The invention relates to the technical field of
chemical synthesis, and particularly discloses a production process of N, N-bis (carboxymethyl)-L-
glutamic acid tetrasodium salt. The method comprises the following steps: firstly, carrying out
nanofiltration on N, N-bis (cyanomethyl)-L-
sodium glutamate reaction liquid through a
nanofiltration membrane with a specific
pore diameter, and then continuously introducing the
nanofiltration liquid into a reactor containing caustic soda liquid to carry out step-by-step
alkaline hydrolysis reaction, so that the N, N-bis (cyanomethyl)-L-
sodium glutamate is converted into N, N-bis (carboxymethyl)-L-
glutamic acid tetrasodium salt at a
maximum rate in an alkaline environment; meanwhile, according to the method, gradient heat preservation is carried out on the
alkaline hydrolysis liquid through a multi-stage series heat preservation device, so that unreacted raw materials or by-products in the
alkaline hydrolysis liquid are fully converted into N, N-bis (carboxymethyl)-L-
glutamic acid tetrasodium salt; and carrying out multi-stage gradient heat preservation on the reaction liquid after the alkaline
hydrolysis reaction, and separating, concentrating and adsorbing the heat preservation liquid after the gradient heat preservation to obtain a high-purity, high-concentration and low-
viscosity N, N-bis (carboxymethyl)-L-glutamic acid tetrasodium water solution.