Designing Microflowreactors for Photocatalysis Using Sonochemistry: A Systematic Review Article

Abstract

Use of sonication for designing and fabricating reactors, especially the deposition of catalysts inside a microreactor, is a modern approach. There are many reports that prove that a microreactor is a better setup compared with batch reactors for carrying out catalytic reactions. Microreactors have better energy efficiency, reaction rate, safety, a much finer degree of process control, better molecular diffusion, and heat-transfer properties compared with the conventional batch reactor. The use of microreactors for photocatalytic reactions is also being considered to be the appropriate reactor configuration because of its improved irradiation profile, better light penetration through the entire reactor depth, and higher spatial illumination homogeneity. Ultrasound has been used efficiently for the synthesis of materials, degradation of organic compounds, and fuel production, among other applications. The recent increase in energy demands, as well as the stringent environmental stress due to pollution, have resulted in the need to develop green chemistry-based processes to generate and remove contaminants in a more environmentally friendly and cost-effective manner. It is possible to carry out the synthesis and deposition of catalysts inside the reactor using the ultrasound-promoted method in the microfluidic system. In addition, the synergistic effect generated by photocatalysis and sonochemistry in a microreactor can be used for the production of different chemicals, which have high value in the pharmaceutical and chemical industries. The current review highlights the use of both photocatalysis and sonochemistry for developing microreactors and their applications.

Review of Experimental Setups for Plasmonic Photocatalytic Reactions

“…These reactors characterized by a small size, low power consumption, and waste reduction properties, rendering them green technologies. MOFC reactors [70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85] have been used in some photocatalytic reactions. Although they have low processing volume, MOFC reactors have features that contribute to high processing efficiency in many applications: (i) Their small fluid channel size results in a high mass transfer rate, thus enabling effective transportation of reactants and products.…”

Heterogeneous photocatalysis in flow chemical reactors

“…Coated reactors immobilise the HPCat as a thin film on the surface of channels within a microfluidic device [210,211]. Coated reactors overcome the disadvantages of fixed beds by permitting much greater freedom of design with respect to the channel dimensions and the flow paths.…”

Modelling of packed bed and coated wall microreactors for methanol steam reforming for hydrogen production

“…Microreactors have been employed for renewable fuel production due to certain benets, such as enhanced mass transfer, better temperature control leading to improved heat transfer and larger surface-area-to-volume ratios. 6,7 Recently microreactors for hydrogen production, from hydrocarbons, have been employed to provide the on-line hydrogen source for polymer electrolyte membrane fuel cells (PEMFCs). The advantages of microreactors make them desirable for highly exothermic and fast reactions.…”

“…The advantages of microreactors make them desirable for highly exothermic and fast reactions. [7][8][9][10] As a result, microreactors have demonstrated a promising outlook for hydrogen production. 11 The type of microreactor used for methanol steam reforming reaction signicantly inuences the fuel conversion and reaction efficiency.…”