A Study of the Production and Combustion Characteristics of Pyrolytic Oil from Sewage Sludge Using the Taguchi Method

Abstract

Sewage sludge is a common form of municipal solid waste, and can be utilized as a renewable energy source. This study examines the effects of different key operational parameters on sewage sludge pyrolysis process for pyrolytic oil production using the Taguchi method. The digested sewage sludge was provided by the urban wastewater treatment plant of Tainan, Taiwan. The experimental results indicate that the maximum pyrolytic oil yield, 10.19% (18.4% on dry ash free (daf) basis) by weight achieved, is obtained under the operation conditions of 450 °C pyrolytic temperature, residence time of 60 min, 10 °C/min heating rate, and 700 mL/min nitrogen flow rate. According to the experimental results, the order of sensitivity of the parameters that affect the yield of sludge pyrolytic oil is the nitrogen flow rate, pyrolytic temperature, heating rate and residence time. The pyrolysis and oxidation reactions of sludge pyrolytic oil are also investigated using thermogravimetric analysis. The combustion performance parameters, such as the ignition temperature, burnout temperature, flammability index and combustion characteristics index are calculated and compared with those of heavy fuel oil. For the blend of sludge pyrolytic oil with heavy fuel oil, a synergistic effect occurs and the results show that sludge pyrolytic oil significantly enhances the ignition and combustion of heavy fuel oil.

Biofuel and Bioenergy Technology

“…These products can be used for bio-briquette fuel production. Bio-oils can be synthesized from sewage sludge by using pyrolysis techniques [3]. Taguchi optimization suggested the best pyrolysis was performed at 450 • C, 60 min and 10 • C/min, which also showed consistency with other research work.…”

“…This Special Issue of Energies on the subject of "Biofuel and Bioenergy Technology" contains the successful invited submissions . A total of twenty-seven technical papers which cover diversified biofuel and bioenergy technology related researches have shown critical results and contributed significant findings in biomass processing [1,2], bio-oil and biodiesel [3][4][5][6][7][8][9][10][11], syngas [12][13][14], biogas/methane [15][16][17][18][19], bioethanol and alcohol-based fuels [20][21][22], solid fuel [23][24][25] and also microbial fuel cell [13,26,27] developments.…”

“…These findings suggest that simple blending could improve the properties of biodiesel or bio-oil tremendously, which is worthy of further investigation. Aside from using bio-oil as a precursor for biodiesel [3], biodiesel could be directly synthesized using other oil materials such as Australian native stone fruit oil [6], rapeseed oil [7], Rhodotorula glutinis [8] and soursop seed oil [9] via transesterification techniques. Transesterification of Australian native stone biodiesel showed a high yield of 95.8% with the response surface methodology optimization and its quality fulfilled the ASTM D6751 and EN14214 requirements [6].…”

Bioenergy Conversion Potential of Decaying Hardwoods

“…In order to have a better overview of the different combustion characteristics, three integrated indexes were computed [39,40].The ignition index (D i ) is calculated using Equation (2):…”

Techno-Economic Assessment of Three Modes of Large-Scale Crop Residue Utilization Projects in China

“…The density of the block is significantly enhanced, which is more favorable for storage and transportation. The molding block can be applied directly for burning, as well as used to generate gas, pyrolytic oil, or machine-made wood charcoal by combining it with a CR pyrolytic process [68]. However, the main barrier of the briquette process utilization lies in the extrusion machine.…”