Field Experience and Laboratory Analysis of Oxidation Catalyst on Dual Fuel Engines

Abstract

A DCL oxidation catalyst for exhaust-gas cleaning has been field tested on a Wa¨rtsila¨ 50 series dual-fuel engine during 5000 hours of continuous operation in an end-user power plant application. The engine has been designed for continuous operation on natural gas (NG), light fuel oil (LFO) as well as heavy fuel oil (HFO), thus giving the consumer a wide variety of fuelling options. All three fuels were used at some point during the 5000 hours field trial. These fuels have different properties such as differing levels of sulphur and ash contents that affect the abatement efficiencies of the oxidation catalyst. A detailed study was performed to understand the effect of different fuels, lube oil poisoning and long running hours on the abatement performance of the oxidation catalyst. The oxidation catalyst was equipped with sample cores that were exchanged during scheduled engine maintenance periods. This allowed parallel field and laboratory evaluation of the emissions abatement and the quantity of lube oil deposits on the catalyst at successive intervals of engine running hours. We will show that the combination of the dual fuel engine and the oxidation catalyst is very robust, even for the different fuels, and it gives low emissions.

Sulfur Poisoning and Regeneration of Pd Catalyst under Simulated Emission Conditions of Natural Gas Engine

“…Catalytic performance was tested in a conventional stainless-steel tubular reactor that is described in a previous paper [9]. Gas compositions used are listed in Table 1 and the gas mixture was fed to the reactor with a space velocity of 100,000 h -1 @STP based on substrate volume unless otherwise specified.…”

Oxidation Catalysts for Natural Gas Engine Operating under HCCI or SI Conditions

“…In contrast to the Pt catalyst, a significant deactivation was observed for the oxidation of all the components, including hydrocarbons, CO and NO, over Pd catalyst after SO 2 aging. Sulfur poisoning and regenerating of Pd catalyst was systematically investigated and discussed in previous papers [8,10,13]. It is generally accepted that PdO is the active site for oxidation under lean-burn conditions, and SO 2 can be oxidized by excess oxygen in the gas stream and form less active Pd-SO 4 with the PdO [6][7][8][9].…”

“…The metallic contaminants, such as Zn and Ca, could mask the active sites and deactivate the catalyst. The origin of these metals is the inorganic remainder of the lubricant oil additives [5,[11][12][13]. Platinum-based catalyst is not sensitive to sulfur, but it is not as active as Pd catalyst for methane and NMHCs oxidation.…”