used in the 1950s the hydrogen/ hy-drocaibon mole ratio and the reformer operating pressure have both been gradually decreased. These developments resulted from improvements in the alumina support, the use of bimetallic catalysts, and finally the introduction of the low-pressure, continuous catalyst regeneration processes. The trends in operation are shown in Table 6.18. 

The process consists of a reactor section, continuous catalyst regeneration unit (CCR), and product recovery section. Stacked radial-flow reactors are used to minimize pressure drop and to facilitate catalyst recirculation to and from the CCR. The reactor feed consists solely of LPG plus the recycle of unconverted feed components no hydrogen is recycled. The liquid product contains about 92 wt% benzene, toluene, and xylenes (BTX) (Figure 6-7), with a balance of Cg aromatics and a low nonaromatic content. Therefore, the product could be used directly for the recovery of benzene by fractional distillation (without the extraction step needed in catalytic reforming). 

Description This new process consists of a reactor section, a continuous catalyst regeneration section and product recovery section. One or more fluidized-bed reactors (1) are used with continuous catalyst transfer to and from the continuous catalyst regenerator (2). The robust regenerable MTO-lOO catalyst is based on a nonzeolitic molecular sieve. Raw (nondewatered) methanol is fed to the low-pressure reactor (1), which offers very high (99%+) conversion of the... 

This is a very slow reaction under normal reforming operation. Feed composition, temperature, H2/hydrocarbon ratio, and the pressure strongly influence the rate of coke deposition. Modern catalysts produce less coke and allow operation under more severe conditions, such as those used in the cyclic and in the continuous catalyst regeneration (OCR) reformers. The different reforming technologies are briefly described later. 

In the major catalytic processes of the petroleum and chemical industries, continuous and steady state conditions are the rule where the temperature, pressure, composition, and flow rate of the feed streams do not vary significantly. Transient operations occur during the start-up of a unit, usually occupying a small fraction of the time of a cycle from start-up to shut-down for maintenance or catalyst regeneration. 

The CCR Meta-4 process features are a hard, highly active and robust catalyst, low catalyst inventory, low operating temperature and pressure, outstanding yields, liquid-phase operation, and continuous operation and catalyst regeneration. 

The modern reforming process operates with continuous regeneration of the catalyst, at low pressure (2 to 5 bar) and high temperature (510-530°C). 

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