Liquid-fed Aerosol Reactors for One-step Synthesis of Nano-structured Particles

Abstract

Aerosol technology is the key process for large-scale production of nano-structured materials such as carbon black, titania and silica. The understanding of gas-phase synthesis was transferred successfully from classic vapor-fed f lames to liquid-fed aerosol reactors, enabling now also the one-step production of demanding and highly functional products. Such aerosol-derived nano-structured metal oxides, mixed metal oxides, and metals on metal oxides find application in the fields of catalysis, sensors, fillers, and electronics, and have advanced the research and development of these reactors in recent years. The four main spray methods include spray pyrolysis in a tubular reactor (SP), spray pyrolysis using a vapor f lame reactor (VFSP), the emulsion combustion method (ECM) and f lame spray pyrolysis (FSP). These methods are discussed and key concepts are compared such as the energy source driving the solvent/fuel evaporation and precursor reaction, final particle formation. Advances in fundamental understanding, scaling and simulation are highlighted. Specific strategies for the production of homogeneous products are presented in context with existing methods and specific applications. Finally, research needs are discussed with respect to new f lame-made materials, instrumental strategies for their production and process optimization, including diagnostic techniques and process simulation.

Liquid Flame Spray—A Hydrogen-Oxygen Flame Based Method for Nanoparticle Synthesis and Functional Nanocoatings

“…Purwanto et al (2011) and Trommer and Bergmann (2015). The several alternative reaction schemes and particle formation mechanisms occurring in the FSP reactor when fabricating, e.g., metal oxide powder, has been discussed on a general level by Mädler (2004).…”

“…Especially flame methods are considered to be optimal for up-scaling (Kammler et al, 2001a;Stark and Pratsinis, 2002;Mueller et al, 2003). Thorough reviews on the flame spray pyrolysis (FSP) techniques for producing nanopowder have been made previously (Pratsinis, 1998;Mädler, 2004;Teoh et al, 2010). The FSP method generates well-defined nanoparticulate material which can be collected as a powder from the exhaust aerosol of the flame (Stepuk et al, 2013;Park and Park, 2015) or sprayed on a surface (Mishra et al, 2014).…”

Microstructure Sensitive Design and Processing in Solid Oxide Electrolyzer Cell

“…2 Spray pyrolysis is a versatile processing technique for preparation of dense and porous single and multi-layered films, ceramic coatings and powders of various materials and morphologies. 61 Classification of different spray processes could be made based on the type of energy source for the precursor reaction such as spray pyrolysis in a tubular reactor (SP), vapor flame reactor (VFSP), the emulsion combustion method (ECM) and flame spray pyrolysis (FSP) 62 or the method of atomizing the precursor, namely air pressurized, electrostatic and ultrasonic spray pyrolysis 63 . In the case that the energy source for precursor reaction is an external energy supply and not from the spray itself, (as in SP and VFSP), method is less sensitive to the choice of precursors and solvent.…”

“…In the case that the energy source for precursor reaction is an external energy supply and not from the spray itself, (as in SP and VFSP), method is less sensitive to the choice of precursors and solvent. 62 .…”

Alkaline-Earth Metal Carbonate, Hydroxide and Oxide Nano-Crystals Synthesis Methods, Size and Morphologies Consideration

“…FSP is usually applied for the preparation of metal and metal-oxide nanoparticles [37,38]. Recently it has been shown that also nanosized salts such as carbonates, phosphates and halogenides can readily be made by flame synthesis [39][40][41].…”