Ideal for fine chemicals and pharmaceuticals
A simple calculation graphically illustrates the efficiency of the continuous process: if a continuous flow reactor yields 10 kilograms of product per hour and operates for 8,000 hours a year, it will have produced 80 metric tons by the end of a 12-month period. In a conventional batch process on a comparable scale, the yield is 100 kilograms per production run, but the latter takes perhaps two days. At the end of around 350 working days, that amounts to a mere 18 metric tons of product. With the use of new types of micromixer, such as those developed at the Institut fuer Mikrotechnik Mainz or the Wendelsheim-based company Ehrfeld, it is now possible to process more than 400 litres of liquid an hour in a production plant the size of a person. For the majority of its products, however, Merck in Darmstadt doesn’t require such a large capacity. Here the main focus is on the production of small amounts of high-grade specialty chemicals and pharmaceuticals made of very expensive raw materials. Yet operating on such a small scale also creates other challenges. “The plants must not only be very efficient but also highly flexible, so that they can be used to make as many different products as possible,” explains Schmalz.
When devising new methods of synthesis, developers are aided by the fact that such microsystems are made up of various modules, each of which forms a different functional unit. Mixers, heat exchangers, reactors, and control components can be combined as required, much in the manner of building blocks. Using such a modular system, it is easy to try out new production methods and vary with them until the optimum has been achieved. Likewise the time-consuming process of scaling up production is also unnecessary with microreaction technology. Once the process has been set up, it can be “equalled up” relatively simply in order to achieve a greater output of consistent quality.
Yet does this spell the end for classic lab apparatus such as the three-necked flask and the test tube? And has the classic batch reactor served its time? Not at all, says Schmalz. As he explains, the traditional methods will still have their place, particularly when long reaction times are necessary or when the reaction results in byproducts that might cause a blockage in the ultra fine channels of a microreactor. Moreover, when it comes to developing completely new methods of synthesis, there is still no viable alternative to classic laboratory procedures. It is also by no means clear whether microreactors will ever be capable of manufacturing millions of tons of a bulk product such as ammonia or sulphuric acid, or whether miniature refineries might one day be used to produce fuels. Yet there are companies who are already working behind closed doors to realize such visions.
A simple calculation graphically illustrates the efficiency of the continuous process: if a continuous flow reactor yields 10 kilograms of product per hour and operates for 8,000 hours a year, it will have produced 80 metric tons by the end of a 12-month period. In a conventional batch process on a comparable scale, the yield is 100 kilograms per production run, but the latter takes perhaps two days. At the end of around 350 working days, that amounts to a mere 18 metric tons of product. With the use of new types of micromixer, such as those developed at the Institut fuer Mikrotechnik Mainz or the Wendelsheim-based company Ehrfeld, it is now possible to process more than 400 litres of liquid an hour in a production plant the size of a person. For the majority of its products, however, Merck in Darmstadt doesn’t require such a large capacity. Here the main focus is on the production of small amounts of high-grade specialty chemicals and pharmaceuticals made of very expensive raw materials. Yet operating on such a small scale also creates other challenges. “The plants must not only be very efficient but also highly flexible, so that they can be used to make as many different products as possible,” explains Schmalz.
When devising new methods of synthesis, developers are aided by the fact that such microsystems are made up of various modules, each of which forms a different functional unit. Mixers, heat exchangers, reactors, and control components can be combined as required, much in the manner of building blocks. Using such a modular system, it is easy to try out new production methods and vary with them until the optimum has been achieved. Likewise the time-consuming process of scaling up production is also unnecessary with microreaction technology. Once the process has been set up, it can be “equalled up” relatively simply in order to achieve a greater output of consistent quality.
A reprieve for the test tube
Yet does this spell the end for classic lab apparatus such as the three-necked flask and the test tube? And has the classic batch reactor served its time? Not at all, says Schmalz. As he explains, the traditional methods will still have their place, particularly when long reaction times are necessary or when the reaction results in byproducts that might cause a blockage in the ultra fine channels of a microreactor. Moreover, when it comes to developing completely new methods of synthesis, there is still no viable alternative to classic laboratory procedures. It is also by no means clear whether microreactors will ever be capable of manufacturing millions of tons of a bulk product such as ammonia or sulphuric acid, or whether miniature refineries might one day be used to produce fuels. Yet there are companies who are already working behind closed doors to realize such visions.
