Engineers building goods and processes, purchasing departments acquiring resources, and environmental departments looking for better treatment and disposal methods all have a role to play in creating a more sustainable future and circular economy.
Better waste and byproduct management is an important area of effort for environmental agencies. Because of the importance of solvents, companies have been recycling them since before 1976, when EPA restrictions came into force. While waste management standards have developed since then, recycling has fluctuated as a viable option for industry. Why? Because it takes more effort to recycle solvents than it does to recycle paper. New technologies have streamlined the process, allowing firms to cut costs and develop new revenue streams while replenishing and safeguarding our natural resources.
Waste Reclamation: Why Solvent Recycling Is So Important in the Manufacturing Industry
Everyone benefits from waste reuse since it reduces energy use, greenhouse gas emissions, natural resource conservation, disposal costs, and, in many cases, more efficient production by utilizing recovered materials.
In the manufacture of products, a range of organic and inorganic solvents are used. Paints and adhesives, cleaners and degreasers, medications, and personal care items are just a few examples. Solvent recycling could also assist a wide range of manufacturing industries, including electronics, automotive, pharmaceuticals, and paint.
Jim Reddy, a product line manager for Veolia’s solvent reclamation business line, describes how solvent is recycled and utilized as a substitute for virgin solvent, as well as why the solvent recovery method is both cost-effective and ecologically beneficial, which manufacturers like.
Solvent Recycling’s Difficulties Made Easy
Reddy has worked in the sector for about 30 years, practically all of them with Veolia. He is in charge of sales and logistics for all solvent reclamation prospects in 20 U.S. states, as well as national sales of Veolia’s reclaimed solvent goods.
“The features of the waste stream that produces solvent recovery are highly dependent,” added Reddy. Waste streams are generated by a range of businesses, including pharmaceuticals, chemical processing, and more. Following the classification of the waste stream, the type of recycling equipment is determined.
“If the waste stream contains solid materials, for example, the solvent would be handled first with a wiping film evaporator, which basically eliminates any particulates and color,” Reddy explained. The solvent could then be placed in one of the solvent distillation columns for fractionation, depending on whether more recycling is required.
Solvent reclamation and recovery can become tricky at this point, as it may require more than one stage. Byproduct recovery and maximizing the lifespan of a resource are less important in traditional linear production methods. Solvent recovery is an important procedure, but it doesn’t have to be difficult.
Other equipment alternatives, such as those listed below, can provide diverse effects in addition to distillation columns.
Evaporator with wiped film
A wiped film evaporator is a heated cylinder that looks like a distillation column but has a rotor running down the center. Paddles are attached to the rotor and function similarly to a blender.
“When a liquid or solvent is introduced to the system, it is spun up against the heated walls, where the solvent is evaporated and the solids are left behind for disposal,” explained Reddy.
Fractionation / Distillation Column
A distillation column is a tall, heated cylinder with a number of trays within of varying heights. There is a temperature difference between the top and bottom of the column when it is heated. Heating from the bottom, for example, will heat the trays at the bottom of the column more than the trays at the top.
“Every chemical has a different boiling point,” Reddy continues, “so the chemicals will reflux, evaporate, and then condense many times as they progress up the trays.” “By doing so, the different solvents can be separated according to their boiling points.” The lower boilers will concentrate towards the top of the column, while the higher boilers will stay at the bottom.”
Molecular Sieve is a method of separating molecules.
A molecular sieve is a piece of equipment with microscopic pores in the media that allow molecules larger than the pore size to flow through while absorbing molecules smaller than the pore size. It’s great for extracting water from a solvent stream since larger solvent molecules can’t be absorbed by the pores, but smaller molecules like water can.
“We pass solvent through the sieve at our facility and successfully separate it from any water in its composition,” Reddy explained. “This allows us to properly purify the solvent before returning or repurposing it.”
Jim describes the most typically recycled solvents, as well as what types of spent solvent streams are treated in which types of equipment, in this tip sheet.
