Method for electrolytic synthesis of butanedioic acid and fixed bed electrochemical reaction device

The invention provides a method for electrolytic synthesis of butanedioic acid and a fixed bed electrochemical reaction device. The method comprises the following steps: by taking a maleic anhydride solution with the mass concentration of 5-20% and a sulfuric acid solution with the mass concentration of 3-15% as an electrolyte, introducing the electrolyte into a circulating tank by virtue of a liquid storage tank; inputting the electrolyte into an electrolytic tank by virtue of a magnetic circulating pump; controlling the temperature of the electrolytic tank to be 30-80 DEG C and the current density to be 200-1000A/m , and electrifying for electrolysis; after reaction, discharging the obtained reaction solution from a liquid outlet of a three-way valve, and performing cooling crystallization on the electrolyte, filtration and drying to obtain butanedioic acid; and recovering the filtrate after filtering out butanedioic acid, adding an appropriate amount of raw materials of maleic anhydride and concentrated sulfuric acid to re-prepare the filtrate into an electrolyte for cycle use. The device comprises the electrolytic tank, the liquid storage tank, the circulating tank, the heat exchanger and the magnetic circulating pump. The method and the device provided by the invention have the beneficial effects of improving the productivity and achieving energy conservation and high efficiency.