A method for the use of a gaseous effluent containing a CO.sub.2 gas fraction and a non-CO.sub.2 gas fraction, including at a first location: providing liquid nitrogen at a temperature less than −196° C., and causing the gaseous effluent to contact the liquid nitrogen to as to capture at least part of the CO.sub.2 present in the CO.sub.2 gas fraction as a mixture of CO.sub.2 particles and liquid nitrogen. Conveying at least part of the mixture to a second location, and at the second location, bringing the mixture into contact with one or more ingredients of a wet concrete before and/or during and/or after the wet concrete is prepared by blending the ingredients of the wet concrete in a blender, so that the mixture extracts heat from said one or more ingredients of the wet concrete, and CO.sub.2 from the mixture partially carbonates Ca-compounds present in the wet concrete.

A method for preparing hydrogen sulfide from sulfur dioxide by electrochemical reduction includes electrochemically reducing sulfur dioxide absorbed in an aqueous solution into gaseous hydrogen sulfide with a membrane electrode, resulting in efficient and selective conversion of the sulfur dioxide absorbed in the aqueous solution into the hydrogen sulfide to avoid a deactivation of a cathode due to colloidal sulfur produced on the cathode and adhesion onto a surface of the cathode, wherein the method is carried out at ambient temperature and normal pressure without addition of a reducing agent, having no waste salts produced, and is simple in operation, and is convenient for large-scale application.

The invention relates to a process for separating off and/or recovering nitrogen compounds, in particular for separating off ammonia and/or recovering or producing nitrogen fertilizer, from a liquid or sludge substrate, in which a liquid or sludge substrate is introduced into a degassing vessel to which subatmospheric pressure is applied and ammonia gas formed is introduced by means of a vacuum pump into at least one scrubber which is located downstream of the degassing vessel and to which subatmospheric pressure is applied and into which acid is introduced, wherein the acid or an ammonium salt-containing liquid obtained in the at least one scrubber is taken off from the at least one scrubber, cooled and subsequently sprayed back into the at least one scrubber. The invention further relates to a plant for carrying out such a process.

The invention relates to a process for separating off and/or recovering nitrogen compounds, in particular for separating off ammonia and/or recovering or producing nitrogen fertilizer, from a liquid or sludge substrate, in which a liquid or sludge substrate is introduced into a degassing vessel to which subatmospheric pressure is applied and ammonia gas formed is introduced by means of a vacuum pump into at least one scrubber which is located downstream of the degassing vessel and to which subatmospheric pressure is applied and into which acid is introduced, wherein the acid or an ammonium salt-containing liquid obtained in the at least one scrubber is taken off from the at least one scrubber, cooled and subsequently sprayed back into the at least one scrubber. The invention further relates to a plant for carrying out such a process.

An abatement apparatus capable of treating exhaust gas with less wet treatment devices than a conventional abatement apparatus is disclosed. The abatement apparatus includes: a pre-wet treatment device; a combustion treatment device; gas introduction lines coupled to process chambers of a film forming device; first flow-path switching devices coupled to the plurality of gas it lines, respectively; a first gas delivery line extending from the first flow-path switching devices to the pre-wet treatment device; a second gas delivery line extending from the first flow-path switching devices to the combustion treatment device; and an operation controller configured to control operations of the first flow-path switching devices to deliver the process gas to the pre-wet treatment device and deliver the cleaning gas to the combustion treatment device.

An abatement apparatus capable of treating exhaust gas with less wet treatment devices than a conventional abatement apparatus is disclosed. The abatement apparatus includes: a pre-wet treatment device; a combustion treatment device; gas introduction lines coupled to process chambers of a film forming device; first flow-path switching devices coupled to the plurality of gas it lines, respectively; a first gas delivery line extending from the first flow-path switching devices to the pre-wet treatment device; a second gas delivery line extending from the first flow-path switching devices to the combustion treatment device; and an operation controller configured to control operations of the first flow-path switching devices to deliver the process gas to the pre-wet treatment device and deliver the cleaning gas to the combustion treatment device.

A chemical process captures and convert hydrogen sulfide (H.sub.2S) gas into elemental sulfur, polysulfide, sulfur dioxide and/or sulfuric acid while regenerating sodium hydroxide capture agent for further use in an initial H.sub.2S capture step. Processing may include initial sodium hydroxide scrubbing of gas streams containing H.sub.2S, electrochemical regeneration of the sodium hydroxide from sodium hydrosulfide or sodium sulfide, recovery of sulfur and/or sulfur dioxide from the electrochemical processing, and production of sulfuric acid from such sulfur and/or sulfur dioxide.

A chemical process captures and convert hydrogen sulfide (H.sub.2S) gas into elemental sulfur, polysulfide, sulfur dioxide and/or sulfuric acid while regenerating sodium hydroxide capture agent for further use in an initial H.sub.2S capture step. Processing may include initial sodium hydroxide scrubbing of gas streams containing H.sub.2S, electrochemical regeneration of the sodium hydroxide from sodium hydrosulfide or sodium sulfide, recovery of sulfur and/or sulfur dioxide from the electrochemical processing, and production of sulfuric acid from such sulfur and/or sulfur dioxide.

A system and method for treating flue gas of a boiler based on solar energy are provided, wherein a heat pump is connected with a heat collector via first and second valves, a carbon dioxide electrolysis chamber is connected with a flue gas pretreatment chamber and a power distribution control module for electrolyzing and reducing carbon dioxide, a gas phase separation chamber is connected with a gas phase outlet to separate a mixture, and discharge the separated gas phase products; a Fischer-Tropsch reaction chamber is connected with the gas phase separation chamber to pass the separated carbon monoxide and hydrogen into a flowing reaction cell, a liquid phase product separation chamber is connected with a liquid phase outlet to separate the liquid phase hydrocarbon fuel products, and separate and supplement electrolyte; an electrolyte cooling circulation chamber is connected with the liquid phase product separation chamber.

Systems and methods are provided for performing hydrodeoxygenation of bio-derived feeds while maintaining the hydrodeoxygenation catalyst in a sulfided state. During hydrodeoxygenation, a hydrogen-containing stream is provided to the hydrodeoxygenation reactor as a hydrogen treat gas to provide hydrogen for the reaction. In some aspects, the hydrogen treat gas used for hydrodeoxygenation can be formed at least in part from hydrogen that has been used as a stripping gas for removing H.sub.2S from a rich amine stream. In other aspects, H.sub.2S can be stripped using water vapor, and a resulting overhead HS stream can be compressed prior to incorporation of the H.sub.2S into a hydrogen-containing stream. The resulting hydrogen-containing stream can include sufficient H.sub.2S to substantially maintain the catalyst in the hydrodeoxygenation stage in a sulfided state.