A process and system for removing ammonia from ammonia-containing purge gas of a urea plant, the process comprising: contacting said ammonia-containing purge gas with carbon dioxide at a low temperature, reaction of ammonia to form crystals of ammonium salts in a multiphase stream, and removal of the solid ammonium salts from the multiphase stream.

The present invention discloses methods for extracting and recycling ammonia in MOCVD processes by FTrPSA. Through pretreatment, medium-shallow temperature PSA concentration, condensation and freezing, liquid ammonia vaporization, PSA ammonia extraction, and ammonia gas purification procedures, ammonia-containing exhaust gases from MOCVD processes are purified to meet the electronic-level ammonia gas standard required by the MOCVD processes, so as to implement recycling and reuse of the exhaust gases, where the ammonia gas yield is greater than or equal to 70-85%. The present invention solves the technical problem that atmospheric-pressure or low-pressure ammonia-containing exhaust gases in MOCVD processes cannot be returned to the MOCVD processes for use after being recycled, and fills the gap in green and circular economy development of the LED industry.

The present invention discloses methods for extracting and recycling ammonia in MOCVD processes by FTrPSA. Through pretreatment, medium-shallow temperature PSA concentration, condensation and freezing, liquid ammonia vaporization, PSA ammonia extraction, and ammonia gas purification procedures, ammonia-containing exhaust gases from MOCVD processes are purified to meet the electronic-level ammonia gas standard required by the MOCVD processes, so as to implement recycling and reuse of the exhaust gases, where the ammonia gas yield is greater than or equal to 70-85%. The present invention solves the technical problem that atmospheric-pressure or low-pressure ammonia-containing exhaust gases in MOCVD processes cannot be returned to the MOCVD processes for use after being recycled, and fills the gap in green and circular economy development of the LED industry.

Disclosed herein are methods of controlling the amount of carboxyl groups attached to a hydrochar, the methods including subjecting a composition that includes a stover composition to hydrothermal carbonization to form a hydrochar, wherein the amount of carboxyl groups attached to the hydrochar can be controlled by the amount of lipids in the composition. Methods of removing ammonia from a gas using disclosed hydrochars and the hydrochars themselves are also disclosed.

Disclosed herein are methods of controlling the amount of carboxyl groups attached to a hydrochar, the methods including subjecting a composition that includes a stover composition to hydrothermal carbonization to form a hydrochar, wherein the amount of carboxyl groups attached to the hydrochar can be controlled by the amount of lipids in the composition. Methods of removing ammonia from a gas using disclosed hydrochars and the hydrochars themselves are also disclosed.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

A method of treating an ammonia-containing purge gas stream on a vessel is described, the method comprising at least the steps of: (a) providing the ammonia-containing purge gas stream from a vessel engine; and (b) passing the ammonia-containing purge gas stream through a first tank containing water to provide a reduced-ammonia vent gas stream.