Intensification Equipment
The achievement of PI relies on the enhancement by orders of magnitude of process equipment performance by active (e.g. agitation, vibration and rotation) or passive methods (e.g. roughening of surfaces, addition of fins, machining of grooves). In order for it to be successful, it must be capable of being applied to all types of process equipment i.e. reactors, mixers, separators and heat transfer equipment such that an entire plant and all of it's unit operations would be intensified. Almost all unit operations employ some form of heat and/or mass transfer so enhancing these transport properties is the key to process intensification.
Protensive is active in developing intensified process equipment for a whole range of unit operations. Because these devices are compact, they may find themselves not just for industrial uses but for light commercial and built environment applications. Protensive offer a number of 'off-the-shelf' units capable of performing heat and mass operations for laboratory and plant operations as well as having the expertise in delivering one-off equipment design, construction and commissioning of process intensification applications across the spectrum. Below is a rundown of the applications, the Company have expertise in and are currently developing.
Catalytic Plate Reactors offer the possibility of intensifying a number of industrial gas phase reactions as well as the opportunity for in-situ reforming fuel feedstocks for commercial fuel cell applications.
Narrow channelled microreactors offer opportunities as processing equipment for rapid reactions in heterogeneous liquid-liquid reactions. Narrow channels can be manufactured by a variety of methods to give a channel width in the region of 10 to 1000mm. The channels may be etched (mechanically or chemically) into metal, glass or plastic sheets. A sheet is placed on top to enclose the channel. In addition, a capillary tube may be employed in the same fashion. The potential of these microreactors as compact portable devices in the CPI is for high value, low volume products, with such a role in pharmaceutical development and manufacture or in the inherently safe processing of exothermic products. It is possible that micro-electronic components (e.g. miniature pumps, valves and sensors) could be incorporated within the channels creating a truly miniature process/laboratory facility on (say) a credit card sized unit, commonly known as "lab-on-a-chip".
Polymer Film Compact Heat Exchangers are an exciting development for heat transfer applications. The use of compact heat exchangers has been employed in industry for decades and therefore could be regarded as a mature field in intensification know-how. Plate-frame, plate-fin in cross-flow and counter-current flow arrangements or spiral configurations have a much larger heat transfer surface per unit area than conventional shell and tube types. Cross-corrugated heat exchangers are very compact and have the advantage of high mechanical strength. Flow passages associated with compact heat exchangers are typically small (Dh < 5mm) and the flow is usually laminar. These cross-corrugated types have conventionally been manufactured from metal, however it has been demonstrated that they can been made of thin corrugated sheets of polymer such as PEEK (Poly Ether Ether Ketone) and perform exceptionally well. The thin sheets (approximately 100mm thick) facilitate a low conduction resistance. PEEK offers mechanical strength and robustness capable of withstanding 10bar pressure at room temperature and operates up to 220oC along with exhibiting excellent corrosion resistance.
A rotating packed bed (RPB) or "Higee" mass transfer machine has different shape and operation mode to a conventional packed tower design. By imposing high acceleration fields upon the fluids, thinner mass transfer films result in higher rates of mass transfer when coupled with packings of high voidage and high specific surface area. Mass transfer operations e.g. distillation, absorption, stripping and liquid-liquid extraction found in conventional packed towers can be carried out in a RPB.
Spinning disc reactors (SDR) are capable of operating as a multifuction device. The disc can be horizontally or vertically mounted on an axle. Liquid fed near or at the centre flows across the surface of a spinning disc under the influence of centrifugal force. This force stretches and contorts the film. The thin liquid films allows for high rates of mass transfer such that it favours absorption, stripping, mixing and reaction processes. Residence times on the disc are low, typically in the range of 3 seconds down to tenths of a second. Both film thickness and residence time are dependent on fluid physical properties, rotational speed and radial location of the fluid. On exiting the periphery of the disc, the liquid is thrown onto an enclosing wall whereupon it drains away. Heating or cooling can be applied to the disc surface and the enclosing wall in order to control fluid temperature.