The present application belongs to the field of modern
coal chemical technology, and particularly relates to a device and method for co-producing
oxalic acid in a
coal-to-
ethylene glycol
system. The device comprises a
hydrolysis kettle, a condenser, a condensate tank, a rectifying
tower, a vacuum
crystallization tank, a vacuum
system, a
crystal dehydration device, a
mother liquor tank, a
drying device, and a storage and packaging
system. The present application uses compressed gas to press and deliver the
crystal slurry, which is directly sent to a
centrifuge, thereby avoiding the deposition of crystals in
pipe bends, valves and pump cavities. Meanwhile, multiple parallel vacuum
crystallization tanks are provided, which are respectively in the states of feeding,
crystallization, discharging and standby according to time differences, thereby linking the front-end continuous rectification with the rear-end intermittent crystallization and ensuring the continuous output of the device. The present application uses a staged anticorrosion material replacement strategy, i.e., the
hydrolysis kettle is made of glass lining material, the rectifying
tower cylinder is lined with Teflon, and C-276
alloy is selected for the key heated components, thereby replacing expensive special metals with non-
metal materials on the premise of ensuring
corrosion resistance, and greatly reducing the equipment cost.