… it’s how much you keep. This legendary advice applies to manufacturing, critical cleaning, and on-site distillation. Distillation is used to recover organic chemicals for re-use, to manage water during the cleaning process, and to minimize waste water. The current economic situation favors distillation. Gerald Camiener, technical director at CBG Biotech/Technologies (Columbus, Ohio), explains that “in the United States, two years ago, industry was not as interested in distillation for recycling water or solvents, because companies were primarily focused on sales. Now that sales of manufactured products are flat, people look to cut costs. The ROI for distillation equipment can be favorable.” Chris Hall, national accounts manager at CBG, sees an approximate 35% growth over the past two years, with prospective buyers from Fortune 500 companies to “ma and pa” operations interested in the systems.
Growing Interest
Matthew Witt, president of Sawyer & Smith Corp. (Castalia, Ohio) sees increasing interest in distillation of solvents used in electronics, including defluxing agents and cleaning agents used for contacts. Camiener notes that university and hospital labs and metal plating operations generate water waste containing toxic chemicals, solvents, and radioisotopes. Fractional distillation recyclers called “concentrators” are able to reduce the volume of such wastes by removing the water component.
Camiener explains that batch distillation (simple distillation) is effective in separating simple solvents from non-volatile chemicals and solids. However, if multiple volatile components are present, fractional distillation is required to recover high-purity solvent. Witt explains that specialty solvents, “particularly high-boiling (over 180°C) safety solvents need vacuum for successful distillation. In addition, many blends are proprietary, and the composition is not readily disclosed. People [call and] say, ‘we have lacquer thinner; we need to distill it.’ [But] we need more information on the specific product to recycle successfully.”
Bill McCormick, president of Serec Corp. (North Kingstown, R.I.) explains that vacuum batch distillation systems “are very synergistic to our cleaning and extraction product lines, and the systems can be stand-alone or in-line.” McCormick adds that they have manufactured units with distillation rates of 8 gpm, with recovery rates of 80 percent for hydrocarbon solvents, and 95-97 percent recovery rates for chlorinated and brominated solvents.
Trends and Regulations
“We first noticed the trend to fractional distillation in hospital recyclers in the United States and Canada,” notes Camiener. He sees growth in Australia, Japan, and China. However, “in Europe, the situation is mixed. In Italy, the government supports laboratories; there is no incentive to purchase recycling stills. In Germany and Switzerland, there are more private labs.” He concludes that “for distillation to be attractive, you have to have larger volumes or mixed waste coupled with governmental environmental regulations that drive up the costs of managing hazardous waste.”
Hall adds that “regulations on chemicals are becoming stricter, and they vary from state to state. Water is a valuable commodity, so now we have water concentrators for aqueous processes. We also have to look at the characteristics of various chemicals, including hazardous chemicals.” Hall estimates that 80-85 percent of their redistillation processes involve hazardous or flammable solvents; this requires careful process design to maximize worker safety. Hall adds that recycling costly solvents including HCFCs, HFCs and HFEs is becoming attractive.
Even low-cost solvents may be cost-effective candidates for recycling. For example, acetone is attractive because it is inexpensive, aggressive and exempt as a VOC. “California has prompted a lot of the regulations; acetone is used like crazy,” explains Witt. He finds 50 percent of inquiries about acetone distillation come from California. Witt adds that acetone is readily distilled with appropriate systems for low flashpoint solvents.
Your Nose May Know
Witt recounts that he “smelled solvent while working on a pre-treatment system for a painting line. It was xylene and was handled by a chemical management service. The company replaced the service with a $34,000 recycler. The ROI was 3.2 months.” So the opportunities for savings may literally be right under your nose.
