Method for preparing nicotinic acid through hydrolysis

The invention relates to the technical field of chemical intermediate synthesis, particularly to a method for preparing nicotinic acid through hydrolysis. The method comprises: taking 3-cyanopyridine,placing in a container, adding deionized water to the container, and stirring to form an aqueous solution; heating the aqueous solution, adding nitrilase, carrying out a reaction for 1.5-2 h at a temperature of 45-50 DEG C under a stirring condition, and carrying out catalytic hydrolysis to form a nicotinic acid solution; placing the nicotinic acid solution into a pressure reducing distillation device, and carrying pressure reducing distillation to obtain a concentrated liquid; placing the concentrated liquid in an oven, and baking for 6-10 h to obtain nicotinic acid with a water content of 2%; placing the nicotinic acid with the water content of 2% in an extruder, and pressing at a pressure of 8 MPa to obtain a nicotinic acid pressing sheet; and breaking the nicotinic acid pressing sheet, and screening with a vi