Linear fluid catalytic cracking

The alkylation unit in a petroleum refinery is situated downstream of the fluid catalytic cracking (FCC) units. The C4 cut from the FCC unit contains linear butenes, isobutylene, n-butane, and isobutane. In some refineries, isobutylene is converted with methanol into MTBE. A typical modern refinery flow scheme showing the position of the alkylation together with an acid regeneration unit is displayed in Fig. 1. 

The earliest applications of zeolites utilized the molecular sieving properties of small pore zeolites, e.g. zeolite A, in separation and purification processes such as drying and linear/branched alkane separation [33]. In 1962 Mobil Oil introduced the use of synthetic zeolite X, an FCC (fluid catalytic cracking) catalyst in oil refining. In the late sixties the W. R. Grace company introduced the "ultra-... 

This process is used by Nan Ya Plastics Corporation to produce, starting from an isomer mixture of octene the alcohol, INA and has a capacity >100 000 mt/a. After 2-EH, INA is the most important plasticizer alcohol, which is a complex mixture of linear and branched Cg alcohols. The most important plasticizer produced from it is diisononyl phthalate (DINP). The raw material sources can be, for example, a Cg fraction from the extraction of Fluid Catalytic Cracking (FCC) C -based polygas, the product of dimerization of butene from a raffinate-2 fraction using the octol or dimersol process, or diisobutylene from the dimerization of isobutylene from raffinate-1. 

Section 2 introduces the idea of back-off and also presents a general linear framework for the back-off methodology while in section 3 the nonlinear back-off synthesis methodology is summarised. Section 4 presents a case study where the regulatory control structure of a fluid catalytic cracking model is investigated. The results of the linear and nonlinear back-off analysis are compared for first time and important conclusions are drawn in section 5. 

In this section a Fluid Catalytic Cracking (FCC) process case study is examined. The aim is to compare the alternative methodologies for regulatory control structure selection presented in sections 2 and 3. The FCC process is particularly suited for this purpose. The process d3mamics described by a low order but highly non-linear set of DAEs. The actual operation of the process is dominated by economics and a small number of disturbances that affect significantly its economics has been identified. Furthermore, the most appropriate control structure for this process is a matter of some controversy, with the conventional structure being criticized in a number of recent publications. 

Other interesting products that can be obtained from waste plastics using combined thermal and catalytic processes are alkylaromatic compounds, which possess industrial applications as automatic transmission fluids (ATF), detergents (linear alkyl benzenes, LAB), and improvers of cetane number in diesel fuels [104]. The process uses as raw material the olefins generated in a previous step of thermal and catalytic cracking, which represent a cheaper source of olefins alternative to the currently existing ones. No special details about the conditions applied for the olefin production are indicated, the emphasis being focused on the alkylation step. Alkylation catalysts comprise conventional Lewis... 

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