The present invention relates to an improved device and method for preparing
hydrogen peroxide having a concentrate of 35% by low purity
hydrogen gas having a concentrate of 90%, which is characterized in that the empty oxidation
tower is changed into a
sieve plate column provided with 2~5 distribution boards therein, wherein the
distribution board comprises four pieces of dismounting type small
sieve plates and is fixed on the intermediate beam, and
sieve pores having a
diameter of 3~10 mm and a percentage of open area of 30~40% are equably arranged on the
distribution board in a prismatic array; each sieve plate is provided with 4~6 downcomers in the extraction column in prior art, which is changed into that each of the upper fourteen sieve plates is provided with one downcomer while each of the lower forty sieve plates is provided with two downcomers, and the topside of the column is filled with 1500~2000 mm
ripple packing, and the distance between the packing and the topside sieve plate is 400 mm, and the
process conditions are optimized so that the oxidation efficiency is improved from 5.7 g / l to 6.1~6.3 g / l, the oxidation yield is more than 95%, the surplus extraction rate is decreased from 0.3 g / l to0.1 g / l, the device can be used for directly producing H2O2 with a concentration of 35% from residual source of
hydrogen of the 95% low purity synthetic
ammonia or
urea device. The device and the technology method are adapted to the
hydrogen peroxide device of the present matching synthetic
ammonia or
urea device to produce H2O2 with a concentration of 35%.