New submerged pipeline renovation method developed by Taisei Corporation has been applied to laying pipeline of Tonen Corporation at Kawasaki port. The method enables new pipeline to be inserted into ...existing pipeline by pressured fluid contained in new pipeline.The fluid inside of new pipeline is sealed. The pressure is added to the fluid which derives forwarding force to new pipeline. Through this force, the new pipeline creeps ahead. This is the first application of the method in Japan. The execution result implies that the method can be employed for submerged pipeline renovation even with longer distance or larger diameter.
Nitrogen oxide (NOx) is the main pollutant produced from power plants and boiler. The development of catalysts that can work to reduce NOx under ambient conditions at a low reaction temperature has ...been required. In this work, we examined the NH3-selective catalytic reduction (SCR) activity of metal oxide-supported gold catalysts in order to develop NH3-SCR catalysts working at low temperatures (<200 °C). Au/CuO showed NH3-SCR activity at 100 °C (NO conversion = 20 %, N2 selectivity = ca. 100 %), though the production of N2O as a by-product caused by NH3 oxidation was observed at a higher reaction temperature. We found that deposition of 0.1 wt% of gold on CuO is sufficient for NH3-SCR to proceed and that NH3 oxidation proceeds with increase in the loading amount of gold (<0.5 %) at a high reaction temperature. Although we measured the NH3-SCR activities of Pt/CuO and Pd/CuO, Au/CuO showed better activity than those of other precious metal catalysts. We also tested binary metal oxide-supported gold catalysts and found that 1 wt%Au/10 wt%CuO/Al2O3 showed the largest N2 yield (45 %) owing to the introduction of other metal oxide species to CuO. The results indicated that a gold catalyst has the potential to catalyze NH3-SCR at low temperatures.
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