摘要:
A process for producing (meth)acrylic acid of the present invention comprises the steps in the following order: a crystallization step of supplying a cooling medium cooled by a heat source device to a crystallizer to obtain a (meth)acrylic acid crystal from a crude (meth)acrylic acid solution; an adjustment step of returning the cooling medium discharged from the crystallizer to the crystallizer without cooling; a sweating step of supplying a heating medium to the crystallizer to partially melt the (meth)acrylic acid crystal, thereby obtaining a melted liquid, and discharging the melted liquid from the crystallizer; and a melting step of supplying the heating medium to the crystallizer to melt the (meth)acrylic acid crystal, thereby obtaining purified (meth)acrylic acid. According to the present invention, purified (meth)acrylic acid with high purity can be obtained.
摘要:
The present invention provides a method for efficiently producing a sulfonic acid group-containing ether compound having a high purity and a good polymerizability while preventing production of a byproduct, and provides a sulfonic acid group-containing ether compound containing fewer impurities and having a good radical (co)polymerizability. The present invention provides a method of producing a sulfonic acid group-containing ether compound by reacting a sulfurous acid compound with a compound represented by the formula (1) : wherein R 1 represents a single bond, a CH 2 group, or a CH 2 -CH 2 group, and R 2 represents H, or a CH 3 group, the method comprising the steps of: adjusting pH of a reaction system to 5.5 or grater with use of an alkaline substance; and adding the compound represented by the formula (1) to a reaction vessel containing the sulfurous acid compound.