Public defence: Rajan Jaiswal

Rajan Jaiswal is defending his thesis for the degree philosophiae doctor (PhD) at the University of South-Eastern Norway.

The doctoral work has been carried out at the Faculty of Technology, Natural Sciences and Maritime Sciences in the program Process, Energy and Automation Engineering.

• Read the thesis here

You are invited to follow the trial lecture and the public defence.

Summary

This PhD work explores the utilization of wastes for energy recovery, aiming to address two global problems: waste management issues and supply for the clean energy demand. The project investigates various challenges encountered when converting wastes to high calorific value feedstock and utilizing such feedstock for energy recovery. Thermal conversion methods, in a gasification rector, have been employed for converting wastes into a valuable product gas. The main combustible gas components from the gasification process are methane, hydrogen, and carbon monoxide, which can be useful for producing biofuels and chemicals or for power generation. The feedstocks from various sources, such as municipal solid wastes, agricultural wastes, garden residue, and industrial wastes, were used as fuel for the gasifier. The low-grade waste feedstocks, paper, fish, garden residue, sawdust, coffee grounds, barley straw, bark, and grass were densified in the pellet form to obtain an enhanced calorific value fuel and better flowability to the gasifier. The syngas production potential of each feedstock and the reactor performance at different reactor operating conditions were assessed based on the carbon conversion efficiency, chemical conversion efficiency, thermal conversion efficiency, and gas yield strengths.

This thesis proposes the optimal parameters necessary for producing mechanically strong and durable pellets with higher calorific value derived from wastes. Similarly, the project employs both experimental techniques and Computational Particle Fluid Dynamic (CPFD) simulations to investigate syngas production potential via gasification of wastes at different operating conditions such as reactor operated in an auto-thermal mode, allothermal mode, different biomass feeding positions, and gasification with different gasifying agents. This project delineates optimal reactor operating conditions required to obtain high quality syngas at different conditions. Furthermore, a robust model has been developed based on the gas velocity to the reactor, which can be used to design a gasifier and set operational parameters to achieve optimum waste gasification.