CN1057079C

CN1057079C - Catalystic rectification and hydrolization technology and equipment for methyl acetate

Info

Publication number: CN1057079C
Application number: CN97101306A
Authority: CN
Inventors: 王良恩; 刘家祺; 苏文瑞; 赵之山; 郑文华; 张金柳
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 1996-02-09
Filing date: 1997-01-08
Publication date: 2000-10-04
Anticipated expiration: 2017-01-08
Also published as: CN1163259A

Abstract

The present invention discloses a catalytic distillation and hydrolyzation technology of methyl acetate, and equipment thereof. The hydrolyzation technology is characterized in that the catalysis hydrolysis reaction is carried out on metering proportioning water and methyl acetate in a reaction area in which cation exchange resin is filled; unhydrolized reactants flow back to the reaction area after being condensed, metered and proportioned; hydrolysate which is the product is pumped from a distillation still below a tower. The hydrolyzation equipment has the structure that the equipment is a cylinder tower body formed by that at least five catalyst structure units filled in the reaction area in a rectifying section contained in the cylinder tower body are vertically staggered, wherein the five catalyst structure units are formed by a strapping package mode. Thus, the catalytic distillation and hydrolyzation technology can obtain ester resolution ratio with any requirement within the range of 35 to 98.5%.

Description

Methyl acetate catalysis rectification hydrolysis technique and equipment thereof

The present invention relates to the heterogeneous catalysis rectification and hydrolization technology of ritalin, and the used catalytic distillation equipment of hydrolysis process.

Ritalin has multiple method for hydrolysis, as alkaline hydrolysis method, acid hydrolyzation and catalyzing cation exchange resin hydrolysis method.At present, in poly-ethanol production process, the hydrolysis of ritalin all is to adopt the catalyzing cation exchange resin hydrolysis method both at home and abroad.The technology of this hydrolysis method has two kinds: one is Zeo-karb fixed bed hydrolysis process, and this is a kind of traditional method for hydrolysis of domestic and foreign current; Two is Zeo-karb heterogeneous catalysis distillation hydrolysis method, is a kind of new hydrolysis process of studying at present.The main shortcoming of traditional technology: the rate of decomposition of ritalin is low, when its water to ester ratio is 0.95/1.0 (mole), generally is about 23-25%, and the concentration of acetic acid is about 14% in the hydrolyzed solution at this moment, and the ratio of sour water weight is about 1.3; Because percent hydrolysis is low, a large amount of unhydrolysed ritalins need reclaim circulation, so equipment is huge and energy consumption is high; There is azeotrope to have the tripping device complexity in the hydrolyzed solution.

Existing Japanese publication (8207,259 and the flat 5-212290 of Te Kai) and Japanese document (CA, 96164550n) report, Japan's catalyzing, rectifying and hydrolyzing methyl acetate still is in the laboratory study stage, its cation exchange resin catalyst has two kinds of types of feed in tower: the first is made fibrous being wrapped on the sticking plaster to ion exchange resin, then is seated in the tower; It two is ion exchange resin and high density polyethylene(HDPE) to be molded into cylindrical under heating and melting, then is filled in the tower.These two kinds of methods are made trouble, and catalyzer is changed and reclaimed difficulty, and especially latter's life-time service catalyzer loss that can come off causes damage.Its hydrolysis process system adopts high water to ester ratio (mole) and high reflux ratio (Kg overhead vapor condensing reflux amount/Kg ritalin inlet amount) to reach the purpose of high de-agglomeration rate, and the energy consumption height is difficult to apply.United States Patent (USP) [US.Pat4215011 (1980)/US.Pat4302356 (1981)/US.Pat4242530 (1980)], disclose the catalyzer filling mode different, but the catalyzer filling mode of the U.S. not to use on methyl acetate catalysis rectification hydrolysis technique with Japan; This filling mode is called for short " tying up packet mode ", promptly catalyzer to tie up the reaction zone that packet mode is filled in tower.

The purpose of this invention is to provide a kind of ritalin is the equipment that carries out the heterogeneous catalysis rectification and hydrolization technology under the catalyzer and be used for this technology at Zeo-karb.

The object of the present invention is achieved like this, described processing method characteristics are the bottom that is filled with the catalytic rectifying tower reaction zone of hydrolyst gel type cation exchange resin after preheating in the ritalin of metering enters, water behind the metering proportion adds from the reaction zone top after preheating simultaneously, the reaction that in reaction zone, is hydrolyzed of ritalin and water, unhydrolysed ritalin and water form minimum azeotrope and pass back into after condensation is measured in the reaction zone in the tower again, extract out the still kettle of product hydrolyzed solution under tower; Above-mentioned processing condition are; Hydrolysis temperature is 55-56 ℃; The mol ratio of water and ritalin is 1-6: 1; The volume ratio of phegma and charging ritalin is 1-9.5: 1; Superficial velocity is every cubic metre of catalyzer 0.23-0.25 cubic meter per hour.

Above-mentioned reaction conditions can require arbitrary selection according to technology, equipment etc., to obtain the ester rate of decomposition of arbitrary requirement in the 35-98.5% scope.

The described equipment that is used for hydrolysis process of purpose of the present invention is catalytic rectifying tower, its constructional feature is suitably to improve behind the reference United States Patent (USP) again, concrete structure is: it comprises a cylinder bodily form body of the tower, body of the tower is divided into reactive distillation section and stripping section, gel filled type cation exchange resin catalyst formation reaction zone on the sieve plate in the reactive distillation section, reaction zone is stacked in the tower by the structural unit vertical interlaced that is filled with Zeo-karb in five at least and forms, described structural unit is the cylinder bodily form, external diameter and tower reaction rectification section internal diameter are complementary, the pouch that this cylinder bodily form structural unit is of a size of the interior filling male ion-exchange resin of 40-80 * 8-16 millimeter by length and width is linked to be unduloid shoulder to shoulder and the onesize tooth profile angle that is pressed into is that the corrugated 60-80 purpose Stainless Steel Cloth of 60-120 degree stacks and is rolled into one deck pouch one deck Stainless Steel Cloth and constitutes, the pitch angle of online every the tooth ripple of Stainless Steel Wire and silk screen limit formation 30-75 degree.

In addition, the material of wrapping up the pouch of Zeo-karb in the tower in the reaction zone is spun silk cloth or nylon cloth or terylen cloth, used Stainless Steel Cloth is a molybdenum titanium Stainless Steel Cloth in the tower, the length of pouch is the height of cylinder bodily form structural unit, in the pouch filling cation exchange resin catalyst height be little bag length 0.6-0.8 doubly.

The present invention is because catalyzer that catalyzing, rectifying and hydrolyzing methyl acetate adopted is to tie up in the reaction zone of reactive distillation section that packet form is seated in catalytic rectifying tower with similar, thereby the invention has the advantages that to be reflected in the described processing condition scope and carry out, corresponding ester rate of decomposition changes at a wide region 35%-98.5%, thereby application person can be according to the processing requirement of the required ester decomposition of arbitrary rate of decomposition of concrete equipment, energy consumption and operational condition selection ester.

Describe the present invention below in conjunction with drawings and Examples.

Fig. 1 is a hydrolysis process flow sheet equipment synoptic diagram of the present invention.

Fig. 2 is a catalytic rectifying tower inner structure cell schematics of the present invention.

Fig. 3 is the structural unit schematic cross-section of Fig. 2.

Fig. 4 is seamed into the floor map of some pouches side by side for the spun silk cloth that constitutes structural unit.

Fig. 5 arranges floor map for each tooth ripple of Stainless Steel Cloth that constitutes structural unit.

Fig. 6 is the structural representation of every tooth ripple among Fig. 5.

As Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5 and shown in Figure 6, the catalytic distillation tower structure is: epimere is a reactive distillation section 15, and hypomere is a stripping section 16.The reactive distillation section: its material is a thermal glass, and tower diameter is 25mm, and tower height is 900mm, in be filled with the structural unit 17 of the gel filled type Zeo-karb of some amount, highly be 460-690mm.Stripping section 16: material is a thermal glass; Tower diameter is 25mm, and tower height is 840mm, is filled with 2.5 * 2.50 ring fillers made from molybdenum titanium Stainless Steel Cloth (silk footpath 0.15mm, 60 orders) in the tower, fills high 243-486mm.

Pouch material in the tower in the catalyst structure unit is spun silk cloth or nylon cloth or woven dacron, and the specification of the Stainless Steel Cloth of the tooth ripple shape of a support and gas channeling is 0.15 footpath, 60 purpose molybdenum titanium Stainless Steel Cloths; Catalyst system therefor is the gel type cation exchange resin, adopt the SK-IA type in the example of the present invention, its concrete structure of the reaction zone of the catalytic rectifying tower that example of the present invention is used is following being made: be seamed into 9 long 55mm with spun silk cloth, the pouch 18 of wide 12mm, fill an amount of gel type cation exchange resin in the bag, 9 pouches join together and constitute unduloid 19, is the right cylinder that 81 useless corrugated molybdenum titanium Stainless Steel Cloths 22 are rolled into one deck cloth bag layer of metal silk screen with the onesize peak height that is pressed into for the 4.3mm tooth profile angle, the right cylinder external diameter is all 25mm mutually with tower 8 internal diameters, and tooth ripple is arranged in parallel and constitutes 45 with

base

20 or 21 and spends obliquitys in the silk screen.Each right cylinder is a structural unit 17, the reaction zone of the reactive distillation section 15 in the tower is by 12 overlapping forming of structural unit vertical interlaced, reaction zone length is 660mm, thereby the tooth ripple of ripple silk net trend is staggered in the neighbouring cylindrical structure unit, to increase gas-liquid fluidic turbulent extent, gas-liquid is fully contacted.

Example 1-9 of the present invention is the following technology of reaction employing in above-mentioned catalytic rectifying tower all; Ritalin is entered the bottom of the reaction zone of tower after preheating by miniature volume pump 2, water is according to a certain ratio added from the reaction zone top after preheating by miniature volume pump 13, unhydrolysed ritalin and water form minimum azeotrope and enter overhead condenser 7, and phlegma all passes back into tower after metering.Hydrolyzed solution is extracted out from still kettle, and this still kettle adopts the there-necked flask 10 of 250mm band thermometer, and with the electric mantle heating, the composition of hydrolyzed solution and the rate of decomposition of ester are tested by island functional activities of the body fluid chromatography.Hydrolysis temperature is the 55-56 degree.Concrete water to ester ratio, superficial velocity, reflux when that the resolvent of the ester of gained and the rate of decomposition of productive rate and ester see following table for details:

Experiment embodiment

The example sequence number	Water/ester (mol)	Superficial velocity m ³Ester/h.m ³Catalyzer	Reflux ratio L/F ml phegma/ml charging ester	Hydrolyzed solution is formed (wt%)				The ester rate of decomposition
				Hydrolyzed solution is formed (wt%)				The ester rate of decomposition	Ester	Alcohol	Water	Acetic acid	％
				1	1.44	0.23	3.92	45.646	Ester	Alcohol	Water	Acetic acid	％	12.556	13.962	19.375	40.2
2	2.10	0.23	3.35	1	1.44	0.23	3.92	45.646	23.485	20.4354	23.516	32.5629	63.8	12.556	13.962	19.375	40.2
2	2.10	0.23	3.35	3	3.00	0.23	3.55	14.9677	23.485	20.4354	23.516	32.5629	63.8	18.8657	31.5949	34.4395	73.8
4	4.53	0.23	4.78	3	3.00	0.23	3.55	14.9677	4.2554	20.2226	40.7473	34.7645	90.9	18.8657	31.5949	34.4395	73.8
4	4.53	0.23	4.78	5	6.00	0.23	5.05	0.6917	4.2554	20.2226	40.7473	34.7645	90.9	17.6987	49.627	31.992	98.5
6	2.50	0.23	7.27	5	6.00	0.23	5.05	0.6917	15.552	21.319	25.703	37.425	74.4	17.6987	49.627	31.992	98.5
6	2.50	0.23	7.27	7	2.00	0.345	3.30	28.3167	15.552	21.319	25.703	37.425	74.4	17.8244	24.3466	29.5121	56.9
8	2.00	0.407	4.49	7	2.00	0.345	3.30	28.3167	28.0215	18.4594	22.5138	31.004	59.4	17.8244	24.3466	29.5121	56.9
8	2.00	0.407	4.49	9	2.10	0.532	3.47	15.823	28.0215	18.4594	22.5138	31.004	59.4	21.5867	25.9864	36.6038	56.5

Claims

1, a kind of methyl acetate catalysis rectification hydrolysis technique, it is characterized in that the ritalin that measures enters the bottom of the catalytic rectifying tower reaction zone that is filled with hydrolyst gel type cation exchange resin after preheating, water behind the metering proportion adds from the reaction zone top after preheating simultaneously, the reaction that in reaction zone, is hydrolyzed of ritalin and water, unhydrolysed ritalin and water form minimum azeotrope and pass back into after condensation is measured in the reaction zone in the tower again, extract out the still kettle of product hydrolyzed solution under tower; Above-mentioned processing condition are: hydrolysis temperature is that the mol ratio of 55-56 ℃ of water and ritalin is 1-6: 1; The volume ratio 1-9.5 of phegma and charging ester: 1; Superficial velocity is every cube of catalyzer 0.23-0.55 cubic meter per hour.

2, a kind of catalytic rectifying tower that is used for claim 1 method, comprise a cylinder bodily form body of the tower (8), tower is divided into reactive distillation section (15) and stripping section (16), be filled with the gel type cation exchange resin in the reactive distillation section on the sieve plate and constitute reaction zone, it is characterized in that reaction zone is stacked in the tower and is formed by structural unit (17) vertical interlaced that is filled with Zeo-karb in five at least, described structural unit is the cylinder bodily form, external diameter and tower reaction rectification section internal diameter are complementary, this cylinder bodily form structural unit is of a size of the pouch (18) of filling male ion-exchange resin in 40-80 * 8-16 millimeter by length and width, and to be linked to be unduloid (19) shoulder to shoulder be that the corrugated 60-80 purpose Stainless Steel Cloth (22) of 60-120 degree stacks and is rolled into the stainless twine net of one deck pouch one deck and constitutes with the onesize tooth profile angle that is pressed into, and online every the tooth ripple (23) of Stainless Steel Wire and silk screen limit form the obliquity of 30-75 degree.

3, catalytic rectifying tower according to claim 2, the material that it is characterized in that the pouch of the interior parcel of reaction zone Zeo-karb in the tower is spun silk cloth or nylon cloth or woven dacron, used Stainless Steel Cloth is a molybdenum titanium Stainless Steel Cloth in the tower, the length of pouch is the height of cylinder bodily form structural unit, in the pouch filling cation exchange resin catalyst height be little bag length 0.6-0.8 doubly.