Uniroyal Chemical Company, Inc.
During many processing steps both toluene and methanol come in contact with water, some of which is stripped before ultimately discarded as wastewater. About 4.9 million pounds of these chemicals are now recovered and recycled back into the process.Uniroyal began by inventorying every wastewater stream leaving the process, and then preparing a detailed mass balance. A few waste streams were eliminated, but only after a detailed engineering study found no adverse impact to product quality, the process equipment, or employee safety. Further study revealed that one piece of process equipment might fail due to stress corrosion cracks, but modifying the process prevented this risk. Uniroyal evaluated the remaining wastewater streams to see if any could be re-used "as-is". A few streams fit this category, but only after they were carefully studied, as always, to ensure no adverse side reactions would occur. The few remaining waste streams were unsuitable for elimination or recycle due to their high salt and by-product content. The only remaining choice was to upgrade the stripper operation to remove more dissolved raw materials for recycling.
This project entailed nothing extraordinary. Uniroyal is proud to show how they conducted their research and implemented improvements according to the waste hierarchy by eliminating what they could first, recycling whatever possible second, and finally improving waste treatment before disposal.
The entire project, completed in two years at a capital cost of $5,000,000, now recovers 4.9 million lbs/yr in methanol and toluene (valued at $700,000/yr) that was previously deep-well disposed.
Details of ReductionsSource: LDEQ