SA516380445B1 - Crude Acrylonitrile Tank - Google Patents

Abstract

A process is provided for maintaining storage of a crude acrylonitrile in a crude tank. The process includes conveying the crude acrylonitrile to the crude tank, adding acid to the crude acrylonitrile in the crude tank in an amount effective for maintaining a pH below a target pH, and maintaining a temperature of the crude acrylonitrile in the crude tank below a target temperature. Fig 2.

Description

Crude Acrylonitrile Tank Full Description Background of the Invention The present invention relates to an improved process for the manufacture of acrylonitrile: and methacrylonitrile and in particular “the present invention relates to a crude acrylonitrile tank process 5 Acrylonitrile is a chemical commodity Important mainly used as a monomer for the manufacture of a wide range of polymeric materials Jie polymeric materials polymers for acrylic fibers used in textiles; And in resins such as Acrylontrill Butadiene Styrene (ABS) and Styrene Acrylontrile (SAN) Acrylontrile. Worldwide, acrylonitrile is produced in quantities exceeding four million 0 metric tons annually. One of the most common processes used to manufacture acrylonitrile or another olefinically unsaturated nitrile is Jie methacrylonitrile is a hydrocarbon reaction suitable Jie propylene or propane to manufacture acrylonitrile or isobutylene to manufacture methacrylonitrile “in the @ammoxidation reactor in the presence of ammonia 28 using air or another source of molecular oxygen such as sale 07008101. Oxidation reactions are used It is also referred to as the ammonia oxidation reactions. Typically a heterogeneous particulate solid catalyst in a fluidized catalyst bed to catalyze the ammonia oxidation reaction and provide the required acrylonitrile or methacrylonitrile in an acceptable conversion yield. In addition to the production of unsaturated nitrile olivanic; The aforementioned ammonia oxidation reactions generally produce other products such as acetonitrile, hydrogen cyanide (HCN) and other co-products. And it was detected

Processes for catalytic ammonia oxidation of an acrylonitrile hydrocarbon feed” eg US Pat. Nos. 5 4503001 4767878 5 4863891 and 5093299 are all included herein by reference. The acrylonitrile product must comply with the specification; They include a maximum amount of specific chemical impurities; Specific amounts of water and polymerization inhibitor, and the water must be controlled

and the polymerization content of the acrylonitrile product to achieve the stability of the acrylonitrile product. Specific levels or ranges of the amount of water and monomethyl ether hydroquinone or the methyl ether of hydroquinone (hereafter referred to as MEHQ in zie acrylonitrile) should typically be maintained. .and require

0 MEHQ Polymerization Inhibitor A specified amount of water to activate and inhibit the non-foaming polymerization of the acrylonitrile product. Specifications such as US and international shipping specifications typically require the least amount of water and inhibitor in an acrylonitrile product to be shipped because an acrylonitrile product without a specified amount of water and inhibitor is highly reactive. The specification typically contains a maximum amount of water and inhibitor content as well because excess inhibitor and water make the desired subsequent reaction

5 for slow and hard acrylonitrile; For example in a customer's plant designed to polymerize acrylonitrile. The specification of an acrylonitrile product typically includes a maximum limit of certain impurities such as hydrogen cyanide, acetonitrile, and acetone. From “AY” unrefined or out-of-specification product must be placed into the carrying tank. In this cla a crude acrylonitrile tank must be put into service to be used as a dala tank for an unrefined product

0 or out of specification. Although the acrylonitrile/methacrylonitrile manufacturing process has been commercialized for years; However, there are still some areas that need to be developed to increase the benefit significantly. aiding crude acrylonitrile from the recovery column typically on acrylonitrile, cyanide, and water; In particular, it is not stable. Hence the crude acrylonitrile is subject to polymerization reactions and loss of the acrylonitrile product. It is useful to save

Claims (1)

Claims of protection 1- A process to maintain the storage of crude acrylonitrile in a crude tank; The process includes: conveying the crude acrylonitrile to the ore storage tank; Measurement of the pH of crude acrylonitrile at one or more locations in the ore tank; add acid to the crude acrylonitrile in the crude tank in an effective amount to keep the pH below the target pH; Where the acid is added to the crude acrylonitrile in the crude tank with the recycle stream; and 0 maintaining the crude acrylonitrile temperature in the crude tank with the sale recycle stream; Cus the temperature of the crude acrylonitrile in the crude tank is maintained at 25 °C or less. 2- The process according to Claim 1 where the crude acrylonitrile includes acrylonitrile, water and hydrogen cyanide (HCN) pH. 3. Process pursuant to claim 1; The target pH is 4.5 or less. 4. Process pursuant to claim 1; Where the target pH 011 is 2.5 to 0 4.5 5- The process according to claim 1 whereby an acid is added when the pH increases from 1 to 0.5 pH unit — 3 1 — 6 - the process according to claim 1; Where the acid is selected from the group consisting of organic acid, sulfuric acid 8010 eli Sl, and mixtures thereof. 7- Process Wy for claimant 6, where the organic acid 8610 organic is selected from the group consisting of acetic acid, glycolic acid, and mixtures thereof. 8- Operation Gg of claim 1 Cus The temperature of the crude acrylonitrile crude tank is measured at one or more measurement locations. 9. The operation according to claim 1; Cus the temperature of the acrylonitrile crude 106 in the crude tank is measured from 1 to 5 measurement locations. 0- Operation according to Clause 9 Cum Each measurement location is at a different tank height. 1- The process according to claim 1; where the [sale] stream 506817 recycle is drawn from the ore reservoir at one or more removal sites. 2- The process according to Clause 11 where the sale stream recycle stream is withdrawn from 0 ore storage at one site to 5 removal sites. 3. The process according to claim 1; where the recycle stream is cooled using a heat exchanger 5 14- Process according to claim 11; Cus the recycle stream is returned to the ore reservoir at one or more sites different from the removal sites. — 4 1 — 5 Operation under claim 1 wherein the recycle stream is effective to provide a turnover rate of 50 to 150 hours. 16- A process for preparing an ore tank to receive ccrude acrylonitrile. The process includes: adding water to an empty crude tank in an effective amount to absorb organic matter under a floating roof of the ore tank; maintain the water temperature in the crude tank at or below 25 °C; Where the water temperature in the ore reservoir is maintained using a Cua recirculation system, the recycle stream is the water withdrawn from the ore reservoir at one or more removal sites; Where acid is added to the ore tank when the water in the tank is 25 degrees Celsius or less. 7- The process according to claim 16) where water is added to the ore storage tank to 6 to 15 in 5 percent of the volume of the crude storage tank. 8- The process according to claim 16 where the recycle stream is cooled using a heat exchanger heat exchanger 0 19- Process according to claim 16) where the water is maintained at a temperature of 1 to 10 degrees C. 0- Process according to claim 16) where the pH of the water is from 3 to 4. 1- The process according to Claim 16) where crude acrylonitrile is added to the crude tank when the crude tank is 25 degrees Celsius or less and the pH is 4 or less. 22- Crude acrylonitrile ala storage tank Includes: 560507 One or more temperature sensors configured to detect temperatures at various temperature elevations in the raw acrylonitrile storage tank 801/10010116 00006; One or more removal sites configured to remove crude acrylonitrile from the “crude acrylonitrile” storage tank 0 pH sensor configured to detect raw PH Jyh SY in raw acrylonitrile storage tank 00006; A return line configured to return part of the sale recycle stream to Oba tcrude acrylonitrile storage and input to add acid to the sale recycle stream 3- Crude acrylonitrile storage tank of claim 22; It also includes a cooler configured to cool the recycle stream drawn from one or more Al locations of the crude acrylonitrile storage tank. 0 24- Crude acrylonitrile storage tank of claim 22; Also includes a console; and a control unit configured to receive a signal from the +86750 sensor pH 071 corresponding to the PH detected die by the sensor 050 pH; The control unit is configured to adjust the acid flow into the crude acrylonitrile storage tank. 5- Crude acrylonitrile storage tank of claim 24; Cua The controller is initialized to receive a signal from the 560507 temperature sensor corresponding to the temperature detected by the 560503 temperature sensor; The controller is configured to adjust the recycle stream flow rate 6- Crude acrylonitrile storage tank of claim 22; The crude acrylonitrile storage tank has a length-to-diameter ratio of 0.5 to 1.5. 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Yew E 1 AAA AAA A AAA A AAA A AAR A LARA ALARA ALARA ALARA ARR RAR AR RRR ARR RR RARY A & < } ¥ ( FY 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