NOVELTY - Recovering ammonium carbonate and ammonium bicarbonate from a liquid solution comprising ammonia or ammonium, comprises: providing liquid solution, stripping ammonia from converted solution in ammonia stripping vessel (30) to produce a gas phase ammonia stream, contacting ammonia stream with scrubbing liquid to produce ammonium bicarbonate and ammonium carbonate; withdrawing an ammonium liquid; recovering a first portion of the ammonium liquid as an ammonium product stream; and contacting a second portion (75) of the ammonium liquid with a carbon dioxide to produce the scrubbing liquid.    USE - The process is useful for recovering ammonium carbonate and ammonium bicarbonate from a liquid solution, preferably an ammonium containing solution generated in the treatment and fermentation of biomass derived syngas (all claimed).    ADVANTAGE - The method is capable of recovering ammonium carbonate and ammonium bicarbonate in a simple and economical manner.    DETAILED DESCRIPTION - Recovering ammonium carbonate and ammonium bicarbonate from a liquid solution comprising at least one of ammonia or ammonium, comprises: (a) providing the liquid solution comprising ammonium at a pH and temperature sufficient to convert at least a portion of ammonium in the solution to free ammonia and provide a converted solution; (b) stripping ammonia from the converted solution in an ammonia stripping vessel to produce a gas phase ammonia stream; (c) contacting the ammonia stream with a scrubbing liquid comprising dissolved carbon dioxide in a scrubbing vessel to produce ammonium bicarbonate and ammonium carbonate; (c) withdrawing an ammonium liquid comprising ammonium carbonate and ammonium bicarbonate from the scrubbing vessel; (d) recovering a first portion of the ammonium liquid as an ammonium product stream; and (e) contacting a second portion of the ammonium liquid with a carbon dioxide containing gas stream and a make-up liquid to produce the scrubbing liquid. INDEPENDENT CLAIMS are included for:    (1) a method-I for recovering ammonium carbonate and ammonium bicarbonate from an ammonium containing solution generated in the treatment of biomass derived syngas, comprising (a-i) generating a syngas stream by the gasification of biomass, (b-i) scrubbing at least a portion of the syngas stream in a syngas scrubber to generate a syngas scrubbing liquid containing ammonium and a scrubbed syngas stream, (c-i) passing the scrubbed syngas stream to a fermentation zone to produce a fermentation product and a tail gas stream comprising carbon dioxide, (d-i) passing the syngas scrubbing liquid to an ammonia stripping vessel and adjusting at least one of the pH and temperature in the ammonia stripping vessel such that the pH is the same as or is more basic than the pKa of ammonia at the temperature in the ammonia stripping vessel to maintain free ammonia in the ammonia stripping vessel, step of (b)-(d) as above per se, and (h-i) passing a second portion of the ammonium liquid into contact with the tail gas stream and a make-up liquid in a gas contacting vessel to produce the ammonia scrubbing liquid;    (2) a process for recovering ammonium carbonate and ammonium bicarbonate from an ammonium containing solution generated in the treatment and fermentation of biomass derived syngas, comprising generating a raw syngas stream by the gasification of biomass, cooling and scrubbing the raw syngas stream in a scrubber/cooler to generate a scrubbed syngas stream and a condensate stream containing volatile compounds and ammonium, step of (c-i) as above per se, and a biosolids stream, passing the biosolids to a digester to decompose the biosolids and recover an ammonium containing solution from the digester, removing volatile compounds from the condensate stream to generate a scrubbed condensate stream containing ammonium, passing at least a portion of the scrubbed condensate stream and the ammonium containing solution to an ammonia stripping vessel and maintaining the pH in the ammonia stripping vessel at least one log unit more basic than the pKa of ammonia at the temperature in the stripping vessel to maintain free ammonia in the ammonia stripping vessel, stripping ammonia from the ammonia stripping vessel with a stripping gas stream to produce an ammonia gas stream, step of (c)-(d) as above per se, and passing at least a portion of the ammonium product stream to the fermentation zone, and contacting a second portion of the ammonium liquid with the tail gas stream and a make-up liquid in a gas contacting vessel to produce the ammonia scrubbing liquid comprising dissolved carbon dioxide;    (3) a method-II for recovery of ammonium values from anaerobic digestion of solid-containing waste from fermentation processes comprising anaerobically digesting at least a portion of the solid containing waste in an aqueous digestion liquor to generate ammonia or ammonium, passing through the aqueous digestion liquor a gas comprising greater than 50 vol.% of carbon dioxide to maintain the pH of the aqueous digestion liquor of 6.5-7.5 and generate a scrubbed gaseous stream, and recovering ammonia from the aqueous digestion liquor; and    (4) in a fermentation process for the anabolic bioconversion of a substrate in an aqueous fermentation broth containing microorganisms, the process generating solid waste, comprising (a1) anaerobically digesting at least a portion of the waste solids in an aqueous digestion liquor to generate ammonia or ammonium and carbon dioxide and provide a digestion liquor containing ammonia, ammonium carbonate and ammonium bicarbonate, (b1) providing the digestion liquor at a pH and temperature sufficient to convert at least a portion of ammonium in the liquor to free ammonia and provide a converted liquor, (c1) stripping ammonia from the converted liquor in an ammonia stripping vessel to produce a gas phase ammonia stream, and (d1) using directly or indirectly at least a portion of the gas phase ammonia stream as a source of nitrogen for the anabolic fermentation.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a method for recovering ammonium carbonate and ammonium bicarbonate from a liquid solution.    Stream (15)    Stripping tower (30)    Gas stripping stream (34)    Ammonia absorption vessel (50)    Second portion. (75)