Rotary evaporators, also known as rotovaps, are a common sight in most chemistry labs. Perhaps surprisingly, this familiar piece of equipment hasn’t changed much since it was first invented in the 1950s. Even though new models of rotary evaporators are developed each year by major manufacturers, the basic principles of operation have remained the same. Until now, that is. In this article, we take a look at how Ecodyst is revolutionizing the world of rotary evaporators; eliminating costly consumables while offering better performance, simpler operation and drastic reductions in lifetime costs.
Rotary Evaporators 101
The first rotary evaporation system in scientific literature was described in 1957 by researchers at the Rockefeller Institute for Medical Research in New York.1 These researchers placed a dilute solution in a round-bottomed flask over a heat source. This flask was connected to another round-bottomed flask, which was partially submerged in an ice bath. The two connected flasks were then evacuated using a vacuum pump and rotated about their axes for even heating and cooling.
|Original schematic for a rotary evaporator (Anal. Chem. 22, 1462–1462 (1950))
By evenly heating the flask containing the dilute solution at reduced pressure, the researchers could easily evaporate the solvent from the solution, which was then condensed in the cooled glass condenser. This yielded a concentrated solution in the heated flask.
Early improvements to this original design included the use of a hot water bath rather than a burner, and the insertion of various traps between the evaporation flask and the condenser. It wasn’t long before the first commercial models were produced. Today, rotary evaporators are used at all scales, from benchtop research models (typically 1 L capacity) to larger models for pilot plants and commercial syntheses with capacities of hundreds of liters. New rotovap models often feature vapor temperature sensing and digital controls for vacuum pressure, temperature and rotational speed.
However, despite incremental changes over the last 60 years, the basic operating principles in today’s conventional rotary evaporators remain the same as they ever were.
Limitations of Conventional Rotary Evaporators
Despite their widespread use, conventional rotary evaporators suffer from some serious drawbacks, most of which can be attributed to the use of glass condensers.
Glass has traditionally been used in chemistry applications due to its low cost and resistance to most chemicals – these properties alone have made it the material of choice for the condensers in virtually all rotary evaporators. However, glass is far from ideal for this purpose: glass is a poor conductor of heat, so conventional rotary evaporators need to work harder to overcome the poor rate of heat exchange through glass condensers.
Other issues with conventional rotary evaporators include high operational costs, inefficient vapor trapping and time-consuming management of dry ice and solvent mixtures.
Revolutionizing the Rotary Evaporator
Ecodyst sought to overcome the limitations of conventional rotary condensers by rethinking several elements of its design, starting with the condenser. At the heart of an Ecodyst rotovap is a metal condenser coil coated with special chemical-resistant polymers. While simple, this change represents a paradigm shift in rotovap design and produces a number of significant advantages over traditional glass condensers.2
The metal condenser, featured in Ecodyst’s Ecochyll X1 condenser, not only offers much better thermal conductivity (and therefore more energy-efficient cooling) than glass, but is also highly durable and has a huge surface area, which allows for customization.
Crucially, the metal condenser is also strong enough to be connected directly to a pressurized refrigeration system. This means that the recirculating chiller needed glycol or water systems can be completely eliminated, saving maintenance and hardware costs as well as drastically reducing the amount of space taken up by the rotovap system.
A completely self-contained coolant circuit means that operating costs are drastically reduced compared to any other type of rotovap setup: the Ecochyll X1 means no need for dry ice, coolant or water. The only operating cost is the cost of the electricity required to power the device; which, thanks to its more efficient design, is around 50% of that required for a conventional glass condenser rotovap. Thanks to these substantial savings, the Ecochyll X1 typically pays for itself within 3-5 years of average use.
Ecodyst cooling technology not only offers cheaper and more efficient operation than competing systems, but also better performance: the efficient condenser reaches in under a minute (compared to 45 minutes for conventional recirculating chillers) and offers much faster rates of evaporation than traditional rotovaps.
Ecodyst Rotovap Systems for the Lab
The Ecochyll X1 is a benchtop cooler/condenser engineered for best-in-class evaporation in lab environments where space is at a premium. Thanks to proprietary smart cooling technology, the Ecochyll X1 sets a new benchmark for reliability and efficiency.
The Hydrogen packs the same condenser technology into an all-in-one rotovap. Combining rotary evaporator and condenser into a single benchtop unit provides the same high performance as other Ecodyst products in a simple-to-use format with a footprint of only 1.8 square feet. Inbuilt digital controls offer precise management of all system parameters, while a remote function enables full PC control and data transfer for further processing.
Ecodyst now offers a full range of rotary evaporators, from 1L benchtop models like the Ecochyll X1 and Hydrogen through to the 200L Ecochyll X9 for process chemistry and commercial applications. Ecodyst’s unique cooling technology enables researchers and industrial chemists alike to move on from expensive and time-consuming management of dry ice and coolant systems, and reap the benefits of high-performance and low-cost extraction.
References and Further Reading
- Craig, L. C., Gregory, J. D. & Hausmann, Werner. Versatile Laboratory Concentration Device. Anal. Chem. 22, 1462–1462 (1950).
- How Ecodyst’s Modern Rotovap Revolutionizes Rotovap Technology. News-Medical.net https://www.news-medical.net/news/20210304/How-Ecodyste28099s-Modern-Rotovap-Revolutionizes-Rotovap-Technology.aspx (2021).