Solubilities of Ammonia and Ammonium Chloride in Ammoniated and Nonammoniated Methanol and Ethylene Glycol between 298 K and 353 K

Abstract

The solubility of ammonia (NH3) and ammonium chloride (NH4Cl) in the systems NH3–CH3OH, NH3–C2H6O2, NH4Cl–CH3OH, NH4Cl–C2H6O2, NH3–NH4Cl–CH3OH, NH3–NH4Cl–C2H6O2, and NH3–NH4Cl–C2H6O2 + 8 % CH3OH are reported for temperature conditions relevant to the crystallization of pure magnesium chloride hexammoniate (MgCl2·6NH3) within the Australian Magnesium (AM) process. The solubility of NH3 in anhydrous methanol and ethylene glycol decreased within the temperature range 298 K to 333 K. The solubility of NH4Cl in methanol increased from 3.3 % at 298 K to 3.7 % at 313 K, and in ethylene glycol the NH4Cl solubility increased approximately linearly with temperature between 313 K and 353 K extending from 9.7 % to 11.9 %, respectively. The solubility of NH4Cl in saturated ammoniated methanol at 298 K was 7.9 % with a corresponding NH3 content of 15.0 %. At 313 K it was 5.5 %, while the NH3 content was approximately 9 %. The solubility of NH4Cl in saturated ammoniated ethylene glycol at 313 K, 323 K, and 333 K was 11.0 %, 11.7 %, and 13.2 %, respectively. The results for the systems NH3–NH4Cl in C2H6O2 and CH3OH indicate that minor amounts of NH4Cl, formed during MgCl2·6NH3 crystallization, will dissolve in ammoniated ethylene glycol and ammoniated methanol and ensure an NH4Cl-free hexammoniate product.

Multiscale Modeling of Multiphase Fluid Flow

“…A decrease in the solubility of ammonia was observed at the ammonium carbamate reaction temperature (333 K) compared to the ammonia solubility at 300 K both in water and ethylene glycol. This effect has been observed experimentally [159,160]. In the case of carbon dioxide, however, the solubility in water decreases drastically at higher CO2 concentrations (above 10% mole fraction where the phase separation was observed) at the temperature of the decomposition reaction.…”

Solubility Measurement and Modeling for the NaCl–NH4Cl–Monoethylene Glycol–H2O System from (278 to 353) K

“…Unlike the study on NaCl, there is scarce information on the solubility of NH 4 Cl in MEG−H 2 O mixtures except for that in pure water or pure MEG. 11 Because the solubility of salts in mixed solvents is of more practical and theoretical importance than those in pure solvents, additional measurements on the solubility of NH 4 Cl in MEG−H 2 O mixtures are required.…”

“…The NaCl–NH 4 Cl–H 2 O system has been extensively investigated due to its importance in areas of atmosphere aerosols, wastewater treatment, and especially the manufacturing of soda. − In the soda combination process, the byproduct NH 4 Cl is recovered by a salting-out crystallization with the addition of NaCl as feed. It is known that monoethylene glycol (MEG) is widely used as an effective antisolvent in crystallization separation processes because MEG is almost nonvolatile (has a boiling point of 470.4 K) and can be fully miscible with many inorganic electrolyte solutions, such as NaCl, NH 4 Cl, Na 2 CO 3 , MgCl 2 , and CaSO 4 . It is of considerable interest to investigate the effect of MEG on the solid–liquid equilibrium of the NaCl–NH 4 Cl–H 2 O system.…”

“…The literature data cover a temperature range of (288 to 323) K in MEG–H 2 O mixtures from pure water to pure MEG, ,− from which the solubility of NaCl were found to decrease with the addition of MEG but is very weakly affected by temperature. Unlike the study on NaCl, there is scarce information on the solubility of NH 4 Cl in MEG–H 2 O mixtures except for that in pure water or pure MEG . Because the solubility of salts in mixed solvents is of more practical and theoretical importance than those in pure solvents, additional measurements on the solubility of NH 4 Cl in MEG–H 2 O mixtures are required.…”

An Efficient, Solvent-Free Process for Synthesizing Anhydrous MgCl2

“…Pownceby et al determined that when the ammonia (>17% supersaturated methanol + NH 3 and NH 3 bubbling) was added into the MgCl 2 · x H 2 O + methanol solution, unexpectedly, MgCl 2 ·6NH 3 did not form. If the feedstock contains anhydrous MgCl 2 + methanol, however, MgCl 2 ·6NH 3 will precipitate. , The presence of excess water favors the formation of magnesium hydroxide (Mg­(OH) 2 ) and ammonium chloride­(NH 4 Cl) in competition with the reaction to form hexammoniate (eqs and ). This unwanted NH 4 Cl is dominant given the presence of significant H 2 O in the system.…”