Slurry Reactor

MINOR ASSIGNMENT

Hydrogenation of p-Nitrophenol to p-Aminophenol on Pd/Carbon Catalysts in a Slurry Reactor

Part 1 Background

1.1 Background P-Aminophenol(PAP) is one kind of phenolic compound, which is an intermediate in the synthesis of paracetamol and acetanilide, phenacetine. P-Aminophenol is very important for agriculture, pigments, engineering polymers and pharmaceutical industry(Vaidya, Kulkarni et al. 2003). Some methods have been reported to synthesize p-Aminophenol, such as using nickel nanoparticles and hydrogenation of nitrobenzene. The problems of these methods are that they are highly corrosive mineral acid or they may form same Fe-FeO sludge(Wang, Yin et al. 2009). Because the growing demand of p-Aminophenol, it is important to explore an efficient and green route. Scientists and engineers are seeking different ways to solve this problem. The direct catalytic hydrogenation of p-Aminophenol could be an efficient method for the preparation of p-aminophenol. The kinetics, controlling mechanism and adsorption isotherms of this process has been reported (Choudhary, Sane et al. 1998; Choudhary and Sane 1999). There are several ways to synthesis p-Aminophenol, such as nitrobenzene to p-aminophenol under Pt/C catalyst (Min, Choi et al. 2008). This reaction is carried out in continuous stirred tank reactors (CSTR). Another example to synthesize p-Aminophenol is to using titania structure on Ni/TiO2 Catalysts for p-Nitrophenol hydrogenation(Chen, Du et al. 2006). Due to cheap price and high catalytic activity of Ni catalyst, it has been used widely in chemical reaction. Moreover, Ni catalyst is easy to remove from slurry reactor. Chen states in his work that it is important to choose catalyst for slurry reaction(Chen, Du et al. 2007). The result shows that TiO2 has significant effect on the dispersion and reduction behavior of titania supported nickel catalyst. Recently years, nano-catalyst was researched in hydrogenation. Nano-Ni catalyst shows higher...