Treating kraft mill extract using bipolar membrane electrodialysis for the production of acetic acid

The objective of this work was to determine the process conditions for converting sodium acetate, the major component of alkaline hardwood extract, into acetic acid and sodium hydroxide using bipolar membrane electrodialysis (BPMED). The effects of current density and sodium acetate concentration in the feed-salt solution were evaluated using synthetic sodium acetate solution in a feed and bleed mode. This mode of operation represents semibatch processing and was useful for determining the current efficiencies, energy consumption, and other system parameters for the production of about 160 g/L of acetic acid; maximum achievable concentration of acetic acid in electrodialysis; and 30 g/L of sodium hydroxide, which is the concentration sufficient for the extraction of sodium acetate from hardwood. The feed and bleed mode experiments performed at 60 mA/cm2 using 130 and 85 g/L sodium acetate as feed-salt solutions produced similar results, except for a small change in the amount of water transported into the acid and base compartments. The feed and bleed mode experiment performed at low current density of 40 mA/cm2 using 50 g/L sodium acetate as feed-salt solution produced almost similar quantities of acetic acid and sodium hydroxide as those in the other feed and bleed mode experiments. However, the energy consumption and current efficiencies were lower than those for the experiments performed at the current density of 60 mA/cm2.

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Recovery of Acid and Base from Sodium Sulfate Containing Lithium Carbonate Using Bipolar Membrane Electrodialysis

Membranes ◽

10.3390/membranes11020152 ◽

2021 ◽

Vol 11 (2) ◽

pp. 152

Author(s):

Wenjie Gao ◽

Qinxiang Fang ◽

Haiyang Yan ◽

Xinlai Wei ◽

Ke Wu

Keyword(s):

Sulfuric Acid ◽

Sodium Hydroxide ◽

Sodium Sulfate ◽

Lithium Carbonate ◽

Environmental Benefits ◽

Raw Material ◽

Process Conditions ◽

Bipolar Membrane ◽

Experimental Conditions ◽

Bipolar Membrane Electrodialysis

Lithium carbonate is an important chemical raw material that is widely used in many contexts. The preparation of lithium carbonate by acid roasting is limited due to the large amounts of low-value sodium sulfate waste salts that result. In this research, bipolar membrane electrodialysis (BMED) technology was developed to treat waste sodium sulfate containing lithium carbonate for conversion of low-value sodium sulfate into high-value sulfuric acid and sodium hydroxide. Both can be used as raw materials in upstream processes. In order to verify the feasibility of the method, the effects of the feed salt concentration, current density, flow rate, and volume ratio on the desalination performance were determined. The conversion rate of sodium sulfate was close to 100%. The energy consumption obtained under the best experimental conditions was 1.4 kWh·kg−1. The purity of the obtained sulfuric acid and sodium hydroxide products reached 98.32% and 98.23%, respectively. Calculated under the best process conditions, the total process cost of BMED was estimated to be USD 0.705 kg−1 Na2SO4, which is considered low and provides an indication of the potential economic and environmental benefits of using applying this technology.

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Three-compartment bipolar membrane electrodialysis for splitting of sodium formate into formic acid and sodium hydroxide: Role of diffusion of molecular acid

Journal of Membrane Science ◽

10.1016/j.memsci.2008.07.059 ◽

2008 ◽

Vol 325 (2) ◽

pp. 528-536 ◽

Cited By ~ 45

Author(s):

J JAIMEFERRER ◽

E COUALLIER ◽

P VIERS ◽

G DURAND ◽

M RAKIB

Keyword(s):

Formic Acid ◽

Sodium Hydroxide ◽

Sodium Formate ◽

Bipolar Membrane ◽

Bipolar Membrane Electrodialysis

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Analytical Methods for Diethylstilbestrol in Feeds and Premixes

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/49.5.895 ◽

1966 ◽

Vol 49 (5) ◽

pp. 895-898

Author(s):

Loyal R Stone

Keyword(s):

Acetic Acid ◽

Analytical Methods ◽

Sodium Acetate ◽

Buffer System ◽

Official Method ◽

Sodium Acetate Solution ◽

Acetate Solution ◽

Acid Buffer System ◽

Acetic Acid Buffer

Abstract Methods are presented in which diethylstilbestrol is extracted from feeds in the Goldfisch apparatus, transferred into alkaline sodium acetate solution to avoid emulsions, and measured colorimetrically in a sodium acetate-acetic acid buffer system. The procedure is rapid, and results agree closely with those obtained by the official method. Procedures are also presented for determination of diethylstilbestrol in molasses and fat mixtures.

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In-Situ Combination of Bipolar Membrane Electrodialysis with Monovalent Selective Anion-Exchange Membrane for the Valorization of Mixed Salts into Relatively High-Purity Monoprotic and Diprotic Acids

Membranes ◽

10.3390/membranes10060135 ◽

2020 ◽

Vol 10 (6) ◽

pp. 135 ◽

Cited By ~ 1

Author(s):

Haiyang Yan ◽

Wei Li ◽

Yongming Zhou ◽

Muhammad Irfan ◽

Yaoming Wang ◽

...

Keyword(s):

Anion Exchange ◽

Current Density ◽

High Purity ◽

Anion Exchange Membrane ◽

Discharge Process ◽

Bipolar Membrane ◽

Liquid Discharge ◽

Bipolar Membrane Electrodialysis ◽

Mixed Salts ◽

Exchange Membrane

The crystalized mixed salts from the zero liquid discharge process are a hazardous threat to the environment. In this study, we developed a novel electrodialysis (SBMED) method by assembling the monovalent selective anion-exchange membrane (MSAEM) into the bipolar membrane electrodialysis (BMED) stack. By taking the advantages of water splitting in the bipolar membrane and high perm-selectivity of MSAEM for the Cl− ions against the SO42− ions, this combination allows the concurrent separation of Cl−/SO42− and conversion of mixed salts into relatively high-purity monoprotic and diprotic acids. The current density has a significant impact on the acid purity. Both the monoprotic and diprotic acid purities were higher than 80% at a low current density of 10 mA/cm2. The purities of the monoprotic acids decreased with an increase in the current density, indicating that the perm-selectivity of MSAEM decreases with increasing current density. An increase in the ratio of monovalent to divalent anions in the feed was beneficial to increase the purity of monoprotic acids. High-purity monoprotic acids in the range of 93.9–96.1% were obtained using this novel SBMED stack for treating simulated seawater. Therefore, it is feasible for SBMED to valorize the mixed salts into relatively high-purity monoprotic and diprotic acids in one step.

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