Solvent Recovery vs Distillation: Which is Best?

Solvent recovery and distillation are critical processes in a range of industries. Both processes are used to separate and purify elements meaning they are helpful means of recovering a range of chemical components. This article will detail both processes and how they measure up against one another.

What is Solvent Recovery

Solvent recovery or solvent extraction is a technique in which chemical compounds are isolated in accordance with their solubilities. Solvent recovery is employed in a range of industries from vegetable oils, perfume, food, cosmetics, pharmaceuticals, manufacturing, cannabis production and mining. Solvent recovery is important because it is used to isolate hazardous materials from sediments and sludge and separate the helpful components from the debris.

An example of this is solvent recovery in the petrochemical refining industry, where it is used to separate petrol by causing them to float to the top or sink to the bottom for easy removal.

Solvent recovery is also important in the hazardous waste industry as it decreases the levels of hazardous waste that needs to be treated. Solvent recovery does not damage the substance which is extracted, just separates the compounds. These compounds are then extracted to be used for a range of purposes according to the industry. Solvent recovery is a means of purifying elements and identify different chemical components.

Rotary evaporators use evaporation to gently and efficiently remove solvents from a range of sample types, including both organic and inorganic analytes and polymeric materials. The sample is heated whilst its boiling point is lowered by a vacuum which is formed by the rotary evaporator. This means that solvent recovery is possible at a much lower temperature.

What is Solvent Distillation?

Solvent distillation is the solvent separation involving application of heat to separate a mixture of liquid of two or more two or more substances. The solvent mixture is heated to boiling point and as a vapor its piped away to a new storage container in which is will cool and condense to an almost pure quality. This results in a distilled solvent which can be reused and wastage which can be disposed of accordingly.

Rotary evaporators are sometimes used in distillation applications as it is faster than traditional techniques as solutions are distilled under reduced pressure at a lower temperature, speeding up the process because of the larger surface area.

The Key Differences Between Solvent Recovery and Distillation

The key difference between solvent recovery and distillation is that solvent recovery purifies a substance whether it is in a solid or liquid phase whereas solvent distillation can only purify a substance in the liquid phase. This means that solvent recovery can be used for more applications and is a more cost-effective solution.

Rotary evaporators from Ecodyst can be used for both distillation and solvent recovery. If you would like to find out more about how we can help you, contact us today.

Understanding how Cold Traps are Used in Vacuum Applications

Cold traps are used to condense vapors present in vacuum applications into a solid or liquid state (excluding permanent gases). The main function of a cold trap is to ensure that there is no contamination inside vacuum applications. Whilst experiments are conducted, containers must sit airtight so no vapor can escape and no extra gas can enter the chamber and cold traps work to stop this.

How Does a Cold Trap Work?

Cold traps are usually made up of two parts, the bottom being a large, thick round tube with ground glass joints. The second is a cap that also has ground-glass connections. The length of the tube is selected so that the cap reaches about half the length.

Cold traps should be assembled so that the down tube connects to the gas source whilst the cap is connected to the vacuum source. This means that vapor phase condensate is unlikely to move up the tube.

Cold traps condense incoming vapors in the chamber to inhibit contamination. It is particularly useful for the removal of large quantities of liquid in freeze-drying.

Cold Trap Applications

Cold traps are used in applications in which the process is coming over in the form of a vapor and must be trapped. There is a range of different traps that can be tailored to the chemical composition of the process.

Some processes have gasses that travel in a vapor form and can easily be trapped once rapidly cooled. This means that the vapor condenses and the condensation can be collected in the trap.

Cold traps are often used in applications that require low-temperature conditions via evaporators such as distillation and condensation. In these applications, the cold trap contains a freezing mixture of dry ice or a coolant and acetone.

Cold Traps and Rotary Evaporators

Cold traps play a critical role in traditional rotary evaporators as it traps gas on a cooled surface in a coagulated manner. The cold trap is placed in between a vacuum vessel and a pump for trapping oil vapor or adsorbing gas. The cold trap is lined with a lead gasket and connected to the vacuum pump and suction container.

The cold trap adsorbs heat from the condenser, keeping the temperatures low, and when gas passes through the water vapor and other gases solidify on the condenser. This then increases the degree of vacuum.

Why Ecodyst’s Revolutionary Technology Replaces Cold Traps

Traditional rotovaps used cold traps that require material such as liquid nitrogen or anti-freeze to cool them. However, Ecodyst’s new revolutionary technology uses continuous cooling, eliminating the need for excess, expensive, and energy inefficient cooling technology.

Cold Trap Terpene Capture—How Does it Work?

Terpenes are aromatic compounds that are present in many plants. They are commonly associated with cannabis plants as they contain high concentrations of terpenes. Terpenes create the characteristic scent of a range of plants – making up the bulk of the fragrance.

Terpenes protect animals from grazing and infectious germs but they can also have some health benefits to humans. Terpene extraction and capture usually refer to terpene in cannabis. This article will discuss the key techniques of terpene capture.

Terpene Capture is Challenging

Extracting terpenes from organic sources can be challenging and time-consuming. That is why it is important to ensure the optimum method is selected. The methods can be generally sorted into two categories: solventless and solvent-based extracts.

What is a Cold Trap?

Cold traps are devices that condense all vapors into liquid or solid, apart from permanent gases. The main reason cold traps are used is to stop vapors produced during an experiment from going into the vacuum pump as they could condense and contaminate it.

Using a cold trap for isolating terpenes involves an oven set at a very low temperature. The oven is filled with plant material under a vacuum. Terpenes have very low vapor pressure meaning they will evaporate very quickly, vacuums help to protect the terpenes from temperature degradation, allowing the change in pressure to do the work and preserve the terpene.

How do Cold Traps for Terpene Extraction Work?

Vacuum Purging

Vacuum purging is a critical aspect of solvent extraction, producing a high-quality end-product. Some terpenes are also removed during the process due to the low vacuum pressure and heat needed to remove the residual solvents.

Without a mechanism for trapping terpenes, the terpenes will enter the vacuum pump and they will likely degrade and cause damage. Using a cold trap helps to preserve the terpene vapors as liquids before they enter the vacuum pump. These terpenes can then be consumed or reintroduced to the material post-process.


High temperatures are needed to decarboxylate and this results in large levels of terpenes being lost to the atmosphere. Cold traps help to collect these volatile organic compounds.


Terpenes are soluble in most solvents. This means that some terpenes vaporize with the solvent whilst it’s being reclaimed from the collection vessel and returned to the solvent tank. Cold traps can separate the terpenes from the solvent vapor steam.

Terpene Capture with Ecodyst

Ecodyst manufactures revolutionary evaporators that work on the same principle as traditional cold traps. The terpenes are removed from the solution before they become damaged by heat.

Instead of the time-consuming cold traps of the past, Ecodyst uses a highly efficient condenser cooling system that offers continuous cooling and rapid condensation.

To find out more about using Ecodyst evaporators in place of traditional cold traps, get in touch with the team today.

Enhanced Sustainability at the University of Oxford with the Ecodyst Hydrogen Rotary Evaporator

Rotary evaporators are found in many chemistry laboratories across the world. They have a range of uses and applications in both research and industry. They are an essential piece of lab equipment that allows for the fast and efficient removal of solvents from samples. This article presents an investigation into the differences between the Ecodyst Hydrogen and standard rotovaps used at The University of Oxford.

Traditional Rotary Evaporators

The condenser in standard rotary evaporators has traditionally been cooled using single-pass water, dry ice, or a recirculating chiller. Using water can result in the use of up to 4.0L per minute and can lead to flooding. Recirculating chillers waste far less water, however, the condenser still needs to be cooled and dry ice is often used for this.

However, dry ice can also be expensive and unsustainable when used in the quantities required for a rotary evaporator system.

 Figure 1

 Ecodyst Patented Technology

Ecodyst has developed its own patented chiller technology that bypasses cooling systems that are less energy-efficient and sustainable. The Hydrogen uses a metal condenser coil that is coated in a chemical resistance polymer, offering many advantages over standard glass condensers. The Ecodyst Hydorgen’s chiller can reach temperatures of less than -34°C.

Figure 2

Comparisons with Existing Set-Ups

Dr. Katrherine England from the Nuffield Department of Medicine, University of Oxford compared the Ecodyst Hydrogen to the department’s existing evaporator setup. This setup consisted of a Heidolph MX07R-20-HD2E recirculating chiller filled with an ethylene glycol solution, an R-200 Buchi Rotavapor, and Buchi B-490 heating bath.

Figure 3 

The Logicall Wireless Solutions energy monitors and online platform were then employed to monitor the equipment. The vacuum controllers were used at the same set points and were not part of the energy calculations.

The two systems carried out the distillation of 100ml of cyclohexane and compared. The operations were carried out separately to compare the overall performance and running costs.

Figure 4

Results of the Comparison

When comparing the two pieces of equipment we can see that the set Ecodyst Hydrogen was ten times faster than the department’s existing rotovap setup.  All of the components were ready within seven minutes whereas the department’s original rotovap took seventy minutes to achieve the -10C set point.

The Hydrogen saved significant amounts of energy, using 49.8% less than the original instrument when carrying out the 100ml cyclohexane distillation. The chiller component used 80.8% less energy to reach this setpoint than the recirculating chiller and once it had reached this point it used 64% less energy overall.

Another benefit of the Hydrogen is that it only takes 5 minutes to reach the point of the chiller being ready. This means that it can be switched off when inactive.

Find Out More

This investigation shows that the Hydrogen rotary evaporator from Ecodyst uses far less energy than its more traditional counterparts. If you would like to learn more about how Ecodyst can help you streamline your vapor condensing practices, get in touch with the team today.


How to Choose the Right Cold Trap

Cold traps safeguard vacuum pumps from being contaminated by vapors being condensed in the device. They also stop oil vapors from backstreaming from the pump back to the system, making the vacuum pumps more efficient and less likely to break down.

In this article, we discuss the types of cold traps available and their benefits and applications.

What is a Cold Trap?

Cold traps are a fundamental part of solvent recovery and are used in vacuum applications where a range of vapors are present. Cold traps condense these vapors into either a solid or liquid state, stopping contamination in the vacuum pump and minimizing the maintenance needs.

Liquid Nitrogen Cold Traps

These solvent recovery systems are of the cold thimble design, meaning the surface of the device contains liquid nitrogen at -187°C. The surface is exposed to the vacuum system and condenses molecules rapidly in the vapor phase. This action leads to a trapping effect, achieving a lower base pressure and a high pumping speed.

Stainless Steel Cold Traps

Cold traps made from stainless steel are popular because stainless steel has so many beneficial attributes. It is corrosion-resistant, meaning coming into contact with vapors will not damage the material.

Stainless steel is also beneficial for cold traps due to how hygienic it is, being extremely easy to clean and sanitize.

Traditional Cold Traps 

Traditional cold traps are extremely inefficient as they need to be extremely cold. This temperature means that large amounts of nitrogen, large amounts of tap water, and anti-freeze would be employed to safeguard the temperature.

Using these materials can be extremely expensive and use excessive amounts of energy. This can increase your company’s overheads and the environmental impacts.

Revolutionary Cold Trap Alternative from Ecodyst

Ecodyst has designed and produced a revolutionary new technology that is an end to the costly and time-consuming practices associated with traditional cold traps.

Ecodyst’s system involves a high-efficiency cooling system that we have produced to offer rapid condensation, continuous cooling, and decrease evaporation time.

Want to Find Out More?

Get in touch with the team at Ecodyst to find out more about how our cold trap alternatives can help with your recovering solvent needs.


What is a Cold Trap?

Cold traps are often used in vacuum applications that contain a range of vapors. Cold traps are used to condense the vapors into a solid or liquid state. The cold trap stops contamination in the vacuum pump, decreasing maintenance requirements and extending the vacuum pump life.

How Does a Cold Trap Work?

Cold traps work by condensing gases onto an adequately cold surface. The vacuum pump removes gas from a chamber and it moves from the chamber and into the cold trap where the gases are condensed or sublimated, preventing these gases from reaching areas of the system that could lead to malfunction.

Sometimes cold traps use temperature monitoring equipment to purposefully condense materials with temperature monitoring equipment. Cold traps maintain their temperatures by an active material such as dry ice or liquid nitrogen.

Cold traps are usually made up of two parts and look like a U-shaped test tube. The bottom of the cold trap is much larger than the top part, with a thick round tube that is safeguarded by surrounding ground-glass joints with a leak-proof cap on top.

Why Use a Cold Trap?

Cold traps come in a range of specifications, and the specifications are dependent on the chemical composition of the process. Some processes involve gasses traveling in a vapor form that can be trapped easily and cooled quickly. This causes the vapor to condense and the condensation collects inside the trap.

Cold traps are also used for experiments that use extremely low temperatures for distillation and condensation. Cold traps in these instances contain a blend of acetone and coolant and work as the condenser.

The Downsides of Cold Traps

Cold traps are often used with rotovaps to capture vapors that move through the condenser. Traditional versions were highly inefficient, using lots of energy to protect the vacuum pump. Cold traps need to be extremely cold meaning they use lots of materials such as liquid nitrogen, tape water, or anti-freeze to safeguard the temperature.

Using these costly materials can be a challenge for companies, increasing overheads and overall carbon footprint.

Rather than using traditional cold traps to stop the gases from getting into vacuum pumps, Ecodyst uses a technology that does not require costly and time-consuming processes. The condenser cooling system developed by Ecodyst provides continuous cooling, fast condensation, and decreased evaporation time.

Should You Choose a Cold Trap for Your Application?

Cold traps are beneficial for many applications, minimizing downtime and maintenance needed for vacuum pumps. However, the inefficiency of traditional cold traps can negate this cost-saving benefit.

To find out more about how Ecodyst’s innovative take on the cold trap can benefit your application, contact us today.

How Ecodyst Evaporators Differ from Cold Traps for Vacuum Pumps

In vacuum applications, cold traps are devices that transform vapors into liquids or solids. The purpose of this is to stop vapors from being evacuated outside of the container, causing contamination of the equipment.

Vacuum pumps remove gas molecules or air particles from a sealed volume, changing the pressure within. This article aims to explain how cold traps for vacuum pumps work, and how Ecodyst’s evaporators differ from this.

How Does a Vacuum Pump Work?

A vacuum pump’s key purpose is to alter the pressure in a contained space to form a partial or full vacuum. This process can be either mechanical or chemical.

Gas molecules flow from high to low to fill the area of volume, attempting to equalize the pressure. This means that when a low-pressure space occurs, gas naturally moves from the high-pressure area until it has equalized. Vacuum pumps use this principle to move gas molecules from one region to the next by altering pressure states.

Capture Vacuum Pumps

Capture pumps have no moving parts and require extremely high vacuum pressure. Capture pumps use cold traps to trap gas molecules, drawing molecules inward to create a vacuum.

Vacuum Pumps for Rotovaps

In most rotovap applications, applying a vacuum pump is helpful and sometimes even entirely necessary. Vacuum pumps lower the pressure in the system, decreasing the boiling point temperature of the solvent meaning evaporation is faster and safer.

Cold Traps and Vacuum Pumps

Cold traps are generally placed between the vacuum pump and the rotovap to safeguard the pump from any additional contamination. Cold traps are usually a critical element of standard rotovaps as they catch any vapors that pass through the condenser.

Cold traps are lined with lead and are connected to both the suction container and the vacuum pump. The cold trap adsorbs the condenser’s heat, ensuring temperatures stay low. This means that when gas moves through the water vapor and other gases solidify on the condenser, the degree of vacuum increases.

Traditional Cold Traps

Standard rotovaps used cold traps that were extremely inefficient to protect the vacuum pump. Cold traps must be extremely cold, resulting in liquid nitrogen, excessive amounts of tap water, and anti-freeze being used to maintain the temperature.

These materials can be costly, and the frequent use of them uses huge amounts of energy, costing companies money and increasing the environmental impacts.

A Better Way

Instead of traditional cold traps stopping gases from reaching vacuum pumps, Ecodyst’s revolutionary new technology eliminates these costly and time-consuming problems. A high-efficiency condenser cooling system has been developed, offering continuous cooling, rapid condensation, and reduced evaporation time.

To find out more about this innovative replacement for traditional cold traps, get in touch with the team at Ecodyst today.

Super-Fast Solvent Recovery with Ecodyst

Solvent recovery is a critical element of any lab used for cannabis extraction. For both winterization and extracting with a liquid solvent requires a bulk solvent recovery technique. This article will explore some of the pitfalls of traditional methods of solvent recovery and how the speed of solvent recovery with Ecodyst can be beneficial to your application.

What is Solvent Recovery?

Solvent recovery is often confused with solvent recycling, however they are vastly different processes. Solvent recovery is a process in which most of the solvent in crude cannabis extract is removed. Solvent recovery can be a lengthy process, causing a huge bottleneck in lab operations if not managed efficiently.

This bottleneck is caused by vast quantities of solvent, for example in the winterization process unrefined oil is dissolved in ethanol at a rate of 10:1. If the lab needs to extract 10 liters of distillate in a day then they must remove over 100 liters of ethanol, meaning this can be a time consuming process.

Traditional Solvent Recovery

Falling Film Evaporators

Falling films are a widely used evaporation techniques that typically use condensing steam as a heating medium. Falling film evaporators are fairly inefficient, taking a significant amount of time to meet heating requirements. They are also extremely expensive as they have very particular design and manufacturing requirements.

Rotary Evaporators

Rotary evaporators are the most widely used tool for solvent recovery across many industries. They use a rotating flask to efficiently evaporate the solvent under a vacuum. Rotary evaporators are inexpensive, however most rotary evaporators are made of glass which means they are more prone to breakages and are thermally inefficient.

Rotary evaporators from Ecodyst are more quick and efficient than the standard, traditional rotovaps. Their metal condensing coils significantly reduce the amount of energy an application requires whilst also decreasing the overall space.

Despite their benefits, rotary evaporators are inefficient for large scale solvent recovery as they take a significant amount of time to successfully evaporate the solvent.

Evaporators for Large Scale Solvent Recovery

The Ecodyst team identified a need in the market to combine the energy efficiency and reduced footprint of their revolutionary rotovaps with a capacity for solvent recovery on a larger scale.

Ecodyst have pioneers their super-large, industrial-sized 200 liter EcoChyll X9, allowing large scale solvent recovery without high energy consumption and operating costs. Solvent recovery traditionally requires a multitude of experienced operators and many hours can now be achieved in a much smaller time scales.

Ecodyst evaporators use a self-cooling technology, offering a novel solution for solvent recovery challenges. These benefits could revolutionize your operations, increasing efficiency and saving money. To find out more, get in touch with the team at Ecodyst today.

The 5 Steps of Cannabis Extraction

Extracting cannabis oil can be a time-consuming process that lacks energy efficiency. As the cannabis industry moves from the black market to a legal one, techniques of extraction and purification have become a focal point for researchers.

Dried cannabis flower has traditionally been used for smoking and vaping, however as the industry grows, the need for cannabis products in various forms increases for both medicinal and recreational use. This article will outline the five key steps in cannabis production and how they are carried out.

Start with Extraction

Cannabis extraction works to concentrate target components for specific products. A range of solvents can be used to extract cannabinoids including ethanol, propane, and petroleum ether. The solvent should be selected according to the differing solubilities of particular cannabinoids.

When using ethanol, the cannabis plant is soaked in ethanol, which reacts with the plant and can bring out a broad range of compounds and stop other compounds from solubilizing. The solvent must then be removed from the solution, using an evaporator decreases the exposure to heat, offers excellent repeatability, and is environmentally friendly.


Winterization is the next step in cannabis extraction, beginning with the material extracted in the previous step. This liquid is made up of cannabinoids, THC/CBD, waxes, fats, lipids, and terpenes. The oil is added to proof alcohol and combined, the alcohol then thins the oil, and the fats and lipids coagulate and freeze ready for filtration. Once the unnecessary elements have been removed, an evaporator is used to remove the alcohol.

Solvent Recovery

Solvent recovery is the step in cannabis extraction where the majority of the solvent in the crude cannabis extract is removed. Solvent recovery can often be a bottlenecking, time-consuming aspect of cannabis extraction. Tools such as high-speed evaporators are well-suited to significantly decreasing the time taken to achieve solvent recovery.


Decarboxylation is the process in cannabis extraction which involves converting THCA and CBDA into THC and CBA via heating and drying. It is a chemical reaction that removes a carboxyl group using heat or chemicals. Decarboxylation traditionally requires the use of a reactor, chiller, condenser, and vacuum pump and will take up to ten hours. The time-consuming nature comes from using thermal fluid to heat the extract which is a very inefficient process.

The Final Step is Distillation

To further refine the cannabis extraction, the oil goes through distillation. In this technique, the extract is heated and each one is separated due to its different boiling point. Rotary evaporators can be used in cannabis extraction distillation as solvents can be distilled under decreased pressure at a low temperature. The process is speeded up due to the larger surface area. Using a rotary evaporator also means the cannabis extraction does not have to be heated to such high temperatures, decreasing cost and environmental impacts.

The Best Tools for Cannabis Extraction

As is shown in this article, evaporators are used in many of the steps that make up the cannabis extraction process. However, traditional equipment such as slow, standard rotary evaporators can be extremely time consuming and costly to run. Ecodyst evaporators set a new standard in cannabis extraction, significantly decreasing the time it takes. The EcoChyll combines high-speed evaporation with high loading capacities and continuous cooling for faster cannabis extraction.

Ecodyst is an expert in the field of cannabis extraction and the use of evaporators. If you would like to find out more, visit their website and explore their wealth of information on this subject and much more.


The New Gold Standard for Rotary Evaporators

Rotary evaporators (or rotovaps) are a staple of numerous laboratories around the world and have been for many years. However, in this time there have been very few major changes with regards to how rotary evaporators operate.

Ecodyst has pioneered a new gold standard for rotary evaporators, modernizing them, making them more accessible, and work better for those that use them.

What Makes the New Rotary Evaporators So Different?

One key difference between traditional rotary evaporators and Ecodyst’s models is the efficacy of the performance. These new rotary evaporators minimize material waste, costs, and the use of excessive water or dry ice. Because rotary evaporators from Ecodyst use constant self-cooling technology on-demand their superior performance does not lead to higher operational costs.

A Rotary Evaporator that Doesn’t Cost the Earth

The chemical-resistant metal condenser technology that Ecodyst uses replaces the standard glass condenser. Because metal is stronger more conductive than glass, devices can utilize a refrigeration line that has a direct connection to condenser coils.

This means that the new rotary evaporators do not use high levels of energy cooling antifreeze or running vast amounts of tap water, nor do they waste dry.

The Benefits of Metal Condensers As Opposed to Glass

Metal is extremely good at conducting heat, which means it is suitable to be used with condensers. Metal is also durable with a broad surface area, meaning it is fully customizable.

Traditionally, glass has always been used as a condenser for rotary evaporators as it is resistant to most chemicals that are used in chemical laboratories. However, glass is not a good conductor of heat, meaning rotary evaporators require additional solutions to overcome the poor heat exchange.

Metal condensers can be coated in polymers that are untouchable by even the most corrosive chemicals, allowing for high-performance, modern rotary evaporators to be developed.

Simplicity is Key

Not only are traditional rotary evaporators inefficient, but they are also challenging and time-consuming to use, significantly slowing down productivity. The inefficiency slows down the overall speed of research and sees scientists spending significant amounts of time on practical issues such as sourcing antifreeze.

The new rotary evaporators from Ecodyst have combined the cooling system with the condensing equipment, eliminating the need for a recirculating chiller as it is all integrated into one simple system. This allows the rotary evaporators to take up far less space in laboratories.

The new rotary evaporators have minimal operating costs, only using a small amount of electricity and its simplicity means it requires less manpower.

Applications that Benefit

Industries that perform chemistry such as environmental, life sciences, cannabis, and chemical industries would greatly benefit from the new rotary evaporators.  They will eventually become the new standard for rotary evaporators across the world, particularly in those areas in which it is difficult to access large amounts of water or dry ice.

If you would like to find out more about how your rotary evaporator could be updated and made more efficient, get in touch with the team at Ecodyst today.