Cumen s

THE PRODUCTION OF CUMENE USING Zeolite CATALYST Aspen Model Documentation

Index
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Process Summary About This Process Process Definition Process Conditions Physical Property Models and Data Chemistry/Kinetics Key Parameters Selected Simulation Results: Blocks Streams References

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PEP Process Module

1

8 Oct 1999

Process Summary
This Aspen Plus model simulatesthe production of cumene by the alkylation of Benzene using Propylene and Zeolite catalyst. The plant is designed to have a capacity of 595 million lb/yr (270,000 t/yr) of cumene at a 0.9 stream factor. This capacity is sufficient to supply cumene to a world-scale phenol plant of about 200,000 t/yr (440 million lb/yr).

PEP Process Module

2

8 Oct 1999

About This Process
Essentially allcumene produced worldwide is used as a feedstock in phenol plants, which convert it to phenol and acetone by cumene peroxidation. Therefore, the cumene and phenol markets are strongly tied. From 1993 to 1998, world cumene demand grew at a rate of 4.7%/yr, increasing from 5.6 million to 7.1 million t/yr. Through 2003, in accordance with announced phenol additions, demand is forecast to grow at4.2%/yr in North America and 5.1%/yr worldwide. Worldwide cumene capacity was estimated at 9.5 million t/yr in 1998 and is projected to reach 10.4 million t/yr by year-end 2003. Starting in 1996, several cumene producers have completed plant revamps using the new zeolite catalyst technology. Because these expansions were introduced ahead of the corresponding phenol additions, the operating rate ofthe world cumene industry declined from 82% in 1995 to about 74% in 1998. The operating rate is expected to recover after the planned start-up of major phenol expansions in 1999 and 2000. The main end uses for cumene, as a phenol intermediate, are bisphenol A, phenolic resins, and caprolactam. Bisphenol A is produced from phenol and acetone, with end-use applications in polycarbonate and epoxyresins. A shift in the phenol derivatives market has taken place in recent years, with bisphenol A overtaking phenolic resins as the major driver for phenol growth. Consequently, pressure has increased for product improvements in both phenol and acetone, in turn creating demand for higher quality cumene produced upstream. In addition to bisphenol A, the main drivers for acetone demand are methylmethacrylate and solvent applications. The growth expected in these markets is lower than that of phenol, which has led to increasing concern over future acetone oversupply. Competitive routes for phenol production, without coproduction of acetone, are still being pursued. Recently, Solutia announced a one-step process for making phenol from benzene, which bypasses the cumene intermediate [see PEPReview 97-6, One-Step Phenol from Benzene by the AlphOx Process (December 1998)]. These alternative phenol processes are not expected to pose a serious threat to the cumene industry in the near future. TECHNICAL ASPECTS The only chemical route to cumene in current commercial practice is the alkylation of benzene with propylene over an acid catalyst. This report evaluates three processes for cumeneproduction, which are respectively based on the following catalysts: solid phosphoric acid (SPA), aluminum chloride (AlCl3), and zeolites. Brief descriptions of the technologies, along with a discussion of their advantages and limitations, are provided below. The Solid Phosphoric Acid-Based Process UOP developed the cumene process using SPA catalyst in the 1940s. It was basically adapted from arefinery process that converted light olefins into gasoline components. Until the early 1990s, the SPA process was the dominant technology for cumene production, with more than 40 plants licensed worldwide.
PEP Process Module 3 8 Oct 1999

The SPA catalyst is a composite of phosphoric acid and a solid binder material, such as kieselguhr or diatomaceous earth. Benzene alkylation with propylene is...