Huntsman Petrochemical LLC

TF5 Organic Waste Minimization and Commercialization

Huntsman Petrochemical is a global manufacturer and marketer of differentiated chemicals. Their Conroe Plant in Texas produces over 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. The washouts of the high levels of organic material are managed through the plant’s high-strength wastewater system, storing the wastewater produced in a tank named T-F-5. Over time, the organic material in T-F-5 separates from the wastewater, forming an organic layer. This organic layer has been disposed of as hazardous waste due to the high levels of Benzene.

In 2015, Huntsman investigated this problem, focusing on the upstream processes where the Benzene may have been generated. The study found that one of the plant’s raw materials containing another chemical, Cyclohexane, was reacting to other materials and producing the Benzene. After discovering this, they isolated the washout stream containing Cyclohexane, preventing it from entering the T-F-5 tank, and disposed of it in another tank. The T-F-5 tank was emptied for a routine inspection and they found that after eliminating the stream containing Cyclohexane, the wastewater that was entering the T-F-5 tank was free of Benzene and therefore no longer required to be treated as a hazardous waste.

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 in a beneficial way.

This project serves as a model for other companies by showing that waste streams can be reduced or even eliminated by investigating the upstream sources. After the inspection in 2015, the Conroe plant went from producing 3,753,240 pounds of hazardous waste to zero.

The costs associated with isolating the process stream were minimal compared to the annual cost savings. Previously, the plant spent almost $700,000 to dispose of their categorized hazardous waste. Not only have they eliminated this expense, but they also now sell their unwanted organic layer to another company, producing revenue which prior to this investigation was a company cost.