Turning trash into treasure: Torrefaction of mixed waste for improved fuel properties. A case study of metropolitan city
Muhammad Umar Farooq,
Khadija Sadiq,
Mehwish Anis,
Ghulam Hussain,
Muhammad Usman,
Yasser Fouad,
M.A. Mujtaba,
H. Fayaz,
A.S. Silitonga
Affiliations
Muhammad Umar Farooq
Institute of Environmental Engineering and Research, University of Engineering and Technology Lahore, P.O. Box 54980, Pakistan
Khadija Sadiq
Institute of Environmental Engineering and Research, University of Engineering and Technology Lahore, P.O. Box 54980, Pakistan
Mehwish Anis
Institute of Environmental Engineering and Research, University of Engineering and Technology Lahore, P.O. Box 54980, Pakistan
Ghulam Hussain
Institute of Environmental Engineering and Research, University of Engineering and Technology Lahore, P.O. Box 54980, Pakistan
Muhammad Usman
Department of Mechanical Engineering, University of Engineering and Technology Lahore, P.O. Box 54980, Pakistan
Yasser Fouad
Department of Applied Mechanical Engineering, College of Applied Engineering, Muzahimiyah Branch, King Saud University, P.O. Box 800, Riyadh, 11421, Saudi Arabia
M.A. Mujtaba
Department of Mechanical Engineering, University of Engineering and Technology (New Campus), Lahore, 54890, Pakistan
H. Fayaz
Modeling Evolutionary Algorithms Simulation and Artificial Intelligence, Faculty of Electrical and Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, Viet Nam; Corresponding author.
A.S. Silitonga
Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW, 2007, Australia; Center of Renewable Energy, Department of Mechanical Engineering, Politeknik Negeri Medan, 20155, Medan, Indonesia
Solid waste management is one of the biggest challenges of the current era. The combustible fractions in the waste stream turn out to be a good energy source if converted into refuse-derived fuel. Researchers worldwide are successfully converting it into fuel. However, certain challenges are associated with its application in gasifiers, boilers, etc. to co-fire it with coal. These include high moisture content, low calorific value, and difficulty to transport and store. The present study proposed torrefaction as a pretreatment of the waste by heating it in the range of 200 °C–300 °C in the absence of oxygen at atmospheric pressure. The combustible fraction from the waste stream consisting of wood, textile, paper, carton, and plastics termed as mixed waste was collected and torrefied at 225 °C, 250 °C, 275 °C, and 300 °C for 15 and 30 min each. It was observed that the mass yield and energy yield decreased to 45% and 62.96% respectively, but the energy yield tended to increase by the ratio of 1.39. Proximate analysis showed that the moisture content and volatile matter decreased for torrefied samples, whereas the ash content and fixed carbon content increased. Similarly, the elemental analysis revealed that the carbon content increased around 23% compared to raw samples with torrefaction contrary to hydrogen and oxygen, which decreased. Moreover, the higher heating value (HHV) of the torrefied samples increased around 1.3 times as compared to the raw sample. This pretreatment can serve as an effective solution to the current challenges and enhance refuse-derived fuel's fuel properties.
