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Title: Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters

Abstract

Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO 2 and H 2S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubilitymore » of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration-based distribution ratios increase from 0.11 to 0.46 as the aqueous phase pH increases from 7.18 to 8.15. Regeneration of the organic extractant solution was carried out by stripping at elevated temperatures to remove the ammonia, with 99% recovery of the ammonia being obtained at 125 C.« less

Authors:
 [1]
  1. Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
937439
Report Number(s):
LBL-28615
TRN: US200819%%126
DOE Contract Number:
AC02-05CH11231; AC03-76SF00098
Resource Type:
Thesis/Dissertation
Resource Relation:
Related Information: Designation of Academic Dissertation: Doctoral Thesis; Academic Degree: Ph.D.; Name of Academic Institution: UC Berkeley
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; AMINES; AMMONIA; AQUEOUS SOLUTIONS; BUFFERS; CARBOXYLIC ACIDS; CATIONS; ENERGY ACCOUNTING; EVAPORATION; FUMARIC ACID; GASES; LACTATES; LACTIC ACID; PHOSPHINIC ACIDS; REGENERATION; SOLUBILITY; SOLVENT EXTRACTION; STEAM STRIPPING; SUCCINIC ACID; WATER

Citation Formats

Poole, Loree Joanne. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters. United States: N. p., 1990. Web. doi:10.2172/937439.
Poole, Loree Joanne. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters. United States. doi:10.2172/937439.
Poole, Loree Joanne. 1990. "Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters". United States. doi:10.2172/937439. https://www.osti.gov/servlets/purl/937439.
@article{osti_937439,
title = {Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters},
author = {Poole, Loree Joanne},
abstractNote = {Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO2 and H2S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration-based distribution ratios increase from 0.11 to 0.46 as the aqueous phase pH increases from 7.18 to 8.15. Regeneration of the organic extractant solution was carried out by stripping at elevated temperatures to remove the ammonia, with 99% recovery of the ammonia being obtained at 125 C.},
doi = {10.2172/937439},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1990,
month = 3
}

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  • Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO 2 and H 2S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine,more » such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration-based distribution ratios increase from 0.11 to 0.46 as the aqueous phase pH increases from 7.18 to 8.15. Regeneration of the organic extractant solution was carried out by stripping at elevated temperatures to remove the ammonia, with 99% recovery of the ammonia being obtained at 125 C.« less
  • In a study of wastewater samples having a COD of 1000 to over 410,000 ppm from two major processes for acetic acid manufacture, solvent extraction was too expensive to be practical unless recovery of a marketable chemical was possible, and acetic acid present at 30 ppm to nearly 18Vertical Bar3< by wt was the only chemical having a market potential. Long-chain, tertiary alkylamines dissolved in organic diluents were the most promising extractants, except for certain wastewaters containing chlorinated acetaldehydes. In small-scale experiments on the phase equilibria, extractant regenerability, mass-transfer characteristics, and emulsification tendencies of amine extractants, the organic diluent hadmore » a large effect; C/sub 9/ ketones were the most attractive diluents. The direct-fixed-capital cost for an extraction process to recover acetic acid from a 22,700 kg/hr wastewater flow containing 5Vertical Bar3< by wt acid was estimated at $1,030,000 with an annual operating cost of $253,000/yr. This gives a return on investment before taxes of 244Vertical Bar3« less
  • The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solventsmore » were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.« less
  • Limestone can be used more effectively as a sorbent for H 2S in high-temperature gas-cleaning applications if it is prevented from undergoing calcination. Sorption of H 2S by limestone is impeded by sintering of the product CaS layer. Sintering of CaS is catalyzed by CO 2, but is not affected by N 2 or H 2. The kinetics of CaS sintering was determined for the temperature range 750--900°C. When hydrogen sulfide is heated above 600°C in the presence of carbon dioxide elemental sulfur is formed. The rate-limiting step of elemental sulfur formation is thermal decomposition of H 2S. Part ofmore » the hydrogen thereby produced reacts with CO 2, forming CO via the water-gas-shift reaction. The equilibrium of H 2S decomposition is therefore shifted to favor the formation of elemental sulfur. The main byproduct is COS, formed by a reaction between CO 2 and H 2S that is analogous to the water-gas-shift reaction. Smaller amounts of SO 2 and CS 2 also form. Molybdenum disulfide is a strong catalyst for H 2S decomposition in the presence of CO 2. A process for recovery of sulfur from H 2S using this chemistry is as follows: Hydrogen sulfide is heated in a high-temperature reactor in the presence of CO 2 and a suitable catalyst. The primary products of the overall reaction are S 2, CO, H 2 and H 2O. Rapid quenching of the reaction mixture to roughly 600°C prevents loss Of S 2 during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO 2 and H 2S. Unreacted CO 2 and H 2S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H 2 and CO, which recovers the hydrogen value from the H 2S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.« less