Hoechst Celanese Chemical Group, Inc.

Year Submitted: 2003

Process: Propylene Recovery

Industry: Chemical Manufacturing

Wastes Reduced: Process Chemicals

Substance: Propylene

Location: Bay City TX

No. of employees: 375

Contact: I. O. Coleman, Jr., Mark Hewlett

Phone: (409) 245-4871, (409) 245-4871

Description:

The Bay City Plant (BCP) of Hoechst Celanese Chemical Group, Inc. began implementation of the propylene vent recovery project in its OXO Alcohols unit in October 1993. The goal of the project was to recover a propylene rich vent stream that previously left the alcohols unit and was burned in the plant boilers to utilize its fuel value. Recovery of this propylene would make the BCP alcohols unit one of the most efficient producers in the world. The second phase of the project involved elimination of direct alcohols emissions to the air at our loading facilities by installing "closed dome" equipment to collect alcohol vapors and send them to a shipping flare to achieve 98% DRE.

P2 Application:

A proprietary process was installed to allow conversion of a majority of the propylene in the vent stream to additional butyraldehyde product which was then combined with the primary butyraldehyde product stream for conversion to sales grade butanol.

Environmental Benefits:

This project is part of the Hoechst Celanese Vision of Excellence to reduce SARA emissions by 80% by 1996. This project reduces the OXO Alcohols unit VOC emissions from plant boilers, storage tanks and loading operations from 279 tons/yr to 180 tons/yr.
This environmental project also solved a seemingly unrelated railcar washing problem. The railcar industry is discontinuing the use of bottom outlet valves on railcars to prevent leaks to the environment. Without these bottom outlet valves, our washing could not drain off wash water after the cars were cleaned. The equipment installed for alcohols vapor recovery allowed removal of wash water through a totally contained system.

Details of Reductions

Additional Information :

This project was both a cost reduction and an environmental improvement project. The increased yield of desired oxo alcohol product provides increased savings and earnings to allow the company to obtain a payback of less than five years on the capital expenditures. And, at the same time, significant environmental benefits were obtained.

Source: TCEQ