Process for reducing pollutants from the exhaust of a diesel engine using a water diesel fuel in combination with exhaust after-treatments

#This invention relates to a process for reducing the level of pollutants from the exhaust of a diesel engine. More particularly, this invention relates to a process for reducing the level of pollutants such as NOx and diesel particulate emissions from the exhaust of a diesel engine wherein a water-diesel fuel emulsion is used as the fuel in combination with exhaust after treatment products to treat the engine exhaust.

#The term “NOx” is used herein to refer to any of the nitrogen oxides NO, NO2, N2O, or combinations thereof. Over the past ten years, increasingly more stringent heavy duty on-highway engine emission regulations have led to the development of engines in which NOx and diesel particulate emissions have been reduced by as much as 70% and 90%, respectively.

#The term “filter” used herein refers to any of the after-treatment filters, traps, particulate filters, particulate traps, and the like.

#The following example illustrates the inventive process. The vehicle tested is an Olympian bus with Euro 2 engine technology being turbo charges, 6 cylinder, 9600 cc, automatic transmission and EEC emissions type 91/542 EWG which is mechanically fuel injected and equipped with an automatic gearbox. The diesel engine has a maximum rated power of 183 kW at 2000 rpm, and 1050 Nm torque at 1450 rpm. A chassis dynamometer is installed on the vehicle. The vehicle is tested at curb weight with an additional load value simulating a typical passenger load.

#Emissions were measured over the Millbrook London Transport Bus Cycle. The test cycle consists of two phases, an inner and outer London phase representing urban and suburban operations, respectively. The inner part of the cycle consists of a highly transient operation, with prolonged periods at idle and reaching a maximum speed of about 35 km/h. The outer part of the cycle is also highly transient, but less time is spent at idle and a maximum speed of about 50 km/h is attained. The percentage change values gives a simple means of comparing the water blend fuel to a given base ULSD case with equivalent exhaust after treatment.

#The emissions tests were conducted in a Variable Temperature Emissions Chamber (VTEC) facility. The dynamometer used allows for full load road and inertia simulation permitting an accurate comparison to be made between laboratory test protocol and on-highway testing. The exhaust gases are sampled via a full flow constant volume sampling (CVS) system; the methodology is similar to that used for passenger car and light duty commercial vehicles for emissions type approval.