An esterification process for producing crude methyl methacrylate (MMA) from methacrylamide (MAM), and at least methanol and water comprising a series of linked reactors (1, n, n+1, . . . N) wherein “n” represents the number of each reactor in the series of reactors (1, 2, 3, 4, 5 etc.), and “N” represents the last reactor in the series, each reactor having an upper part and a lower part, wherein the reactors are set up in a serial way so that there is a counter current flow between a gaseous phase and a liquid phase, the liquid phase flowing from a first reactor (1) of the series toward a last reactor (N), and the gaseous phase flowing from the last reactor (N) toward the first reactor (1), the first reactor of the series comprising:
- methacrylamide, methanol and water lateral inlets,
- the last reactor comprising a lateral steam inlet located at the lower part,
- and each reactor also comprising:
- at least a liquid phase outlet located at the bottom of the lower part,
- at least a gaseous phase outlet, at the top of the upper part,
- at least a gaseous phase inlet at the lower part, the reactors being connected in such a manner that the gaseous phase outlet of reactor (n+1) is linked to the gaseous phase inlet of reactor (n) with the exception of the last reactor, wherein the at least a gaseous phase inlet is the lateral steam inlet,
- at least a lateral liquid phase inlet located at the lower part, the reactors being connected in such a manner that the liquid phase outlet of reactor (n) is linked to the lateral liquid phase inlet of the reactor (n+1) with the exception of the first reactor, wherein the at least a lateral liquid phase inlet includes the methacrylamide, methanol, and water lateral inlets,
- at least another lateral liquid phase inlet located at the lower part, the liquid phase
- outlet of reactor (n) being linked to said another lateral liquid phase inlet of said reactor (n);
- wherein said series of linked reactors further comprises an additional reactor (N+1) comprising:
- at least a first and a second lateral liquid phase inlet located at the lower part,
- at least a gaseous phase outlet at the top of the upper part,
- at least a liquid phase outlet located at the bottom of the lower part, and
- at least a lateral steam inlet located at the lower part,
- said additional reactor (N+1) being connected in a parallel way to the last reactor (N) of the series in such a manner that said additional reactor (N+1) is alternatively linked to a penultimate reactor (N−1), the gaseous phase outlet of the additional reactor (N+1) being linked to a gaseous phase inlet at the lower part of said penultimate reactor (N−1), a liquid phase outlet at the bottom of the lower part of said penultimate reactor (N−1) being linked to the first lateral liquid phase inlet of the additional reactor (N+1), and the liquid phase outlet of said additional reactor (N+1) being linked to the second lateral liquid phase inlet of said additional reactor (N+1);
- said process comprising the steps of:
- a) introducing methacrylamide, methanol and water through the lateral inlets, wherein the inlets are located in a lower part of the first reactor,
- b) extracting a gaseous phase from the top of the reactors via the at least a gaseous phase outlets and introducing said gaseous phase of reactor (n+1) into the at least a gaseous phase inlet at the lower part of reactor (n), with a distributor located inside reactor (n) for mixing said gaseous phase with the liquid flow, wherein said distributor comprises a pipe running horizontally from a lateral wall of the reactor to the middle of the reactor with the end located in the middle of the reactor comprising at least three nozzles in the liquid phase, with at its end at least three nozzles in the liquid phase, wherein said distributor,
- c) extracting the liquid phase from the bottom of the reactors via the liquid phase outlets,
- d) introducing at least a portion of said liquid phase of reactor (n) into the reactor (n+1) via the at least a lateral liquid phase inlet located at the lower part of reactor (n+1), and
- e) introducing steam laterally into the last reactor via the lateral steam inlet located in the lower part of the last reactor.