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Microchannel technology intensifies distillation process


Fig. 1.


Microchannel process technology shows great promise for increasing efficiency and reducing energy use in industrial processes ranging from biofuels production to the production of chemicals. Now it is being applied to intensify distillation processes. Laura Silva explains how.


Velocys uses microchannel slabs,


rather than cylinders, with single channel diameters ranging from 0.1–10mm.


are simple, the huge distillation units and tall distillation columns that do the job in refineries and chemical plants are very inefficient. The efficiency of conventional distillation technologies is just 24–40 per cent. This, in turn, bumps up energy consumption, with all that that implies in terms of cost and environmental footprint. Bearing in mind that separations account for 60 per cent of the energy used in the chemical and petroleum refining industries and of that 95 per cent, or nearly 6 per cent of total US energy consumption, is used for distillation, finding ways improving the efficiency of distillation processes is a very worthwhile goal. Microchannel technology is one promising way forward. This developing field of chemical processing, which involves reducing the dimensions of reactor systems, is a form of process intensification that works by minimising heat and mass transfer limitations. This, in turn, results in more rapid production rates. Devices using microchannel technology are characterised by parallel arrays of microchannels with diameters in the range of


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istillation plays a key role in many process chemical and refining applications. Although the principles behind distillation


0.1–5.0mm. In microchannel devices processes are accelerated 10- to 1000-fold by reducing heat and mass transfer distances and decreasing transfer resistances between process fluids and channel walls. This process intensification makes it possible to optimise capital, energy, environmental and safety benefits, and to significantly decrease equipment size/ production-capacity ratio, energy consumption and waste production. Like the microelectronics that revolutionised the computer industry, microchannel technology shrinks the hardware while at the same time improving performance. When applied to distillation, microchannel technology offers the potential for great improvements in efficiency for a number of distillation applications, and enables the efficient, cost-effective distributive distillation at industrial scales. Its environmental credentials are also impressive. Microchannel distillation can significantly reduce energy consumption and greenhouse gas emissions from both the


petroleum (7.174 exajoules (EJ); 305 MMTCO2) and the chemicals (6.86 EJ; 316 MMTCO2) industries – the two most energy-intensive industries now operating.


In conventional distillation towers bulk quantities of liquids and gases come into contact on trays or in packing. In contrast, in


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