JPS6121927B2 - - Google Patents

Description

[Detailed description of the invention]

Catalytic alkylation of isobutane is known in the art and involves combining olefins and isobutane in the presence of an acid catalyst to produce high octane single branched chain hydrocarbons (alkylates) for use in aviation gasoline and motor fuels. It is. In particular, olefin and isobutane are combined in a reactor in the presence of an acid catalyst and an exothermic reaction occurs. The acid is then separated from the reactor effluent. After separation of the acid, the reactor effluent goes to a series of distillation columns to separate the inert alkanes, unreacted isobutane for recycling, and recover the alkylate. Treatment is also carried out on some of the effluent to remove residual acids and undesirable reaction products. A variation of this process was to use vaporization of a portion of the reactor effluent for reactor cooling.
(See Hydrocarbon Processing, September 1974, p. 206.) Current art alkylation methods have several drawbacks. First, a large amount of refrigerant, usually water or air, is required to condense the overhead stream from the distillation column. Second, only a portion of the reactor effluent is evaporated when cooling the reactor. This vapor is recovered as isobutane for recycling. The residual liquor containing the alkylate and a large amount of isobutane must be treated to remove contaminants such as residual acid and distilled to separate the isobutane and alkylate. The larger the stream, the larger the deisobutanization tower needs to be, and the more heat required to effect the separation. The present invention reduces or eliminates these drawbacks and also substantially reduces the energy required for the process. The present invention comprises (a) contacting an olefin with a molar excess of isobutane and an inert alkane in the liquid phase in a reactor in the presence of an acid catalyst to react substantially all of the olefin, thus reacting the acid catalyst and the alkylate, isobutane; obtaining a liquid quantity comprising a hydrocarbon mixture comprising an inert alkane; (b) separating the acid catalyst from the hydrocarbon mixture; (c) separating the hydrocarbon mixture of (b) in a gas-liquid separator; (d) compressing and condensing the vapor overhead stream of (c) in a compressor effluent condenser to obtain a liquid residue containing isobutane and alkylate and a vapor overhead stream containing isobutane and an inert alkane; (e) distilling the liquid residue of (c) or the condensed overhead vapor stream of (d) in one or more distillation columns with one or more column condensers; In a process for the catalytic alkylation of isobutane with olefins, which consists of separating isobutane from inert alkanes and alkylates, a portion of the hydrocarbon mixture of (b) is evaporated and a group consisting of a column condenser or compressor effluent condenser is used. An improved method characterized by cooling one or more condensers selected from: In other words, the present invention involves reacting an olefin and a molar excess of isobutane in the presence of an acid in an alkylation zone to form a liquid effluent, removing the liquid effluent from the alkylation zone, and removing the liquid effluent from the alkylation zone. treating a liquid to recover an alkylate, the treatment comprising evaporating at least a portion of the liquid effluent to form a vapor and subsequently condensing the vapor by cooling; The improvement according to the invention is characterized in that the liquid effluent from the alkylation zone is cooled by passing it into indirect heat exchange with the vapor to be condensed. Using the present invention, the amount of isobutane that must be treated and recovered in the distillation column can be significantly reduced, cooling water for the column overhead condenser is no longer required, and the various distillation columns can be operated at substantially lower pressures. Enhances the separation process. A key feature of the invention is the use of reactor effluent to cool the condenser in the alkylation process. By using the effluent in this manner, there are substantial savings in operating costs and investment in new equipment. In FIG. 1, olefin and isobutane feeds are placed in a pressure reactor containing an acid catalyst. The stream exiting the reactor contains acid catalyst, alkylate, isobutane, and inert alkanes. This stream is then sent to an acid separator where the acid catalyst is separated from the hydrocarbon mixture and returned to the reactor. The resulting hydrocarbon mixture is 1
to one or more condensers to provide the necessary cooling. The use of this hydrocarbon mixture for condenser cooling is the invention. The effluent from the condenser then passes to a gas-liquid separator where the isobutane is partially recovered as a vapor. This vapor is compressed, condensed and returned to the reactor by a process not shown in the drawings. The liquid from the separator passes to a deisobutanizer where the isobutane is distilled overhead for recycle and the alkylate product is recovered as a bottom stream. In more detail in FIG. 2, olefin and isobutane are mixed in line 101 and reactor 10
3, where the reactants are mixed with an acid catalyst and
Reacts to form an alkylate. The product exits the reactor through line 105 and goes to acid separator 107. Here the acid is separated from the hydrocarbon mixture and
It is returned to the reactor through line 108. A hydrocarbon mixture containing alkylate, isobutane, and inert alkanes leaves the acid separator through line 109. This hydrocarbon mixture flows through lines 111 and 11.
2 to cool the condenser. In particular, line 111 shows how the invention can be applied to a deisobutanizer. The hydrocarbon mixture is passed through line 111 to condenser 115 where at least a portion of the hydrocarbon mixture is vaporized to provide cooling to the condenser. After providing cooling, the hydrocarbon mixture is passed through line 116 to gas-liquid separator 117. In the same manner, the hydrocarbon mixture is passed through line 112.
is removed from the other column condenser and compressor effluents by removing at least a portion of the hydrocarbon mixture in the condenser and sending the condenser effluent through line 114 to gas-liquid separator 117. Provide cooling to other condensers such as liquid condensers. In a similar manner, the hydrocarbon mixture is used to cool the reactor via line 110 and then air is passed through line 113.
Send to liquid separator. Gas-liquid separation is performed in the gas-liquid separator 117. The vapor contains primarily isobutane and inert alkanes, and the liquid contains isobutane and alkylate. Steam is sent through line 118 where it is compressed and condensed in steam system 119. Steam system 119 typically uses one or more columns to remove inert alkanes, such as propanes, from isobutane. Then the isobutane flow is on line 1.
20 and is sent to the second gas-liquid separator 121. The liquid isobutane stream is returned to the reactor through line 122 and the vapor is returned to the steam system through line 118. The liquid from the first gas-liquid separator 117 containing isobutane and alkylate passes through line 123 to treatment zone 125 where residual acid and acidic compounds in the hydrocarbon mixture are removed.
After treatment, the liquid is sent through line 129 to deisobutanizer 131. Heat is applied to the column by line 133. Isobutane is distilled, line 1
35 exits the tower as vapor. This vapor is condensed in overhead condenser 115 and the condensed isobutane is split for reflux to the column and as recycle through line 137 to the reactor. The alkylate product is recovered through line 139 as a liquid residue. FIG. 3, which is similar to FIG. 2, shows another embodiment of the invention. The hydrocarbon mixture containing alkylate, isobutane, and inert alkanes is in line 1.
Exit the acid separator through 09. The hydrocarbon mixture is then passed through lines 111 and 1
12 to provide cooling to the condenser. line 111
, a pressure reducing valve 141 is located before the column condenser 115. This valve maintains the hydrocarbon mixture in line 111 in a liquid state. The above valve is the condenser 11
5 and exits line 116, allowing for a downstream pressure reduction of the hydrocarbon mixture. The pressure is reduced sufficiently to allow vaporization of the hydrocarbon mixture in condenser 115. Some evaporation occurs through valve 141 and condenser 11.
It can occur between 5. A similar valve 140 is shown that reduces the pressure of the hydrocarbon mixture in line 110 that provides cooling to reactor 103. Other pressure reducing valves (not shown) can also be found in line 112 going to other condensers. FIG. 3 also shows a deisobutanizer 131 with a vapor side draw 142. n-Butane can be removed from this column as vapor in line 142 and condensed in column condenser 143. Typically, a refrigerant is used in line 144 to provide cooling to condenser 143.
However, this cooling can also be provided using a hydrocarbon mixture in line 112 with a suitable pressure reducing valve. Side-drawing n-butane can be used in other embodiments of the invention as well as the embodiment specifically shown in FIG. FIG. 4 shows a steam system that can be used as steam system 119 in the apparatus of FIG. After being used as a refrigerant, the hydrocarbon mixture passes through line 113 to air.
It is sent to liquid separator 117 where gas-liquid separation occurs. Steam is sent through line 118 to compressor 145. The vapor is then compressed in a compressor and exits through line 146 to compressor effluent condenser 147.
Cooling is provided by line 148 to condenser 147 to condense the compressed vapor effluent. The cooling means can be chilled water, but in other embodiments of the invention 112 hydrocarbon mixtures with suitable pressure reducing valves can also be used. The compressed and condensed vapor effluent exits the condenser through line 149. A portion of this compressed and condensed effluent passes through line 150 to distillation column 152. The remainder is sent through line 151 to second gas-liquid separator 121, as also shown in FIG. Typically, distillation column 152 is a depropanizer. Heat is applied to the column by line 153. The propane is distilled and exits the column overhead as vapor in line 154. This steam is transferred to the overhead condenser 155.
It is condensed in In one embodiment of the invention, line 1
A mixture of 12 hydrocarbons is used to cool the condenser after depressurization. After providing cooling, the hydrocarbon mixture is
It is sent to a gas-liquid separator 117 through line 114 as shown. Condensed propane from condenser 155 is routed to line 15
6 and is divided for reflux to the column and removed as product through line 157. The bottom product of this column, containing primarily isobutane, is sent to line 158.
and is sent to the gas-liquid separator 121. Yet another embodiment of the invention is shown in FIG. In this embodiment, the alkylation reaction is carried out in such a way that a vapor effluent and a liquid effluent are produced by the alkylation reactor. This method is well known, as exemplified by Massan, US Pat. No. 3,187,066 (republished as Re 26060). As shown in FIG.
from there to reactor 172 where an alkylation reaction occurs. The resulting vapor reaction effluent is transferred to reactor 172.
via conduit 176 and sent to a conventional steam system 178 for isobutane recovery. Liquid reaction effluent exits reactor 172 through conduit 180;
It is sent to condenser 182 where it is partially evaporated.
The partially vaporized liquid reactor effluent is passed through conduit 184 to a gas-liquid separator 186 where vapor and liquid are separated from each other. Separated steam is transferred to conduit 1
88 to steam system 178 where reactor 1
It is processed along with the steam reactor effluent produced at 72. The liquid stream exiting the gas-liquid separator 186 is routed through conduit 19.
0 to the deisobutanizer 192, where it is separated. Alkylate products are removed from the isobutanizer tower 1.
92 via conduit 194 as column bottoms, while isobutane-enriched vapors exit deisobutane column 192 via conduit 196. conduit 196
The isobutane-enriched vapor therein passes through condenser 182 and therein in indirect heat exchange relationship with the liquid reactor effluent obtained from reactor 172. Due to the cooling effect created by the evaporation of the liquid reactor effluent in condenser 182, the isobutane-rich vapor in condenser 182 condenses into an isobutane-rich liquid stream.
A portion of this isobutane-rich liquid stream is routed through conduit 1
98 for reflux, and the remainder is sent to conduit 200
and then recycled to reactor 172. Condensed isobutane recovered from vapor system 178 is also recycled to reactor 172 via conduit 202 as shown. As those skilled in the art will appreciate, steam system 178 typically includes a compressor to facilitate condensation of the steam sent thereto. According to the invention, this compressor can be a multi-stage compressor if desired, and furthermore, the steam fed to the compressor from the gas-liquid separator 186 or similarly from the gas-liquid separator 121 of FIG. of,
Rather than being sent to the first stage of this compressor, it can also be sent to the second stage. The advantages of the invention are numerous. First, the feed to the deisobutanizer is reduced, thereby reducing the volume of the process stream. Typically, this treatment consists of an alkaline wash followed by a water wash. The size of the alkaline processor is reduced and the cost of the necessary equipment is saved. The second advantage is the size of the deisobutanizer. Since more isobutane is evaporated in the reactor effluent, less isobutane needs to be recovered in the distillation column. This means a reduction in both the size of the column and the heat input required for operation. Still further advantages are found by using the effluent stream as a cooling medium for overhead condensers located on other distillation columns of the process, such as deisobutanizers and depropanizers, debutanizers. The use of an effluent stream allows lower operating temperatures and pressures in this column than can be achieved using water or air. Also, not using water as a refrigerant can reduce or eliminate the size of associated equipment such as cooling towers. This reduction in column operating temperature and pressure serves to increase the relative volatility of the base components and means that less energy input in hot form is required to perform the necessary separations. Unique savings in equipment efficiency are made because the water used to condense overhead is no longer needed and the heat to the separation column is reduced. The present invention will be explained below using preferred specific examples. In a preferred concept of the invention, the reactor effluent, after acid separation, is sent to an overhead condenser on the distillation column in the process. This concept is preferred because lower temperatures can be achieved using reactor effluent than when using cooling water. The lower temperature and pressure of the column significantly enhances the separation process. 1
If more than one condenser is to be cooled by the effluent stream, they can be connected in parallel or in series. Preferably, they are connected in parallel to minimize cost. There are typically at least two distillation columns, a deisobutanizer for separating isobutane from the alkylate product and a depropanizer for removing lighter propane from the isobutane. In some cases a third column is also included to separate butane from the alkylate. A variation of the invention is to use the reactor effluent stream at other points in the process that require cooling. This can be in addition to, or exclusive of, the overhead condenser cooling on the distillation column. Condensers are also commonly located at other locations in the distillation column, such as for cooling liquid residues or condensing vapor sidestream withdrawals. For example, instead of having a de-butanizer, butane can be removed from the process as vapor drawn from a point in the de-isobutanizer. The reactor effluent can be used to condense this vapor to obtain a liquid butane product. Another variation of the invention is to use the reactor effluent to cool the compressed vapor effluent stream from the first gas-liquid separator. This compressed vapor containing isobutane and some inert alkanes needs to be condensed before being sent further to the distillation column to remove the inert alkanes or before being returned to the reactor as recycled isobutane.
The reactor effluent can be used in the vapor compressor effluent condenser, thereby eliminating additional use of cooling water. The present invention can be used in any catalytic alkylation process involving acid catalysts. Acid catalysts that can be used are known in the art and include, but are not limited to, sulfuric acid and hydrofluoric acid. Preferred in the present invention is the use of a sulfuric acid catalyst. The reaction conditions and parameters remain unchanged according to the present invention. Usually the reactor is 1~200Psig and -10~50℃
operated at a temperature of Olefin feeds to alkylation processes are also known in the art and are typically hydrocarbons having 2 to 5 carbons and are not affected by the present invention. Typically the composition of the olefin feed will depend on the particular application, but may consist of propylene, butenes or amylenes. The olefin feed may also contain various inert alkanes such as propane, butane. The olefin can be mixed with isobutane before or in the reactor. Generally, the higher the ratio of isobutane to olefin in the feed stock, the higher the alkylate yield. This external ratio is usually about 5 to 1, but can be 15 to 1 or more. The present invention takes advantage of this ratio by recovering isobutane for recycling in a more efficient and less expensive manner than current technology. By using the present invention with existing equipment, this ratio can be increased, thereby improving the octane number of the product without being limited by the size of the deisobutanizer. As mentioned above, when desired, the hydrocarbon mixture being used to provide cooling can be passed through a pressure reducing valve before entering the condenser. The pressure is reduced sufficiently to allow evaporation and provide greater cooling within the condenser. The pressure can be reduced from 1 to about 50 psig. Preferably, this pressure is reduced from 3 to about 5 psig. Example 1 and Comparative Example A Hydrocarbon Processing Literature 1974,
A computer simulation of the alkylation method was performed as described in the September issue, page 206. Sulfuric acid was used as the acid catalyst. The reactant feed for both examples is shown in Table 1 in barrels/day and is a combination of isobutane, butylene, and inert alkanes. Table 1 Reactant Feeds to the Alkylation Process Isobutane 3830 Butylene 3090 Inert Alkane 1385 For comparison, the amount of product and its 98.5 octane number were kept constant in both examples. Isobutane in the reaction zone was kept at 80% of total feed and recycle. Due to the large amount of inert alkanes recycled into the effluent cooling stream in this invention, this has the effect of increasing the isobutane/olefin ratio in the reactor.
Other reactor operating conditions were the same in both cases. Comparative Example A illustrates existing technology. The reactor effluent after acid separation was used to cool the reactor. After cooling, the effluent was sent to the first gas-liquid separator. The liquid from this separator constituted the treated stream and was sent as feed to the deisobutanizer. Chilled water was used as the refrigerant in the tower's overhead condenser. In Example 1 illustrating the present invention, the reactor effluent, in addition to cooling the reactor, was sent in parallel to the overhead condenser of the deisobutanizer. After cooling, the reactor effluent was collected in the first gas-liquid separator.
Table 2 shows the results of these two examples. Amounts shown are in barrels/day.

【table】

Table 2 As can be seen from Table 2, much more of the isobutane (IC ₄ ) contained in the reactor effluent is evaporated and recovered more efficiently. The present invention reduces the amount of isobutane feed to the deisobutanizer column by more than 40%, thereby reducing both the size of this column and the equipment required for distillation. Example 2 Using the same feed composition and reaction conditions as Example 1, Example 2 demonstrates the effectiveness of overhead condenser cooling on the deisobutanizer with reactor effluent alone. Thoroughly wipe off the cooling water, and the cooling effect of the reactor effluent will reduce the pressure of the deisobutanizer from 150 psig.
Allowed to decrease to 17 psig. This pressure reduction improves separation and reduces the amount of heat required for operation.
35.7 MMBTU/hr, over 40% less heat than required by the existing technology of Comparative Example A.

[Brief explanation of the drawing]

FIG. 1 shows a simplified block diagram of the invention. FIG. 2 shows the alkylation process of the present invention in more detail. FIG. 3 is similar to FIG. 2, but shows an embodiment of the invention in which a pressure reducing valve is used on the reactor effluent and the vapor n-butane withdrawal is from the deisobutanizer. FIG. 4 shows in more detail a steam system that can be used as the steam system shown in FIG. FIG. 5 shows yet another embodiment of the present invention in which the process is practiced in conjunction with an alkylation reactor that produces both liquid and vapor effluents.

Claims (1)

[Claims] 1 (a) A reaction involving an alkylate, isobutane, an acid catalyst, and an inert alkane by contacting an olefin with an excess molar amount of isobutane and an inert alkane in the presence of an acid catalyst in a reactor. Make a vessel effluent,
(b) separating the acid catalyst from the reactor effluent to form a separator effluent; and (c) performing liquid-gas separation on the separator effluent to form a liquid residue containing isobutane and alkylate. and an overhead vapor stream comprising isobutane and an inert alkane; (d) distilling the liquid residue to separate the alkylate product as a liquid residue and the isobutane as a vapor distillation effluent; Prior to the liquid-gas separation step, a portion of the separator effluent is sent as a cooled effluent in indirect heat exchange with the vapor distillation effluent to condense the isobutane in the vapor distillation effluent and to cool the vapor distillation effluent. Evaporate a portion and then (f) liquid-
A method for catalytic alkylation of isobutane using an olefin, which is characterized by carrying out a gas separation step. 2. The method of claim 1, wherein a portion of the cooling effluent is evaporated by reducing the pressure of the cooling effluent prior to indirect heat exchange. 3. The method of claim 1, including the step of removing residual acid and impurities from the liquid residue of (c) before distilling said residue. 4. The method of claim 1, wherein said condensed isobutane of (e) is recycled to said reactor. 5. The method of claim 1 including the step of compressing and condensing said overhead vapor stream of 5(c) to obtain a condensed overhead vapor stream. 6. The method of claim 5 including the step of subjecting said condensed overhead vapor stream to a liquid-vapor separation with a liquid containing condensed isobutane from said separation. 7. The method of claim 6, wherein said condensed isobutane is recycled to said reactor. 8. Utilizing a portion of the cooling effluent of (e) above to condense the overhead vapor stream by directing the portion of the cooling effluent in indirect heat exchange with the overhead vapor stream. Scope 5 method. 9 from the alkane distillation by distilling a portion of the above condensed vapor stream to remove the inert alkanes therefrom and sending the vapor alkane effluent from the alkane distillation in indirect heat exchange with a portion of the cooled effluent from the alkane distillation. 6. The method of claim 5 including the step of condensing the vaporized alkane effluent of . 10. The method of claim 9, wherein the inert alkane is propane. 11. The distillation of the liquid residue of (c) includes the removal of n-butane as a vapor side stream, by sending the vapor side stream in indirect heat exchange with a portion of the cooled effluent of (e). Claim 1: A method of condensing said side stream. 12 Olefin and excess molar isobutane are reacted in the alkylation zone in the presence of acid to form a liquid effluent, the liquid effluent is removed from the alkylation zone, and the thus removed liquid effluent is used for alkylate recovery. In a continuous process for the production of alkylates, the process comprises evaporating at least a portion of the liquid effluent to form a vapor and then condensing the vapor by cooling. A method characterized in that the vapor is cooled by directing liquid effluent from the zone in indirect heat exchange with the vapor. 13. The method of claim 12, wherein the liquid effluent sent in indirect heat exchange with said vapor is partially evaporated during said cooling. 14 Sufficiently reducing the pressure of the liquid effluent sent in the indirect heat exchange with the steam before the indirect heat exchange,
14. The method of claim 13 allowing at least partial evaporation of said liquid effluent during said cooling. 15. The method of claim 14, wherein liquid effluent sent in indirect heat exchange with said steam passes directly from said alkylation zone through a pressure reducing valve and into indirect heat exchange with said steam. 16. Claim 1, wherein treating said liquid effluent comprises distillation of a liquid stream obtained from said liquid effluent.
Method 4. 17. The treatment of the liquid effluent comprises distilling the liquid stream obtained from the liquid effluent in a deisobutanizer to obtain an isobutane-enriched vapor and an alkylate-enriched liquid resid. 15. The method of claim 14, wherein the saturated vapor is cooled and condensed by indirect heat exchange with a liquid effluent. 18. The method of claim 17, wherein treating said liquid effluent includes partially evaporating said liquid effluent to obtain a liquid stream and a vapor stream, and wherein said liquid stream is sent to said deisobutanizer. 19 by directing the liquid effluent in indirect heat exchange with the reaction mixture in the alkylation zone,
19. The method of claim 18, which performs partial evaporation of said liquid effluent. 20 separating the liquid effluent from the alkylation zone into a first portion and a second portion, sending the liquid effluent of the first portion to indirect heat exchange with the reaction mixture in the alkylation zone; The liquid effluent of said second portion is sent to indirect heat exchange with said steam to effect said cooling, and then the liquid effluent from said first and second portions are mixed together for gas-liquid separation. 19. The method of claim 18, wherein said liquid and vapor streams are separated from each other. 21. The method of claim 19, wherein said vapor stream is condensed by cooling and wherein said vapor stream is cooled by sending liquid effluent from said alkylation zone in indirect heat exchange with said vapor stream. . 22. sending a portion of the condensed vapor stream to a depropanizer to remove propane by distillation, said depropanizer generating a propane-enriched vapor;
22. The method of claim 21, wherein said propane-rich vapor is condensed by said liquid effluent. 23. Treatment of said effluent for alkylate recovery comprises recovery of propane in vapor form by distillation;
15. The method of claim 14, wherein cooling of said vapor propane is accomplished by condensing said vapor propane by cooling and passing liquid effluent from said alkylation zone in indirect heat exchange with said vapor propane. . 24. Treating the liquid effluent comprises evaporating at least a portion of the liquid effluent to obtain a liquid stream and a vapor stream, separating the vapor stream from the liquid stream and subsequently condensing by cooling, 15. The method of claim 14, wherein the vapor stream is condensed by cooling the liquid effluent from the oxidation zone by passing it in indirect heat exchange with the vapor stream. 25. The method of claim 12, wherein the olefin is a hydrocarbon having 2 to 5 carbons. 26. The method of claim 12, wherein the olefin is propylene. 27. The method of claim 12, wherein the olefin is selected from the group consisting of butylenes or amylenes. 28. The method of claim 12, wherein the acid catalyst is sulfuric acid. 29. The method of claim 12, wherein the acid catalyst is hydrofluoric acid. 30 (a) Contacting the olefin, a molar excess of isobutane, and an inert alkane in the presence of an acid catalyst in a reactor to form a reactor effluent containing the alkylate, isobutane, acid catalyst, and inert alkane. ,(b)
separating the acid catalyst from the reactor effluent;
forming a separator effluent; (c) performing liquid-gas separation on the separator effluent to obtain a liquid residue comprising isobutane and an alkylate and an overhead vapor stream comprising isobutane and an inert alkane; d) compressing and condensing said overhead vapor stream to produce a condensed overhead vapor stream; and (e) distilling a portion of said condensed overhead vapor stream to produce isobutane as a liquid residual product and unsaturated vapor as a vapor distillation effluent. separating the activated alkanes; (f) sending a portion of the separator effluent as a cooled effluent in indirect heat exchange with the steam distillation effluent prior to a liquid-vapor separation step; A process for the catalytic alkylation of isobutane with olefins, characterized in that the inert alkanes are condensed and a portion of the cooled effluent is evaporated, followed by (g) carrying out a liquid-vapor separation step on the cooled effluent. 31. The method of claim 30, wherein the inert alkane is propane. 32 Contact the olefin with a molar excess of isobutane and an inert alkane in the liquid phase in the presence of an acid catalyst to react substantially all of the olefin, thus reacting the acid catalyst and the alkylate, isobutane, and inert alkane. (b) separating the acid catalyst from the hydrocarbon mixture; and (c) separating the hydrocarbon mixture of (b) above in a gas-liquid separator to separate isobutane and the alkylate. (d) compressing and condensing the vapor overhead stream of (c) above in a compressor effluent condenser;
producing a condensed overhead vapor stream and (e) distilling the liquid residue of (c) in one or more distillation columns with one or more column condensers to separate the alkylate product from the isobutane; A process for the catalytic alkylation of isobutane with olefins comprising evaporating a portion of the hydrocarbon mixture of (b) to cool one or more condensers utilized in steps (d) and (e). A method characterized by: 33. The method of claim 32, wherein the column condenser is a condenser for a column overhead vapor stream. 34. The method of claim 32, wherein the olefin is a hydrocarbon having 2 to 5 carbon atoms. 35. The method of claim 32, wherein the olefin is propylene. 36. The method of claim 32, wherein the olefin is selected from the group consisting of butylenes or amylenes. 37. The method of claim 32, wherein the acid catalyst is sulfuric acid. 38. The method of claim 32, wherein the acid catalyst is hydrofluoric acid. 39. Claim 32, wherein the column condenser is a condenser for the overhead vapor stream of the deisobutanization column.
the method of. 40. The method of claim 32, wherein the column condenser is a condenser for a depropanizer overhead vapor stream.