Ammonium Bicarbonate is produced by combining carbon dioxide and ammonia:
Ammonia gas passed into a strong aqueous solution of the sesquicarbonate (a 2:1:1 mixture of (NH4)HCO3, (NH4)2CO3, and H2O) converts it into normal ammonium carbonate ((NH4)2CO3), which can be obtained in the crystalline condition from a solution prepared at about 30 °C. This compound on exposure to air gives off ammonia and reverts to ammonium bicarbonate.
Compositions containing ammonium carbonate have long been known.
They were once produced commercially, formerly known as salt volatile or salt of hartshorn.
It was obtained by the dry distillation of nitrogenous organic matter such as hair, horn, leather.
In addition to ammonium bicarbonate, this material contains ammonium carbamate (NH4CO2NH2), and ammonium carbonate ((NH4)2CO3). It is sometimes called ammonium sesquicarbonate.
It possesses a strong ammoniacal smell, and on digestion with alcohol, the carbamate is dissolved leaving a residue of ammonium bicarbonate.