Characterization of a new miniCAST with diffusion flame and premixed flame options: Generation of particles with high EC content in the size range 30 nm to 200 nm

Figures & data

Table 1. Operational gas flow ranges for the miniCAST BC and specifications of the used gases.

Gas line	Gas	Range (L/min)
Fuel	Propane (>99.95%, Carbagas, Rümlang, Switzerland)	0–0.1
Mixing air for propane	Air (pressurized air)	0–1.3
Oxidation air	Air (pressurized air)	0–2.0
Oxygen to oxidation air	Oxygen (Alphagaz 1 Oxygen (Q50), Carbagas, Switzerland)	0–1.0
Dilution air	Air (pressurized air)	10.0–20.0
Quench gas	Nitrogen (pure from liquid N2 tank)	5.0–7.0
Oxygen to quench gas	Oxygen (Alphagaz 1 Oxygen (Q50), Carbagas, Switzerland)	0–3.0

Table 2. Series of experiments performed to characterize the miniCAST BC.

Examined properties	Constant parameters	Varied parameters	Series
Diffusion flame
Influence of C/O ratio	Propane (mL/min)	Oxidation air (L/min)
	60	0.8–2.0	A
	70	1.0–2.0	B
Addition of O2 into oxidation air	Propane (mL/min) / oxidation air (L/min)	O2 (mL/min)
	60/1.0	0–175	C
	61/1.5	0–100	D
Variation of propane and oxidation air with overall constant C/O ratio	C/O ratio	Propane (mL/min) / oxidation air (L/min)
	0.22	50–62 / 1.6–2.0	E
	0.25	40–70 / 1.14–2.0	F
	0.3	30–80 / 0.715–1.905	G
	0.4	40–90 / 0.715–1.608	H
	0.5	60–90 / 0.858–1.285	I
Premixed flame
Characteristics of premixed flame	Propane (mL/min) / oxidation air (L/min)	Premixed air (mL/min)
	60/0.9	0–550	J
	60/1.0	0–450	K
	60/1.1	0–425	L
	60/1.2	0–350	M
	60/1.3	0–300	N
	61/1.5	0–200	O
	60/1.6	0–150	P
Quench gas
Addition of O2 in quench gas	Propane (mL/min) / oxidation air (L/min) / mixing air (mL/min) / flow of quench gas (L/min)	Quench N2 (L/min) / O2 (L/min)
	60/0.9/0/7	7–5/0–2	Q
	60//1.2/0/7	7–5/0–2	R
	61/1.5/0/7	7–5/0–2	S
	61/1.5/150/7	7–5/0–2	T
	60/2.0/0/7	7–5/0–2	U

Figure 1. Schematic illustration of the setup used for the characterization of the miniCAST BC. The new options available in the miniCAST BC are marked bold (and in red in the online version of the document).

Figure 2. GMD (and associated uncertainty) of particle size distribution for particles generated with a diffusion flame as a function of the overall C/O ratio, with the gray dashed line at C/O = 0.3 marking overall stoichiometric conditions. The gas flow rates of each series A–I are summarized in Table 2; the condition of each single operation point can be found in Table S1.

Figure 3. Correlation of (a) EC/TC ratio and (b) AAE with GMD of the number size distributions for the particles generated with diffusion flames. The gas flow rates of each series A–I are summarized in Table 2; the condition of each single operation point can be found in Table S1.

Figure 4. GMD (and associated uncertainties) of particle size distribution for particles generated with a premixed flame as a function of the overall C/O ratio. The gray dashed line at C/O = 0.3 marks the overall stoichiometric conditions. Series J–P possess different starting points (point corresponding to the highest overall C/O ratio). The C/O ratio is tuned by gradually increasing the amount of mixing air in the fuel. The gas flow rates of each series are summarized in Table 2; the condition of each single operation point can be found in Table S2.

Figure 5. Correlation of (a) EC/TC ratio and (b) AAE with GMD of the size distributions for particles generated with premixed flames. The gas flow rates of each series are summarized in Table 2; the condition of each single operation point can be found in Table S2.

Table 3. Summary of the properties of the analyzed miniCAST soot in comparison with diesel and aircraft soot. The miniCAST BC number and mass concentrations have been corrected for the dilution factor (1:91) but not for coagulation or diffusion losses in the tubes.

Property	miniCAST BC soot						Diesel soot	Aircraft soot
	Diffusion flame				Premixed flame
	C/O < 0.25	0.25 < C/O < 0.31	C/O > 0.31		C/O < 0.3	C/O > 0.3
GMD [nm]	≤60–180	180–210	≤40–160		≤30–180	≤40–180	5–20^a & 30–150^a,^b,^c	10–50^g,^h,^i
Number concentration [#/cm^3]	2 × 10^5–3 × 10^7	1 × 10^7–3 × 10^7	1 × 10^7– 5 × 10^7		2 × 10^6–3 × 10^7	7 × 10^6–4 × 10^7	10^5–10^9^d –10^6/10^8^c	∼10^13–10^15 #/ kg fuel^h,^j 10^7–10^8^k
Mass concentration [mg/m^3]	1–60 eBC (880nm)	40–180 eBC (880nm)	0.2–130 eBC (880nm)		0.1–160 eBC (880nm)	0.4–150 eBC (880nm)	0.1–10^3^c	0.5–100 mg/kg fuel^h,^j 20–200 TC^k
EC/TC [%]	<70–95	>90	2–60		50–95	1–90	60–85^e	∼10–70^k 80–100*^,g
AAE [-]	≤1.4 ± 0.2	≤1.2 ± 0.1	1.1–4.5		1.1–1.7	1.1–4.5	1.1^f	–

^a Puzun et al. (2011).

^b Ess et al. (2016).

^c Caroca et al. (2011): depending on usage of DPF, fuel and operating conditions.

^d Kittelson (1998).

^e Lu et al. (2012).

^f Schnaiter et al. (2003).

^g Abegglen et al. (2016) *only valid for particles >100 nm due to experimental restrictions.

^h Lobo et al. (2015).

ⁱPopovitcheva et al. (2000).

^j Durdina et al. (2017).

^k Cheng et al. (2009).

Puzun, A., S. Wanchen, L. Guoliang, T. Manzhi, L. Chunjie, and C. Shibao. 2011. Characteristics of Particle Size Distributions About Emissions in a Common-Rail Diesel Engine with Biodiesel Blends. Procedia Environ. Sci. 11 (C):1371–8. doi:10.1016/j.proenv.2011.12.206.

 Google Scholar

Ess, M. N., H. Bladt, W. Mühlbauer, S. I. Seher, C. Zöllner, S. Lorenz, D. Brüggemann, U. Nieken, N. P. Ivleva, and R. Niessner. 2016. Reactivity and Structure of Soot Generated at Varying Biofuel Content and Engine Operating Parameters. Combust. Flame 163:157–69. doi:10.1016/j.combustflame.2015.09.016.

 Web of Science ®Google Scholar

Caroca, J. C., F. Millo, D. Vezza, T. Vlachos, A. De Filippo, S. Bensaid, N. Russo, and D. Fino. 2011. Detailed Investigation on Soot Particle Size Distribution During DPF Regeneration, Using Standard and Bio-diesel Fuels. Ind. Eng. Chem. Res. 50 (5):2650–8. doi:10.1021/ie1006799.

 Web of Science ®Google Scholar

Kittelson, D. B. 1998. Engines and Nanoparticles: A Review. J. Aerosol Sci. 29 (5–6):575–88. doi:10.1016/S0021-8502(97)10037-4.

 Web of Science ®Google Scholar

Lu, T., Z. Huang, C. S. Cheung, and J. Ma. 2012. Size Distribution of EC, OC and Particle-Phase PAHs Emissions from a Diesel Engine Fueled with Three Fuels. Sci. Total Environ. 438:33–41. doi:10.1016/j.scitotenv.2012.08.026.

 PubMed Web of Science ®Google Scholar

Schnaiter, M., H. Horvath, O. Möhler, K. H. Naumann, H. Saathoff, and O. W. Schöck. 2003. UV-VIS-NIR Spectral Optical Properties of Soot and Soot-Containing Aerosols. J. Aerosol Sci. 34 (10):1421–44. doi:10.1016/S0021-8502(03)00361-6.

 Web of Science ®Google Scholar

Abegglen, M., B. T. Brem, M. Ellenrieder, L. Durdina, T. Rindlisbacher, J. Wang, U. Lohmann, and B. Sierau. 2016. Chemical Characterization of Freshly Emitted Particulate Matter from Aircraft Exhaust Using Single Particle Mass Spectrometry. Atmos. Environ. 134:181–97. doi:10.1016/j.atmosenv.2016.03.051.

 Web of Science ®Google Scholar

Lobo, P., L. Durdina, G. J. Smallwood, T. Rindlisbacher, F. Siegerist, E. A. Black, Z. Yu, A. A. Mensah, D. E. Hagen, R. C. Miake-Lye, et al. 2015. Measurement of Aircraft Engine Non-volatile PM Emissions: Results of the Aviation-Particle Regulatory Instrumentation Demonstration Experiment (A-PRIDE) 4 Campaign. Aerosol Sci. Technol. 49 (7):472–84. doi:10.1080/02786826.2015.1047012.

 Web of Science ®Google Scholar

Popovitcheva, O. B., N. M. Persiantseva, M. E. Trukhin, G. B. Rulev, N. K. Shonija, Y. Ya. Buriko, A. M. Starik, B. Demirdjian, D. Ferry, and J. Suzanne. 2000. Experimental Characterization of Aircraft Combustor Soot: Microstructure, Surface Area, Porosity and Water Adsorption. Phys. Chem. Chem. Phys. 2 (19):4421–26. doi:10.1039/b004345l.

 Web of Science ®Google Scholar

Durdina, L., B. T. Brem, A. Setyan, F. Siegerist, T. Rindlisbacher, and J. Wang. 2017. Assessment of Particle Pollution from Jetliners: From Smoke Visibility to Nanoparticle Counting. Environ. Sci. Technol. 51 (6):3534–41. doi:10.1021/acs.est.6b05801.

 PubMed Web of Science ®Google Scholar

Cheng, M. D., E. Corporan, M. J. Dewitt, and B. Landgraf. 2009. Emissions of Volatile Particulate Components from Turboshaft Engines Pperated with JP-8 and Fischer-Tropsch Fuels. Aerosol Air Qual. Res. 9 (2):237–56. doi:10.4209/aaqr.2008.11.0059.

 Web of Science ®Google Scholar