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S. Chourasia et al.
2.2 Experiment Methodology
A B30 blend of 15% castor and rapeseed each biodiesel and 70% diesel (C15R15)
has been directly selected from the previous research work using the MCDM technique for the identification of optimum percentage of duel biodiesel based on their
performance, combustion and emission characteristics. In the current experiment,
water has been added as an additive in the range of 0–5% with an interval of 1%
for the preparation of W/O (water in oil)-type emulsified biodiesel–diesel blend. A
mixture of lipophilic and hydrophilic has been chosen as a surfactant in a range of
0–3% with an interval of 1%, and the hydrophilic–lipophilic balance (HLB) ratio
has been selected as 4.3, 5 and 6. SPAN 80 (Sorbitan monooleate) (HLB 4.3) and
TWEEN 80 (Polysorbate 80) (HLB 15.0) are chosen as a surfactant. A combination
of all the abovementioned ranges of water, surfactant and HLB ratio has been considered for the selection of best stable blend, which is blended for 4 h at 3000 RPM
using mechanical stirrer at room temperature. All the experiments were carried out
with a constant 20° BTDC of injection timing, 220 bar of injection pressure, and
18-compression ratio has been directly selected from the previous research work [9].
The engine has been operated at various loading conditions such as 0–100% load
with an interval of 25% and with 10% overloading at 110% having 0–12 kg load with
an interval of 3 kg and an overload of 13.2 kg for all the emulsified stable blends.
95% of confidence level has been maintained by taking readings six times as per the
student-t chart.
3 Result and Discussion
3.1 Stability Analysis
The stability of emulsified fuel can be defined as the property of fuel in which the
mixture of additives and fuel keeps themselves in a homogenous state with respect
to time and surrounding temperature. The stability of two-phase W/O emulsion has
been calculated based upon the separation percentage and volumetric sedimentation
of the water and biodiesel–diesel blend as per ASTM D3707-89 and D3709-89. The
stability of the emulsified fuel depends on the emulsification technique, process time,
water concentration, quantity of surfactant and stirring intensity. At every interval
of every 1 h, the separation percentage of the emulsion is observed and recorded.
The separated percentage of water in emulsified fuel gets settled at the bottom of the
measuring cylinder, which is prepared from various blends with a variation in HLB
ratio and surfactant percentage.
The most stable blend among the abovementioned range of HLB and surfactant
percentage is found to be HLB 6 and 2% surfactant. The droplet diameter of the
micro-emulsions is found to be 1.68 µm, and it should not vary away from 0.1 to
20 µm. Figure 3 shows only water percentage variation from 1 to 5% with HLB 6
S. Chourasia et al.
2.2 Experiment Methodology
A B30 blend of 15% castor and rapeseed each biodiesel and 70% diesel (C15R15)
has been directly selected from the previous research work using the MCDM technique for the identification of optimum percentage of duel biodiesel based on their
performance, combustion and emission characteristics. In the current experiment,
water has been added as an additive in the range of 0–5% with an interval of 1%
for the preparation of W/O (water in oil)-type emulsified biodiesel–diesel blend. A
mixture of lipophilic and hydrophilic has been chosen as a surfactant in a range of
0–3% with an interval of 1%, and the hydrophilic–lipophilic balance (HLB) ratio
has been selected as 4.3, 5 and 6. SPAN 80 (Sorbitan monooleate) (HLB 4.3) and
TWEEN 80 (Polysorbate 80) (HLB 15.0) are chosen as a surfactant. A combination
of all the abovementioned ranges of water, surfactant and HLB ratio has been considered for the selection of best stable blend, which is blended for 4 h at 3000 RPM
using mechanical stirrer at room temperature. All the experiments were carried out
with a constant 20° BTDC of injection timing, 220 bar of injection pressure, and
18-compression ratio has been directly selected from the previous research work [9].
The engine has been operated at various loading conditions such as 0–100% load
with an interval of 25% and with 10% overloading at 110% having 0–12 kg load with
an interval of 3 kg and an overload of 13.2 kg for all the emulsified stable blends.
95% of confidence level has been maintained by taking readings six times as per the
student-t chart.
3 Result and Discussion
3.1 Stability Analysis
The stability of emulsified fuel can be defined as the property of fuel in which the
mixture of additives and fuel keeps themselves in a homogenous state with respect
to time and surrounding temperature. The stability of two-phase W/O emulsion has
been calculated based upon the separation percentage and volumetric sedimentation
of the water and biodiesel–diesel blend as per ASTM D3707-89 and D3709-89. The
stability of the emulsified fuel depends on the emulsification technique, process time,
water concentration, quantity of surfactant and stirring intensity. At every interval
of every 1 h, the separation percentage of the emulsion is observed and recorded.
The separated percentage of water in emulsified fuel gets settled at the bottom of the
measuring cylinder, which is prepared from various blends with a variation in HLB
ratio and surfactant percentage.
The most stable blend among the abovementioned range of HLB and surfactant
percentage is found to be HLB 6 and 2% surfactant. The droplet diameter of the
micro-emulsions is found to be 1.68 µm, and it should not vary away from 0.1 to
20 µm. Figure 3 shows only water percentage variation from 1 to 5% with HLB 6