SA516380473B1 - Fouling Reduction in The Acetonitrile Removal Steps of Acrylonitrile Recovery - Google Patents

Abstract

A method is provided comprising adding acid to a reflux stream, and conveying the reflux stream to an acetonitrile fractionator, wherein the acid reduces fouling in the acetonitrile fractionator. Fig 3.

Description

Fouling Reduction in The Acetonitrile Removal Steps of Acrylonitrile Recovery Full Description

BACKGROUND OF THE INVENTION This disclosure is directed at an advanced system and process for the manufacture of acrylonitrile or metacarbonitrile. Specifically directed to reduce dirt in an advanced way in the steps of removing acetonitrile during the extraction of acrylonitrile

There are several common processes and systems for the manufacture of acrylonitrile and metacarbonitrile; See eg US Patents Nos. 3,936,360, 3,433,822, 3,399,120 and 59 Propylene, ammonia and oxygen (as constituents of atmosphere) feed an acrylonitrile reactor which contains a catalyst acting as a fluidized bed. The usual procedure is to run the reactor with an excess amount of ammonia placed in the feeder taking into account the amount of propylene fed to the reactor. Some excess ammonia burns in

0 reactor due to severe conditions before it can bond with propylene to form acrylonitrile. The remaining amount of excess ammonia comes out; It is commonly referred to as ammonia from the reactor in the effluent gas stream. This gas passes through a cooler and then a quenching vessel to remove excess ammonia. See eg US Patents Nos. 3,936,360, 4,166,008, 4,334,965, 4,341,535, 5,895,635, and 6, 7193,776.

5 The usual processes include extraction and purification of the acrylonitrile/metacarbonitrile produced through the direct reaction of hydrocriones selected from a group consisting of broyan, propylene, isobutylene, ammonia and oxygen in the presence of a catalyst and these processes are carried out by diverting the reactor flow containing acrylonitrile/metacarbonitrile for the first column (quenching). Where the reactor effluent is cooled by a water stream Jf the cooled effluent containing acrylonitrile/metacarbonitrile is diverted to and in the second column (absorber)

0 The cooled stream is connected to the second water stream to absorb acrylonitrile / methacrylonitrile in the second water stream and the second water stream containing acrylonitrile / metacrylonitrile is transferred from the column to the second column

First distillation (extraction column) to separate the acrylonitrile / methacrylonitrile ore from the second water stream for the second distillation column (main column) to remove at least some impurities from the acrylonitrile / methacrylonitrile ore and convert the semi-pure acrylonitrile / methacrylonitrile to a third distillation column (production column) to obtain a product Acplonitrile / methacrylonitrile. See US Patents Nos. 4,334,295 and 4,238,295 describing the usual processes in which acetonitrile is separated from acrylonitrile in a single distillation column. In these usual operations; The downstream of the acetonitrile fraction is directed to an extraction column or an extractive distillation column. The problem with conventional processes and systems is the accumulation of hydrogen cyanide in a highly boiling compound which breaks down below the required temperatures of the acetonitrile binder. The dissociation of the high-boiling compound 0 releases free hydrogen cyanide in a critical form which causes it to polymerize and create dirt in the acetonitrile hasoxide. Dirt can cause poor operation of the acetonitrile fractionator, which results in a die. Unit shutdown. Clean the acetonitrile fractionator shaft and remove dirt. In addition, an amount of ammonia passes through the quenching stage as the quenching reaction is not effective 7100. This ammonia tends to accumulate. GENERAL DESCRIPTION OF THE INVENTION 5 On this basis, one aspect of this disclosure is to provide safe and effective cost-effective process devices that reduce and/or remove dirt from the acetonitrile fractionator column. By; The process involves adding acid to the reflux stream and transferring the reflux stream to the acetonitrile partition. On the AT side the process involves transferring the downstream current from the acetonitrile partition column to the quenching column. 0 On this side; The lower stream contains at least some acid. And from another Gils, the device contains “ae” acetonitrile form for producing an overhead stream that includes the acetonitrile “return line” form to transfer the reflux current of the acetonitrile separator; An acid adding line is formed to add acid to the reflux stream.

The aspects mentioned above and others and the features and advantages of the current disclosure will be clear through the description

The following outline and the content illustrated thereof, which are to be read in parallel with the accompanying graphics.

Brief description of the drawings

We may understand more embodiments of the invention and its functionality when we present the following description taking into account the attached drawings and the numbers here referring to the same features in and in the attached drawings:

Figure 1 is a schematic flow diagram according to at least one of the disclosure terms.

Figure 2 is a schematic flow diagram according to at least one of the disclosure terms.

Figure 3 illustrates the flow diagram of Method 300 according to the disclosure requirements.

Detailed description:

0 on one side”; The method or process includes the step of adding acid to the reflux stream of the acetonitrile fraction. By; The process involves diverting the reflux stream of an acetonitrile separator consisting of an upper plate and multiple plates under the upper plate where the conversion step involves transferring the reflux current to the upper plate where the acid reduces fouling in the acetonitrile separator. on the one hand; The process involves directing the downstream of the acetonitrile fraction to the abatement vessel. as an anthropomorphic

5 The acid added to the return stream of the acetonitrile partitioner is acidic. on the one hand; Routing the acetonitrile splitter downstream would involve taking the sha from the acetonitrile splitter downstream Vly would head to the quenching column and forwarding at least one ga to the quenching vessel. By; Acid can be added to the reflux stream at a lower dosing rate to prevent or reduce the formation of polymers in the acetonitrile moiety and to reduce the cost of cleaning as well as to extend the operation of the acetonitrile moiety.

0 The downstream of the acetonitrile partitioner may be directed to the quenching vessel so that the pH of the lower section of the quenching column is maintained at a specified level or range eg lane; Below the neutral level of pH equal to 7 and on the other hand the pH is what

Between 5 to 7,5 On the other hand, the pH ranges from 6 to 7,5. The step of adding the lower gall acid of the extraction column may lower its pH and sha disturb the chemical balance of the high-boiling compounds present at that location during the process. By; The hydrogen cyanide problem was solved by adding acid to the regeneration line returning to the upper plate of the acetonitrile sequester when the lower stream of the acetonitrile sequester returned to the quenching column; It does not return to the extraction column in the ola extraction as in the usual acetonitrile process. The acid performs the function of a polymerization inhibitor by maintaining the pH in a range similar to that in which hydrogen cyanide is present in the stream and the acetonitrile partition does not polymerize causing dirtiness in the 0 column of the acetonitrile partition. The acid is then returned to the Quenching Vessel with a stable pH below the neutral level of 4.5 to about 6; It can be used to remove ammonia from the reactor effluent in the acrylonitrile unit. Figure 1 and Figure 2 are a schematic flow diagram corresponding to at least one aspect of this disclosure. Specifically, Figure 1 and Figure 2 are an illustrative diagram of the embodiments of the present invention in 5 the acrylonitrile extraction process. The rich solution or aqueous solution of absorbent 300 containing acrylonitrile, acetonitrile, hydrogen cyanide, water and impurities passes through the second line of heating exchanger 4 where the rich solution is preheated with the solvent/weak solution 222 of line 223 of heat exchanger 4. After heating; The rich solution leaves the exchanger 4 via line 6 and passes into the extraction column 7. The extractive 0 distillation takes place in the extraction column 7 with the addition of a solvent passing into the extraction column through line 8. Solvent/weak solution 222; It may split as a result of or after passing through exchanger 4 into a solvent solution passing through heat exchanger 236 and line 8 to the upper section 207 of extraction column 7 and a weak solution stream passing through line 224. Solvent/weak solution 222 may be supplied by extraction heat device 226. Apparatus Extraction temperature 226 may receive vapor 228

From extraction column 7 via line 230. Steam 228 may take extraction column 7 from a specific place such as at plate 232 or just above it in the lower section 227 of extraction column 7. Plate 232 may be the lowest plate in extraction column 7 and it is called Lad plate The first is in the extraction column 7. The steam 228 is probably transmitted through the pump 229 from the extraction column 7 to the extraction heat device 226.

The weak solution passing through line 224 lay is sent to absorbent 300. Heat exchange probably takes place at heat exchanger 234 before the weak solution stream passing through line 224 is sent to absorbent 300. Heat through exchanger 210 may be saved for distillation in extraction column 7. Three streams are removed from the extraction column 7. Vol The upper stream consisting of acrylonitrile 0, hydrogen oxide, water and some impurities is removed from the extraction column 7 and passed to the extractor or acetonitrile separator 215. The upper stream 203 which includes acetonitrile may be removed from the upper section of the separator The acetonitrile 215 via the line 216. The lower fluids 209 from the lower part 5 of the acetonitrile fraction 215 may return to the extraction column 7 through the line 218. Pump 9 is usually used to return the liquid through the line 218 to the extraction column 7. It has been found that it is preferable to transfer the lower fluids 5 209 from the lower part 205 to the suppression eles 10 through the line 221. The lower streams from the extractor shaft 7 may be removed by means of the line 51 and overburdened by the pump 53

Through line 220 to quenching vessel column 10 or waste disposal. as an anthropomorphism Stream containing acetonitrile in line 216 Lay is transferred to ESA 235 and exits as bottom capacitor stream 245. Bottom capacitor stream 245 rema splits at junction point 247 into reflux 0 stream 251 in loopback line 217 and raw acetonitrile stream 253 in raw acetonitrile line 7 . By; The return current 251 in the return line 217 probably returns to the top plate 1 of the acetonitrile separator 215. ia from stream 215 rema is added to line 216 on Gob line 239. From the side easly the vapor phase containing acetonitrile and water Gling of hydrogen cyanide is drawn from extraction column 7 as a bypass stream 214 sling to a separator acetonitrile;

5. Hash of acetonitrile 215 may form a column containing several plates. Pump 225 REMA is used to pump retrieval through retrieval line 217 and/or crude acetonitrile line 237. On one side; The process involves adding acid to the reflux stream. As will be described later, “adding acid to the return stream” may include adding acid to the return line 217, adding acid upstream in line 216, adding acid to the return line 239, and a combination of each. On the part of the OAT, the acid may be added prior to capacitor 235 or at the end of it. At the beginning of the concentrator 235 provides a more dilute concentration of the acid The addition of the acid at the end of the condenser produces a higher concentration of acid for the moiety of acetonitrile 215 From AT Gils acid CES 235 is added to reduce dirt in the condenser On the one hand; acid 0 transferred to the condenser 235 is most effective when the acid is sprayed into tubular chips in the condenser which are covered Lila with sprays of acid. The acid can be transferred to the tubular chips in the condenser 235 oo nozzles such as for example a fully cone spray nozzle. eg (JU Nozzle It is perpendicular to the tubular wafers and up to an angle of 60 degrees from the perpendicular to the tubular wafers. On the one hand, an organic acid or an organic acid derivative may be added, for example, “5-acetic acid or glycol acid” via line 213 to retrieval line 217. On the other hand An organic acid or an organic acid derivative may be added, eg (JE) h flicker of acetic or glycol acid” via line 233 to superimpose in line 216 of the acetonitrile fraction 215. On the side (Al) an organic acid or an organic acid derivative may be added; For example, “JB acetic acid or glycol acid” via line 243 to return stream 239. On the other hand, adding organic acid 0 or an organic acid derivative; for example “Jia acetic acid or glycol acid” via line 213 to line retrieval 217 or/or via line 243 to retrieval line 239 to line 216 prior to upstream entry into CBSA 235 Halll and fouling may be in the acetonitrile hasp 215; EKA 235 or/and other devices; eg; When directing the downstream of the acetonitrile fraction 215 to the quenching vessel; corresponding to the quenching column 7.

The acetonitrile fractionator 215 may be formed or designed to concentrate a dilute solution/acetonitrile stream which may be sent to another device for further purification and/or extraction of the acetonitrile. as an anthropomorphism The downstream 211 of the acetonitrile isolator 215 rema is transmitted by pump 55 through line 221 to quench vessel 0. As a solidification; The downstream 211 of the acetonitrile fraction 215 may be connected via line 9 to the downstream extraction column in line 51 in which the combined downstreams may be conveyed by the pump 53 through line 0 to the quenching vessel 10 or to the waste disposal. As shown in Figure 2; Quenching vessel 10 aaa to receive reactor gas effluent or gaseous stream 12 through pass 14. Reactor effluent gas 12 may include acrylonitrile and ammonia. Reactor effluent gaseous 12 may cool in the reactor effluent cooler before entering the quenching vessel 10. In quenching vessel 0 10 the quenching liquid includes the downstream of the acetonitrile partition contacts and quenches the reactor effluent gas 12. Acid 36 (eg sulfuric acid) may be added via line 38 to the quenching vessel 6. Because of the acid in the downstream 211 that ang to the quenching vessel 10 the amount of acid added through line 38 may be reduced. Quenching fluid 36 includes liquid flowing out of lower quench 42 from quench 5 receptacle 10 through line 44. Water may be added via line 46 to quench receptacle 10 through inlet 48 or else (Sad) added to quench fluid 16 or elsewhere in the recirculation circuit The liquid formed by streams 17, 44 and 65. Quenching liquid 16 is distributed through line 44 and returns to lines 5 and 17 using pump 50. Stream 67 may be withdrawn as part of the quenching liquid exit through line 4. In order to maintain a relatively constant current in the sale circuit) Circulate the liquid by balancing the liquid 0 added via lines 38, 46, 220 and 221. Stream 67 removes neutral reactor products formed (eg ammonium sulfate) and is useful for Load to prevent unwanted product build-ups in the liquid recycling circuit; ‎Jo Corroded Products. The downstream outflow 42 from suppression vessel 0 may derive from line 44 at the intake point 52. The upper stream 13 may pass through line 15 from suppression vessel 10 to suppression after cooler 240. Cold water 5 may be used for suppression after cooler 240 to cool the upper stream 13 and quench quenching after coolant.

The rich solution may move by pump 242 from lower section 250 of quench after cooler 240 to rich solution line 2 or/and recirculation line 248 and return to upper section 252 of quench after cooler 0. After cooling of the upper stream 13 by quench after cooler 240; Stream may exit quenching after coolant 0 as stream 244. Stream 244 may be transported via line 246 to absorbent 300. A weak solution from line 224 may enter the upper part 254 of absorbent 300. Gas escaping 256 from absorbent 300 may be sent to an incinerator (not shown) . Stream 258 may combine with the rich solution conveyed through pump 260 to line 2. Stream 258 may combine with the rich solution from the quench after

coolant 240 eg at connection points 264. on one side; Controller 11 may be a pada to operate one or more signals depending on measured variables; for example 0; The pH of the lower acetonitrile hash 209 in the lower stream 205 of the acetonitrile hash 215 or the lower acetonitrile hash 211 in line 221 or line 9 as measured by the pH sensor (not shown in Figure 1). Controller 11 may be designed to determine if the measured variables of lef are below a predefined range for the variables. and those skilled in all will discern that according to revelation; the measured variables may be any suitable variable useful for operation in the acetonitrile fractionator” eg; The pH of the lower acetonitrile moiety is 9 or 211 as discussed before; or the liquid level measured with a level controller (not shown in Figure 1) on the bottom 205 of the acetonitrile fractionator 215; or current controller (not shown in Figure 1) associated with the liquid current in the line or lines discussed herein. Controller 11 may pada to control the operation of one or more devices by means of communication lines or radio communication (0 not shown in Figure 1) In the event that the measured parameters are lower or higher than the preset range, eg (JU) controller 11 may aad to adjust the amount of acid added through lines 213 or 233 to reach the desired pH of the reflux stream 251 so as to reduce fouling in the acetonitrile fraction 5. Those skilled in the art will recognize that according to this disclosure, controller 11 may have a paca to control the operation of the pump(s) or/or valves for adding acid through lines 5 213 or/and 233 in order to reach range ( ranges) predefined . and those skilled in

— 1 0 —

Art will recognize that Controller 11 or a similar controller may be located far from the level controller or current controller (not shown in Figure 1) or may be aware of or include a level controller or current controller. Sil gf Those skilled in the art will recognize that according to this disclosure; Controller 11 may have been designed to actuate the devices shown in Figure 2 and the pump(s) and/or valve(s) associated with these devices.The test was performed to demonstrate the advantages of adding acid to the acetonitrile partition 215 and orienting the lower acetonitrile partition to the quenching vessel 10 instead of routing the bottom acetonitrile partition to a column Extraction 7 depending on the process

without adding acid to the acetonitrile moiety 215. We obtained the following data. DATA TEST - Unit 1 includes a quench vessel shown in Figure 1 that has been operated to illustrate the reduction of ammonia formation in the upper line 216 of the acetonitrile partition 215. Ammonia in 0 top line 216 is a by-product of the hydrogen cyanide polymerization reaction; It is therefore indicative of unwanted polymerization of the acetonitrile fraction 215. Unit 1 'in the presence of acid' was run with acetic acid added to the upper plate of the acetonitrile fraction 215 as above; and the lower acetonitrile fraction was sent via line 211 to quenching vessel 10. Unit 10 1 'In the absence of 'aes' it has been worked without the addition of acetic acid or any other acid and in this way the

5 lower acetonitrile fractionator to extraction column 7 via line 18. The results we obtained by running Bas olf 1) = acid in the presence and running it in the absence of ann as mentioned above are shown in the following table. Table Unit 1 in the presence of acid Unit 2 without the acid number dua ammonia pH number gall per million pH ammonia ppm

— 1 1 — solution 169 149

A 0 column 5,3 449 32 429 J to extract the lower plate No. | 6,2 Unspecified 6.1 116 50 in column J of extracting plate number unspecified 124 33 in column J of extracting plate number unspecified 7.9 184 21 in column J of extracting Ere 6,2 Unspecified 7,1 Unspecified lower acetonitrile hash 6.4 188 upper acetonitrile The test data shown above show the effects of adding acetic acid to the upper acetonitrile hash as the pH of the stream was lowered from 8,9 to 6,4. from direction; Lowering the pH in the extraction column reduces unwanted polymerization. There is a symmetry in lowering the concentration of ammonia in the fractionator

Upper acetonitrile for example from 188 ea ppm to 9 ppm when acetic acid is added. This drop in ammonia in the upper acetonitrile compartment; or in other words; The stream passing through line 216 is believed to be the result of acetic acid attaching to ammonia forming ammonium acetate and removing it from stream 211 to quench 10. Wis may be the result of hydrogen cyanide remaining in solution as xanohydrin without dissociating to its original components and then polymerizing which causes the release of ammonia. Ammonia is a by-product of the hydrogen cyanide polymerization reaction. The addition of acetic acid to the stream clearly lowers the amount of ammonia present and demonstrates the detection efficacy. from one side”; Choosing a pH level is a balance between reducing dirt and using building foams. from this side»; The use of pH levels as described in this disclosure 0 allows the use of carbon steel construction. Figure 3 illustrates the flow diagram of the 300 method along with the disclosure aspects. Method 300 may be implemented using Seal described earlier. Step 301 involves directing the downstream of the acetonitrile fractionator column to the quench slog. on one side; The acetonitrile fractionator includes multiple plates and the acid addition step of the return stream of the acetonitrile fractionator column involves adding acid to the upper plate 5 of the multiplates of the acetonitrile fractionator. On one hand, the step of adding acid to the reflux stream of the acetonitrile partitioner involves adding acetic acid to the reflux stream. From (ula) the step of adding acid to the reflux stream was carried out to lower the pH of the upstream of the acetonitrile partitioner. On the one hand, the step of adding acid to the reflux stream resulted in the reduction of the pH of the upstream of the acetonitrile partitioning from higher than 7.0 to less than 7.0. On the one hand, the addition of 0 acid to the reflux stream resulted in lowering the pH of the upper stream of the acetonitrile partitioner from above 0 to less than 6.5. 0 to about 6,4.

By; The steps for directing the downstream of the acetonitrile fraction into the quenching vessel include redirection

The downstream of the acetonitrile separator stops flowing to the extraction column until the downstream flows

fractionate the acetonitrile to the quenching vessel.

The presented invention can be applied to any acrylonitrile recovery process in which there is an extraction column and

One or more distillation columns. Additional distillation columns consist of hydrogen cyanide column

a drying column to remove water and a production column to extract the acrylonitrile product. However, it can be collected

All these separate processes in a single distillation column remove SS from hydrogen cyanide and water as is

shown in the drawing.

With all of the above specifications for this listing associated with certain preferred models listed; and many 0 details presented for the purpose of explanation; It will be obvious to those gifted in art that this

Disclosure is subject to more models and those particular details mentioned above can vary considerably

Without deviating from the main idea of this disclosure. It must be understood that the properties of this disclosure are subject to modification

or alteration, alteration, or substitution while preserving the spirit and extent of this disclosure or without departing from the extent

protection elements. (Jl) The dimensions, numbers, sizes, and shapes of the various components5 can be interchanged to suit specific uses. leg This (ula) is the particular models annotated and described

Here only intended for explanation.

Claims (1)

Claims 1- A process to reduce dirt formation in the acetonitrile removal steps of the acrylonitrile extraction process includes: delivery of a side stream comprising acetonitrile from an Acrylonitrile extraction column du yu sh <I to an acetonitrile separator; Connect an overhead current from the acetonitrile splitter to “iia upstream condensation to obtain a backflow; adding acid to the reflux stream; Connecting the reflux current to the acetonitrile divider 0 2 - operation according to claim 1; In which the acid reduces dirt in the condenser. 3- The process according to claim 1 in which the acetonitrile fractionator consists of an upper tray and multiple trays located below it so that the conduction step includes the transfer of the backflow current to the upper tray. 4. The process under claim 1; Where the acid is selected from the group consisting of acetic acid; glycolic acid; derivatives of acetic acid; derivatives of glycolic acid; and mixtures of it. 0 5 - operation according to claim 1; The step of adding acid to the reflux stream lowers the pH of the upper stream of the acetonitrile partition 6 - process according to claim 1; The step of adding acid to the reflux stream maintains the pH of the upper stream of the acetonitrile partition within range limits. — 5 1 — 7 - the process under claim 5; The step of adding acid to the reflux stream lowers the pH of the upper stream of the acetonitrile partition column from 8.0 to the LM pH of 6.5. 8. The process pursuant to claim 5; Soha adding acid to the reflux stream lowers the pH of the upper stream of the acetonitrile partition column to pH 3 by 6.4 9- Process according to claim 6 », where the step of adding acid to the reflux stream maintains the pH of the upper stream of the acetonitrile partition at 0, at 7.0. 0- Process according to Clause 6”, where the step of adding acid to the reflux stream maintains the pH of the upper stream of the acetonitrile fraction at 6.5. 5 11- The process according to Clause 6 », where the step of adding acid to the reflux stream maintains the pH of the upper stream of the acetonitrile partition at 6.4. 2. The process pursuant to claim 1; It also includes an overhead capacitor to obtain back current. 0 13 - operation according to claim 12; In which the acidification step of the return stream includes the addition of acid to the upper stream of the acetonitrile fraction 4 - process according to claim 13; It also includes directing an acetonitrile fraction precipitate stream into a suppression vessel. — 6 1 — 5- The process according to claim 14 (Cus) includes the precipitate stream of the acetonitrile fraction (aay acetonitrile) from acid added to the reflux stream during the step of adding acid to the reflux stream ¢. 16. Process pursuant to claim 15; also includes the supply of a gaseous stream containing acrylonitrile and ammonia to the abatement vessel; contact of the gaseous stream with a quenching liquid; The quench fluid comprises the acetonitrile fraction precipitate stream 7. Process according to claim 14; In which the routing step involves connecting gia from the material stream 0 acetonitrile precipitate to the quenching vessel and deliver eda from the acetonitrile precipitate stream to an extraction column. 8- The process according to claim 1 also includes the transfer of part of the return current to an overhead stream from the condensed lef acetonitrile separator. 9. The process under claim 1; in which the pH of the precipitate stream is 7. 0 - process according to claim 1; The pH of the precipitate stream is between 5 and 7.5. 1. The process under claim 1; In which the pH of the precipitate stream is between 6 to 7. 2- Apparatus for applying processes according to claims 1 to 21; Includes: 5 an acetonitrile separator designed to produce an overhead stream consisting of acetonitrile sada reflux line to carry a reflux stream for the acetonitrile reflux stream; and — 7 1 — line to add acid lige to add acid to the return stream. 3. The device of claim 22; Also included is a capacitor designed for top-stream cooling and generation of the condensed acetonitrile product Cus ald incorporating the return current ga from the condensed 5-acetonitrile product. 4. The device of claim 22; Gua acetonitrile splitter includes a top tray and multiple trays located underneath and the reflux line Jil configures the reflux stream to the upper tray. 10 5 The device of claim 22; And in it the acid contains acetic acid. 6- The apparatus according to Clause 22 contains a control device designed to control the addition of acid to the reflux stream. 15 7 The device of claim 26; The control is configured to control the acid addition to lower the pH of the upper stream. 8. The device of claim 27; Where the control is configured to keep the pH of the upper stream 0 within the limits of the Le range 9- Instrument per claim 27 where the control is configured to lower the upper LAL pH from 8.0 to a pH of 6.5. 30 - The device of claim 27; The control is configured to lower the upstream pH from 7.0 to a pH of 6.4 — 1 8 — 1- The device according to protection element 23, in which the acid line is prepared to add acid to the upper stream. 32 - The device of claim 22; It also contains a paca path line to transfer edn from the acetonitrile fraction precipitate stream to the quench vessel. 3- The device of claim 32; In it, the precipitate stream includes some acid added to the reflux stream. 4. The device pursuant to claim 33; where the quenching vessel is configured to receive a gaseous stream containing acrylonitrile and ammonia and the gaseous stream is in contact with a quenching liquid; The quenching liquid includes the precipitate stream of acetonitrile fraction (grey : : i H : Pe : i H A Eo Me 3 H = of 3 God Re Gt 1 3 period for hE 1 2] : Ka l a a 3. A ay TR a a = EVIE ES a a he a a re BN J 8 oS PU Ws Shenk 2 N bs Apple A 1 A PE C CR i wd SOBA Rae Moa q Tew i, NS wo? 0( 0( :+( PTECNA ' FAL DY Ha 0 8 d no l a a Tre : = 0 H b "NAS od NL SS SS had 1 rie RES 3 H ui § a 5 1 H 8 a 1 HE at 3 H 1 L : = FE i 1 a es Meg aa wed 1 Pe we aa MS Pa 1d Ria i a i Pod 3 HI 4 HI 0 3 Ra Next 7 L L ¥ Po + goo BS [H HIG] oe § 0 i NS i HER - - God! uh i gla To 1 nt x § LR. ! =o A Pod XT Get Tenet Yat 3 5 1 H [RE Aha A Laney od 2 A GE ha N oh = 5, ie A: ER 0 + To RE = 1 i and Sale 3 A 1 m aa N BR Hd NE oo 3 ul a Tad 1 + y + 2 for “m 3: i Bie m for 2 H oe for H PL 01 NE Py A ; 0 a : a 3 } s 4 3 iH (2 N wi 8 * R ¥ pe 1 3 rh 1 e wd 0 1 and 1 i > Looe ey d 3 aed 8 m 3. e n and 1 8 Ei "EE H F A i { d, = 3 ow N 4 7 1 eha 8 Poa { 8 of 4 º 3 3 + > no lee 0 1 ada 1 Ix] J NEE RUE : : ¥ : 1 b and 7 0 i By X 5 0 l(l([(l) For _ (01000000008 3.1 1 1 pi A 4 iio J LMA: Pe Ly 2 Eps - rT —— Lx 4 0 of Ed NG 5 ER Fo Su Ser 1 .* tuberculosis J 1 L Beep 3 m wy ws : B SA 31 1 - 1 x 5 2 A : 0 > RNC [13 Ro SE. § N S ™N Lo i 3 DE RECN A B = 3 A J 1 . - a5 a ACTIN | m 3 i jin l i ol 1 1 11 3 + 3 a l | m ; BB - re 3 Nd A lham a 43 [ yo > ae = EE \ vd 5 a : : : N 0 A § rd - > E ─ JE bo I 3 : I 0 3 AH : | 1 J Nf a ( | ا ْ H 8 1 0 4 Susa 1 = !ba a live A rd 1 rey > a 0 0 3 FN : "m = i N 0 1 Lx live Support Tan % mah hal aa: log questions? A, Se, the six series, PLEA, to: A, L, JS, Al,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, A, a,,,,,,,,,, a, ma, Loy this aj 3 : 0 #dose energy the ast ple 1 a or 2 : 2 b 2 E = ER 5 DA pt i TRY H Gogg an SE dah oR i “For an object that can see 1 mcl?* Sued Authority for Intellectual Property RE .¥ + \ A 0 § 8 Ss o + < M SNE A J > E K J TE I UN BE Ca a a a ww > Ld Ed H Ed - 2 Ld, provided that the annual financial consideration is paid for the patent and that it is not null and void for violating any of the provisions of the patent system, layout designs of integrated circuits, plant varieties and industrial designs, or its implementing regulations. Ad Issued by + bb 0.b The Saudi Authority for Intellectual Property > > > This is PO Box 1011 .| for ria 1*1 v= ; Kingdom | Arabic | For Saudi Arabia, SAIP@SAIP.GOV.SA