Analysis of the particulate emissions and combustion performance of a direct injection spark ignition engine using hydrogen and gasoline mixtures

Abstract

Analysis of the Particulate Emissions and Combustion Performance of a Direct Injection Spark Ignition Engine Using Hydrogen and Gasoline Mixtures AbstractThree different fractions (2%, 5%, and 10% of stoichiometric, or 2.38%, 5.92%, and 11.73% by energy fraction) of hydrogen were aspirated into a gasoline direct injection engine under two different load conditions. The base fuel was 65% iso-octane, and 35% toluene by volume fraction. Ignition sweeps were conducted for each operation point. The pressure traces were recorded for further analysis, and the particulate emission size distributions were measured using a Cambustion DMS500. The results indicated a more stable and faster combustion as more hydrogen was blended.Meanwhile, a substantial reduction in particulate emissions was found at the low load condition (more than 95% reduction either in terms of number concentration or mass concentration when blending 10% hydrogen). Some variation in the results occurred at the high load condition, but the particulate emissions were reduced in most cases, especially for nucleation mode particulate matter. Retarding the ignition timing generally reduced the particulate emissions. An engine model was constructed using the Ricardo WAVE package to assist in understanding the data. The simulation reported a higher residual gas fraction at low load, which explained the higher level of cycle-by-cycle variation at the low load.

Improving gasoline direct injection (GDI) engine efficiency and emissions with hydrogen from exhaust gas fuel reforming

“…Previous research into hydrogen blended gasoline combustion [36] has indicated that hydrogen initiates a significant reduction in nucleation mode particles. Guided by work elsewhere on soot formation in ethylene-hydrogen flames [37], they concluded that hydrogen addition inhibits soot nucleation by slowing or reversing the hydrogen abstraction reaction, the mechanism by which polycyclic aromatic hydrocarbons grow to form soot.…”

“…Elsewhere though, EGR has been reported to increase particle number emissions from a port fuel-injected (PFI) engine [21]. Hydrogen enhancement has been shown to reduce PM formation in GDI engines [3,22] and so it may be expected that REGR will result in further reductions over conventional EGR.…”

Experimental investigation of particle emissions under different EGR ratios on a diesel engine fueled by blends of diesel/gasoline/n-butanol

“…It is widely accepted that polycyclic aromatic hydrocarbons (PAHs) develop within the soot particle nuclei when their structures reach a sufficiently large size. The key reactions for the growth of aromatic rings from benzene are known as HACA (Hydrogen Abstraction Carbon Addition) [37]:…”

“…As for surface growth, the two dominant reactions in the HACA surface reactions are the following [37]:…”

Reducing Emissions of Polycyclic Aromatic Hydrocarbons and Greenhouse Gases from Engines Using a Novel Plasma-Enhanced Combustion System

“…PAHs, especially benzo(a)pyrene, not only injure the respiratory and immune system but also cause cell mutation and cancers such as lung and skin (Grevenynghe et al, 2003;Ji et al, 2009;Verhelst et al, 2009). Recently, much progress has been made in the control of combustion processes to limit the formation of environmentally harmful species such as hydrogen addition (Ji et al, 2010a, b;Wang et al, 2010;Zhao et al, 2010;Wang et al, 2011), biodiesel addition (Bueno et al, 2011;Valentino et al, 2011), methanol/ethanol addition (Berta et al, 2006;Graham et al, 2008;Abrantes et al, 2009;Najafi et al, 2009;Westphal et al, 2010;Lee et al, 2011;Ozsezen et al, 2011), ether oxygenate additives (Alex et al, 2007), premixed n-heptane flames (Li et al, 2007), and engine modification (Alkidas, 2007;Wel et al, 2007;Canakci, 2008).…”