Sensitivity of Diesel Particulate Material Emissions and Composition to Blends of Petroleum Diesel and Biodiesel Fuel

Figures & data

FIG. 1 Denuded and undenuded EC and OC emission rates. (a) Influence of denuding aerosol on elemental carbon (EC) emission rates, and on (b) organic carbon emission rates. Backup filters correspond to quartz fiber filters preceded by Teflon membrane filters (TEF) collecting semivolatile organics.

FIG. 2 Fine particle mass, OC and EC emissions rates and the calculated organic mass to organic carbon ratio for PM emissions for each condition: (a) Mass, EC and denuded OC emission rates; (b) calculated organic mass (OM) to organic carbon (OC) ratios for PM_2.5.

FIG. 3 Size resolved EC and OM emission rates in diesel exhaust from the combustion of (a) pure petroleum diesel, (b) pure soybean oil based biodiesel, and (c) pure beef tallow based biodiesel fuels.

FIG. 4 PM_2.5 emission rates of detected dominant organic compound functional groups. (a) Fatty acid methyl esters, fatty acids, and other organics. (b) Polycyclic aromatic hydrocarbons, hopanes and steranes, and n-alkanes.

FIG. 5 PM_2.5 emission rates of speciated organic compounds: (a) n-alkanes, and (b) fatty acid methyl esters.

TABLE 1 Emission rates of organic species in fine particulate matter from the combustion of different blends of petroleum diesel and soybean oil and beef tallow based biodiesel fuels

	Organic compounds emission rates (μg/kg CO2)
Species	B0	Unc	B50	Unc	B100	Unc
	Soybean oil based biodiesel
PAHs	6.33	0.827	1.68	0.238	1.25	0.200
Hopanes and Steranes	8.86	0.680	8.19	0.640	10.6	0.819
n-alkanes	146	1.04	95.4	0.844	26.2	0.217
Fatty acid methyl Esters	ND	–	2300	329	8750	1090
	Beef tallow based biodiesel
PAHs	6.33	0.827	1.49	0.217	1.00	0.181
Hopanes and Steranes	8.86	0.680	6.10	0.476	10.5	0.797
n-alkanes	146	1.04	44.9	0.688	19.0	0.229
Fatty acid methyl Esters	ND	–	2360	313	6490	702
ND: Below the method detection limit.

TABLE 2 Emission rates of analyzed fatty acid methyl esters in fine particulate matter from the combustion of different blends of petroleum diesel and soybean oil and beef tallow based biodiesel fuels and fatty acid methyl ester composition of the different fuel blends

	Soybean oil based biodiesel						Beef tallow based biodiesel
Species	B0	Unc	B50	Unc	B100	Unc	B0	Unc	B50	Unc	B100	Unc
Emission rates ( μ g/kg CO2)
Hexadecanoic acid methyl ester	ND	–	309	145	1090	280	ND	–	912	244	1550	366
Octadecanoic acid methyl ester	18.5	11.1	168	37.7	524	108	18.5	11.1	543	112	1500	303
Oleic acid methyl ester	ND	–	467	110	1840	381	ND	–	614	138	2320	477
Linoleic acid methyl ester	ND	–	1200	270	4710	966	ND	–	145	80.6	831	200
Linolenic acid methyl ester	ND	–	117	25.9	485	99.3	ND	–	16.2	7.71	81	19.2
Total	18.5		2260		8650		18.5		2230		6280
Fuel composition ( μ g/gal fuel)
Tetradecanoic acid methyl ester	0.183	0.0300	1.17	0.0300	2.18	0.0300	0.183	0.0300	33.3	0.0300	63.9	0.0300
Hexadecanoic acid methyl ester	1.86	ND	193	ND	462	ND	1.86	ND	406	ND	972	ND
Heptadecanoic acid methyl ester	0.201	0.0125	1.69	0.0125	3.23	0.0125	0.201	0.0125	12.7	0.0125	26.1	0.0125
Octadecanoic acid methyl ester	1.37	ND	76.6	ND	198	ND	1.37	ND	282	ND	713	ND
Palmitoleic acid methyl ester	ND	0.0225	ND	0.0225	ND	0.0225	ND	0.0225	18.4	0.0225	38.4	0.0225
Oleic acid methyl ester	1.84	ND	285	ND	816	ND	1.84	ND	460	ND	1320	ND
Linoleic acid methyl ester	1.46	0.0450	879	0.0450	2660	0.0450	1.46	0.0450	187	0.0450	495	0.0450
Linolenic acid methyl ester	ND	0.0225	91.7	0.0225	271	0.0225	ND	0.0225	16.7	0.0225	46.9	0.0225
Total	6.91		1530		4410		6.91		1420		3680
ND: Below the method detection limit.
Bold values indicate significantly high emission rates. Non-bolded values are near or below the delection limit.

FIG. 6 PM_2.5 emission rates of speciated organic compounds: (a) all analyzed PAH species, and (b) high molecular weight (HMW) PAH species.