Nanoparticle production processes reactors

Another difference between Co and Fe is their sensitivity towards impurities in the gas feed, such as H2S. In this respect, Fe-based catalysts have been shown to be more sulfur-resistance than their Co-based counterparts. This is also the reason why for Co F-T catalysts it is recommended to use a sulphur-free gas feed. For this purpose, a zinc oxide bed is included prior to the fixed bed reactor in the Shell plant in Malaysia to guarantee effective sulphur removal. Co and Fe F-T catalysts also differ in their stability. For instance, Co-based F-T systems are known to be more resistant towards oxidation and more stable against deactivation by water, an important by-product of the FTS reaction (reaction (1)). Nevertheless, the oxidation of cobalt with the product water has been postulated to be a major cause for deactivation of supported cobalt catalysts. Although, the oxidation of bulk metallic cobalt is (under realistic F-T conditions) not feasible, small cobalt nanoparticles could be prone to such reoxidation processes. 

A simple microfluidic reactor system He et al. [124] for the effective synthesis of enzyme-functionalized nanoparticles offers many advantages over batch reactirais, including excelloit enzyme efficiencies. Better control of the process parameters in the microfluidic reactor system ovct batch-based methodologies enables the production of silica nanoparticles with the optimum size for efficient enzyme immobilization with long-term stability. The synthetic approach used glucose oxidase and two different nucleation catalysts of similar molecular mass the natural R5 peptide, and PEI polymer... 

The higher levels of control provided by the microreactors over the reaction parameters as compared to the conventional batch method and the production of pure phase copper sulfide nanoparticles in less than 3 seconds makes this method very attractive. The copper(II) complex of 1,1,5,5-tetra-iso-propyl-2-thiobiuret was used as a single source precursor for the synthesis of copper sulfide nanoparticles in a continuous flow process. " The nanoparticles had spherical morphology and were produced either as a pure CU7S4 or CU7S4 with minor impurities of CU9S5. Fig. 8 shows a schematic diagram of the flow reactor used by O Brien et al. ... 

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