A reductant injecting device, including: a honeycomb structure including: a pillar shaped honeycomb structure portion having partition wall that defines a plurality of cells each extending from a fluid inflow end face to a fluid outflow end face; and at least one pair of electrode portions arranged on a side surface of the honeycomb structure portion; an outer cylinder having an inlet side end portion and an outlet side end portion, the inlet side end portion comprising a carrier gas introduction port being configured to introduce a carrier gas, the outlet side end portion comprising an injection port being configured to inject ammonia; a urea sprayer arranged at one end of the outer cylinder; and a spray direction switcher configured to be able to switch a spray direction of the aqueous urea solution.

Systems for and methods of treating a fluid containing siloxanes, silanes and/or other silicon compounds. A hot box is configured to receive an initial flow of the fluid, react the flow with water at a temperature and pressure suitable for hydrolysis to generate a first treated flow, in which at least a portion is hydrolyzed to produce silicon dioxide and methane, and discharge the first treated flow. A solid removal mechanism can be configured to receive the first treated flow, separate at least a portion of the silicon dioxide as solid material, and discharge the remaining components as a second treated flow. Techniques of the present disclosure can lead to very low siloxane levels.

A method for removing at least one odorous contaminant from a fluid stream by filtering the fluid stream with a filtration medium. The filtration medium includes a chemically modified activated carbon. The method is useful for removing one or more volatile organic compounds and/or one or more volatile thiol compounds, particularly terpenes (e.g., alpha-pinene and myrcene), nonanol, decanol, o-cymene, and benzaldehyde from the fluid stream. In some embodiments, the fluid stream is a cannabis grow house exhaust stream.

A reducing agent injection device includes a honeycomb structure and a urea spraying device spraying a urea water solution in mist form. In addition, the reducing agent injection device includes a carrier gas inlet that introduces carrier gas f between the urea spraying device and the honeycomb structure. The exhaust gas treatment method of the present invention supplies the urea water solution from the urea spraying device into the cells from the first end face of the honeycomb structure body to generate the ammonia, while introducing the carrier gas f from the carrier gas inlet, and injecting the ammonia to the outside to treat exhaust gas containing NO.sub.X.

A reducing agent injection device includes a honeycomb structure and a urea spraying device spraying a urea water solution in mist form. A pair of electrode members is formed in the honeycomb structure. The honeycomb structure of the reducing agent injection device, the hydraulic diameter HD, defined as HD=4×S/C, when the area of the cross section of one of the cells in the cross section perpendicular to the cell extending direction is S, and the peripheral length of the cross section of one of the cells is C, is 0.8 to 2.0 mm. Also, the open frontal area OFA of the honeycomb structure in the cross section perpendicular to the cell extending direction is 45 to 80%.

A reducing agent injection device includes a first honeycomb structure and a urea spraying device spraying a urea water solution in mist form. A pair of electrode members is formed in the first honeycomb structure. The ratio L/D of length L in the cell extending direction of the honeycomb structure body to diameter D of the cross section perpendicular to the cell extending direction is 0.5 to 1.2. Also, it is preferable that a urea hydrolysis catalyzer is provided in the second end face side of the honeycomb structure body, with a gap from the second end face.

The present invention relates to a method for generating ammonia from an ammonia precursor substance and to the use thereof for reducing nitrogen oxides in exhaust from industrial facilities, from combustion engines, from gas engines, from diesel engines or from petrol engines.

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC) or a passive NOx adsorber (PNA), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst, which may also include an additional PNA.

The present disclosure relates to the technical field of industrial waste gas purification, in particular to a core-shell structured catalyst, a preparation method and use thereof. The present disclosure provides a core-shell structured catalyst including a metal oxide-molecular sieve as a core and porous silica (SiO.sub.2) as a shell, where the metal oxide-molecular sieve includes a molecular sieve and a metal oxide loaded on the molecular sieve, the metal oxide includes an oxide of a first metal and an oxide of a second metal, the first metal is Fe, Cu, Ti, Ni or Mn, and the second metal is Ce or La. The core-shell structured catalyst of the present disclosure can enable effective removal of HCN and AsH.sub.3 at the same time with a stable effect, and no secondary pollution.

The present invention discloses a method of preparing a catalyst for low-temperature synergistic catalytic purification of NO.sub.x and HCN in a flue gas, and the use thereof. Citric acid is dissolved in ethanol to obtain a citric acid/ethanol solution; tetrabutyl titanate is added, mixed uniformly to obtain a tetrabutyl titanate-citric acid/ethanol solution; glacial acetic acid is added dropwise to react for 30-40 min to obtain a solution A; the metal salt solution was added dropwise into the solution A, mixed uniformly and added with nitric acid, ammonium hydroxide is added dropwise to adjust the pH value, and the temperature is raised at a constant speed to obtain a gel B; dried and then then baked at a temperature of 300-500° C. for 3-4 h, cooled in the furnace, pulverized, tableted and sieved to obtain the catalyst for the low-temperature synergistic catalytic purification of NO.sub.x and HCN in the flue gas.