In a method for physical and thermochemical treatment of biomass, the biomass moisture content is reduced in a dryer and ammonia (NH.sub.3) is also released from the biomass during drying. The dried biomass is then either pyrolyzed in a pyrolysis reactor and the pyrolysis gas is forwarded to and combusted in a combustion device to form flue gas, or is combusted in a combustion facility unit to form flue gas. In either case the flue gas is fed to a mixer. Oxygen (O.sub.2) is metered to the flue gas in the mixer and is fed directly to the dryer as drying gas. As the drying gas passes through the dryer, the sulfur dioxide (SO.sub.2) contained in the drying gas and/or the sulfur trioxide (SO.sub.3) chemically reacts with the ammonia (NH.sub.3) to form ammonium sulfite ((NH.sub.4).sub.2SO.sub.3) and/or ammonium sulfate ((NH.sub.4).sub.2SO.sub.4). Also a treatment facility physically and thermochemically treats the biomass.

In a method for physical and thermochemical treatment of biomass, the biomass moisture content is reduced in a dryer and ammonia (NH.sub.3) is also released from the biomass during drying. The dried biomass is then either pyrolyzed in a pyrolysis reactor and the pyrolysis gas is forwarded to and combusted in a combustion device to form flue gas, or is combusted in a combustion facility unit to form flue gas. In either case the flue gas is fed to a mixer. Oxygen (O.sub.2) is metered to the flue gas in the mixer and is fed directly to the dryer as drying gas. As the drying gas passes through the dryer, the sulfur dioxide (SO.sub.2) contained in the drying gas and/or the sulfur trioxide (SO.sub.3) chemically reacts with the ammonia (NH.sub.3) to form ammonium sulfite ((NH.sub.4).sub.2SO.sub.3) and/or ammonium sulfate ((NH.sub.4).sub.2SO.sub.4). Also a treatment facility physically and thermochemically treats the biomass.

Methods, systems, and apparatuses for anaerobic digestion of waste fibrous material and the recovery of nutrients are provided. Methods, systems, and apparatuses disclosed herein provide mechanisms to release dissolved gases from anaerobic digester effluent. Methods, systems and apparatuses disclosed herein can recover one or more nutrients from anaerobic digested effluent using a range of temperatures, aeration rates, aeration times, pH ranges, and settling times.

Methods, systems, and apparatuses for anaerobic digestion of waste fibrous material and the recovery of nutrients are provided. Methods, systems, and apparatuses disclosed herein provide mechanisms to release dissolved gases from anaerobic digester effluent. Methods, systems and apparatuses disclosed herein can recover one or more nutrients from anaerobic digested effluent using a range of temperatures, aeration rates, aeration times, pH ranges, and settling times.

The invention relates to a method for recovery of urea dust and ammonia from a gas stream by contacting said gas stream with an aqueous sulphuric acid solution, thus forming an acid solution of ammonium sulphate and urea, characterized in that the acid solution is concentrated to a melt comprising less than 5 wt % of water, which melt is subsequently transferred into solid particles comprising urea and ammonium sulphate.

The invention relates to a method for recovery of urea dust and ammonia from a gas stream by contacting said gas stream with an aqueous sulphuric acid solution, thus forming an acid solution of ammonium sulphate and urea, characterized in that the acid solution is concentrated to a melt comprising less than 5 wt % of water, which melt is subsequently transferred into solid particles comprising urea and ammonium sulphate.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

A process for producing ammonium sulfite and ammonium bisulfite from an ammonia gas stream. The process involves injected sulfur dioxide into a circulating liquid stream to an optimal pH that captures gaseous ammonia from a gas stream. The captured ammonia reacts with sulfur dioxide and water to form the desired products.

A process for producing ammonium sulfite and ammonium bisulfite from an ammonia gas stream. The process involves injected sulfur dioxide into a circulating liquid stream to an optimal pH that captures gaseous ammonia from a gas stream. The captured ammonia reacts with sulfur dioxide and water to form the desired products.

Methods, systems, and apparatuses for anaerobic digestion of waste fibrous material and the recovery of nutrients are provided. Methods, systems, and apparatuses disclosed herein provide mechanisms to release dissolved gases from anaerobic digester effluent. Methods, systems and apparatuses disclosed herein can recover one or more nutrients from anaerobic digested effluent using a range of temperatures, aeration rates, aeration times, pH ranges, and settling times.