RE-EVALUATION OF THE INFLUENCE OF TEMPERATURE AND TOTAL ACID NUMBER ON NAPHTHENIC CORROSION BY ELECTROCHEMICAL NOISE TECHNIQUE

• DOI: 10.22533/at.ed.01719091016

• Palavras-chave: ATENA

• Keywords: electrochemical noise, corrosion, naphthenic acids, petroleum refining.

• Abstract:

  The control of corrosion by

  naphthenic acids is one of the biggest

  challenges of the refineries that process viscous

  oil. This corrosion process, which mainly affects

  the circuits of elevated temperatures, can

  cause rapid mass loss and hardware failures.

  Its monitoring enables the evaluation of the

  effectiveness of a corrosion control program and

  the establishment of operational limits. Among

  the used techniques, there is the monitoring

  of the composition of the streams of crude oil

  and the measurement of corrosion rate (mass

  loss coupons, electrical resistance, ultrasound,

  etc.). Many researches have been developed

  aiming both information on critical operating

  parameters and new methods of monitoring,

  but there are few options that provide online

  predictive and proactive control of the corrosive

  process. This research proposes the use of

  the use of Electrochemical Noise technique

  as an evaluation tool control parameters and

  monitoring corrosion by naphthenic acids in

  critical process conditions. ASTM A335 P5

  material was evaluated in oily media with

  total acid numbers (NAT) of 2.5, 8.0 and 28.0

  mgKOH/g at temperatures between 100 °C to

  250 °C. It was observed that, under the studied

  conditions, the temperature is the predominant

  variable, inducing increased Reaction Charge

  with its increase. Moreover, the evaluation of

  Noise Resistance and Frequency of Events

  demonstrated that there is a predominance of

  general corrosion in milder temperatures, with

  an incidence of localized corrosion above 200

  °C.

• Número de páginas: 15