Eliminating waste stream in Texas
Huntsman’s plant in Conroe, Texas, produces more than 400 different specialty chemical products, primarily amines, polyols and carbonates. To meet customer demand, process units and storage tanks are frequently washed out to accommodate the next product. But these washouts put high levels of organic material through the plant’s wastewater system and, over time, the material must be disposed as hazardous waste due to high benzene levels.
After studying the problem, Huntsman determined one of the plant’s raw materials contained cyclohexane, which was reacting with other materials to produce the benzene. So the plant isolated the washout stream containing cyclohexane, preventing it from entering the storage tank and disposing of it in another tank. As a result, the benzene-free wastewater no longer required treatment as a hazardous waste
After the change, hazardous waste production at the plant dropped from 3.7 million pounds to zero, eliminating $700,000 in hazardous waste disposal costs. In addition, the plant found a customer to use the organic layer that was stored in the separate tank to blend with their products and use it in a beneficial way.
The project won a 2019 Texas Environmental Excellence Award for pollution prevention from the Texas Commission on Environmental Quality.