The invention relates to the production of (meth)acrylic acid, and to implementation of a step of condensing water contained in a recycled gas effluent and/or in the air feed in a (meth)acrylic acid production process, which further includes a process for purifying a reaction mixture comprising (meth)acrylic acid without using azeotropic solvent and based on the use of two distillation columns.

The present invention relates to an acrylic acid production equipment which includes a raw material gasification apparatus for converting liquefied propylene into a propylene gas; an oxidation reaction apparatus for converting the propylene gas into crude acrylic acid; and a purification apparatus for converting the crude acrylic acid into acrylic acid, wherein the raw material gasification apparatus includes a heating apparatus in the inside thereof and also includes a heating apparatus in the periphery including at least a bottom of the raw material gasification apparatus, by which not only energy can be effectively utilized, but also it is possible to achieve a stopping operation efficiently and within a short time.

The present invention relates to an acrylic acid production equipment which includes a raw material gasification apparatus for converting liquefied propylene into a propylene gas; an oxidation reaction apparatus for converting the propylene gas into crude acrylic acid; and a purification apparatus for converting the crude acrylic acid into acrylic acid, wherein the raw material gasification apparatus includes a heating apparatus in the inside thereof and also includes a heating apparatus in the periphery including at least a bottom of the raw material gasification apparatus, by which not only energy can be effectively utilized, but also it is possible to achieve a stopping operation efficiently and within a short time.

The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavourings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavourings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

A process for producing acrylic acid from carbonaceous materials such as biomass. The carbonaceous material, such as biomass, is gasified to produce synthesis gas. The synthesis gas then is subjected to a plurality of reactions to produce acrylic acid.

A process for producing acrylic acid from carbonaceous materials such as biomass. The carbonaceous material, such as biomass, is gasified to produce synthesis gas. The synthesis gas then is subjected to a plurality of reactions to produce acrylic acid.

The invention relates to a process for preparation of at least one of methacrylic acid and a methacrylic acid ester, comprising the process stepsgas phase oxidation of at least one C.sub.4 compound, quenching of the reaction phase, separation and purification of the obtained methacrylic acid and optionally esterification, wherein the C.sub.4 compound is a methacrolein comprising mixture, originating from at least two different methacrolein sources, a first methacrolein source being a feed stream obtained by the heterogeneously catalyzed gas phase oxidation of isobutylene or tert-butyl alcohol or isobutylaldehyde or a mixture of two or more thereof, a second methacrolein source being a feed stream obtained by the reaction of propionaldehyde with a C.sub.1 extending agent, preferably formaldehyde, and where said methacrolein can be obtained either completely from the first methacrolein source, or completely from the second methacrolein source or from any mixture of both.

The invention relates to a process for preparation of at least one of methacrylic acid and a methacrylic acid ester, comprising the process stepsgas phase oxidation of at least one C.sub.4 compound, quenching of the reaction phase, separation and purification of the obtained methacrylic acid and optionally esterification, wherein the C.sub.4 compound is a methacrolein comprising mixture, originating from at least two different methacrolein sources, a first methacrolein source being a feed stream obtained by the heterogeneously catalyzed gas phase oxidation of isobutylene or tert-butyl alcohol or isobutylaldehyde or a mixture of two or more thereof, a second methacrolein source being a feed stream obtained by the reaction of propionaldehyde with a C.sub.1 extending agent, preferably formaldehyde, and where said methacrolein can be obtained either completely from the first methacrolein source, or completely from the second methacrolein source or from any mixture of both.

The present invention provides a production method which is capable of stably producing a catalyst that enables a production of methacrylic acid with high selectivity. A method of producing a catalyst used for a production of methacrylic acid includes (i) preparing a slurry A1 containing a heteropolyacid containing at least phosphorus and molybdenum or a salt of the heteropolyacid containing at least phosphorus and molybdenum, (ii) preparing a slurry A2 satisfying the following Formula (I) and Formula (II) using the slurry A1, (iii) mixing the slurry A2 and a raw material liquid B containing a cationic raw material to prepare a slurry C, and (iv) drying the slurry C, α.sub.A2/α.sub.A1≤0.95 (I), 2≤D.sub.A2≤50 (II), wherein, in Formula (I), α.sub.A1 represents a half-value width (μm) of a particle size distribution of the slurry A1, α.sub.A2 represents a half-value width (μm) of a particle size distribution of the slurry A2, and in Formula (II), D.sub.A2 represents a median diameter (μm) of the particle size distribution of the slurry A2.