SU1395719A1 - Method of recovering chemicals from vapour-gas discharges of sulfate pulp production - Google Patents

Abstract

The invention relates to the pulp and paper industry and allows increasing the degree of regeneration of hydrogen sulfide and process stability. Steam-gas emissions from the solvent of the melt-recovery boiler unit are fed to a gas-liquid heat exchanger for cooling. The condensate formed during the cooling of vapor-gas emissions is separated and drained into the circulation tank. After the heat exchanger, gas-vapor emissions are fed to the jet washer and washed with a condenser and green liquor. Excess irrigation solution overflowing the circulation tank is returned to the melt solvent. Induction, 1vka emissions are carried out at a ratio of condensate and green liquor from 10: 1 to 20: 1, 1 or 2. S (l

Description

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The invention relates to a method for the regeneration of chemicals from steam-gas emissions of the solvent of the melt-sulphate pulp production and can be used for the regeneration of tiepHHX liquors in soda-recovery boilers.

The aim of the invention is to increase the degree of regeneration of hydrogen sulfide and process stability; The drawing shows a technological diagram explaining the implementation of the proposed method. Intermediate a) TH method includes cooling vapor-gas emissions from the melt solvent in the gas-liquid heat exchanger I, formation of condensate, subsequent flushing of the emissions in the jet gas scrubber, obtained with | H1M condensate and green liquor when the ratio is from 10: 1 to 20: 1 | and return of the washing liquid to the melt solvent.

The addition of green liquor to the condensate of water vapor in a selected interval of ratios makes it possible to regulate the process of purifying gases from hydrogen sulfide with variations in the composition of the gas being purified and thereby increase the degree of regeneration of hydrogen sulfide.

. The vapor – gas emissions from the solvent of the melt 1 enter the gas – liquid heat exchanger 2, where the main condensation of water vapor, heat utilization and partial trapping of chemicals by condensate occur. The condensate containing trapped chemicals is separated and drained into circulation tank 3. In the same. the circulating tank is supplied with green liquor and then the mixture with condensate is pumped by pressure pump 4 to the nozzle device of the mixer jet jet nozzle 5 sec. After the mixer tube the gas-liquid mixture is fed into the droplet separator 6 o The liquid in the dropper 6 is drained into the circulating Tank Sp The excess irrigating solution overflows 7 from the circulating tank 3 and returns to the solvent 1.

Example. Gas-vapor emissions from solvent melt, sodoregenerator0

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capacity of 320 tons of absolutely dry matter (a.c.o.) per day in an amount of 10,000 m Uch under operating conditions, humidity 70%, dust 10 g / nm dry gas and hydrogen sulfide concentration 0.3 g / nm dry gas is fed to the cooling gas-liquid heat exchanger. The condensate formed during the cooling of vapor-gas emissions is separated and drained into the circulation tank. After the heat exchanger, steam-gas emissions are fed into the jet-washing washer and washed with condensate and green liquor. An excess of irrigation solution is returned to the solvent through the overflow of the circulating tank.

The table shows the embodiments of the method with different ratios of condensate and green liquor, as well as prototype experiments.

As can be seen from the table, the proposed method allows to increase the degree of regeneration of hydrogen sulfide to 98.0- 98.3%, whereas in the known method it is 37-97% (in 12 the hydrogen sulfide is not captured, but even excreted).

In addition, the process according to the proposed method is more reliable, since it eliminates the influence of fluctuations of vapor-gas emissions on the efficiency of hydrogen sulfide regeneration and allows stabilizing this process.

Claims (1)

Invention Formula The method of regeneration of chemicals from steam-gas emissions of sulphate pulp production, including cooling the vapor-gas emissions from the melt solvent to form condensate, separating the condensate, then flushing the emissions with condensate and green liquor and returning the spent washing liquid to the melt solvent, which is the purpose of increasing the degree of hydrogen sulfide regeneration and process stability, flushing of emissions is carried out at a ratio of condensate and green liquor from 10: 1 to 20: K Yu about go go N Well 01 and 00 but t O eight About fO oh oh oh about G-) about 1L with about "I Cvl 00 BUT about about o 1L o - - - cm with about ON with s sj- sh PTS G- about. about 1L g with P CVIщ oo oo hchA oo 00 g ON o 00 - o hg o t o o o - cm with about with And R oh oh. " about " about with about S h o cx EI about with ,about with 00 cm with go about SP 00 ) about sh "" cm 00 m about 00 rt about oo sh kfl o-cm I r-f "W - W-4I o see 1P cho oo with S l about t about o. with 3f / f.