US 2015.0053616A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2015/0053616 A1 Himeno et al. (43) Pub. Date: Feb. 26, 2015 (54) DEHYDRATION OF WATER CONTAINING Publication Classification SOURCE OF FORMALDEHYDE, ANDA METHOD FOR PRODUCING AN (51) Int. Cl. ETHYLENICALLY UNSATURATED CO2F I/44 (2006.01) CARBOXYLCESTER BOID 71/02 (2006.01) BOID 6/36 (2006.01) (71) Applicant: Lucite International UK Limited, (52) U.S. Cl. Southampton (GB) CPC .............. C02F I/448 (2013.01); B01D 61/362 (2013.01); B0ID 71/028 (2013.01); C02F (72) Inventors: Yoshiyuki Himeno, Hiroshima (JP); 2101/34 (2013.01) Ken Ooyachi, Hiroshima (JP); USPC ........................................... 210/640; 210/651 Masahide Kondo, Hiroshima (JP) (21) Appl. No.: 14/379,051 (57) ABSTRACT (22) PCT Fled: Feb. 18, 2013 Disclosed are methods for dehydrating a water containing source of formaldehyde in which water is separated from the (86) PCT NO.: PCT/UP2O13AOS4639 water containing source of formaldehyde using a Zeolite membrane. In certain aspects, the water containing source of S371 (c)(1), formaldehyde includes a separation enhancer having a rela (2) Date: Aug. 15, 2014 tive static permittivity ranging from 2.5 to 20, and the water containing source of formaldehyde may further include Related U.S. Application Data methanol. In certain aspects, (meth)acrylic acid alkyl ester (63) Continuation of application No. PCT/JP2012/054498, may be produced using the dehydrated source of formalde filed on Feb. 17, 2012. hyde. O - 16 17 18b. E} 8 E. 8as 15 //ZZZ 2) 2227 14 11 12 Patent Application Publication Feb. 26, 2015 Sheet 1 of 2 US 2015/005361.6 A1 FIG. 1 Patent Application Publication Feb. 26, 2015 Sheet 2 of 2 US 2015/005361.6 A1 FIG 2 25a =•**************************? ******************************************••••••••~~~~-..-…-..-.-.-.-.-.-. **********************************~~~~~~~~~~~~~~.…….……..….……–……….….…. ?. »|-8-~~~~~~~~~~~~~~~~~ *.***************~~~~~~~~~&w.• &}|-*************--~~~~~~~~~~~~~~~~ US 2015/005361.6 A1 Feb. 26, 2015 DEHYDRATION OF WATER CONTAINING CITATION LIST SOURCE OF FORMALDEHYDE, AND A METHOD FOR PRODUCING AN Patent Literature ETHYLENICALLY UNSATURATED CARBOXYLCESTER O010 PTL 1 JP-A-2006-265123 TECHNICAL FIELD SUMMARY OF INVENTION 0001. The present invention relates to a method for dehy Technical Problem dration of water containing Source of formaldehyde, and a 0011. However, the method disclosed in PTL 1 had an method for producing (meth)acrylic acid alkyl ester. insufficient dehydration performance. BACKGROUND ART 0012. The present invention is made from the viewpoint of these problems, and it provides a method for dehydration of a 0002 Recently, a method for producing (meth)acrylic water containing source of formaldehyde having an excellent acid alkyl ester by reacting a carboxylic acid ester with form dehydration performance, and a method for producing (meth) aldehyde in the presence of a catalyst (vapor-phase conden acrylic acid alkyl ester using a dehydrated source of formal sation reaction) has been developed. For example, when dehyde obtained by dehydration of the water containing methyl propanoate is used as carboxylic acid ester, methyl source of formaldehyde. methacrylate is obtained as shown in the following formula (I). Solution to Problem CH, CH, COOCH+HCHO->CH CH 0013. According to a first aspect of the present invention, (CHOH) COOCH->CH C(CH)– there is provided a method for dehydration of a water con COOCH+HO (I) taining source of formaldehyde comprising the step of con 0003 Formaldehyde is used in the form of formalin in tacting the source of formaldehyde with a zeolite membrane many cases. Formalin is an aqueous solution containing in a manner effective to separate at least part of the water from formaldehyde, and generally contains methanol as a stabi the source of formaldehyde wherein the water containing lizer. Therefore, when formalin is used as a raw material of Source of formaldehyde comprises a separation enhancer (meth)acrylic acid alkyl ester, water is introduced into the having a relative static permittivity of between 2.5 and 20 at reaction system. When water is present in the reaction system, 20° C. and atmospheric pressure and wherein the water con inhibition of the reaction progression and deterioration of the taining source of formaldehyde further contains methanol. catalyst are more likely to occur. 0014 Preferably, the water is separated from the said 0004. A further reaction with an acetal is shown in the water containing source of formaldehyde by Zeolite mem following formula (II). brane pervaporation or Zeolite membrane vapor permeation, and more preferably, the water is separated by vapor perme ation. 0005. A theoretical example of formula (II) with a 0015 Typically, in the process of the invention, the water dimethoxymethane is shown in the following formula (III). enriched fluid is the permeate and the dehydrated source of formaldehyde is the retentate. However, it is possible for the CH, CH, COOR+CHOCHOCH->CH, C(: dehydrated source of formaldehyde to be the permeate and CH) COOR+2CH-OH (III) the water enriched fluid to be the retentate. 0006. The use of dimethoxymethane thus theoretically 0016. According to a further aspect of the present inven provides an anhydrous system which avoids the difficulty of tion there is provided a method for producing an ethylenically Subsequent water separation and/or Subsequent product unsaturated carboxylic ester, preferably, an C. Bethylenically hydrolysis. In addition, the use of dimethoxymethane avoids unsaturated carboxylic ester by contacting a source of form the use of free formaldehydebut nevertheless acts in a general aldehyde with a carboxylic acid ester in the presence of a sense as a source of formaldehyde. The absence of water and catalyst, wherein a dehydrated source of formaldehyde is free formaldehyde could greatly simplify the separation of obtained by contacting a water containing Source of formal methyl methacrylate from the product stream. dehyde with a zeolite membrane in a manner effective to 0007. However, in practice, formula (III) is problematic separate at least part of the water from the water containing because methanol dehydrates to dimethyl ether and water. In source of formaldehyde to produce the said dehydrated addition, dimethoxymethane decomposes under catalytic source of formaldehyde and the dehydrated source of form conditions to dimethylether and formaldehyde. Any water aldehyde is used as the said source of formaldehyde for the formed in these reactions can hydrolyse the ester feedstock or said method. product to its corresponding acid which may be undesirable. 0017 Aparticular preferred feature of the further aspect of 0008. In addition, the presence of water in the reaction the present invention is that the water containing source of mixture increases catalyst decay so that the presence of water formaldehyde contains a separation enhancer having a rela may be undesirable even in the production of ethylenically tive static permittivity of between 2.5 and 20, more preferably unsaturated carboxylic acids. and according to the first or further aspects of the present 0009. Therefore, when (meth)acrylic acid alkyl ester is invention the relative static permittivity is between 3 and 15, produced, there is a demand to reduce the amount of water and most preferably between 4 and 10, especially, between 4 which is introduced to the reaction system, and, for example and 8 at 20° C. and atmospheric pressure. a method of dehydration by distillation of an aqueous solution (0018. By “atmospheric pressure” herein is meant 101.325 of formaldehyde has been proposed (see PTL 1). kPa. US 2015/005361.6 A1 Feb. 26, 2015 0019. By “relative static permittivity” is meant the ratio of 0032 5. The method for dehydrating a water containing the electric field strength in a vacuum to that in a given Source of formaldehyde according to any one of 1 to 4. medium at a frequency of Zero, this is commonly known as wherein the separation enhancer is carboxylic acid ester. the dielectric constant. 0033 6. The method for dehydrating the water contain 0020. It has been found that the separation enhancer car ing source of formaldehyde according to claim 5, wherein the boxylic acid ester is particularly effective. The carboxylic carboxylic acid ester is selected from methyl methacrylate, acid ester is preferably methyl propanoate, methyl acrylate, methyl acrylate, methylpropanoate ethylethanoate or methyl methyl methacrylate, ethyl ethanoate or methyl ethanoate, ethanoate. more preferably, the carboxylic acid ester is methyl pro 0034 7. The method for dehydrating the water contain panoate or methyl ethanoate, and most preferably, the car ing source of formaldehyde according to claim 6, wherein the boxylic acid ester is methyl propanoate. carboxylic acid ester is methyl propanoate. 0021 A preferred feature of the further aspect of the 0035 8. The method for dehydrating the water contain present invention is that a water containing source of the ing source of formaldehyde according to any one of 1 to 7. separation enhancer is combined with the water containing wherein the Zeolite membrane is a Linde Type-A orchabazite Source of formaldehyde to produce a combined source and Zeolite membrane. wherein the combined source is dehydrated in accordance 0036 9. The method for dehydrating the water contain with the first or further aspect of the invention to provide the ing Source of formaldehyde according to 8, wherein the said dehydrated source