An ammonia supplying system using ammonium salt to reduce the NOx emissions of a 1.1 MW marine engine

• Published in: Journal of marine engineering and technology Vol. 22; no. 1; pp. 45 - 54
• Main Authors: Woo, Sang-Hee, Raza, Hassan, Kang, Won-Mo, Choe, Sang Bom, Im, Myeong Hwan, Lim, Kyung Sun, Nam, Jeong Gil, Kim, Hongsuk
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 02.01.2023
• Subjects: ammonia; Ammonium carbamate; marine engine; SCR (selective catalytic reaction)
• ISSN: 2046-4177; 2056-8487
• DOI: 10.1080/20464177.2022.2127402

A solid-SCR (selective catalytic reduction) system using ammonium carbamate (AC) was designed to improve NO x emission reduction efficiency and compensate for the shortcoming of the UWS (urea water solution)-SCR system applied to marine diesel engines. The solid-SCR system was installed on the exhaust line of a 1.1 MW engine for electric power generation in a ship, and its performance of emissions reduction was compared with the existing UWS-SCR system. The NO x emitted from the engine was 9.2 g/kWh, and it is reduced to 1.94 g/kWh when using the UWS-SCR system. Using the solid-SCR system significantly lowered NO x emissions to 0.3 g/kWh, which was 15% of the UWS-SCR system. In addition, the solid-SCR system showed fewer ammonia slip characteristics than the UWS-SCR system. In the solid-SCR system, gaseous ammonia was directly supplied in the exhaust line, and it mixed well with the exhaust gas and reacted well with NO x in the SCR catalyst. An endurance test of the solid-SCR system was conducted for 210 h during actual ship operation. The NO x reducing efficiency was maintained at higher than 90% for 210 h. The AC consumption rate was 1.7-4.3 kg/h for the endurance test.