Refinery Fluid Catalytic Cracking Unit Research Articles

Adoption of Pareto Charts in the Analysis of Input Variables Interaction and Selection of Input-Output Pairings in a Refinery Fluid Catalytic Cracking Unit

This paper presents a study of the effects of input variables (main factors) and their couplings on key process variables(responses) in a refinery fluid catalytic cracking (FCC)unit using pareto analysis. Five responses namely, Riser temperature(Trx),Regenerator temperature(Trg) ,flue gas oxygen concentration, (Od ),Gasoline yield(y2 ), Light gases yield(y3 )) and four main factors, namely gasoil feed rate(Fgr), regenerated catalyst flow rate(Frc),combustion air flow rate(Fa ), combustion air temperature(Ta )and were studied in a regular two-layer experimental design that generated 32 numerical experiments. A combination of Design Expert software and an in-mouse FCC unit simulator was used to conduct the numerical experiments from which pareto plots were generated as a tool for response-factor analysis. Results from this study show that Frc and Fgr are the only significant main factors with respect to riser temperature response. While the significance is of the order Frc> Fgr, Frc produced negative effect while Fgr produced positive effect on riser temperature while the interaction factor (Fgr+Frc) is the only cross-coupling .Cross -coupling of variables is more significant in the regenerator as two interaction factors (Fgr+Frc) and (Frc+Fa ) featured prominently and produced significant effects on regenerator temperature and flue gas oxygen concentration, respectively. The ranking of the effects on regenerator temperature is Frc>Fa > Fgr while that on flue gas oxygen concentration is Frc>Fgr>Fa . Results further show that while Frc, Fgr and Fa produced positive effects on regenerator temperature, only Fa produced negative effects in flue gas oxygen concentration. Moreover, the four main factors in this study and their couplings did not dhow direct effects on gasoline yield and light gases yield respectively. The results are in tandem with FCC unit behaviour and thus assert the merit in the adopted tool.

Asia to lead global refinery fluid catalytic cracking units’ capacity growth by 2024

Asia to lead global refinery fluid catalytic cracking units’ capacity growth by 2024

China to dominate Asian refinery fluid catalytic cracking units capacity growth by 2024

HZSM-5 was prepared by the hydrothermal method using TPAOH as a structure directing agent without Na+ addition. The calcination process for removing the organic templates was studied and particularly the influence of calcination temperature on zeolite structure and acid property was investigated. It was found that dehydrogenation of Brønsted acid sites in zeolite framework occurred with the elevation of calcination temperature, leading to a decrease of catalytic activity for n-decane cracking. To recover the Brønsted acid sites in zeolite lost during calcination, the calcinated zeolite was treated with various reagents, including H2O, H2O2, NH3 and NH4Cl, to turn Lewis acid sites back to Brønsted acid sites. Among them, the NH4Cl treatment was found to be the most effective way, which increased conversion of n-decane from 6% to 77% and increased the B/L acid sites ratio from 0.503 to 3.95. This enhancement of catalytic cracking ability is probably related to the formation of an intermediate active component ([AlO4]0) during high temperature calcination, and these intermediate sites promoted the protonation of Lewis acid sites in the NH4Cl treatment process.

Global refinery fluid catalytic cracking units (FCCU) market outlook to 2024 - identify growth segments and opportunities

Global refinery fluid catalytic cracking units (FCCU) market outlook to 2024 - identify growth segments and opportunities

Upgrading of heavy coker naphtha by means of catalytic cracking in refinery FCC unit

The upgrading of heavy coker naphtha under conditions of the industrial fluid catalytic cracking (FCC) unit has been investigated, with the aim of obtaining light olefins and a gasoline fraction suitable to be used in the blending of motor fuels. The experiments have been conducted in a riser simulator reactor at: 500 and 550 °C; catalyst to oil mass ratio, 6 gcat goil−1; and, contact time, 3 to 12 s. Moreover, the effect of the properties of two commercial equilibrium catalysts on the products has been also assessed. Products have been grouped in: dry gas, liquefied petroleum gases, gasoline, light cycle oil and coke. The presence of strong acid sites in the catalyst favors the formation of light olefins, yielding a 5 and 3.3 wt% of propylene and butenes, respectively, at 550 °C and 6 s. A higher content of zeolite (with moderate acid strength sites) and a bigger size of the mesopores of the matrix promote the formation of a commercially interesting gasoline fraction with a yield of 90 wt% under the same conditions, with a concentration of aromatics, naphthenes, n-paraffins, olefins and iso-paraffins of 25, 10, 28, 21 and 15 wt%, respectively, and a RON of 84.

Catalytic pyrolysis of polyolefin waste into valuable hydrocarbons over reused catalyst from refinery FCC units

Abstract A commingled polyethylene/polypropylene (PE/PP) mixture was pyrolysed over used fluid catalytic cracking (FCC) commercial equilibrium catalyst (RCat-c1) using a laboratory fluidised-bed reactor operating isothermally at ambient pressure. The conversion at 390 °C for RCat-c1 catalyst (81.5 wt%) gave much higher yield than silicate (only 18.3 wt%). Greater product selectivity was observed with RCat-c1 as a post-use catalyst with about 53 wt% olefins products in the C3–C6 range. The selectivity could be further influenced by changes in reaction conditions. Valuable hydrocarbons of olefins and iso-olefins were produced by low temperatures and short contact times used in this study. It is demonstrated that the use of spent FCC commercial catalyst and under appropriate reaction conditions can have the ability to control both the product yield and product distribution from polymer degradation, potentially leading to a cheaper process with more valuable products.

FUZZYFCC: Fuzzy logic control of a fluid catalytic cracking unit (FCCU) to improve dynamic performance

In this paper, fuzzy logic control of a fluid catalytic cracking unit (FCCU) is proposed. Fluid catalytic cracking (FCC) process is a unit that converts heavy distillates like gas oil or residues to gasoline and middle distillates using cracking catalyst. About 45% of worldwide gasoline production comes from FCC processes and its ancillary units. Since a typical FCC unit can process a large amount of the feedstock into more valuable products, the overall economic benefits of a refining could be considerably increased if proper control and optimization strategies are implemented. FCC processes are known to be very difficult to model and control because of the large process scale, complicated hydro-dynamics and complex kinetics of both cracking and coke burning reactions. One of the more heavily investigated terms of nonlinear control, in the field of “intelligent control”, is that due to fuzzy logic controllers (FLCs). FLCs have been successfully applied to a stream of difficult, nonlinear dynamical process such as FCC. Here, with an application to a Turkish refinery FCC unit of FLC fuzzy results obtained using Matlab-Fuzzy Logic Toolbox version 6.5 were found to be acceptable. The paper indicates how fuzzy logic control (FLC), as a promising control technique, would be effectively used for improved process control of FCC in refinery process industry.

The use of solid state nuclear magnetic resonance (NMR) to study the effect of composition on the properties of equilibrium fluid cracking catalysts (FCCs)

Solid state nuclear magnetic resonance (NMR) spectroscopy together with microactivity testing have been used to characterize the changes that occur in a fluid cracking catalyst (FCC) during gas oil cracking in a refinery fluid catalytic cracking unit (FCCU). The 29 Si NMR spectra of fresh FCCs show the well known five peaks pattern attributed to the presence of HY-type crystals. However, after aging, equilibrium FCCs are generated in which the 29 Si NMR spectrum of the zeolitic component is reduced to one main dominant resonance near −107 ppm representative of T[4Si,0Al] sites. Thus, irrespective of composition, extensive dealumination of the cracking component in FCCs occurs during recirculation in a FCCU yielding 29 Si NMR spectra in which the presence of framework Al is no longer visible. Similar conclusions have been obtained from the corresponding 27 Al MAS NMR spectra showing that the dealuminated faujasite structure in equilibrium FCCs contains only extra-framework Al(IV), Al(V), and Al(VI) species. In the presence of tin, vanadium effects on the coordination of Al and Si in equilibrium FCCs, could not be observed by 29 Si or 27 Al NMR spectroscopy.