Method and device for stripping ammonia from liquids

A method for controlling the fermentation of organic material comprising undesirable volatile compounds, said method comprising the steps of

• a) providing a fermentor comprising a liquid medium comprising organic material and a biomass capable of fermenting said organic material,
• b) diverting said liquid medium to a side stream of the fermentor in the form of a shunt,
• c) contacting said liquid medium in said shunt with cold steam at a first pressure below 1 bar, thereby obtaining a cold steam comprising volatile compounds and liquid medium at least partly stripped for volatile compounds,
• d) condensing said cold steam comprising volatile compounds, thereby obtaining a first condensed liquid medium,
• e) injecting hot steam into said first condensed liquid medium at a second pressure of at least 1 bar,
• f) stripping off at least part of said volatile compounds comprised in said first condensed liquid medium, and obtaining a hot steam of volatile compounds and a condensed liquid medium stripped for essentially all volatile compounds, and
• g) redirecting said liquid medium at least partly stripped for volatile compounds in step c) to said fermentor, and/or returning said condensed liquid medium stripped for essentially all volatile compounds in step f) to said shunt or to said fermentor, wherein said stripping of volatile compounds and said redirection of said at least partly stripped liquid medium controls the fermentation of said organic material.

A method for stripping volatile compounds from a liquid medium, said method comprising the steps of

• a) providing an aqueous liquid medium comprising volatile compounds, and
• b) diverting said liquid medium comprising volatile compounds to a shunt operably linked to a heating source and a condensing device,
• c) obtaining cold steam in an evaporator by adding heat to a sample of aqueous liquid and reducing the pressure below a predetermined reference pressure, and
• d) directing said cold steam through said liquid medium comprising volatile compounds in the shunt of the stripper device at said pressure below the predetermined reference pressure, thereby stripping off volatile compounds and obtaining a cold volatile compound-comprising steam, and
• e) diverting said cold volatile compound-comprising steam at said pressure below the predetermined reference pressure to a first condensing device, and
• f) condensing in a first condensing step said cold volatile compound-comprising steam at said pressure below the predetermined reference pressure, thereby obtaining a first condensed aqueous liquid medium comprising volatile compounds, and
• g) diverting said first condensed aqueous liquid medium comprising volatile compound to a stripper unit, and
• h) stripping off the volatile compound from said first condensed aqueous liquid medium comprising volatile compound by heating said first condensed aqueous liquid in said stripper unit at a higher second pressure, and obtaining a liquid with a reduced concentration of volatile compounds.