How To Prepare High-Purity Water for the Petrochemical and Biofuels Industries
By Brad Buecker
The extraction of inexpensive gas and oil from shale formations (known as “plays”) in the last several years has spurred significant growth of the U.S. petrochemicals industry. And, even though the biofuels/biochemical industry has moved along in fits and starts, new, full-scale plants continue to come on line.
At all of these plants, steam is or will be a necessary commodity for process operation and often supplemental power production. Yet, plant owners, operators, and other technical personnel may not always recognize the importance of producing high-purity makeup for steam generation until steam generators are afflicted with boiler and steam piping failures. Many of these lessons have already been learned in the power industry, but have not necessarily translated to other industries.
Typically, the makeup treatment process for a surface water source involves, in order, large solids removal by screens or settling basins, suspended solids removal, and finally dissolved solids removal to produce the water needed for the plant. We will focus on the last two processes.
In the past, clarification/media filtration was a common technology used for suspended solids removal. Clarification remains a quite viable process, particularly in applications where lime/soda ash softening is needed to reduce raw water hardness, or where high concentrations of suspended solids are an issue. Rivers are a good example of the latter, when heavy precipitation may stir up huge quantities of mud and silt.
This article examines several of the most modern techniques for high-purity makeup water production. Because of space limitations, the article does not substantially address pretreatment, which is becoming an ever increasing issue of importance because of the declining lack of fresh water for industrial makeup
Log in or Subscribe to Access the Full Article
To read or download full-length articles you need a subscription to Ultrapure. Please log in or subscribe below.