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Supporting Information
Bioslurry as a Fuel. 7: Spray Characteristics of Bio-Oil and Bioslurry via Impact and Twin-Fluid Atomizers Mansoor Hassani Ghezelchi,1 Manuel Garcia-Perez,2 Hongwei Wu1,* 1
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth WA 6845, Australia
2
Biological Systems Engineering, Washington State University, L. J. Smith 205, P.O. Box 64120, Pullman, Washington USA, 99164-6120
*Corresponding Author. E-mail: [email protected]; Tel: +61-8-92667592; Fax: +61-8-92662681
This supporting information contains: 7 figures; 4 tables; and 12 pages.
S1
1. INTRODUCTION Spray and atomization characteristics of liquid fuels are important considerations for the applications (such as combustion) of these fuels. Particularly, the determination of droplet size and average mean diameter of a spray is essential. There are two categories of methods developed for measuring spray droplet size and average mean diameter.1 One category is based on optical methods2-5 such as light scattering techniques. These methods have respective advantages and disadvantages6 and require the establishment of sophisticated and expensive optical systems. The other category of is the mechanical approach that deploys a suitable solid surface (such as glass) to allow droplets strike on surface. Images were then taken and analysed for droplet size measurement. Therefore, the mechanical method has advantages of simplicity, low cost, visibility and reliability. However, the mechanical method suffers from several drawbacks. Firstly, as permanently pressed, the droplets need to be corrected by a correction factor to obtain real diameters of the droplets. 7 Conventionally, a constant correction factor is used, e.g. 0.5 for clean glass surface.1 This is a problem because the correction factor is known to be dependent on fluid properties (such as viscosity, surface tension etc) and droplet size. 1 Second, there are overlapping issues among droplets upon striking on the surface. Thirdly, the effect of potential evaporation on droplet size analysis is largely unknown. Lastly, the accuracy of droplets size analysis in past studies was largely limited by the low resolution of the photographs. This study has developed an improved mechanical method for measuring the droplet size of the sprays of liquid fuels and the method has been validated using diesel, biodiesel and their blends. The novelties of method are four fold: i) adoption of a flexible correction factor for a droplet based on its fluid properties and size; ii) design of the spray to minimize droplets overlapping; iii) deployment of high-resolution camera which enables the analyses submicron droplets photographed on glass plate (Figure S1) and iv) estimation of the effect of droplet evaporation.
Figure S1. Macro photography of diesel fuel droplet eliminating the shadow of droplets at 10 bar pressure by pressure swirl atomizer
S2
2. DIESEL, BIODIESEL AND THEIR BLENDS FOR EXPERIMENTS Automotive diesel fuel and biodiesel (rapeseed oil, methyl ester) were purchased from commercial suppliers in Western Australia for experiments in this study. Four blends of biodiesel and diesel was then prepared at various blending ratios (based on volume) in closed containers with magnetic stirrer to produce homogenous mixtures. Therefore, a total of 6 liquid fuel samples were used in the experiments, denoted as D100, B20, B40, B60, B80 and B100. Here, B20 refers to mixture of 20%vol biodiesel and 80%vol diesel while D100 and B100 refer to diesel and biodiesel fuels, respectively. Table S1 indicates the chemistry of liquid fuels samples, determined by an elemental analyser (Model: 2400 Series II CHNS/O, PerkinElmer). The surface tension, density, viscosity and contact angle of the fuels were measured at room temperature (25 °C). The surface tension of the liquid fuel samples were measured using a tensiometer (Model: Sigma 701, KSV Instruments Ltd). The Wilhelmy technique 8 was employed with one millimeter platinum rod at 25 °C controlled by a water bath. Fuel density was measured using a digital density meter (Model: DMA4500, Anton Paar). The viscosity of these liquid fuels were measured using a rotational rheometer (Model: HAAKE MARS II, Thermo Scientific) with conical sensor (C35/4° Ti) at 25 °C. The contact angles of different liquid fuels were measured using a KSV Contact Angle Meter (Model: CAM 101, Camera: Imaging source DMK21F04, Software: KSV CAM Software V3.81). The average contact angle for left and right of sessile droplet was measured and reported for 5 datum points at room temperature of small and large samples on glass surface. Table S1. Elemental analysis of fuels (wt. %) Fuel C Diesel 86.32 B 20 84.60 B 40 82.71 B 60 80.91 B 80 78.94 Biodiesel 76.89
H 13.68 13.12 13.40 13.14 12.78 12.35
N 0 0.01 0.02 0.03 0.03 0.05
S 0
Bioslurry as a Fuel. 7: Spray Characteristics of Bio-Oil and Bioslurry via Impact and Twin-Fluid Atomizers Mansoor Hassani Ghezelchi,1 Manuel Garcia-Perez,2 Hongwei Wu1,* 1
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth WA 6845, Australia
2
Biological Systems Engineering, Washington State University, L. J. Smith 205, P.O. Box 64120, Pullman, Washington USA, 99164-6120
*Corresponding Author. E-mail: [email protected]; Tel: +61-8-92667592; Fax: +61-8-92662681
This supporting information contains: 7 figures; 4 tables; and 12 pages.
S1
1. INTRODUCTION Spray and atomization characteristics of liquid fuels are important considerations for the applications (such as combustion) of these fuels. Particularly, the determination of droplet size and average mean diameter of a spray is essential. There are two categories of methods developed for measuring spray droplet size and average mean diameter.1 One category is based on optical methods2-5 such as light scattering techniques. These methods have respective advantages and disadvantages6 and require the establishment of sophisticated and expensive optical systems. The other category of is the mechanical approach that deploys a suitable solid surface (such as glass) to allow droplets strike on surface. Images were then taken and analysed for droplet size measurement. Therefore, the mechanical method has advantages of simplicity, low cost, visibility and reliability. However, the mechanical method suffers from several drawbacks. Firstly, as permanently pressed, the droplets need to be corrected by a correction factor to obtain real diameters of the droplets. 7 Conventionally, a constant correction factor is used, e.g. 0.5 for clean glass surface.1 This is a problem because the correction factor is known to be dependent on fluid properties (such as viscosity, surface tension etc) and droplet size. 1 Second, there are overlapping issues among droplets upon striking on the surface. Thirdly, the effect of potential evaporation on droplet size analysis is largely unknown. Lastly, the accuracy of droplets size analysis in past studies was largely limited by the low resolution of the photographs. This study has developed an improved mechanical method for measuring the droplet size of the sprays of liquid fuels and the method has been validated using diesel, biodiesel and their blends. The novelties of method are four fold: i) adoption of a flexible correction factor for a droplet based on its fluid properties and size; ii) design of the spray to minimize droplets overlapping; iii) deployment of high-resolution camera which enables the analyses submicron droplets photographed on glass plate (Figure S1) and iv) estimation of the effect of droplet evaporation.
Figure S1. Macro photography of diesel fuel droplet eliminating the shadow of droplets at 10 bar pressure by pressure swirl atomizer
S2
2. DIESEL, BIODIESEL AND THEIR BLENDS FOR EXPERIMENTS Automotive diesel fuel and biodiesel (rapeseed oil, methyl ester) were purchased from commercial suppliers in Western Australia for experiments in this study. Four blends of biodiesel and diesel was then prepared at various blending ratios (based on volume) in closed containers with magnetic stirrer to produce homogenous mixtures. Therefore, a total of 6 liquid fuel samples were used in the experiments, denoted as D100, B20, B40, B60, B80 and B100. Here, B20 refers to mixture of 20%vol biodiesel and 80%vol diesel while D100 and B100 refer to diesel and biodiesel fuels, respectively. Table S1 indicates the chemistry of liquid fuels samples, determined by an elemental analyser (Model: 2400 Series II CHNS/O, PerkinElmer). The surface tension, density, viscosity and contact angle of the fuels were measured at room temperature (25 °C). The surface tension of the liquid fuel samples were measured using a tensiometer (Model: Sigma 701, KSV Instruments Ltd). The Wilhelmy technique 8 was employed with one millimeter platinum rod at 25 °C controlled by a water bath. Fuel density was measured using a digital density meter (Model: DMA4500, Anton Paar). The viscosity of these liquid fuels were measured using a rotational rheometer (Model: HAAKE MARS II, Thermo Scientific) with conical sensor (C35/4° Ti) at 25 °C. The contact angles of different liquid fuels were measured using a KSV Contact Angle Meter (Model: CAM 101, Camera: Imaging source DMK21F04, Software: KSV CAM Software V3.81). The average contact angle for left and right of sessile droplet was measured and reported for 5 datum points at room temperature of small and large samples on glass surface. Table S1. Elemental analysis of fuels (wt. %) Fuel C Diesel 86.32 B 20 84.60 B 40 82.71 B 60 80.91 B 80 78.94 Biodiesel 76.89
H 13.68 13.12 13.40 13.14 12.78 12.35
N 0 0.01 0.02 0.03 0.03 0.05
S 0
