Water-soluble Inhibitor Research Articles

Control of Internal Corrosion Of a Products Pipe Line System

Abstract This article considers the matter of controlling internal corrosion in a products pipe line system and reports experience with two control methods. A laboratory method of evaluating a particular oil soluble inhibitor is described, as well as the application of the laboratory method to control the degree of protection in the pipe line and to facilities beyond the pipe line. A specific method of determining the amount of inhibitor in the product also is discussed and proper interpretation of the laboratory data is emphasized. Experience referred to covers the corrosion control in a single 8-inch products pipe line transporting only premium and regular grades of motor fuel and 100 and 115 grades of aviation gasoline. This includes use of a water soluble inhibitor for several years but because the degree of protection desired was not realized and because the protection ended at the pipe line terminus, decision was made to substitute an oil soluble inhibitor. Factors considered in selecting the oil so...

Use of High Molecular Weight Corrosion Inhibitors In Petroleum Refineries

Abstract The theory of adsorbtive inhibitors is discussed briefly. An account is given of tests by coupons and in refinery equipment evaluating the effect of three semi-polar compounds in reducing the corrosion of refinery equipment. Data on concentrations, technique of additions to streams, coincident use of ammonia, cost per barrel of charge, percentages discharged in effluent and percentage retained in stream are given. Considerable information is revealed indicating the detergent action of the inhibitors assists in reducing deposits on tubes and in pumps and other equipment and thereby extends the period between shutdowns for cleaning. Significant reductions in the corrosion rates in crude distillation units, steam reboilers, straight run deisobutanizers, vacuum pumps, alkylation units, TCC units and other refinery equipment are reported. The author concludes water soluble inhibitors tested are sufficiently soluble in hydrocarbons to provide corrosion protection.

Part 2. Inhibitors in Cargo

Abstract* Part 2. Inhibitors in Cargo. Magnitude of corrosion losses in tankers is detailed. One typical tanker in coastwise service, after 195 mixed cargoes, or approximately eight years' service, had top 18 feet of all cargo bulkheads renewed at a direct cost of $250,000, an average of $1300 per voyage. Lower bulkheads must be replaced in four years, making total corrosion cost $50,000 to $75,000 a year for direct steel replacement costs. Additional costs include $3000 to $8000 a day for lost time while ship is under repair, the difference between normal drydocking and extensive bulkhead renewal being three to four weeks. Tests on paints, dehumidification, metallic coatings, cathodic protection and water soluble inhibitors show these to be unsatisfactory. An oil soluble inhibitor, on the basis of a 9 months' comparative test, show Monsanto Chemical Company's Santoline C has sufficient merit to warrant additional investigation.