The invention relates to an energy-saving process for synergistically recycling
hydrogen peroxide and dilute sulphuric acid in acid-making
tail gas desulfurization, which comprises the following steps: S1,
tail gas desulfurization reaction: introducing
tail gas discharged from a final absorption
tower of an acid-making
system into a tail gas desulfurization
tower, and spraying a
hydrogen peroxide solution from the upper part of the desulfurization
tower to generate dilute sulphuric acid with the
volume concentration of 20-25%; s2, graded collection of dilute sulphuric acid: when the
volume concentration reaches 22%-25%, conveying the dilute sulphuric acid to a
dilute acid storage tank by a
dilute acid pump; when the
volume concentration is lower than 22%, returning to the desulfurization tower for continuous recycling; s3, recycling and distributing dilute
sulfuric acid: recycling the dilute
sulfuric acid in a
dilute acid storage tank in two paths: (1) conveying the dilute
sulfuric acid with the volume ratio of 80-85% to an acid-making dry absorption process to prepare finished acid with the volume concentration of 93% or 98%; (2) conveying dilute sulphuric acid with the volume ratio of 15-20% to a purification process; s4,
hydrogen peroxide is dynamically supplemented, and it is ensured that the residual concentration of
hydrogen peroxide in dilute sulfuric acid is maintained to be 0.1%-0.5%. Accurate consumption control of
hydrogen peroxide and resource recycling of dilute sulphuric acid can be realized.