Microwave‐assisted pyrolysis (MAP) is a new thermochemical process that converts biomass to bio‐oil. Compared with the conventional electrical heating pyrolysis, MAP is more rapid, efficient, selective, controllable, and flexible. This chapter provides an up‐to‐date knowledge of bio‐oil production from microwave‐assisted pyrolysis of biomass. The chemical, physical, and energy properties of bio‐oils obtained from microwave‐assisted pyrolysis of biomass are described in comparison with those from conventional pyrolysis, the characteristics of microwave‐assisted pyrolysis as affected by biomass feedstock properties, microwave heating operations, use of exogenous microwave absorbents, and catalysts are discussed. With the advantages it offers and the further research and development recommended, microwave‐assisted pyrolysis has a bright future in production of bio‐oils that can effectively narrow the energy gap and reduce negative environmental impacts of our energy production and application practice.
Part of the book: Pyrolysis
Heat and mass transfer in outward convex corrugated tube heat exchangers is of significant importance for the optimization, fabrication, and application of outward convex corrugated tube heat exchangers. This chapter gives a deep investigation of the heat and mass transfer in outward convex corrugated tube heat exchangers. Based on the experimental setup developed, the performances of a novel outward convex corrugated tube heat exchanger are presented. Simulation methods are then used to detail the heat and mass transfer at tube side and shell side of the outward convex corrugated tube heat exchanger, and these include the flow structure, temperature distribution, and turbulence kinetic energy. Heat and mass transfer enhancements of the outward convex corrugated tube heat exchanger are also studied, and they are from tube side, shell side, and overall system aspects. Finally, multi-objective optimization of the outward convex corrugated tube heat exchanger is conducted to obtain the optimal performances through using Response Surface Methodology (RSM) and Non-dominated Sorting Genetic Algorithm (NSGA-II). Main conclusions and future outlook are then briefly stated and summarized. We firmly believe that the contents presented in this chapter can not only enrich the knowledge of heat exchangers but also develop methods for studying heat exchangers.
Part of the book: Heat and Mass Transfer