Denitrification
JGC C&C’s denitrification catalysts are honeycomb catalysts developed in-house at the start of the 1970s, based on a patent under the former Mitsubishi Petrochemical Co., Ltd. (now Mitsubishi Chemical Corporation). Since the adoption of the technology in Japan ahead of the world in the 1970s, JGC C&C has established its position as a technological leader for more than 40 years.
Denitrification catalysts fulfill the functions of efficiently breaking down the nitrogen oxides (NOx) that are present in the gas that is being treated, into harmless nitrogen and water, through selective catalytic reduction (SCR) reaction that uses NH3 as the reducing agent.
Vanadium is the mainstream component used in denitrification catalysts, mainly as a carrier for titanium oxide. JGC C&C has strived to optimize this titanium oxide, and is an unparalleled manufacturer in the world possessing manufacturing technology for both titanium oxide carriers and catalysts.
Hence, based on the track record that we have built up over the past 50 years, we are able to propose suitable catalyst designs based on the conditions of the gases to be treated and the requirements of our customers.
An example is application, categorized by uses and based on the number of cells, as shown in the photograph. In coal firing, there is a high content of soot and ash originating from coal contained in the effluent gases. The number of cells is set at 15 – 25 cells in order to prevent clogging due to this soot and ash.
In the gas firing of LNG, etc., there is hardly any soot and ash in the effluent gases; hence, effort is made to increase the number of divisions and reduce the quantity of catalysts.
Vanadium, which is an active ingredient of catalysts, has the function of reducing NOx under the presence of NH3; on the other hand, it has the adverse effect of oxidizing the SOx present in effluent gases. The oxidation of SO2 to become SO3 during denitrification reaction can lead to problems with the equipment in the latter phases. JGC C&C can design catalysts while taking into consideration the suppression of SO2 oxidation.
