Water treatment cuts deposition at oil and solvent recovery plant

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Chem. Process. (Chicago); (United States)

OSTI ID:5509555

Guevara, N Jr; Weir, G; Toy, D A

To accommodate its process water needs, the Oil and Solvent Process Company (OSCO) of Azusa, CA uses city water containing over 69 ppm calcium (as CaCO/sub 3/) and over 15 ppm silica. The company requires a flow rate of 1800 gpm to cool its evaporative condensers. The previous water treatment program was unsatisfactory and, because of this, many of the cooling water condensers at the plant would regularly clog due to deposition. Of specific concern are the water chemistry limits (and corresponding deposition) of: calcium carbonate, calcium sulfate, calcium phosphate, and silica. The chemical treatment program prescribed and initiated at OSCO includes: a molybdate-based mild steel corrosion inhibitor; a tolytrizole-based copper corrosion inhibitor, acid for pH control, chlorine and 1.5% chloromethylisothiazolin for bacterial control, and phosphonate and polyacrylate for inorganic antifouling. After over a year of operation under the prescribed chemical treatment program, OSCO has found that deposits have not occurred - even under operating conditions with calcium levels as high as 1850 ppm (as CaCO/sub 3/), a calcium sulfate multiplier exceeding 3.6 million, orthophosphate levels of 5 ppm (as PO/sub 4//sup =/), and silica levels as high as 315 ppm. There has been evidence that previous deposits have been removed. Condenser vacuums have subsequently risen from around 12'' to about 25'', effectively doubling production in the distillation condensers. Corrosion rates for mild steel, copper, and admiralty have been measured at below 2.1, 0.1, and 0.1 mpy, respectively with no signs of pitting. No observable chloride stress corrosion was noted in stainless steel.

• Research Organization: Oil and Solvent Process Co., Azusa, CA
• OSTI ID: 5509555
• Journal Information: Chem. Process. (Chicago); (United States), Journal Name: Chem. Process. (Chicago); (United States) Vol. 48:12; ISSN CHPCA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CALCIUM PHOSPHATES
CALCIUM SULFATES
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CONDENSERS
COOLANTS
CORROSION INHIBITORS
CORROSION PROTECTION
DEPOSITION
FOULING
HYDROGEN COMPOUNDS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PH VALUE
PHOSPHATES
PHOSPHORUS COMPOUNDS
POLLUTION ABATEMENT
SCALING
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SULFATES
SULFUR COMPOUNDS
USES
VAPOR CONDENSERS
WATER
WATER POLLUTION ABATEMENT