SU850181A1 - Method of regeneration of waste glycol adsorbent - Google Patents

Description

(54) METHOD FOR REGENERATING SUBSTITUTED ABSORBENT-GLYCOL

The invention of fire retardant gas and gas condensate storage facilities and underground gas storage facilities is intended for the regeneration of glycols, in particular, the glycol used as an absorbent, can be used in the gas, oil and chemical industries. A known method for the regeneration of glycol by heating under vacuum. When carrying out the regeneration process under vacuum, an increase in the concentration of the absorber is achieved at a lower temperature M. However, the known method cannot be effectively applied to the regeneration of glycol solutions containing mineral salts. The closest to the proposed technical essence and the achieved result is the method of regeneration of the spent absorbent - glycol by heating it to 125-140 ° C, followed by rectification and return obtained (F of the centered glycol at the drying stage 2. The disadvantage of this method is that when the absorbent, diethylene glycol, is heated to 14 ° –150 ° C, the solubility (due to evaporation of water) of mineral salts contained in it decreases, as a result of which they precipitate on the surface of heat exchange and mass transfer equipment vania, impairing their work (overheating, burnout, clogging cap plates, etc.), and reduce the efficiency of the regeneration process. In addition, when 407Og / l salt is reached in diethylene glycol, it loses desiccation and is removed from regeneration The purpose of the invention is to ensure the possibility of carrying out the regeneration of mineralized glycol and increasing its concentration. The goal is achieved by the method of regeneration of the spent abscess - glycol by heating it with subsequent regeneration, in gly ol ne. Red hot is subjected to elektrodiapiza at (shock level 4-31 mA / cm.

11ri 3f ohm heating the glycol vedug to the temperature IO-125С.

SnAb allows spaking concentrations in regenerated diethyleneglycrate to be reached at appropriate levels (6.3 g / l, 1.2 g / l and 0.7 g / l), and no salt deposits are observed on the Raschig columns of the column. When PS is reduced compared to the known method of 15–20Ps at the regeneration temperature, the degree of regeneration of diethylene glycol is, on average, 3–4%.

With the content of diethylene glycol in water-salt solutions up to 6–80%, the viscosity of the latter rises to 6–12 s.

The electrodialysis of solutions with increased viscosity is associated with a number of complications, for example, with an increase in the viscosity of the solutions, the limiting current density decreases back to the pro-ordinal square root of viscosity. The diethylene glycol solution viscosity hampers the removal of heat during electrodialysis in an electrodialysis apparatus, which may cause dangerous overheating of ion-exchange membranes, in particular, the main component of the electrodialysis apparatus. Therefore, the electrodialysis of diethyl glycol solutions should be carried out at lower current densities. However, a low current density significantly reduces the yield in tszhu, which ultimately leads to a small degree of desalting, especially with large conceptrats of salts in the diethylecpikap solution. It has been established that the optimum current density during the electroscopic analysis of the solutions (DEG DEG, depending on the concentration of the initial solution and the flow rate of workers

cm / s

The number of losses in desorber, g (at the end of the cycle)

The pile in the intermembrane space is 4 to 31 mA / cm.

When the current drops below 4 mA / cm, the recovery of the diethylene glycol solution is inefficient, and the current density above 31 mA / cm results in concentration polarization, which also leads to the termination of the electrolysis process.

Example. The method was tested on a pilot plant with a capacity of 5 l / h of regenerated diethylene glycol.

In the tank, an aqueous solution of diethylene glycol with a concentration of 80% containing 60 g / l of mineral salts (5 g / l of hardness salts, the rest is NoCE) is prepared, which is pumped into the electrodialysis chamber. At the outlet of the chamber, an aqueous solution of diethylene glycol with a concentration of 90% and with a salt content of 5 g / l is sent to a preheater, where it is heated to 12 ° C. The diethylene glycopte leaving the preheater is sent to a column, filled with Raschig rings and heated by an electric coil. Water vapor is discharged from the top of the column, and diethylene glycol, whose concentration in relation to its concentration at the outlet of the electrodialyzer rises by an amount of the order, is discharged from the bottom into the tank and ethylene glycol. Thereafter, the regeneration cycle is repeated.

Ol maintain a given source

Concentrations of diethylene glycol and salts periodically after each cycle, after 1 hour, appropriate amounts of water and salts are added to the tank.

The table presents data on the glycol concentration.

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Claims (2)

 О Thus, when drying 10 mprv-m of gas per year, the proposed method allowed us to obtain an econo lative effect only by reducing the loss of denetyphenoglycol in the amount of 150 thousand rubles. This is due to the fact that, in order to enable the regeneration of mineralized glycol and the increase in its concentration, to be carried out, the glycol is subjected to electrodialysis before heating at a current density of 4-31 mA / cm. 2. The method according to and. 1, that is, with the fact that the glycol is heated to a temperature of 10 ~ 125 ° C. Sources of information taken into account during the examination 1. US patent No. 3841832, cl. 159-16, published. 1974,. 2. Zhdanova N. V, and Khalif A. P. The dehydration of natural gases. M., Nedra, 1975, p. ZO (prototype).