Method and apparatus for recovering absorbing agents in acid gas treatment

A continuous process for acid gas removal comprising the following steps:

• (a) introducing into an absorber having an absorber interior and an absorption zone located in the absorber interior a mixture of process gas and acid gas comprising
• a process gas selected from the group consisting of:
• a hydrocarbon,
• a mixture of hydrocarbons,
• synthesis gas, and
• a mixture of nitrogen and hydrogen, and
• about 1 to about 99 percent by volume
• of an acid gas selected from the group consisting of:
• carbon dioxide,
• hydrogen sulfide,
• other sulfur containing gases, and
• mixtures of the acid gases,
• wherein percent by volume is based on the total volume of
• the mixture of process gas and acid gas
• introduced into the absorption zone;
• (b) counter-currently contacting in the absorption zone
• the mixture of process gas and acid gas referred to in step “a”
• with an
• absorbent chemical,
• and
• water,
• the absorbent chemical and water
• are in solution prior to contact and
• (c) removing the process gas overhead
• from the absorption zone;
• (d) removing the absorbent chemical and water solution
• with the acid gas absorbed therein
• from the bottom of the absorption zone;
• (e) introducing the solution from step “d”
• into a regenerator having a regeneration interior and a regeneration zone located in the regeneration interior;
• (f) separating a mixture of
• acid gas, absorbent chemical, and water from the solution referred to in step “e”,
• the separated absorbent chemical and water portion
• being in the form of vapor, and
• removing the separated mixture of acid gas, absorbent chemical, and water
• overhead from the regeneration zone;
• (g) introducing the separated mixture of acid gas, absorbent chemical, and water referred to in step “f”
• to a static mixing zone not located in the absorber interior, wherein the static mixing zone includes a static mixing device having a tubular casing with a longitudinal axis and at least one mixing element in the form of crossed webs disposed at an angle with the longitudinal axis, the webs being disposed in at least two groups, the webs of any one group of elements extending substantially parallel to one another and the webs of one group crossing the webs of the other group,
• wherein supplemental washing water is added and intimately mixed with the separated mixture of acid gas, absorbent chemical, and water referred to in step “f”, thereby creating a water washed separated mixture of acid gas, absorbent chemical, and water solution, and wherein the separated mixture of acid gas, absorbent chemical, and water solution and the supplemental washing water have co-current flows;
• (h) passing the water washed separated mixture of acid gas, absorbent chemical, and water solution of step “g”
• into a cooling zone
• wherein the temperature of the water washed separated mixture is reduced;
• (i) removing the balance of the solution referred to in step “f”
• from the bottom of the regeneration zone;
• (j) passing the solution from step “i”
• into a cooling zone
• wherein the temperature of the solution is reduced;
• and
• (k) recycling the solution of step “j” to the absorption zone.