If your manufacturing process generates waste solvent, you have both an environmental liability and an increase in your operating costs. The first step in minimizing both is to review your process for ways to decrease the amount of waste generated. Once that is accomplished, there are a number of ways to deal with the waste generated:

OFF SITE DISPOSAL

Have your waste picked up by a reputable waste hauler for proper disposal. Usually this involves fuel blending. The draw back to this method is cost of disposal plus the cost of replacing the solvent contained in the waste. Your liability continues from when it leaves your plant until it is certified as being disposed of.

OFF SITE re claiMER

This involves your liability of shipping your waste to the re claimer. They typically return only a portion of the solvent contained in your waste. The quality and the actual blend of solvents you get back may not be what you sent them. The quantity of replacement is less then fuel blending, but still a sizeable cost.

ON SITE RECOVERY

On-Site recovery of the solvent by a mobile distillation company is the third method. They distill a portion your solvent from your waste for re-use and dispose of the residue using your utilities. The cost of this service is very high unless the quantity to be distilled is sufficient to justify bringing the truck on site. This could involve accumulating your waste, adding to your inventory and liability.

IN-HOUSE RECOVERY

You purchase a distillation unit based upon your waste generation per day. You lower your inventory by distilling your solvent from your daily waste generated.

As an example:

• Waste generated per day = 55 gallons
• Solids in the waste = 10% or 5.5 Gallons
• Solvent in the waste = 49.5 Gallons
• Desired residue 60% solids - 40% solvent (a typical pumpable waste)
• You distill 45.9 gallons of your solvent back for reuse (93% recovery of the available solvent in your waste).
• You replace only 3.6 Gallons of solvent.
• You dispose of 9.1 Gallons of a 60% - 40% residue.

The cost to accomplish this is minimal and determined by the Latent Heat value of your solvents (BTU's required to distill one gallon per hour) and your cost of electrical power (KW's per hour)

Some examples:

• SOLVENT BTU's per GALLON
• n-Butyl Acetate 970.9
• n- Butyl Alcohol 1,715.2
• Ethyl Acetate 1,185.0
• Ethyl Alcohol 2,376.0
• MEK 1,279.7
• Xylene 1,058.4

If your waste is Ethyl Acetate and your power cost is $ .10 per KW then;

• Latent heat (/) KW's per BTU = KW required (x) $ per KW.
• 1,185.0 (/) 3414 (KW's per BTU) = 0.347 (x) $ .10 = $ .035 per gallon
• You get back 45.9 Gallons of Ethyl Acetate for $1.61.
• To that add the replacement cost for 3.6 gallons of new solvent and the cost of disposal for 9.1 gallons of residue.

A comparison of In House Recovery versus any of the other methods, will yield a high degree of savings and when applied against the cost of equipment, a typical Return On Investment can be less than 12 to 14 months. IN HOUSE RECOVERY SAVES MONEY WHILE MINIMIZING YOUR LIABILITY today!