14 DAY TRIAL // Scientists are constantly looking for new techniques that can improve efficiency and provide better control of chemicals and development processes.
Until recently, chemical processing typically involved the use of conventional processing equipment that held relatively large amounts of materials in relatively large reactor vessels. If the reactions being performed were highly exothermic (heat-generating reactions), the possibility of runaway reactions leading to fires or explosions was high.
For instance, researcher Fernando Benito Lopez investigated the possibilities of the so-called lab-on-a-chip, a microreactor chip in which chemical reactions can take place under (high) pressure, with stationary and continuously flowing substances.
The first chip he designed was made of silicon fiber and could withstand a pressure up to 600 bar (about the same as atmospheric pressure)
Chemical reactions in such a chip took place under pressures ranging from 110 to 690 bar with continuously flowing substances. Increasing pressure and the rapid mixing were found to favorably affect the rate of the reaction, up to 1.7 times faster than the advanced, expensive conventional equipment.
Successful reactions were directed for pressures up to 600 bar and for volumes ranging from microliters to nanoliters. The combination of pressure and the reduced dimensions of the equipment were found to lead to faster reaction rates than in the equipment used to date, whilst the safety risks decreased significantly.
The results were very promising. The reaction rate increased compared to conventional equipment, the measurements were accurate and safety was not a problem.
Moreover, it was possible to follow and regulate the reaction during the process, without the need for a miniaturized Total Analysis System.
His chip has microchannel structures that contain a series of reagent injection ports, a diffusion mixing zone, a reaction area and an output port. It offers advantages for future applications, like the fact that the low mass of liquid in the chip at any moment allows reaction temperatures to be rapidly changed and tightly controlled, and any exotherms to be safely handled, making the microreactor ideal for reproductible reaction control.
This system could provide significant technical and cost benefits in process developments.