Separation energy efficiency

Short residence time, minimal downstream separation, energy efficient, zero waste, low inventory, improved intrinsic safety, improved process flexibility, reduced area required, rapid product grade change, rapid response to market needs, improved control. 

Linkage exists between separation energy efficiency and long-term environmental sustainability, and some facts help to clarify this connection. By United Nations estimates, the world currently has 6.7 billion global inhabitants and, only 1.2 billion people live in more-developed countries 1 such as North America, western Europe, and so on, while 5.5 billion reside in less-developed countries [2]. Estimates suggest... 

Recovery and Purification. AH processes for the recovery and refining of maleic anhydride must deal with the efficient separation of maleic anhydride from the large amount of water produced in the reaction process. Recovery systems can be separated into two general categories aqueous- and nonaqueous-based absorption systems. Solvent-based systems have a higher recovery of maleic anhydride and are more energy efficient than water-based systems. 

J. Douglas and A. Amamath, Free Concentration an Energy-Efficient Separation Process, EPRI Journal, p. 17,1989. 

Thus the concaster combines in a single process what previously took two separate processes. This is both highly energy-efficient and produces a better quality product. 

When the flowsheet is complex and involves numerous process steps, a low-energy efficiency will result. The metals titanium and magnesium are difficult to reduce, and their production involves chloride intermediates which are produced from the oxide raw materials. Titanium requires magnesium or sodium as the reducing agent, and these metals are themselves obtained by electrolytic processes which are energy-intensive. Another feature which may add to the complexity of the process flowsheet is the need to separate impurities and by-products using special processes this is the case with copper, lead, and nickel. 

Fig. 3. Current efficiency for hydrogen separation. Calculated overall energy efficiency vs. current density of hydrogen purification for conditions of Table 1 including reversible work O excluding reversible work.

The microwave technique has also been found to be a potential method for the preparation of the catalysts containing highly dispersed metal compounds on high-porosity materials. The process is based on thermal dispersion of active species, facilitated by microwave energy, into the internal pore surface of a microporous support. Dealuminated Y zeolite-supported CuO and CuCl sorbents were prepared by this method and used for S02 removal and industrial gas separation, respectively [5], The results demonstrated the effective preparation of supported sorbents by micro-wave heating. The method was simple, fast, and energy-efficient, because the synthesis of both sorbents required a much lower temperature and much less time compared with conventional thermal dispersion. 

Although SMR is a well-developed technology, there is room for further technological improvement, in particular, with regard to energy efficiency, gas separation, and H2 purification stages. 

There are two main issues concerning the chemistry of the reaction and the separation. One is how to separate the hydriodic acid and sulfuric acid produced by the Bunsen reaction. The other is how to carry out the hydrogen iodide (HI) decomposition section, where the presence of azeotrope in the vapor-liquid equilibrium of the hydriodic acid makes the energy-efficient separation of HI from its aqueous solution difficult, and also, the unfavorable reaction equilibrium limits the attainable conversion ratio of HI to a low level, around 20%. 

There are four principal factors that are paramount in selecting the best separation technique. They are the energy required for the separation, the capital required for the equipment used in the separation, the efficiency/effectiveness of the separation, and the vitality of the catalyst after the separation. General process considerations include ... 

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