As more companies are working to enhance the sustainability of their waste management practices, those that need to dispose of solvent-based materials face unique challenges.
Many solvents used in manufacturing may be hazardous when they are spent or no longer can be used. If they are deemed to be hazardous, they must be managed and disposed of safely and according to regulations.
For many companies, that means embracing zero waste principles that strive to keep their waste out of landfills or from being poured down the sink. As these zero waste ideas have evolved over time, so has the ability to take solvent waste and make it part of a system that embraces a true circular economy concept that keeps materials at their highest value.
What Is Zero Waste?
To understand how zero waste ideas have transformed the way many companies handle their solvent waste disposal, it is first important to know about the overall concept of zero waste.
What is zero waste? The goal behind zero waste is to send nothing to a landfill and reuse as much as possible. The term “zero waste” is used across many industries, but it is becoming more widely accepted in industries that produce hazardous waste and among companies working to improve their sustainability initiatives.
In fact, many companies are seeing the value of replacing a “linear” economic model with a circular one that promotes extending the life of materials and essentially producing zero waste. Some of these benefits include experiencing a competitive advantage, seeing reduced costs, minimizing environmental impacts and enjoying a boosted public image.
How does a company that disposes of solvent-based liquids, solids and sludge incorporate zero waste? Below we’ll take a closer look at industrial solvents and how solvent distillation plays a role in working toward zero waste.
What Are Industrial Solvents?
Solvents are molecules that can dissolve other molecules, known as solutes. A solvent can be solid, liquid or gas.
A solvent’s molecules pull apart the solute’s molecules, and eventually the solute’s molecules become evenly distributed throughout the solvent. This homogeneous mixture cannot be separated physically.
In other words, heat or another chemical process must be applied to the solution in order to separate the solvent from the solute. Popular solvents include water and organic compounds like benzene, tetrachloroethylene and turpentine.
How Does Solvent Distillation Work?
Through the application and removal of heat, solvent distillation separates a liquid or vapor mixture of two or more substances into its component fractions of desired purity. The solvent distillation recovery process is based on the fact that the vapor of a boiling mixture is richer in low boil point components. After the vapor cools and condenses, the liquid condensate is ready to be sold back into industry.
How does a solvent distillation unit work? After a company has generated and transported its hazardous waste to a solvent distillation facility, the following occurs:
- A fingerprint analysis is conducted, which identifies the waste and sorts it.
- Liquid drums in the unit are pumped and filtered, after which solvents are pumped to the distillation unit. Here, volatilized solvent vapors expand into the fractionation column of the unit.
- A heat exchanger cools off the solvent.
- After cooling, solvents are directed to a finished product tank.
- Workers then package the product into drums and totes for distribution back into industry.
There is typically a portion of the original mixture that does not vaporize. This remains at the bottom of the recovery still and can be recovered and used as an alternative fuel source in some industries.
Of the solvents used in industry, the most common ones recycled in a solvent distillation unit include:
- Aliphatic: Mineral spirits and naphthas
- Aromatics: Toluene and xylene
- Halogenated hydrocarbons: Fluorocarbons, methylene chloride, perchloroethylene, trichloroethylene and 1,1,1 trichloroethane
- Alcohols: Isobutyl alcohol, isopropyl alcohol, N-butyl alcohol and methanol
- Ketones: Acetone, methyl isobutyl ketone and methyl ethyl ketone
- Esters: Ethyl acetate
If your company produces solvents in addition to the ones outlined above, you can check our eBook, Acceptable Waste Codes Guide, to determine whether your facility can take advantage of solvent distillation.
Although solvent distillation is a critical process in enhancing a company’s sustainability in industry today, it is just one part of a bigger picture that works toward zero waste.
How Has Zero Waste Transformed Solvent Waste?
Closed loop recycling offers manufacturers that generate solvent waste the opportunity to incorporate zero waste principles into their waste management. Solvent distillation is one component of closed loop recycling.
At Temarry Recycling, closed loop recycling is a restorative and regenerative process. It embraces circular economy concepts with the goal to recycle materials indefinitely so that the properties of the materials do not degrade.
With existing spent physical products like industrial solvents, here’s how the process works at our facility.
A waste to energy process begins the circular loop:
- Organic solids with sufficient BTU are converted to energy in the form of steam.
- Waste is fed by a conveyor into the primary stage for thermal destruction at 1500 degrees F.
- All vapors and gases are then directed to secondary thermal treatment at 1500 degrees F.
- Inorganic solids, or ash, from the primary stage are quenched and fall into an ash hopper.
- Heat is then directed to a 200-horsepower steam generator.
- The remaining gases are directed to a modern two-stage venturi scrubber to ensure that only clean water vapor is emitted into the atmosphere.
Next, the solvent distillation process continues the circle:
- Using the steam from the waste to energy process as energy to power the recovery stills, spent solvents are re-manufactured.
- This allows the solvents to be sold back into industry for their original solvent properties.
Finally, a water treatment closes the circular loop:
- This treatment process extracts usable water from industrial hazardous wastes.
- Treated water is then used on-site for industrial needs, including the waste to energy equipment and in the cooling tower.
The above regenerative process achieves zero waste because nothing is wasted. Even more beneficial for manufacturers, however, is the fact that closed loop recycling takes zero waste to the next level. That’s because closed loop recycling takes a material, recycles it and makes it into the same product it once was.
This has an enormous impact for manufacturing industries because this type of system reuses all components indefinitely. With solvent distillation, for example, all recycled solvents are reintroduced back into industry as a solvent, reducing the consumption of natural resources.
What Benefits Have Zero Waste Ideas Provided?
By embracing zero waste ideas, companies like Temarry Recycling have created a process that allows manufacturers to handle their waste disposal in a way that allows them to reap the benefits while protecting the environment.
In addition to meeting a manufacturer’s sustainability initiatives, this innovative transformation in solvent waste disposal has provided several benefits, particularly to companies located on the West Coast due to location.
Many hazardous waste disposal companies offer to transport spent solvents to fuel blending facilities.
Fuel blending combines spent solvents with compatible flammable materials. Tanker trucks filled with these blended materials often must travel across the United States to reach fuel blending facilities in Kansas and Arkansas, especially when a generator is located along the West Coast.
However, for West Coast generators, having a facility that provides closed loop recycling nearby can provide financial benefits in the form of reduced transportation expenses, such as fuel costs and man hours required for transport. Temarry Recycling, for example, is located just 40 miles east of San Diego, California, in Tecate, Mexico.
Carbon Footprint Decreased
This close proximity has a second benefit … a reduction in a company’s carbon footprint.
Because Temarry is the only closed loop recycling facility serving the western United States, any company in the region that takes advantage of this disposal method for its solvent waste will also see an immediate reduction in fuel usage for transportation. This, in turn, will reduce your carbon footprint tremendously, as shown below:
Because of the short transport distance between companies operating in the western United States and Temarry, these companies enjoy a reduction in cradle to grave liability.
What is cradle to grave liability? In the United States, you, as the waste generator, are responsible for your waste from the moment it leaves your facility until it is disposed of or recycled in a Treatment, Storage and Disposal Facility (TSDF).
When transporting hazardous waste to Mexico through Temarry Recycling, the waste generator’s liability for that waste ends at the U.S. border. It’s at the border where Temarry becomes the Principal Responsible Party in the United States and Recicladora Temarry de Mexico accepts generator liability in Mexico.
Finally, studies show that companies that embrace sustainable practices are more appealing to consumers. And, while there is the saying, “All press is good press,” that’s not necessarily true when it comes to environmental stewardship.
In other words, implementing sustainable and responsible practices in your company not only reduces your bottom line and environmental impact, it benefits your reputation as a company as well. It’s simply good business.