Heat process intensification

C.H. (1997) Compact heat exchangers as chemical reactors for process intensification (PI). Process Intensification in Practice, BHR Group Conference Series, Publication No. 28, pp. 175-189. 

Anxionnaz, Z., Cabassud, M., Gourdon, C., and Tochon, P. (2009) Hydrodynamic study and optimisation of the geometry of a heat exchanger/reactor. 2nd European Process Intensification Conference 2009, Venice. 

For the sake of developing commercial reactors with high performance for direct synthesis of DME process, a novel circulating slurry bed reactor was developed. The reactor consists of a riser, down-comer, gas-liquid separator, gas distributor and specially designed internals for mass transfer and heat removal intensification [3], Due to density difference between the riser and down-comer, the slurry phase is eirculated in the reactor. A fairly good flow structure can be obtained and the heat and mass transfer can be intensified even at a relatively low superficial gas velocity. 

In practice, the process regime will often be less transparent than suggested by Table 1.4. As an example, a process may neither be diffusion nor reaction-rate limited, rather some intermediate regime may prevail. In addition, solid heat transfer, entrance flow or axial dispersion effects, which were neglected in the present study, may be superposed. In the analysis presented here only the leading-order effects were taken into account. As a result, the dependence of the characteristic quantities listed in Table 1.5 on the channel diameter will be more complex. For a detailed study of such more complex scenarios, computational fluid dynamics, to be discussed in Section 2.3, offers powerful tools and methods. However, the present analysis serves the purpose to differentiate the potential inherent in decreasing the characteristic dimensions of process equipment and to identify some cornerstones to be considered when attempting process intensification via size reduction. 

A detailed characterization of micro mixing and reaction performance (combined mixing and heat transfer) for various small-scale compact heat exchanger chemical reactors has been reported [27]. The superior performance, i.e. the process intensification, of these devices is evidenced and the devices themselves are benchmarked to each other. 

Phillips, C. H., Development of a novel compact chemical reactor-heat exchanger, in Green, A. (Ed.), Proc. of 3rd Int. Conf on Process Intensification for the Chemical Industry, BHR Group Conference Series, Vol. 38, pp. 71-87, Professional Engineering Publishing (1999). 

Microreactor and microprocess technology has, in some fine-chemical cases, approached commercial applications and become competitive with existing technology. Two main developments are awaited. Firstly, optimizing the process protocol conditions such that the chemistry is set to the limit of the reactor s capabilities in terms of mass and heat transfer. This so-called novel chemistry approach achieves the highest process intensification and can improve the costing of microprocess... 

In recent years, micro-structured reactors have attracted considerable attention for a variety of applications [61, 62]. Such micro devices are characterized by a laminar flow, and the very high surface-to-volume ratio they provide leads to increased mass and heat transfer, offering the potential for process intensification. 

Heat transfer has been identified by Rlay 13 as an important area in which process intensification is expected to offer major benefits in terms of energy efficiency, pollution control and plant operating costs. So-called passive techniques including modifying the walls of a plant unit, for example, are routinely used to improve heat transfer coefficients in... 

JACHUCK, R. J. J. and Ramshaw, C. Heat Recovery Systems CHP 14 (5) (1994) 475. Process intensification heat transfer characteristics of tailored rotating surfaces. 

Aoune A, Ramshaw C. Process intensification heat and mass transfer characteristics of liquid films on rotating discs. Int J Heat Mass Transfer 1999 42 2543-2556. 

Gilchrist K, Lorton R, Green RJ. Process intensification applied to aqueous Li B+ rotating absorption chiller with dry heat rejection. 7th UK National Conference on Heat Transfer, Nottingham, U.K., Sept. 10-12, 2001. 

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