Design and Development of a Low Cost SCR System for NOx Reduction in a Diesel Engine

Abstract

After-treatment of exhaust gases are generally preferred to control engine emissions since engine hardware demands no significant modification. Selective Catalytic Reduction (SCR) is a promising after-treatment method for NOx reduction in Diesel engines. In the present work an exhaust gas treatment system, involving Urea injection and an activated carbon catalyst chamber were designed and fabricated, for NOx control, in a Diesel engine. Activated carbon catalyst, which can perform at low temperatures, was expected to make the system cost-effective. Experiments were conducted at 60 percentage and 80 percentage of the maximum engine load. Apart from Diesel, engine was also fuelled with Bio-Diesel developed from chicken slaughter waste. The results demonstrated the capability of developed SCR system in reducing NOx emissions. The Nitric Oxide (NO) emission was reduced by 47 percentage 29 percentage for Bio-Diesel and Diesel respectively, at a brake power of 3kW, without increasing HC emission and sacrificing efficiency. Significant reduction in NO was also obtained at 2kW.