Development of sulfonated carbon-based catalysts from glycerol and cow dung for biodiesel production from high free fatty acid oils
In this research, cost efficient and environmental friendly sulfonated carbon-based catalyst was prepared from glycerol (CG) and cow dung (CD) and subsequently functionalized with concentrated sulfuric acid (H2SO4) at different sulfonation time. The physico-chemical properties of the prepared cat...
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| Format: | Thesis |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/104332/1/SHATESH%20KUMAR%20AL%20SANGAR%20-%20IR.pdf |
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| Summary: | In this research, cost efficient and environmental friendly sulfonated carbon-based
catalyst was prepared from glycerol (CG) and cow dung (CD) and subsequently
functionalized with concentrated sulfuric acid (H2SO4) at different sulfonation time.
The physico-chemical properties of the prepared catalysts were characterized by using
X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), X-ray
photoelectron spectroscopy (XPS), temperature programmed desorption-ammonia
(TPD-NH3), Thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET)
surface area, variable pressure scanning electron microscope (VPSEM), high resolution
transmission electron microscopy (HR-TEM), X-ray Fluorescene (XRF) analysis and
CHNSO elemental analysis. The carbon that was sulfonated with H2SO4 for 10 h (SCG-
(10) and SCD-(10) catalysts) were chosen to be used in optimization studies due to the
synergistic effect of good physicochemical properties including high amount of acid
sites and sulfur attached to carbon. The amount of sulfur and total acidity were
increased significantly after being sulfonated at different time of reflux; whereas, the
SCG-(10) and SCD-(10) catalysts showed the highest total amount of acidity 35117.14
μmol/g and 16653.49 μmol/g, respectively. The esterification of palm fatty acid
distillate (PFAD) over SCG-(10) catalyst was optimized via the one-variable-at-a-time
technique, and fatty acid methyl ester (FAME) of 97.8% was achieved at optimum
conditions of 1 h reaction time, 90 °C reaction temperature, 5 wt% catalyst loading, and
18:1 methanol-to-oil molar ratio. The SCG-(10) catalyst was successfully reused for 7
cycles and it was found that the catalytic activity maintained with >96% of FAME yield
for the first three run. The synthesized PFAD-derived biodiesel has complied with the
international biodiesel standards of EN14214 and ASTM D6751. The amount of sulfur
in biodiesel are lower than the maximum limit of ASTM D6751. Taguchi approach
using four parameters at four-level, L-16 (44) of experiment design was employed to
compare the experimental results. Reaction temperature was the most influenced
control parameter on biodiesel production with high S/N ratio and F-value. The optimum conditions for the highest biodiesel production was at reaction temperature at
level 4 (90 ℃), methanol to PFAD molar ratio at level 3 (18:1), catalyst loading at level
4 (6 wt. %) and reaction time at level 3 (1.5 h). As SCG-(10) catalyst showed super
catalytic performance in esterification of PFAD, it also been used for simultaneous
esterification-transesterification of waste cooking oil (WCO) and chicken fat oil (CFO).
The methyl ester production from WCO and CFO were also successfully performed by
using SCG-(10) catalyst and obtained FAME yield 92.3% (optimum conditions of 5 wt%
catalyst loading with 22:1 methanol to WCO molar ratio for 3 h reaction time and 100
℃ reaction temperature) and 90.8% (optimised conditions of 5 wt% catalyst loading
with 18:1 methanol to CFO molar ratio for 1 h reaction time and 70 ℃ reaction
temperature), respectively. In addition, SCD-(10) catalyst was used in esterification of
PFAD and achieved high FFA conversion of 96.5% at optimum parameter of 18:1
methanol to PFAD molar ratio, 4wt% of catalyst loading and 90 °C reaction
temperature within 1 h reaction time. SCD-(10) catalyst is capable to convert PFAD to
biodiesel with FFA conversion >90% for 3 consecutive cycles. As a conclusion, both
SCG-(10) and SCD-(10) catalysts can be easily recovered, impressive catalytic activity
and efficient for biodiesel production with high reusability. |
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