Multi-stage adsorption

Let us mention Ya.B. s contribution to the theory of multi-stage adsorption, reflected in his Candidate of Sciences thesis. 

A multi stage adsorption process is also assumed by Leykin et al. [85]. Prior to the increased uptake of the protic electrolyte by multilayer-like adsorption according to the GAB model in stage (2) is the protonation of the polymer chains in stage (1). An analogue... 

Design variations are used to recover paraxylene efficiently from feedstocks (-22% PX) in a multi-stage system, competitive with adsorption-based systems. 

There are two obvious ways of removing the remaining hydrocarbon contamination. Multi-stage stripping could be used but the most economical and simplest method is to add a carbon bed adsorption step to the process as indicated in Figure 1. Carbon bed removal can be justified only in conjunction with the evaporator system where the hydrocarbon contamination is very low. The concentration of soluble organic components in a system where the evaporator is not used is simply too high and the bed is exhausted too quickly. 

Feed concentration of PX is used efficiently Technology is flexible to process a range of feed concentrations (75 wt%-95 wt% PX) using a single refrigeration system Design variations are used to recover paraxylene efficiently from feedstocks (-22% PX) in a multi-stage system, competitive with adsorption-based systems. 

Rates of adsorption of HgTeOg and H3PO4 on alumina have been studied under varying pH conditions at 25 The experimental data were interpreted in terms of a multi-stage reaction, dominated by dissociative processes on the alumina. The assumed reaction of surface ions with anions in solution was rd order in relation to acids, suggesting that the loose surface complexes have unrestricted orientation of anions. 

Separations involving phase transfer distillation, sublimation, liquid-liquid distribution, gas-solid, and liquid-solid adsorption, both single and multi-stage. 

Redox reactions at the interface between immiscible liquids fall into two classes. The first class includes spontaneous processes that occur in the absence of external electromagnetic fields. This type of redox transformation has been investigated in bioenergetics [2], model membrane systems [20] and at oil/water interfaces [1]. Redox reactions in the second class occur at the interface between immiscible electrolytes when external electrical fields are applied to the interface, and under these conditions interfacial charge transfer reactions take place at controlled interfacial potentials [11, 35, 36]. Such electrochemical interfacial reactions are usually multi-stage processes that proceed through five stages (i) diffusion of reactants to the interface (ii) adsorption of reactants onto the interface (iii) electrochemical reaction at the interface (iv) desorption of products from the interface (v) diffusion of products from the interface. 

In the reverse flow type, the hydrotreater reactor is fed with fresh and recycled feeds, and is operated to accomplish partial conversion of that combined feed in the first stage. A graded HDT-HCK bed or a multi-functional catalyst can be used in the first stage. A very effective H2 separation is used for the first-stage effluent gas. A bottoms fractionator or an adsorption unit is used for removal of heavy PAHs. Carbon adsorption extends the catalyst life. The liquid product of the first reactor is mixed with a mixture of fresh and recycled H2. The whole second stage effluent is hydrotreated in the first stage. 

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