| dc.description.abstract | Agricultural waste is considered an alternative energy resource, in addition to raw biomass. Besides serving as an energy source, agricultural waste is environmental friendly and cost-effective. This study provided a complete analysis and conversion process of Jatropha de-oiled cake. Starting from the pyrolysis of the Jatropha waste, the pyrolysis products (liquid and solid) were upgraded into more valuable energy products using thermo-chemical and physico-chemical treatments.
Atmospheric pyrolysis of Jatropha residue yielded 12% of bio-oil, 24% of aqueous product, 38% biochar, and 15.7% syngas. The heating values of bio-oil, biochar, and gaseous product were obtained at 33, 28, and 1.2 MJ/kg, respectively. The properties of liquid product suggested the possibility to use it as biofuel but further upgrading process would be needed to improve the quality. Likewise, biochar, a carbonrich material, was considered a precursor for the activated carbon production.
The response surface method was used to identify the effects of activation parameters (impregnation ratio, activation temperature, and time) on activated carbon yields and characteristics. Highest yield (69.8%) was achieved with the highest ratio between biochar and KOH (1.8) and lowest activation temperature (600oC). The surface area of activated carbon was significantly improved from pyrolysis biochar (1.51 m^2/g). The optimum surface area of 285 m^2/g was achieved. The adsorption ability analysis showed that the activated carbon with highest surface area could remove 90.3% of Acetaminophen from the solution.
Fractional distillation of bio-oil revealed the effectiveness of removing the water from the bio-oil. The qualities of organic distillate fractions were significantly improved from the original bio-oil such as low moisture content, low acidity, and high heating value. However, the separation of aqueous phase indicated that the major compounds in the aqueous phase were water, oxygenates and nitrogenates. The catalytic hydrotreatment of bio-oil distillate using Pd/C as a catalyst showed an improvement in product qualities. The optimum condition was achieved at 200°C with the highest upgraded bio-oil yield of 64.9%. The upgraded products from both fractional distillation and catalytic upgrading suggested a potential useful source of fuels.
The overall mass and energy conversion efficiencies for energy conversions process of Jatropha waste were achieved at 74.3% and 54.5%, respectively. The CO2 emissions due to the electricity consumed during the productions of activated carbon, bio-oil distillate (BD1), and the hydrotreating distillate were found at 4.3, 0.43, and 1.8 g CO2 de-oiled cake, respectively. The obtained positive NER and NEB values referred to the effectiveness and sustainability of the energy production system. | en |
