This study employed the Box-Behnken design in response surface methodology (RSM) to optimize pre-distillation and pressurized distillation column parameters in methanol distillation. Statistical and fitting analyses demonstrated the effects of operational parameters and their interactions on product purity and operating costs. Results showed that for methanol mass fraction in the product

the top distillate of the predistillation column (

D

1

)

the interaction between

D

1

and the top distillate of the pressurized distillation column (

D

2

)

and the interaction between the theoretical plates of the pressurized distillation column (

N

2

) and its reflux ratio (

R

2

) significantly affected the outcome

in addition to pressurized distillation column parameters. Acetone mass fraction was mainly influenced by pre-distillation column parameters and their interactions

with minimal relation to the pressurized distillation column. Operating costs were primaril

y affected by the reflux ratio (

R

)

withdrawal (

D

) of both columns

and their interactions. Optimization strategies involved increasing theoretical plates and reducing reflux ratios compared to the initial plan

achieving energy-saving and consumption-reduction goals. The process required the pressurized distillation column ‘s methanol mass fraction to exceed 99.80%

acetone mass fraction below 2 × 10

-8

and formaldehyde mass fraction below 5 × 10

-9

with a feed rate of 6100 kg·h

-1

. Plans A

B

and C achieved energy-savings of 29.80%

21.78%

and 25.50% respectively

while ensuring separation efficiency and product quality. This research provides theoretical and practical guidance for optimizing the methanol distillation process

helping to reduce energy consumption and production costs

thereby enhancing corporate competitiveness.