Hydrocarbon processes alkylation

In this subsection we will concern ourselves with those light ends processes which effect a chemical change in the hydrocarbon mixture alkylation, polymerization. 

Hydrocarbon alkylation process Alkylation catalyst based on H3P04/ 108... 

Industrial applications of zeolites cover a broad range of technological processes from oil upgrading, via petrochemical transformations up to synthesis of fine chemicals [1,2]. These processes clearly benefit from zeolite well-defined microporous structures providing a possibility of reaction control via shape selectivity [3,4] and acidity [5]. Catalytic reactions, namely transformations of aromatic hydrocarbons via alkylation, isomerization, disproportionation and transalkylation [2], are not only of industrial importance but can also be used to assess the structural features of zeolites [6] especially when combined with the investigation of their acidic properties [7]. A high diversity of zeolitic structures provides us with the opportunity to correlate the acidity, activity and selectivity of different structural types of zeolites. 

MLDW [Mobil lube dewaxing] A catalytic process for removing waxes (long-chain linear aliphatic hydrocarbons and alkyl aromatic hydrocarbons) from lubricating oil. Developed by Mobil Research Development Corporation and operated at Mobil Oil refineries since 1981. Eight units were operating in 1991. 

Sulphuric acid is the largest volume chemical in the world with an annual production of about 180 mill, t/year which is used primarily for phosphate fertilizers, petroleum alkylation, copper ore leaching and in smaller quantities for a number of other purposes (pulp and paper, other acids, aluminium, titanium dioxide, plastics, synthetic fibres, dyestuffs, sulphonation etc.). The major sulphur sources for sulphuric acid production are sulphur recovered from hydrocarbon processing in the refineries and from desulphurisation of natural gas, SO2 from metallurgical smelter operations, spent alkylation acid, and to a minor extent mined elemental sulphur and pyrites. A simplified flow sheet of a modem double-absorption plant for sulphuric acid production from sulphur is shown in Fig. 1. 

Careful preliminary tests were necessary to demonstrate the suitability of these methods for the present study. In particular, it was necessary to verify that the radioactivity detectable in the polymer may not be caused by contamination or other processes different from the ones taken into consideration. It was then found that it is possible to remove throughly from the polymer the last traces of unreacted ethylaluminum or of its soluble complexes with titanium compounds by washing with anhydrous hydrocarbon. No alkylation of the preformed polymer caused by triethylalu-minum or its derivatives has been observed (4 ). 

Chaput. G.. et al. Pretreat Alkylation Feed, 1 Hydrocarbon Processing, 51 (September 1992). 

Butylenes are four-carbon monoolefins that are produced by various hydrocarbon processes, principally catalytic cracking at refineries and steam cracking at olefins plants. These processes yield isomeric mixtures of 1-butene, cis- and tra s-butene-2, and isobutylene. Derivatives of butylenes range from polygas chemicals and methyl t-butyl ether, where crude butylenes streams may be used, to polybutene-1 and LLDPE, which require high-purity 1-butene. In 1997, the estimated consumption of butylenes (in billions of pounds) was alkylation, 32.0 MTBE, 12.0 other, including polygas and fuel uses, 0.5. 

Fig. 18.23. Alkylation—Technology Solutions Division of ConocoPhillips. Include combination reactor/settler (1), main fractionator (2), and small propane stripper (3). (Source Hydrocarbon Processing, 2004 Refining Process Handbook. CD-ROM. September 2004 copyright 2004 by Gulf Publishing Co., all rights reserved.)...

Eastman, A., et al., Consider Online Monitoring of HF Acid When Optimizing Alkylation Operations, Hydrocarbon Processing (Aug. 2001). 

Graham, W. A., "Alkylation Integrates Acid Plant", Hydrocarbon Processing, (August, 1972). 

Zeolites are solid acid catalysts which are widely used in hydrocarbon processing, such as naphtha cracking, isomerization, dispropornation and alkylation. During reactions carbonaceous materials called coke deposit on the zeolite and reduces its activity and selectivity. Coke deposited not only covers the acid sites of the catalyst, but also blocks the pores, and restrain reactants from reaching the acid sites, leading to the decrease in the apparent reaction rate (1, 2). Here, we will mainly deal with the intracrystalline diffusivity of zeolites, and will discuss the relationship between it and the change in catalyst selectivity. 

H. Lcmer and V.A. Citarella. Improve alkylation efficiency. Hydrocarbon Processing, Novem ben 9( 99l),... 

Forrey, K. Schrage, C. Trouble shooting HF alkylation. Hydrocarbon Process. 1996,45 (1), 107-114. Crowe, W.H. Marysiuk, A.M. How to work safely with HF alkylation. Hydrocarbon Process. 1965, 44 (5), 192-194. 

D Amico, V. et al. (2006) Consider new methods to debottleneck clean alkylate production. Hydrocarbon Processing, February, p. 65. 

On the basis of plant construction information found in Hydrocarbon Processing, about 70% of the alkylate plants built in last 10 years use sulfuric acid as the catalyst (4). In the United States, currently more than 50% of the alkylate produced use sulfuric acid as the catalyst, but in other countries, perhaps 60% of... 

Processes Using Sulfuric Acid as the Catalyst. The process designed by Stratco, Inc., more than 50 years ago has experienced numerous modifications since then. In addition, Stratco was purchased by the DuPont Chemical Company several years ago and is now frequently referred to as DuPont-Stratco. In about 2001, 34% of all alkylates produced in the world was in a Stracto unit (3). A somewhat higher percentage is probably now produced on the basis of published information found in Hydrocarbon Processing. 

Bott, L. L., 1965, How nalco makes lead alkyls, Hydrocarbon Process. Pet. Refiner, 44 115-118. 

Dispersing sulfuric acid or HF in hydrocarbons in alkylation processes... 

Fig. 15.19. Alkylation—Stratco, Inc. Includes contactor (1), acid settler (2), flash drum (3), deisobutanizer (4), compressor (5), and depropanizer (6). (Hydrocarbon Processing, 69, no. 11, p. 132, Nov. 1990 copyright 1990 by Gulf Publishing Co. and used by permission of the copyright owner.)...

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