Roles of Fluidization Technology in Thermal Engineering for a Sustainable Future

Over the last decade, the self-heat recuperation technology based on the exergy recuperation for innovative energy saving in which process heat is recuperated and recycled without adding heat has been developed and applied to various energy-intensive thermal and reaction processes such as drying, CO₂ chemical absorption, sea water desalination, chemical reaction systems, resulting in the reduction of energy consumption by a factor of 1/3-1/12 compared to conventional heat recovery. Self-Heat Recuperation Technology has been proved to be an effective method to cut the huge energy consumption in the chemical industry because of heat circulation. The minimum exergy required for heat circulation can be quantified by calculating the waste heat via exergy destruction due to heat transfer.

Fluidized beds have an excellent ability to rapid transfer heat and maintain a uniform temperature. Thus, the self-heat recuperative heat circulation system in the energy intensive process by using fluidized bed has a great potential for the energy saving. In this paper, the thermodynamic mechanism for exergy recuperative drying and evaporation processes by using fluidized bed is elucidated in terms of exergy analysis with thermodynamic identity and energy conversion equation in the vector notation for energy with exergy and anergy and the temperature – entropy (T-S) diagram which can express the inequivalence between work and heat and the irreversibility of the process due to the entropy generation. In addition, the exergy recuperative H₂ production system by using a internal circulating fluidized bed for the biomass gasification will be described.