The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

Described is related to nano-structured composite materials for removing harmful chemical air pollutants and odors from the air to prevent people from breathing in disease-causing chemicals and provide them with clean indoor air. The nano-structured composite materials comprise nano-catalysts embedded in the pores of nano-structured substrate materials selected from the group consisting of nano-porous carbon, nano-porous rare earth oxide, nano-porous zeolite, nano-porous alumina and nano-porous silica. The nano-scale synergy of nano-catalysts and nano-structured substrate materials provides effective air filtration materials for the complete trapping and elimination of the full spectrum of chemical air pollutants including both organic and inorganic compounds and odors for indoor spaces, which HEPA or activated carbon filters cannot achieve.

This invention belongs to the technical field of green preparation of environmentally friendly catalysts, and discloses a preparation method and application of mesoporous FeCu—ZSM-5 molecular sieve, in particular to a method for synthesizing mesoporous FeCu—ZSM-5 molecular sieve by one-pot method and the application in selective catalytic reduction (SCR) denitration reaction. This invention firstly proposes to combine the two calcinations after demolding and ion exchange into one, that is, the original powder is directly calcined to prepare a FeCu—ZSM-5 molecular sieve. The molecular sieve has several advantages such as window with wide temperature window, low cost, good hydrothermal stability and high SCR denitrification activity. Besides, the synthesis process does not use a (large) pore template, nor does it use a post-treatment method to construct the mesopores. Therefore, the method of the invention not only has the advantages of simple process, simple operation, but also good economic and environmental benefits.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

A zeolite membrane composite includes a porous support and a zeolite membrane formed on the support. The zeolite membrane includes a low-density layer that covers the support, and a compact layer that covers the low-density layer. The compact layer has a higher content of a zeolite crystalline phase than the low-density layer. By in this way forming the compact layer on the low-density layer that covers the support, the thin compact layer with no defects can be formed more easily than in the case where a compact layer is formed directly on a support.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A process discharge gas polluted material removal device with a regenerating means of a polluted oxidation catalyst includes: an oxidation catalyst tower connected to a pipe circulating a process discharge gas including a combustible material, an organic material, an inorganic material, and nitrogen oxide and having a first temperature and having an oxidation catalyst embedded therein, the oxidation catalyst oxidizing and removing the combustible material; and a plasma reactor connected to the oxidation catalyst tower in front of the oxidation catalyst, generating a synthesis gas including hydrogen and having a high temperature of 300° C. or more by a plasma reaction, and supplying the synthesis gas including the hydrogen to the oxidation catalyst to regenerate the oxidation catalyst poisoned by the organic material and the inorganic material.

A process for the removal of nitrous oxide (N.sub.2O) contained in a process off-gas in an axial flow reactor. The process includes the steps of (a) adding an amount of reducing agent into the process off-gas; (b) in a first stage passing in axial flow direction the process off-gas admixed with the reducing agent through a first monolithic shaped catalyst active in decomposing nitrous oxide by reaction with the reducing agent to provide a gas with a reduced amount of nitrous oxide and residual amounts of reducing agent; and (c) in a second stage passing the gas with a reduced amount of nitrous oxide and residual amounts of the reducing agent in axial flow direction through a second monolithic shaped catalyst active in oxidation of the residual amounts of the reducing agent.

The invention relates to a method for treating metal strip in a directly fired furnace through which the metal strip is guided. The furnace is fired directly by gas burners and has a non-fired zone through which the exhaust gases from the fired zone flow and thus heat the metal strip. After leaving the non-fired zone, the exhaust gases from the furnace undergo post-combustion in an afterburner chamber. According to the invention, methane is injected into the non-fired zone, which causes nitrogen oxides contained in the waste gas to be converted into hydrogen cyanide.

This disclosure is directed to catalyst compositions, catalytic articles for purifying exhaust gas emissions and methods of making and using the same. In particular, the disclosure relates to a catalytic article including a catalytic material on a substrate, wherein the catalytic material has a first layer and a second layer. The first layer provides effective lean NO.sub.x trap functionality and the second layer provides effective three-way conversion of carbon monoxide, hydrocarbons, and nitrogen oxides (NO.sub.x).