Method of concentrating and separating glyphosate in high salt content glyphosate mother liquor by film technique

[0015] Example 1:

[0016] In the process of preparing glyphosate by the alkyl ester method, the 10000kg mother liquor after neutralization and separation of triethylamine is pumped into the raw material liquid tank after pressure filtration by a filter press or a bag filter or a precision filter. The glyphosate mother liquor is pumped into a multi-media filter containing activated carbon to remove the viscous liquid from the mother liquor with a pump with a head of 20m, and then the micro-particles in the mother liquor are directly removed through a 50μm microporous filter membrane. The mother liquor reaches water quality. When the pollution index SDI is less than or equal to 5, it will enter the first-level membrane system after being pressurized by the high-pressure pump. The glyphosate mother liquor solution entering the primary membrane system is separated into two strands after the primary membrane separation. The solution rich in glyphosate on the concentrated side returns to the front-end inlet. When the concentration of glyphosate in the solution reaches 5%, it will be concentrated The liquid is pumped into the No. 1 storage tank, a total of 2000kg, the light side solution is pressurized by a high-pressure pump with a head of 600m, and then enters the secondary membrane system. The glyphosate light liquid entering the secondary membrane system is separated into two streams after being separated by the secondary membrane. The concentrated side solution returns to the inlet of the primary nanofiltration membrane system, and the light side glyphosate light liquid rich in sodium chloride has a lift of 300m. The high-pressure pump enters the three-stage membrane system after being pressurized. The light glyphosate solution entering the tertiary membrane system is separated into two streams after being separated by the tertiary membrane. The concentrated solution is returned to the inlet of the secondary nanofiltration membrane system, and the sodium chloride-rich solution on the light side is collected in the No. 2 storage tank. A total of 8000kg.

[0017] Concentrate 2000 kg of liquid in the No. 1 storage tank through a double-effect concentration system to obtain 980 kg of glyphosate water with a mass fraction of 10.01%.

[0018] The 8000kg liquid in the No. 2 storage tank is separated by membrane to obtain 6000kg of sodium chloride-rich solution and 2000kg of water. 6000kg of sodium chloride-rich solution is directly used for the crude brine of chlor-alkali.

[0019] Example 2:

[0020] 200kg of sulfuric acid was added to the 2000kg mother liquor for preparing glyphosate by air oxidation of glyphosate to adjust PH=1.2, and 350kg of glyphosate technical medicine and 1840kg mother liquor were obtained through filtration and separation. Ammonia gas 20kg was passed into the mother liquor, PH=2.5. The mother liquor is press-filtered by a filter press or a bag filter or a precision filter and then pumped into the raw material liquid tank. The glyphosate mother liquid in the raw material liquid tank is pumped into a multi-media filter containing activated carbon by a 30m pump. Remove the viscous liquid in the mother liquor, and then directly remove the micron particles in the mother liquor through a microporous filter membrane with a pore size of 50μm. When the mother liquor reaches the water pollution index SDI≤5, it is pressurized by a high-pressure pump and enters the primary membrane system. The glyphosate mother liquor solution entering the primary membrane system is separated into two strands after the primary membrane separation. The solution rich in glyphosate on the concentrated side returns to the front-end inlet. When the concentration of glyphosate in the solution reaches 3%, it will be concentrated The liquid is pumped into the No. 1 storage tank, a total of 600kg, the light side solution is pressurized by a high-pressure pump with a head of 150m, and then enters the secondary membrane system. The glyphosate light liquid entering the secondary membrane system is separated into two streams after being separated by the secondary membrane. The concentrated side solution returns to the inlet of the primary nanofiltration membrane system, and the light side glyphosate light liquid rich in sodium chloride has a lift of 300m. The high-pressure pump enters the three-stage membrane system after being pressurized. The light glyphosate solution entering the tertiary membrane system is separated into two streams after being separated by the tertiary membrane. The concentrated solution is returned to the inlet of the secondary nanofiltration membrane system, and the sodium chloride-rich solution on the light side is collected in the No. 2 storage tank. A total of 1200kg.

[0021] The 600kg of liquid in the No. 1 storage tank is concentrated by a double-effect concentration system to obtain 180kg of glyphosate water with a mass fraction of 10.11%.

[0022] Concentrate 1200kg of liquid in No. 2 storage tank through a combination of membrane separation and double-effect concentrator to obtain 205kg of ammonium sulfate.

[0023] Example 3:

[0024] In the process of preparing glyphosate by the alkyl ester method, the 10000kg mother liquor after neutralization and separation of triethylamine is pumped into the raw material liquid tank after pressure filtration by a filter press or a bag filter or a precision filter. The glyphosate mother liquor is pumped into a multi-media filter containing activated carbon to remove the viscous liquid from the mother liquor with a pump with a head of 20m, and then the micro-particles in the mother liquor are directly removed through a 50μm microporous filter membrane. The mother liquor reaches water quality. When the pollution index SDI is less than or equal to 5, it will enter the first-level membrane system after being pressurized by the high-pressure pump. The glyphosate mother liquor solution entering the primary membrane system is separated into two strands after the primary membrane separation. The solution rich in glyphosate on the concentrated side returns to the front-end inlet. When the concentration of glyphosate in the solution reaches 2%, it will be concentrated The liquid is pumped into the No. 1 storage tank, a total of 5000kg, the light side solution is pressurized by a high-pressure pump with a head of 100m, and then enters the secondary membrane system. The light glyphosate liquid entering the secondary membrane system is separated into two streams after being separated by the secondary membrane. The concentrated side solution returns to the inlet of the primary nanofiltration membrane system, and the light side glyphosate light liquid rich in sodium chloride has a head of 200m. The high-pressure pump enters the three-stage membrane system after being pressurized. The light glyphosate solution entering the tertiary membrane system is separated into two streams after being separated by the tertiary membrane. The concentrated solution is returned to the inlet of the secondary nanofiltration membrane system, and the sodium chloride-rich solution on the light side is collected in the No. 2 storage tank. A total of 5000kg.

[0025] The 5000kg of liquid in the No. 1 storage tank is concentrated by a double-effect concentration system to obtain 960kg of glyphosate water with a mass fraction of 10.13%.

[0026] After separating 5000 kg of liquid in the No. 2 storage tank through membrane separation, 3000 kg of sodium chloride-rich solution and 2000 kg of water are obtained. 3000kg of sodium chloride-rich solution is directly used for the crude brine of chlor-alkali.