The disclosure relates generally to reducing mercury emissions from a coal power plant. Specifically, a method for treating a gas stream containing mercury is provided that includes injecting a mercury oxidant or absorbent and a carrying agent into a gas stream that was produced by heating or burning a carbonaceous fuel comprising mercury. The carrying agent vaporizes after being injected into the gas stream. The mercury oxidant or absorbent and a carrying agent may be injected before passing the gas stream into a gas scrubber.

Refrigeration systems with a purge for removing non-condensables from the refrigerant and an acid filter for remove acid from the refrigerant are provided. The acid filter can be operatively connected to the purge. Optionally, the purge can include a separating device for separating non-condensable gases from condensable refrigerant gases and an acid filter is provided to remove acid from the condensable refrigerant gases.

Technologies for combusting hazardous compounds such as chemical warfare agents and related compounds are disclosed. In embodiments, the technologies include systems and methods for combusting such compounds in an internal combustion engine, such as a spark ignition internal combustion engine, a diesel engine, or the like. The technologies described herein further include components for treating an exhaust gas stream produced by combustion of hazardous compounds. In embodiments such components include a scrubber that utilizes a scrubbing media such as soil to removing acid gases from the exhaust stream.

The use of a composition including at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, the acido-basic neutralising agent having at least 2 pKa's and being characterised by: pKa 1≤pKa 2, pKa 1>2, pKa 2<12, 4<½ (pKa 1+pKa 2)<10 pKa 1, representing the smallest of the basic pKa's and pKa 2 representing the largest of the acidic pKa's. Also, a method for decontaminating an atmosphere contaminated by a corrosive gas comprising the spraying of the neutralising agent, and to a decontamination device.

A particulate composition said composition comprises a metal carbonate and/or a metal bicarbonate and a compound of aluminium, characterised in that the weight ratio of metal carbonate plus metal bicarbonate compounds to said compound of aluminium is at least 3:1. The composition is useful for removing halogenated compounds from a hydrocarbon-containing process stream.

Provided is a process for separating an organic isocyanate prepared by reacting an organic amine with a stoichiometric excess of phosgene in the gas phase from the gaseous crude product obtained in the reaction, the process comprising the steps of (i) at least partially condensing the crude product stream containing at least the isocyanate, hydrogen chloride and unconverted phosgene by contacting with at least one liquid stream containing at least one quench liquid in a first separation apparatus to obtain a liquid stream containing at least some of the quench liquid and some of the isocyanate and a gas stream containing at least hydrogen chloride, evaporated quench liquid and phosgene, (ii) discharging the liquid stream obtained in step (i) via a first liquid outlet and of the gas stream obtained in (i) via a first gas conduit and (iii) at least partially condensing and/or absorbing the gas stream discharged in step (ii) through the first gas conduit, wherein that the at least partial condensation and/or absorption is effected in step (iii) by direct introduction of at least one cooling fluid, wherein the cooling fluid is introduced directly into the first gas conduit via at least one addition unit assigned to the first gas conduit.

An agent for removing a halogen gas, such as chlorine, in a waste gas by means of reduction; a method for producing this agent; a method for removing a halogen gas by use of this agent; and a system for removing a halogen gas. The agent for removing the halogen gas contains at least pseudo-boehmite, that serves as a host material, and a sulfur-containing reducing agent, that serves as a guest material. 1-8% by weight of the reducing agent, in terms of elemental sulfur, based on the total amount of the pseudo-boehmite and sulfur-containing reducing agent is present in the agent. At least one inorganic compound selected from among oxides, carbonates salts and hydrocarbon salts of alkaline earth metal elements, transition metal elements and zinc group elements is additionally contained in the agent as a third component.

An air treatment unit may include an air inlet to receive a flow of input air for treatment and a reaction reservoir configured to hold an aqueous air treatment solution. The air treatment unit may also include an air dispersing element flow connected with the air inlet, wherein the air dispersing element is configured to convert at least a portion of the flow of input air into a plurality of microbubbles for introduction into the aqueous air treatment solution, such that an amount of one or more target gas species contained within the plurality of microbubbles is reduced through reaction with the aqueous air treatment solution. The unit may include an air outlet configured to output treated air from the reaction reservoir.

Several embodiments of the present technology are directed to the removal of one or more air pollutants using cooling and/or calcium-containing particles. In some embodiments, a method for removing air pollutants comprises flowing a gas stream having calcium-containing particles and one or more of mercury or hydrochloric acid molecules, and cooling the gas stream, thereby causing at least a portion of the calcium-containing particles to adsorb to the mercury and/or hydrochloric acid molecules in the gas stream. The method can further comprise, after cooling the gas stream, filtering the gas stream to remove at least a portion of the calcium-containing particles having adsorbed mercury and hydrochloric acid.

A flue gas denitration system includes a catalytic reactor accommodating a plurality of catalytic modules, into which a flue gas flows, and a flue gas heater provided on an upstream side of the catalytic reactor in a flow direction of the flue gas. In the flue gas denitration system, switched are a first denitration state in which the flue gas is denitrated by using the plurality of catalytic modules in the catalytic reactor and a second denitration state in which the flue gas is denitrated by using a catalytic module(s) less than those used in the first denitration state while a temperature of the flue gas flowing into the catalytic reactor is made higher than that in the first denitration state by using the flue gas heater. Thus, by making the temperature of the flue gas flowing into the catalytic reactor higher, it is possible to suppress deterioration in denitration performance in the case of using part of the plurality of catalytic modules for denitration.