MXPA99010359A - Process for the alkylation of benzene - Google Patents

Abstract

A process for the alkylation of benzene contained in a mixed refinery stream is disclosed wherein the refinery stream (2) is first subjected to hydrogenation (14) of higher olefins prior to alkylation (12) to the benzene with selected types and quantities of lower olefins (1). Streams containing sulfur compounds may be pretreated by hydrodesulfurization. All of the process steps are advantageously carried out in distillation column reactors (10) to take advantage of that mode operation.

Description

PROCESS FOR BENZENE ALKYLATION DESCRIPTION OF THE INVENTION The present invention relates to a process for the alkylation of benzene contained in a mixed refinery stream. More particularly, the invention relates to a process wherein olefin-containing feeds are hydrogenated to remove olefins and then subjected to alkylation of benzene with controlled types and amounts of olefins. The process is also defined by the pretreatment of sulfur-containing refinery streams by hydrodesulfurization of any organic sulfur contained within the stream. All process steps can be carried out in distillation column reactors to take advantage of that mode of operation. Ethylbenzene and eumeno are currently produced by reaction of benzene and the respective olefin, ie, ethylene or propylene by acid catalysis. In some known processes, the catalyst is highly corrosive and has a relatively short life, for example, AICI3, H3PO4 or clay, BF3 or alumina, and others require periodic regeneration, for example, molecular sieves. In addition, the exothermicity of the reaction and the tendency to produce polysubstituted benzene require conversions of Lower benzene per step with high volume recycling in conventional processes. To overcome many of the disadvantages of conventional processes, a process has been developed in which the reaction of the olefin with benzene is carried out concurrently with the separation of the products by fractional stripping. One embodiment of that process is described in U.S. Patent 5,243,115 which utilizes a reaction system wherein the components of the reaction system are concurrently separable by distillation using the catalyst structures such as the distillation structures. Such systems are described variously in U.S. Patent 4,215,011; 4,232,177; 4,242,530; 4,250,052; 4,302,356; and 4,307,254. In addition, a variety of catalyst structures for this use are described in U.S. Patent Nos. 4,443,559 and 5,348,710 which are incorporated herein. The reduction in the lead content of gasolines and the use of compounds against the impact of lead have led to a search for other ways to improve the number of blending components for gasoline. Alternatives for the use of compounds against the impact of lead are chemical processing and the use of other additives.

A common process widely used by the refinery industry to improve the naphtha of origin, up to high octane gasoline is the catalytic reforming. Due to the multiplicity of the compounds in the original naphtha, the real reactions that occur in the catalytic reformation are numerous. However, some of the many resulting products are aryl or aromatic compounds, all of which exhibit high octane numbers. The aryl compounds produced depend on the starting materials that in a refinery are controlled by the boiling scale of the naphtha used and the source of crude oil. The "reformed" product from a catalytic reforming process is commonly called reformed and is frequently separated into two fractions by conventional distillations, a light reformate having a boiling range of about 46.1-121.1 ° C (115-250 ° C) F) and a heavy reformer having a boiling scale of 121.1-176.6 ° C (250-350 ° F). The aryl compounds in each fraction therefore depend on their boiling points. The light reformate contains lower boiling or lighter aryl compounds, for example, benzene and toluene. Light reforming is that portion that contains benzene and lighter components. Now the complex model for gasoline requires the strict reduction of benzene content of gasoline, while maintaining the_ octane of gasoline. An effective means of achieving this is the lease of benzene, although olefin streams for that purpose may be expensive or otherwise employed. Thus in one embodiment of the present invention the olefins normally intended for the fuel gas are used for the alkylation. Benzene is also contained in appreciable amounts and in other refinery streams such as direct-acting naphtha and to a lesser extent naphtha for catalytic piezo-pyrolyzers. The conventional method of producing benzene for the alkylation reaction has been the extraction of benzene solvent from such mixed refinery streams followed by distillation to remove the benzene from higher boiling point aromatics such as toluene and Also, a considerable amount of energy must be applied to separate the solvent from the extracted aromatic compounds. The annihilation of the benzene contained in a naphtha from a catalytic reformer unit has been eliminated. suggested in U.S. Patent 5,082,990 which also suggests the use of the concurrent reaction / distillation previously described, however, the alkylation of benzene is simply to reduce the concentration of benzene to meet the expected EPA requirements and improve the octane. The olefins used for the alkylation are contained in another mixed refinery stream which generally consists of a discharge gas from a catalytic piezo-pyrolysis unit. The mixture of olefins together with the mixture of aromatic compounds leads to a complex mixture of products which may include alkylated toluene and dialkylated products. This is not a problem in a process described since the purpose is to produce gasoline. - More recently it has been found that a primary cause of catalyst deactivation in aromatic alkylation processes is the presence of high concentrations of olefin. The inventors of the present have determined that an exponential ratio exists between the olefin concentration and the catalyst life, therefore, the alkylation requires careful control of the olefin reagent, in addition, the deactivation is faster with higher olefins than C4 The light reformate itself also contains "olefinic compounds that are high boiling. Likewise, "benzene from steam or catalytic piezo-pyrolysis also contains appreciable olefins." Higher-boiling olefins are longer-chain unsaturates that can also react with aromatics or with themselves.

The reaction of these higher olefinic compounds is undesirable because they cause coking and contamination of the catalyst causing accelerated curing of the catalyst. * A problem associated with the use of direct-acting naphtha or naphtha from a stream or the catalytic piezo-pyrolyzate process is that naphtha may contain sulfur contaminants, such as thiophene, which in "the boiling scale of benzene It is in piezo-pyrolyzed naphthas as centanes in direct-acting naphthas.Thophene is an undesirable contaminant in either ethylbenzene or eumeno.Sulfur contaminants, such as -the ones that can be found in direct-acting naphtha from of a crude distillation column may also be mercaptans which are poisons for the olefin hydrogenation catalysts It is an advantage of the present invention that the benzene in a straight operating naphtha or reforming stream is alkylated to ethylbenzene or eumeno without the step of extra solvent extraction It is another advantage of the present invention that olefins in reforming or directing naphtha stream ecta are hydrogenated to increase catalyst life. It is another advantage of the present invention that the organic sulfur is removed from the naphtha fraction " before hydrogenation to avoid poisoning the catalyst. In summary, the present invention is a process for the alkylation of aromatic compounds, in particular benzene, contained in a reformed stream, a stream of direct naphtha or another fraction of naphtha, which comprises treating naphtha to remove the unsaturated materials, which comprises olefins, diolefins and acetylenes, and then rent benzene to produce ethylbenzene or eumeno. In order to protect the hydrogenation catalyst and to otherwise improve the materials for use as gasoline components, feeds containing sulfur compounds are preferably treated to remove them, for example by hydrodesulfurization. Each stage of the process, for example, the hydrogenation of the unsaturates and the alkylation, is preferably carried out in a distillation column reactor to take advantage of the concurrent reaction and the distillation within each reactor. The olefin feed to the alkylation reaction is preferably added before the alkylation catalyst bed thus allowing the mixing of the reactants before contact with the catalyst bed.

Also, in order to achieve high selectivity towards monoalkylation (which is a preferred aspect of the present invention), there is a large excess of organic aromatic compound for the olefin in the reactor in the range of 2 to 100 moles of aryl preferably at least 50 per mole of olefin. BRIEF DESCRIPTION D? THE DRAWINGS FIGURE 1 is a schematic flow diagram of one embodiment of the invention. FIGURE 2 is a schematic flow chart of a second embodiment of the invention. In a mode used to treat the naphtha feed containing sulfur compounds, the hydrodesulfurization takes place in a first distillation column reactor that takes H2S and light-tipped vapors. The desulphurized waste is taken to a second tower that acts as a dehexanizer that takes Ce and the lighter material that contains vapors leaving benzene while saturating olefins, diolefins and acetylenes. The C7 and the heavier materials are considered as waste. The outgoing vapors are fed to a third distillation tower containing a catalyst suitable for the alkylation of benzene with either ethylene or propylene. The alkylated product, either ethylbenzene or eumeno, is removed as waste.

Unreacted lower boiling material is removed from the top. If there is no sulfur present in the naphtha, for example, a reformed naphtha, the first tower is not used. In another embodiment, the octane number of the light reformate is improved by subjecting all light naphtha to the treatment for removal of the unsaturated materials and then to the alkylation with a controlled lower olefin contained in the waste gas from an FCCU. "In one embodiment the hydrogenation is carried out in the same column as the alkylation, both being operated as catalytic distillations.The aryl compounds react catalytically with the olefinic compounds to preferably produce mono-substituted alkylated aryl compounds having an higher octane number and lower specific gravity than the original aryl compounds.At the same time, the alkylated aryl compounds: are fractionated from the unreacted materials.The catalytic distillation structure provides the catalytic sites and the distillation sites. The "alkylated aryl compounds are removed from the distillation reactor at a point below the fixed alkylation bed and the unreacted materials are removed at the top at a point on the fixed alkylation bed. The examples Suitable acid catalysts include molecular sieves (mol sieves) such as zeolites. To prevent the curing of undue catalyst from the alkylation catalyst, the higher boiling and other unsaturated olefins contained within the light reformate can be saturated by hydrogenation in a separate bed of the hydrogenation catalyst before introduction to the alkylation bed.This can be done in a conventional fixed bed in front of the reactor of distillation column.More preferably the hydrogenation is carried out in a distillation reaction zone in the distillation column reactor located below the alkylation zone.The alkylation olefin, for example, the FCCU discharge gas must be fed on the -hydrogenation zone "and below the alkylation zone where it is combined with the light reforming having a reduced olefin content that rises from the hydrogenation zone. As in the alkylation zone, the catalyst is in the form suitable for a distillation structure. The "source of the aromatic component can be from catalytic reforming or from a steam, a catalytic piezo-pyrolyzed process, or a crude distillation (direct-acting naphtha)." As noted above, the boiling material (43.3 ° -121.1 ° C) (110-250 ° F) - light reforming from a catalytic reformer can contain appreciable quantities of higher olefin. Light naphtha from steam or catalytic piezo-pyrolysis processes contain more of the higher olefins and in addition appreciable amounts of organic sulfur compound, predominantly mercaptans and some thiophenes. Thiophene in particular is considered a contaminant of benzene and benzene products. The olefin source may be a relatively pure stream or from the FCCU as described above. In a catalytic fluid pyrolysis, a "gas oil" stream having a boiling range of about 315.5-704.4 ° C (600-1300 ° F) is combined with a fine catalytic substance, usually a zeolite material, high temperatures, approximately 482.2-565.5 ° C - (900-1050 ° F), which separate or divide the longer chain hydrocarbons into shorter chain hydrocarbons. Some gas is produced, of the amount that depends on the severity of the separation, the gas that is also rich in saturated compounds, that is, ethylene, propenes and butenes. Since the compounds have value, they are usually recovered and used or sold separately. However, the unsaturated compound or olefin separation results in "waste gas" having an olefin content of up to 10 moles as a percentage. This waste gas is normally used as fuel in refinery heaters. This stream is also an adequate source of olefins for the alkylation described herein. The FCCU waste gas contains a variety of non-recovered olefins, although the predominant olefinic compounds are ethylene, propylene (propenes) and butenes. The rest of the gas is made up of several saturated hydrocarbons. The typical total olefin content is 42.1 percent, divided into ethylene, 11.1 percent, propene, 30.6 percent; and butenes and higher compounds, 0.4 percent. In any case, the olefinic components contained in the waste gas will always have a boiling point than the higher olefins of the light naphtha. In the most general mode, the purpose is to improve the octane of a light reformer. The boiling of the complete light reformate at about 43.3-121 ° C (110-250 ° F) is fed together with the hydrogen to a distillation column reactor below a distillation zone containing hydrogenation catalyst in the form of a structure of catalytic distillation where the olefinic materials contained in the reformate are saturated leaving the aromatic compounds. A gas containing controlled olefin containing only lower olefins such as the FCCU waste gas described above is fed over the hydrogenation zone but below a zone of alkylation in the distillation column reactor. The light reforming of the removed olefins is consumed in the alkylation zone containing the alkylation catalyst also in the form of a catalytic distillation structure where the aromatics are alkylated by the lower olefins. The alkylated aromatics are distilled downwards and are eventually taken as residues from the distillation column reactor. The unreacted materials are taken as outgoing vapors with most of which are returned as reflux. In a preferred embodiment, the naphtha and the hydrogen are fed below a hydrogenation / distillation zone in a first distillation column reactor. The molar ratio of hydrogen to olefin in the naphtha is from about 10 to 1, preferably 1.5 to 1. The olefinic compounds in the light reforming are combined with hydrogen in the presence of the hydrogenation catalyst to saturate substantially all of the olefinic material. The conditions within the hydrogenation zone are such that the olefins are hydrogenated although the aromatics remain. The first distillation column reactor is operated as a dehexanizer to remove the C, and the lighter material containing the benzene as outgoing vapors. The C7 and the heavier materials "are removed as waste. The waste material can be passed to the gasoline mixture tank or sent to a hydrodealkylation unit for additional production of benzene. "The hydrocarbon stream containing olefins together with a stream of hydrogen at a hydrogen partial pressure of at least 0.1 psia to less than 70 psia, preferably less than 50 psia is fed to a distillation column reactor. Very low totals can be used for optimal results in some of the current hydrogenations, preferably in the range of 50 to 150 psig with the same excellent results.Catalysts that are useful in the hydrogenation reaction used in the invention include Group metals VIII Any suitable hydrogenation catalyst, for example Group VIII metals of the Periodic Table of the Elements as the main catalyst component, can be used alone or with promoters and modifiers such as palladium / gold, palladium / silver, cobalt / zirconium, platinum , nickel preferably deposited on a support such as alumina, refractory brick, pumice stone, bond, silica, resin or similar. Generally the metals are deposited as the oxides on an alumina support. The supports are usually extruded or spheres of small diameter. He The catalyst must then be prepared in the form of a catalytic distillation structure. The catalytic distillation structure must be able to function as a catalyst and as a mass transfer medium. The catalyst must be adequately supported and separated within the column to act as a catalytic distillation structure. In a preferred embodiment the catalyst is contained in a woven wire mesh structure as described in U.S. Patent No. 5,266,546, which is incorporated for reference. Other catalytic distillation structures useful for this purpose are described in U.S. Patent Nos. 4,731,229, 5,073,236 and 5,431,890 which are also incorporated for reference. The present invention performs hydrogenations in a packed catalyst column which can be seen to contain a vapor phase and some liquid phase as in any distillation. The distillation column reactor is operated at a pressure such that the reaction mixture is boiling in the catalyst bed (distillation conditions). The current process for olefin saturation operates at the top pressure of the distillation column reactor on the scale between 0 and 350 psig, preferably 250 or less adequately at 35 to 120 psig, and temperatures in the distillation reaction residue zone in the range of 65.5 to 110 ° C (150 to 230 ° F), preferably from 79.4 to 93.3 ° C (175 to 200 ° F), for example 79.4 to 82.2 ° C (175 to 180 ° F) at the required partial pressures of hydrogen. The space velocity per hour by weight of feed (WHSV), which is comprised herein to represent the feed unit weight per hour entering the reaction distillation column per unit weight of the catalyst in the feed structures. Catalytic distillation can vary over a very wide range within other condition parameters, for example 0.1 to 35 hr "1. In the current process the temperature is controlled by operating the reactor at a given pressure to allow partial vaporization of the reaction mixture The exothermic heat of the reaction is therefore dissipated by the latent heat of the vaporization of the mixture.The vaporized portion is taken as outgoing vapors and a portion of the condensable material which condensed and is returned to the column as reflux The liquid flowing down causes additional condensation inside the reactor as is normal in any distillation. of condensation liquid inside the column provides excellent mass transfer to dissolve the hydrogen inside the liquid reaction and the "concurrent transfer of the reaction mixture to the catalytic sites." Although this mode of operation condensation results in the excellent conversion and selectivity of the current process and allows the lower partial pressures of the hydrogen and the observed reactor temperatures. additional is that - this reaction can gain from the catalytic distillation which is the washing effect that the rnal reflux provides to the catalyst thus reducing the accumulation and coking of the polymer.The rnal reflux can vary over the range of 0.2 to 20 L / D (liquid weight just below the distillate bed / catalyst weight) to give excellent results The "residues from the second distillation column reactor are fed to a third distillation column that serves as the alkylator. The third distillation column reactor contains a catalytic distillation structure in the upper portion which is an acid catalyst contained in a vessel of suitable distillation structure. The residues from the second distillation column reactor and the olefin, either ethylene or propylene, are fed below the catalyst bed. Also, in order to achieve high selectivity towards monosubstitution (which is a preferred aspect of the present invention), there is a large excess of benzene for the olefin in the reactor in the range of 2 to 100 moles of benzene per mole of. olefin, ie the net molar feed ratio of benzene to olefin may be close to 1: 1, although the system is operated to main a substantial molar excess of benzene to olefin in the reaction zone. The benzene within the stream reacts with either ethylene or propylene to form the desired alkylated product-methylbenzene or eumeno. The alkylating product is removed as waste and the unreacted material is removed as leaving vapors Suitable acidic catalysts include molecular sieves (mol sieves) and cation exchange resins More specifically the molar sieve or the resin catalyst package Cation exchange is of such a nature that it allows the flow of steam through the bed, providing a sufficient surface area for catalytic contact as described in the previously noted US Patents Nos. 4,215,011, 4,302,356 and 4,443,559 which are incorporated herein. The "catalyst" package is preferably placed in the upper portion of the distillation column reactor, most preferably occupying one third to one half of the column and extending substantially towards the upper end of the column. .

The success of catalytic distillation is supported by an understanding of the principles associated with distillation. First, because the reaction is occurring concurrently with the distillation, the initial reaction product is removed from the reaction zone as fast as it is formed. The removal of the alkylation product minimizes polysubstitution, decomposition of the alkylation product and / or oligomerization of the olefin. Second, since the reaction mixture is boiling, "the temperature of the reaction is controlled by the boiling poof the mixture at the pressure of the system." The heat of the reaction simply creates more boiling, but the temperature increases. the reaction has an increased driving force because the reaction products have been increased and can not contribute to a reverse reaction (Le Chatelier's Principie) As a result, a large amount of control over the scale of the reaction and the distribution of the products can be achieved by regulating the pressure of the system, and by adjusting the production (dwell time = space velocity per hour of liquid) it gives greater control of the product distribution and the degree of olefin conversion. in the reactor is determined by the boiling poof the liquid mixture present at any given pressure. lower portions of the column will reflect the composition of the material in that part of the column, which will be "greater than the outgoing vapor, that is, at constant pressure a change in temperature in the system indicates a change in the composition in the column. To change the temperature, the pressure is changed, the temperature control in the reaction zone is controlled by pressure, increasing the pressure, the temperature in the system increases and vice versa, it can also be seen that in the catalytic distillation as in any distillation there is a liquid phase (internal reflux) and a vapor phase.Therefore, the reagents are partially in liquid phase allowing a denser concentration of molecules for the reaction, considering that the concurrent fractionation separates the product and materials unreacted, providing the benefits of a liquid phase system (and a vapor phase system) while avoiding the detriment of having all the components of the reaction system continuously in contact with the catalyst which would limit the conversion for the equilibrium of the components of the reaction system. Referring now to FIGURE 1, the simple octane improvement process is shown. The distillation column reactor is shown at 10 with the upper and lower quarters of the column filled with the structure of standard distillation, for example, packaging or trays. The upper middle section of the column is filled with the alkylation catalytic distillation structure as indicated at 12. The light reforming feed is fed into the column below the catalytic hydrogenation reaction zone 14 by means of line 2 The hydrogen can be fed via line 15 by mixing with the light reforming or directly (not shown) in the column under the bed 14. Saturated compounds are substantially completely removed and light reforming passes from the hydrogenation zone for mixing with the olefin feed from line 2 which is free of inherent unsaturates. This allows control of the total olefin in the alkylation zone and removes the undesirable higher olefins.The FCCU gas is fed into the column below the catalytic reaction zone 12 by "means of line 1. The olefinic compounds in The FCCU gas reacts with the aryl compounds in the light reforming in the reaction zone to form higher boiling arylated aryl compounds that are distilled out of the catalyst within the lower distillation section. Any unreacted light reformate and FCCU gas that can be brought down and boil again within the reaction zone for "additional" reaction, while the "bottom product" comes out of the bottom from the column through the line 8. Generally the lightest unreacted components are taken through the upper part through line 5 to the condenser 13 where the unreacted light reforming condenses. The unreacted products combined (gas and reformed) are then passed to the accumulator 11 through line 4 where the gases are allowed to separate from the liquid reforming. The "unreacted gases are taken to the upper parts of the accumulator by means of line 3 and the liquid light reformat taken where it can be sent to the distillation colurana as reflux by means of line 6 or recombined with the alkylated product by means of of line 7. The recombined product having a higher octane number and a lower specific gravity than the original light reformate can be taken for storage by means of line 9. Such conventional articles as valves, reheaters, slide currents, etc. are not shown, although it would be obvious to those installing such equipment.A general process scheme can be seen in FIGURE 2. A C5 naphtha at 204.4 ° C (400 ° F) contains aromatics, olefins and alkanes, is fed by means of the flow line 101 to a first distillation column 110. The first distillation serves as a reactor of desulphurisation to remove H2S and light-tip salient vapor 102. The distillation reaction zone 128 contains a hydrodesulfurization catalyst prepared as a distillation structure. The hydrogen by means of line 104 is fed to the reactor concurrently with the hydrocarbon. The C5 and the heavier material are taken as waste from the distillation column 110 via line 107 and combined with hydrogen from the flow line 103 in the flow line 105 for feed to a column reactor. distillation 130 under a distillation reaction zone 132 containing a hydrogenation catalyst prepared as a catalytic distillation structure. Olefins, diolefins and acetylenes "are saturated while leaving the unsaturated aromatics C7" and the heavier hydrocarbons are taken as waste from tower 130 by means of line 109. Fraction C5 and Ce is taken as steam outgoing 131 to a capacitor / accumulator 136/137 that allows excess hydrogen to vent. A portion of the upper liquid fraction is returned as reflux to column 130 and a portion is fed via line 111 to tower 140 below a distillation reaction zone 134 which contains an alkylation catalyst prepared as a catalyst structure. catalytic distillation. The appropriate olefin, ethylene or propylene, is fed through the line 121. The alkylate product, either ethylbenzene or eumeno, which "is of a higher boiling point than the feed, is removed as a waste by means of line 119. The material without reaction exits above, by means of line 135 and it is condensed and accumulated in a condenser / accumulator 138/139 and a portion returned to column 140 as reflux and a portion removed above, by means of flow line 117. Any such polyalkylated products, such as diethylbenzene or dipropylbenzene, are removed As residues, polyalkylates can be separated from mono-substituted products and recycled to the reactor for conversion to mono-substituted products. The three columns would include upper capacitors and waste reheaters all of which are not shown!

Claims (18)

1. CLAIMS 1. A process for the alkylation of aryl compounds contained in a light reformate characterized in that it comprises: (a) treating a light reformate containing aryl compounds and unsaturated compounds to remove the unsaturated materials, (b) feeding the treated light reformate and an olefin lower than an aromatic alkylation zone under alkylation conditions to react at least a portion of the aryl compounds with the lower olefinic compounds to form a reaction products containing alkylated aryl compounds having a higher octane number and a higher specific gravity than the aryl compounds in the light reforming stream; And (c) fractionating the reaction product to remove a fraction of heavier alkylated aryl compounds and a lighter non-alkylated fraction.
2. 2. A process for the alkylation of the aryl compounds contained in a light reformate characterized in that it comprises: (a) treating a light reformate containing aryl compounds and unsaturated compounds to remove the unsaturated materials, (b) feeding the treated light reformate and an olefin lower than the distillation column reactor where (c) concurrently! (I) the boiling of the light reformate in a distillation reaction zone containing a fixed bed acid catalyst prepared as a distillation structure catalytically reacts this way in at least a portion of the aryl compounds with the lower olefinic compounds to form alkylated aryl compounds having a higher octane number and a lower specific gravity than the aryl compounds in the light reforming stream; and (II) fractionating the resulting aryl-alkylated compounds from the unreacted material; (d) removing the alkylated aryl compounds from the distillation column reactor at a point below the reaction zone; and (e) removing unreacted materials from the distillation column material at a point on the reaction zone. 3_.
3. The process according to claim 2, characterized in that the unsaturated compounds are removed from the light reformate by hydrogenation of the light reformate.
4. 4. The process in accordance with the claim 3, characterized in that it further comprises (a) feeding the light reformate containing unsaturated compounds to a distillation column reactor, which contains a hydrogenation catalyst prepared as a distillation structure, within a hydrogenation feed zone; (b) feeding the hydrogen into the feed zone, and "(c) contacting the light reforming stream and the hydrogen with the catalytic distillation structure of hydrogenation in a distillation reaction zone by catalytically reacting in this manner at least a portion of the unsaturated compounds to form saturated compounds 5.
5. The process in accordance with the claim 4, characterized in that the unsaturated compounds comprise higher olefins.
6. The process according to claim 2, characterized in that it further comprises separating any unreacted gas from any unreacted light reformat and combining the alkylated aryl compounds with the unreacted light reformate to provide a mixture having a higher number octane than the light reforming stream.
7. 7. The process for the alkylation of benzene contained in a light naphtha comprising the steps of: (a) "feeding (I) a stream of naphtha" "containing benzene, olefins, diolefins, acetylenes and organic sulfur compounds and (II) hydrogen to a first distillation column reactor where the organic sulfur compounds are hydrogenated to H 2 S which is withdrawn as leaving vapors together with the light ends, and C 5 and the heavier materials are removed as waste, (b) to feed the waste containing benzene and olefins and additional hydrogen to a second distillation column reactor where olefins, diolefins and acetylenes are hydrogenated to alkanes and the CG and lighter material are separated as second vapors from C7 and the heavier material that is considered as' waste; (c) feeding the second leaving vapors together with an olefin selected from the group consisting of ethylene and propylene to a third distillation column reactor where the benzene reacts with the olefin to produce an alkylated product, and the alkylated product is separated as a third residue from the rest of the material O, and C6 which is taken as vapors leaving from the third distillation column reactor.
8. 8. The process in accordance with the claim 7, characterized in that the olefin is ethylene and the alkylated product comprises ethylbenzene.
9. 9. Processed according to claim 7, characterized in that the olefin is propylene and the product acylated comprises eumeno.
10. 10. The process in accordance with the claim 8, characterized in that the acylated product further comprises diethylbenzene.
11. 11. The process in accordance with the claim 9, characterized in that the alkilateted product also comprises dipropylbenzene.
12. 12. "The process according to claim 7, characterized in that the partial pressure of hydrogenation within the first distillation column reactor is less than 70 psi
13. 13. The process according to claim 7, characterized in that the partial pressure of hydrogen within the second distillation column reactor is at least 70 psi
14. 14. The process according to claim 7, characterized in that the molar ratio of the benzene to the olefin within the third distillation column reactor is about 20: 1.
15. 15. The process according to claim 8, characterized in that the third waste stream is substantially pure ethylbenzene.
16. 16. The process according to claim 9, characterized in that the third waste stream is substantially pure eumeno.
17. 17. A process for the production of eumeno characterized in that it comprises the steps of: (a) feeding (I) a stream of naphtha containing benzene, olefins, diolefins, acetylenes and organic sulfur compounds and (II) hydrogen to a first reactor from distillation column where the organic sulfur compounds are hydrogenated to H2S which is removed as vapors outgoing together with the light ends, and Cs and the heavier materials are removed as waste, (b) to feed the vapors leaving benzene and olefins and additional hydrogen to a second distillation column reactor where olefins, diolefins and acetylenes are hydrogenated to alkanes and C6 and lighter material are separated as second vapors from C7 and the heavier material that is considered as waste; (c) feeding the second leaving vapors together with the propylene to a third distillation column where benzene reacts with propylene to produce eumeno and eumeno is separated as a third residue from the rest of material C5 and Cg that is taken as vapors from the third distillation column reactor
18. 18. A process for the production of ethylbenzene characterized in that it comprises the steps of: (a) feeding (I) a stream of naphtha containing benzene, olefins, diolefins, acetylenes and organic sulfur compounds and (II) hydrogen to a first distillation column reactor where the sulfur compounds organic are hydrogenated to H2S which is removed as vapors along with the light ends, and C5 and the heavier materials are removed as waste, (b) to feed the vapors that contain benzene and olefins and additional hydrogen to a second reactor. of distillation column where the olefins, diolefins and acetylenes are hydrogenated to aléanos and the C6 - and the lighter material is separated or second vapors leaving from C7 and the heavier material that is taken as waste; (c) feeding the second leaving vapors together with ethylene to a third distillation column reactor where the benzene reacts with ethylene to produce ethylbenzene and the ethylbenzene product is separated as a third residue from the Cg material which is combusted as vapors from the third distillation column reactor.