An apparatus for purifying gas where gas is treated in a multistage treatment having at least two ejector stages, a motive medium including liquid, steam or gaseous agent at high pressure injected by an ejector of the ejector stage, and the gas is sucked into the same ejector and mixed with the motive medium for forming a mixture, at least a part of gas and/or liquid phase of the mixture is supplied to a second ejector stage having so that a second motive medium which includes liquid, steam or gaseous agent is injected to the ejector and the gas and/or the liquid phase is sucked into the same ejector in which the gas and/or liquid phase is mixed with the second motive medium for forming a second mixture, at least one of the mixtures includes an additive for removing impurities of the gas, and a purified gas is formed.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 2 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m.sup.3/h)/(m.sup.3/h). The disclosure also pertains to a prilling tower having a gas stream treatment system comprising a Venturi ejector at the top of the prilling tower, and to a method of modifying an existing prilling tower.

The present invention relates to a method for inhibiting the formation of dioxin-like compounds in solid waste incineration flue gases, belonging to the field of cleaning of solid waste incineration flue gases. In accordance with the present invention, when incineration flue gases cool down to 500450 C., the flue gases are introduced into an inhibition reactor where copper chlorides in flue gas particulates mix and react with inhibitors to convert into copper metaphosphate so as to inactivate the copper chlorides which can catalyze the formation of dioxin-like compounds and control dioxin-like compound pollutants in incineration flue gases at the source. Compared with the prior art, the invention can effectively control the main formation ways of dioxin-like compounds in solid waste incineration flue gases by optimizing inhibitors and reaction conditions. The method of the invention does not affect the residual heat utilization of solid waste incineration flue gases, so solid waste incineration has a better resource utilization effect. The ammonium dihydrogen phosphate inhibitor used in the invention has the advantages of high inhibition efficiency, strong operability, low cost and environment protection, providing the technology with good application feasibility.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

A mixing apparatus for mixing a precursor substance of a reducing agent with exhaust gas, having a housing that provides a mixing chamber and a silencer. The housing inlet side has an inlet connection for exhaust gas and an outlet side having an outlet connection for reducing agent intermixed with the exhaust gas to be discharged. Longitudinal axes of the inlet and outlet connections are offset and parallel relative to one another. An introduction device introduces a precursor substance of the reducing agent and is positioned at the inlet side in a region of the outlet connection longitudinal axis. A length of the housing between the inlet and outlet side at least 1.9 to 7 times a diameter of the inlet connection. A width of the housing is maximally 3 times the diameter of the inlet connection.

A reactive composition comprising between 60% and 98% by weight of sodium bicarbonate, between 1% and 40% by weight of sodium carbonate and between 0.02% and 2.0% by weight of ammonia, expressed in the form of ammonium ions NH.sub.4.sup.+, and comprising from 0.01 to 5% by weight of a compound selected from the group consisting of hydrocarbons, fatty alcohols, fatty acids, and fatty acid salts.

A mercury sorbent and method for enhancing mercury removal performance of activated carbon from flue gas by the addition of non-halogen ammonium-containing compounds are provided herein.

A carbonaceous feedstock gasification power generation facility, and a method for regulating a gas for drying gas this carbonaceous feedstock, are disclosed with which it is possible to expand the range of the types of carbonaceous feedstocks that can be used. High-temperature exhaust gas, low-temperature exhaust gas and extreme high-temperature exhaust gas are bled from the furnace respectively at a high-temperature bleed position, a low-temperature bleed position and an extreme high-temperature bleed position. When these exhaust gases are mixed, the flow volume of the extreme high-temperature exhaust gas supplied to at least one of the exhaust gases, that is, the high-temperature exhaust gas or the low-temperature exhaust gas, is adjusted such that the temperature of at least one of these exhaust gases, that is, the high-temperature exhaust gas or the low-temperature exhaust gas, reaches a prescribed temperature.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.