HPD Office Locations
Turnkey Salt Purification & Caustic Concentration System
Shintech, Inc., the largest producer of polyvinyl chloride (PVC) in the United States, desired to become more vertically integrated in its production operations in addition to expanding its production capacity to meet growing demand in the North American market.This vertical integration includes the production of the PVC precursor vinyl chloride monomer (VCM) from a dedicated in-plant chlor-alkali facility.
Critical Process Equipment
The world's largest single-stage salt crystallizer at Shintech, Inc.
In order to achieve the desired production goals, major chemical processing equipment was necessary to generate the large quantities of high-quality sodium chloride as raw material needed to support the chlor-alkali plant operations. Other processing needs for the plant included concentration equipment of the by-product caustic soda.
Due to the scale of the facility and the highly complex effort in overall plant design and construction, Shintech required a reliable partner to provide these vital components.
HPD was selected to provide the salt purification plant and caustic soda evaporation system for Shintech's new Plaquemine facility.This was due to HPD's commercially demonstrated experience in this industry with the ability to manage and execute large-scale, turnkey construction projects.
Process Equipment Description
Caustic soda evaporation system from HPD
Production goals at the new Plaquemine manufacturing plant were ambitious. The equipment HPD was contracted to design, supply, and install were critical to the success of the plant in reaching these goals.
The salt purification system, essentially the heart of the plant, consisted of a single-stage salt crystallizer fed by an upstream reactive brine pre-treatment process. Driven by mechanical vapor recompression (MVR), the system is designed with a nameplate capacity of 820,000 metric tons per year (mtpy) of high-quality sodium chloride that is utilized in the chlor-alkali plant. When completed, this system would be the largest, single-stage evaporated salt system in the world.
The companion project awarded to HPD involved a by-product of the chlor-alkali plant. An evaporator system was needed to concentrate the merchant membrane cell caustic from 32 wt% to 50 wt%. This system would produce 1,520 metric tons per day (mtpd of sodium hydroxide on a dry basis.
The concentration system was designed as a steam-driven, triple-effect, falling film evaporation train and is configured to maximize steam economy. The challenge for HPD was to design the system with a minimum turndown of 15% of design capacity required by Shintech.
Website: www.hpdsystems.com
