Limits...
Experimental investigation into the oxidation reactivity and nanostructure of particulate matter from diesel engine fuelled with diesel/polyoxymethylene dimethyl ethers blends

View Article: PubMed Central - PubMed

ABSTRACT

This paper focuses on oxidation reactivity and nanostructural characteristics of particulate matter (PM) emitted from diesel engine fuelled with different volume proportions of diesel/polyoxymethylene dimethyl ethers (PODEn) blends (P0, P10 and P20). PM was collected using a metal filter from the exhaust manifold. The collected PM samples were characterized using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The TGA results indicated that the PM produced by P20 had the highest moisture and volatility contents and the fastest oxidation rate of solid carbon followed by P10 and P0 derived PM. SEM analysis showed that PM generated from P20 was looser with a lower mean value than PM emitted from P10 and P0. Quantitative analysis of high-resolution TEM images presented that fringe length was reduced along with increased separation distance and tortuosity with an increase in PODEn concentration. These trends improved the oxidation reactivity. According to Raman spectroscopy data, the intensity, full width at half-maximum and intensity ratio of the bands also changed demonstrating that PM nanostructure disorder was correlated with a faster oxidation rate. The results show the use of PODEn affects the oxidation reactivity and nanostructure of PM that is easier to oxidize.

No MeSH data available.


HRTEM images and the corresponding skeleton images: (a) P0, (b) P10, (c) P20 at low load and (d) P0, (e) P10, (f) P20 at high load. HRTEM images with magnified 1,000,000×. Skeleton image is obtained after image processing procedures: Choose an image region (red circle), then the three steps follow (a) Fourier transform; (b) binary conversion; (c) skeletonized image.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120283&req=5

f5: HRTEM images and the corresponding skeleton images: (a) P0, (b) P10, (c) P20 at low load and (d) P0, (e) P10, (f) P20 at high load. HRTEM images with magnified 1,000,000×. Skeleton image is obtained after image processing procedures: Choose an image region (red circle), then the three steps follow (a) Fourier transform; (b) binary conversion; (c) skeletonized image.

Mentions: As SEM images could not completely reflect the nanostructure of primary particles, HRTEM was used in this study. HRTEM images were digitized and analyzed using image processing software to gain nanostructure parameters (La, Ds and Tf). The major steps of method are as follows: a region with clear carbon layers is selected in the HRTEM image and converted into black and white. From this binary image, a skeletonizing process was used and each fringe was changed to a one-pixel width for further statistical analysis. The original HRTEM images and the final skeleton images are depicted in Fig. 5.


Experimental investigation into the oxidation reactivity and nanostructure of particulate matter from diesel engine fuelled with diesel/polyoxymethylene dimethyl ethers blends
HRTEM images and the corresponding skeleton images: (a) P0, (b) P10, (c) P20 at low load and (d) P0, (e) P10, (f) P20 at high load. HRTEM images with magnified 1,000,000×. Skeleton image is obtained after image processing procedures: Choose an image region (red circle), then the three steps follow (a) Fourier transform; (b) binary conversion; (c) skeletonized image.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120283&req=5

f5: HRTEM images and the corresponding skeleton images: (a) P0, (b) P10, (c) P20 at low load and (d) P0, (e) P10, (f) P20 at high load. HRTEM images with magnified 1,000,000×. Skeleton image is obtained after image processing procedures: Choose an image region (red circle), then the three steps follow (a) Fourier transform; (b) binary conversion; (c) skeletonized image.
Mentions: As SEM images could not completely reflect the nanostructure of primary particles, HRTEM was used in this study. HRTEM images were digitized and analyzed using image processing software to gain nanostructure parameters (La, Ds and Tf). The major steps of method are as follows: a region with clear carbon layers is selected in the HRTEM image and converted into black and white. From this binary image, a skeletonizing process was used and each fringe was changed to a one-pixel width for further statistical analysis. The original HRTEM images and the final skeleton images are depicted in Fig. 5.

View Article: PubMed Central - PubMed

ABSTRACT

This paper focuses on oxidation reactivity and nanostructural characteristics of particulate matter (PM) emitted from diesel engine fuelled with different volume proportions of diesel/polyoxymethylene dimethyl ethers (PODEn) blends (P0, P10 and P20). PM was collected using a metal filter from the exhaust manifold. The collected PM samples were characterized using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The TGA results indicated that the PM produced by P20 had the highest moisture and volatility contents and the fastest oxidation rate of solid carbon followed by P10 and P0 derived PM. SEM analysis showed that PM generated from P20 was looser with a lower mean value than PM emitted from P10 and P0. Quantitative analysis of high-resolution TEM images presented that fringe length was reduced along with increased separation distance and tortuosity with an increase in PODEn concentration. These trends improved the oxidation reactivity. According to Raman spectroscopy data, the intensity, full width at half-maximum and intensity ratio of the bands also changed demonstrating that PM nanostructure disorder was correlated with a faster oxidation rate. The results show the use of PODEn affects the oxidation reactivity and nanostructure of PM that is easier to oxidize.

No MeSH data available.