Insights of Selective Catalytic Reduction Technology for Nitrogen Oxides Control in Marine Engine Applications

Abstract

The international shipping industry is facing increasingly stringent limitations on nitrogen oxide (NOx) emissions. New solutions for reducing NOx emitted by marine engines need to be investigated to find the best technology. Selective Catalytic Reduction (SCR) is an advanced active emissions control technology successfully used in automotive diesel engines; it could be applied to marine engines with ad-hoc solutions to integrate it in the exhaust of large engines. In this study, a commercial SCR was tested at the exhaust of a diesel engine in inlet gas conditions typical of a marine engine. The SCR system consisted of a custom monolith (provided by Hug-Engineering AG) that enabled seamless integration for a broad range of engine sizes; the active phases were V2O5 (3 wt%)-WO3 (7 wt%)-TiO2 (75 wt%). The monolith was studied at the laboratory scale for its in-depth chemical/physical characterization and by means of an intermediate-scale engine, reproducing the exhaust gas conditions of a full-scale marine engine. The system’s effectiveness in terms of NOx removal for the selected engine operating conditions was evaluated in a wide range of temperature and NOx emissions values and for different quantities of the reduction agent (AdBlue or ammonia) added to exhaust gases. The investigated technological solution resulted in efficient NOx emission control from a marine engine.

Optimization of the Uniformity Index Performance in the Selective Catalytic Reduction System Using a Metamodel

“…When the urea solution is injected into the high-temperature exhaust gas, NH 3 is generated through a thermaldecomposition chemical reaction and hydrolysis reaction as shown in Equations ( 1) and (2), respectively. When it is mixed with exhaust gas and distributed across the catalyst, the NOx is reduced to nitrogen and water as represented in Equation (3) [24,25].…”

NH3-NO SCR Catalysts for Engine Exhaust Gases Abatement: Replacement of Toxic V2O5 with MnOx to Improve the Environmental Sustainability

“…A commercial catalyst (VWTi), provided by Hug Engineering (ElringKlinger Group), with composition 3wt% V 2 O 5 -7wt% WO 3 /75wt% TiO 2 -6wt% bentonite-9wt% glass fiber was used as reference. Details about chemical physical properties were reported elsewhere by some of us [18].…”

“…The reference commercial catalyst, VWTi, has SSA 55.6 m 2 /g, pore volume 0.21 cm 3 /g and mean pore size 15 nm [18].…”

“…Compared with the pattern of WTi, the deposition of Mn did not produce any new crystalline phase, no characteristic peaks of MnO 2 were detected even at high loading (12MnWTi). As far as the VWTi reference, only peaks of the anatase phase were identified [18], being a commercial catalyst likely deposited over a less common titania.…”

Influence of hydrogenated diesel/H2O2 blend fuel on diesel engine performance and exhaust emission characterization

“…Numerous researchers are dedicated to developing new or improved after-treatment technology to reduce NO X , PM and non-methane volatile organic compounds (NMVOC) emissions [19][20][21][22] . Selective Catalytic Reduction (SCR) is the most sophisticated active emissions control technology utilized effectively in diesel engine vehicles 23,24 . SCR uses a monolith catalyst to convert NOx into water (H 2 O) and diatomic nitrogen (N 2 ) 7 .…”