Basic study on the on-board removing low concentration SO₂ under the high space velocity conditions

Abstract

NO_x emitted from diesel is one of the main air pollutants for most countries. To reduce the emission of NO_x could promote to diffuse diesel vehicles. A NO_x storage / reduction (NSR) catalyst has been developed for the diesels. The catalyst in NSR is strongly poisoned by sulfur. We have researched reaction characteristics of CaCO₃ with sulfur dioxide by using a thermogravimetry. We obtained desulfurization breakthrough characteristic for CaCO₃. As a result, packed bed reactor of CaCO₃ absorbed SO₂ about 0.174 g-SO₂/g- CaCO₃. The absorption efficiency of CaCO₃ was more than 99.4%. According to this result, it was found that the necessary amount of the absorbent was supposed to be 1.40 kg or 1.68 L for 100,000 km running.