403 results about "Elemental mercury" patented technology

A halogen-containing gas is injected into a flowing transport air/sorbent stream at a point close to the point where the sorbent and transport air first mix to maximize the residence time available for the halogen-containing compound to be adsorbed onto the sorbent surface prior to the sorbent being injected into a flue gas containing mercury. This process maximizes the benefit and utilization of the halogen-containing reagent by placing it exactly where it is needed to facilitate elemental mercury removal—on the surface of the sorbent. The sorbent particles with their loading of adsorbed halogen-containing reagent enter the flue gas with a high reactivity for the removal of elemental mercury.

A system 26 for removing elemental mercury or mercury compounds handles carbonaceous sorbent 28 of a starter batch stored in a silo 30 in an agglomerated state. The sorbent 28 is fed by a feeder 32 to a separation device 34, which comminutes (if necessary) and de-agglomerates the sorbent particles 28 to their primary size distribution. This device 34 may be a particle-particle separator or a jet mill, where compressed air or high-pressure steam is the energy source. The de-agglomerated sorbent 28 of a contact batch created from the starter batch is conveyed by an airsteam for injection at a contact location 66 in a flue gas duct whereat carbonaceous sorbent of the contact batch adsorbs mercury from the flue gas.

A system 26 for removing elemental mercury or mercury compounds handles carbonaceous sorbent 28 of a starter batch stored in a silo 30 in an agglomerated state. The sorbent 28 is fed by a feeder 32 to a separation device 34, which comminutes (if necessary) and de-agglomerates the sorbent particles 28 to their primary size distribution. This device 34 may be a particle-particle separator or a jet mill, where compressed air or high-pressure steam is the energy source. The de-agglomerated sorbent 28 of a contact batch created from the starter batch is conveyed by an airsteam for injection at a contact location 66 in a flue gas duct whereat carbonaceous sorbent of the contact batch adsorbs mercury from the flue gas.

A method to reduce emissions in flue gas due to combustion of coal in a combustion unit including the steps of: combusting coal in a primary combustion zone of the combustion unit; releasing elemental mercury from the combustion into the flue gas; injecting NH₄Cl, NH₄Br, or NH₄I into the flue gas; oxidizing the elemental mercury with halogen from the additive; adsorbing the oxidized mercury generated by the combustion of the coal with an adsorbent in the flue gas, and collecting the adsorbent with the oxidized mercury in a combustion waste treatment system.

A method of treating a coal combustion flue gas, which includes injecting a molecular halogen or thermolabile molecular halogen precursor able to decompose to form molecular halogen at flue gas temperature. The molecular halogen coverts elemental mercury to mercuric halide adsorbable by alkaline solids such as subbituminous or lignite coal ash, alkali fused bituminous coal ash capturable in whole or part by electrostatic precipitators (ESPs), baghouses (BHs), fabric filters (FFs), dry flue gas desulphurization solids, with or without subsequent adsorption by a liquid such as a flue gas desulphurization scrubbing liquor.

A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S2- ions to convert Hg2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe2+ ions, which could otherwise induce the unwanted reduction of Hg2+ to the form, Hg0.

Chlorine and sulfide species are separately introduced to a flue gas passing through a scrubber in order to remove the elemental and oxidized mercury from the gas through the precipitation of mercuric sulfide at near 100% efficiency.

The invention presents a device for the removal of elemental mercury from flue gas streams utilizing a layer of activated carbon particles contained within the filter fabric of a filter bag for use in a flue gas scrubbing system.

Metal sulfides having a micro-porous structure are disclosed for use as sorbents for removal of mercury from flue gas. Systems are disclosed for making and using micro-porous particulates at least partially composed of alkaline earth metal and transition metal sulfides as sorbents. Calcium sulfide micro-porous powders derived from the high temperature reduction of calcium sulfate and calcium sulfite are disclosed to be reactive substrates for a group of sorbents for adsorption of mercury from the myriad of coal combustion flue gases produced by the utilities industry, as well as from natural gas and gaseous and liquid hydrocarbons. Controlled addition of one or more of polyvalent metal ions, chloride ions, polysulfide ions, and sulfur to the micro-porous calcium sulfide substrate produces the sorbent. The sorbents are useful for cost-effectively adsorbing elemental mercury and oxidized mercury species such as mercuric chloride from flue gases, including those containing acid gases (e.g., SO.sub.2, NO and NO.sub.2, and HCI), over a wide range of temperatures.

A method and system are provided for creating a mercury halide standard, and for using that standard to test a mercury analyzer system. Gaseous elemental mercury of a known concentration from a gas cylinder and a halogen donor are fed to a reaction chamber where they react to form mercury halide. The mercury halide is fed to a mercury analyzer system where it is converted to reform gaseous elemental mercury which is then measured by a mercury analyzer. By comparing either the amount of elemental mercury supplied to the reaction chamber or the amount of mercury halide formed in the reaction chamber with the amount of elemental mercury converted from the mercury halide, the ability of the mercury analyzer system to convert mercury halide to gaseous elemental mercury can be evaluated.

The present invention is generally directed to removing a trace element from a liquid hydrocarbon feed. The liquid hydrocarbon feed, containing the trace element, is mixed with the water along with a hydrocarbon-soluble additive. While being mixed, a compound, which in some cases is preferably insoluble, is formed by the hydrocarbon-soluble additive chemically reacting with the trace element. A phase separation device, such as a desalter or an oil-water separator, receives the oil-water emulsion containing the compound and resolves the mixture to produce the compound, effluent brine, and effluent liquid hydrocarbon with a reduced concentration of the trace element as compared to the liquid hydrocarbon feed. In some embodiments, the present invention is directed to removing elemental mercury from a liquid hydrocarbon feed. A hydrocarbon-soluble sulfur-containing additive, typically an organic polysulfide, is mixed with the liquid hydrocarbon feed and water. The hydrocarbon-soluble, sulfur-containing additive reacts with the mercury, rapidly forming an agglomeration of mercuric sulfide which is then dispensed with the effluent brine or the effluent liquid hydrocarbon.

A method for removing mercury, and in particular elemental mercury, from a fluid stream by blending the fluid stream with a second stream comprising iodine. The blended stream is then passed through at least one filter, which is capable of removing oxidized forms of mercury from gas streams.

A mercury removal apparatus for a liquid hydrocarbon of the present invention includes a conversion device 2 which converts a mercury component in a raw liquid hydrocarbon into elemental mercury to obtain a first liquid hydrocarbon containing the elemental mercury; and a first stripping device 4 which brings the first liquid hydrocarbon into counter-current contact with a first stripping gas, thereby transferring the elemental mercury in the first liquid hydrocarbon to the first stripping gas to obtain a second liquid hydrocarbon in which the amount of the elemental mercury decreases and a first gaseous hydrocarbon containing the elemental mercury.

A process is disclosed for decreasing the level of elemental mercury contained in a liquid hydrocarbon stream by a) contacting the liquid hydrocarbon stream with a water stream containing an oxidizing agent for conversion of at least a portion of the Hg(0) to Hg(II); b) extracting at least a portion of the Hg(II) from the liquid hydrocarbon stream into the water stream, thereby forming a treated liquid hydrocarbon stream and a waste water stream containing water and Hg(II); and c) separating the treated liquid hydrocarbon stream from the waste water stream.

Methods for facilitating the removal of mercury from flue gases by converting elemental mercury to oxidized mercury and subsequently capturing the oxidized mercury. In one aspect, a method of removing mercury from a mercury-containing flue gas may include the steps of introducing into the flue gas a sulfide source in an effective amount to convert elemental mercury to gaseous oxidized mercury and then capturing the gaseous oxidized mercury.

A system and method is provided for the removal of mercury from flue gas. Effective removal of mercury is obtained by oxidation of elemental mercury, with highly reactive halogen species derived from dissociation of halogen compounds at moderate temperatures brought into contact with the flue gas with or without the addition of carbon.

The invention relates to a non-noble metal mercury-free catalyst for acetylene hydrochlorination reaction, a preparation method and application thereof. The preparation method comprises the steps of: 1) preparing a mixed solution of a copper salt, an ammonium salt and phosphoric acid, or a mixed solution of a copper salt, an ammonium salt and phosphate; 2) adding activated carbon into the mixed solution obtained in step 1 for soaking; 3) spin-drying the soaked activated carbon, and conducting heating and drying to obtain the catalyst. Through the synergistic effect of multiple components, the catalyst prepared by the method provided by the invention acquires good catalytic stability and high low-temperature activity, and under a reaction temperature of 130DEG C and the existing mercury catalyst running pressure condition and feeding intensity, more than 96% of conversion per pass and more than 99% of vinyl chloride selectivity can be obtained. As the technical conditions of the catalyst for acetylene hydrochlorination reaction are similar to those of the existing mercury catalyst, renovation of existing equipment is unnecessary, and the mercury catalyst can be replaced easily on the existing equipment.

To provide mercury-removal adsorbents, a method of producing mercury-removal adsorbents, and a method of removing mercury by adsorption which are capable of realizing efficient removal of mercury by adsorption from liquid hydrocarbon, thermal power station exhaust combustion gas, natural gas, off gas of various process plants, and so on which contain mercuries in various forms such as elemental mercury, ionic mercury, and organic mercury, and a concomitant hindering mercury adsorption.

Mercury-removal adsorbents carrie potassium iodide in an amount of 27 to 70% of a total adsorbent weight, and a volume of pores with a 1 μm pore diameter or more in the mercury-removal adsorbents is 0.6 mL/g or more. These mercury-removal adsorbents are filled in, for example, an adsorption tower 10, and a hydrocarbon liquid is passed therethrough (mercury removal step). In a case where the hydrocarbon liquid contains saturated water, a dehydration unit 9 or the like is installed on a preceding stage of the adsorption tower 10 to dehydrate the hydrocarbon liquid (dehydration step).

A selective catalytic reduction apparatus has at least first and last catalyst layers in series for reducing nitrogen oxides in a flue gas, at least one interstage heat exchanger located after the first layer and before the last layer, that lowers flue gas temperature, and that acts as a mixing body to lower the standard deviation of the NH₃/NO ratio entering catalyst layers after the first catalyst layer, thus providing better consumption of both ammonia and NOx in the reactor than would be achieved in the absence of the at least one interstage heat exchanger.