Syngas production in a downdraft gasifier using food waste: a case study

ABSTRACT

The energy production potential of some common food waste, including cooked rice, “eba,” orange, yam, and potato peels, has been studied through thermodynamic modeling and simulation. The key gasification processes were modeled individually in ASPEN PLUS. The component properties were calculated with Peng-Robinson’s equation of state. The effect of the equivalence ratio (ER), steam-to-biomass ratio (STBR), and gasifier operating temperature on the composition, cold gas efficiency (CGE), and higher heating value (HHV) of the syngas was studied. Results revealed that the production of H₂ and CO₂ reduces with the increase in ER and increases with STBR. The molar fraction of CO is inversely proportional to that of CO₂. Increasing ER causes an increase in oxidizer within the gasifier and a corresponding increase in the molar fraction of N₂. Reduction in STBR reduces both the N₂ content and heating value of syngas. Syngas from both feedstocks has heating values ranging from 18.48 to 11.04 MJ/kg, with food waste yielding higher HHV than hardwood. The CGE for hardwood ranges from 55.6% to 74.95%, while for food waste, it ranges from 49.3% to 57%. This study demonstrates the production of high-quality syngas from locally sourced food waste.

KEYWORDS:

• Downdraft gasification
• ASPEN Plus simulation
• equivalence ratio
• steam to biomass ratio
• syngas production yield

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Mufutau Adekojo Waheed

Mufutau Adekojo Waheed is a Professor of Thermofluids in the Mechanical Engineering Department at the Federal University of Agriculture Abeokuta (FUNAAB). He holds a Doctor of Engineering Science Degree in Mechanical Engineering from the Aachen University of Technology (RWTH), Aachen, Germany. His research interests encompass heat and mass transfer, computational fluid dynamics, energy and exergy study, solar energy heating and cooling techniques, and biofuels. He has over 190 published articles and received several awards and recognition.

Olalekan Olaoluwa Olamide

Olalekan Olaoluwa Olamide is a Lecturer in the Department of Mechanical Engineering, Federal University of Agriculture, Abeokuta. He graduated from the University of Lagos (Nigeria) with a Master in Mechanical Engineering. His research interests include bioenergy, computational fluid dynamics, renewable energy and energy systems modelling and simulation.

Anthony Chijioke Adingwupu

Anthony Chijioke Adingwupu is a Senior Lecturer in the Department of Mechatronics Engineering, Igbinedion University, Okada. He holds a PhD in Mechanical Engineering from the University of Benin in Nigeria. His research interests are in applied energy, waste management, thermofluids and computational fluid dynamics.

Christopher Chintua Enweremadu

Christopher Chintua Enweremadu is a Professor in the Department of Mechanical Engineering, University of South Africa. He has more than 80 published articles in the field of renewable energy with several awards/recognition for his works in the same field. His research areas include biomass, alternative fuel (biogas, biodiesel and bioethanol) production, characterization and testing, solar energy and heat transfer.