Recovering ammonia for example from composting

Process for recovering ammonia from an initial aqueous mixture comprising ammonium ions and ammonium salts, the process comprising steps of:

• providing an initial aqueous mixture,
• desorbing ammonia using humid, heated air to obtain a desorbing liquid phase and a desorbing gas phase,
• separating the desorbing liquid phase,
• mixing the desorbing gas phase with a capture gas to obtain a gas mixture, and
• condensing the gas mixture to obtain a condensate comprising ammonium ions and salt, and an outlet gas,
• wherein the desorbing liquid phase comprises ammonium ions and ammonium salts in a total concentration of less than 100 ppm, wherein the capture gas comprises carbon dioxide in an amount of at least 50,000 ppm, and
• wherein the total concentration of ammonium ions and ammonium salts in the condensate is higher than the total concentration in the initial aqueous mixture.

An ammonia recovery system for performing ammonium recovery, the system comprising:

• a desorber configured to receive an initial aqueous mixture at a liquid inlet and discharge a desorbing liquid phase at a liquid outlet, and to receive a humid, heated air at a gas inlet and discharge a desorbing gas phase at a gas outlet;
• a supply of a capture gas comprising carbon dioxide in an amount of at least 50,000 ppm, the system being configured to mix the desorbing gas phase with the capture gas to form a gas mixture;
• and
• a condenser configured to receive the gas mixture at a gas inlet and discharge an outlet gas at a gas outlet and a condensate at a liquid outlet;
• wherein the initial aqueous mixture comprises ammonium ions and ammonium salts, and the desorber being configured to desorb ammonium ions and ammonium salts from the initial aqueous mixture into the desorbing gas phase so that the desorbing liquid phase comprises ammonium ions and ammonium salts in a total concentration of less than 100 ppm;
• and
• wherein the condenser is configured to condense the gas mixture to form the condensate comprising a higher total concentration of ammonium ions and ammonium salts than the total concentration in the initial aqueous mixture.

A system for composting organic mass and recovering ammonia, said system comprising:

• a compositing system comprising:
• a composting container for performing composting of composting mass, and means for agitating said composting mass, wherein the composting container is configured to receive organic mass at a mass inlet and discharge compost at a mass outlet, wherein the composting container is essentially gas tight and is configured to allow discharge of a composting gas comprising ammonia and carbon dioxide;
• an ammonia recovery system comprising:
• a composting gas condenser configured to condense said composting gas into an initial aqueous mixture comprising ammonium ions and ammonium salts;
• a desorber configured to receive the initial aqueous mixture at a liquid inlet and discharge a desorbing liquid phase at a liquid outlet, and to receive a humid, heated air at a gas inlet and discharge a desorbing gas phase at a gas outlet;
• a supply of a capture gas comprising carbon dioxide in an amount of at least 50,000 ppm, the system being configured to mix the desorbing gas phase with the capture gas to form a gas mixture;
• and
• a condenser configured to receive the gas mixture at a gas inlet and discharge an outlet gas at a gas outlet and a condensate at a liquid outlet;
• wherein the desorber is configured to desorb ammonium ions and ammonium salts from the initial aqueous mixture into the desorbing gas phase so that the desorbing liquid phase comprises ammonium ions and ammonium salts in a total concentration of less than 100 ppm;
• and
• wherein the condenser is configured to condense the gas mixture to form the condensate comprising a higher total concentration of ammonium ions and ammonium salts than the total concentration in the initial aqueous mixture.