Analysis of Thickness Decline and Residual Life Prediction of Corroded Sulfolane Pipes in Oil Refineries
Muhammad Ichsanudin, Affan Arsyada, Imam Prabowo, Intan Istiqomah

Universitas Pembangunan Nasional Veteran Yogyakarta

Abstract

One of the supporting systems in petroleum processing activities is the sulfolan supply system. Sulfolane is a compound that plays a very important role in petroleum processing, especially in extracting aromatic compounds from crude oil. However, sulfolane is toxic and harmful to human health and corrodes structures when it reacts with oxygen. A study on the residual thickness of sulfolan pipes was conducted to determine the aggressiveness of sulfolan in corroding the pipe structure. Thickness measurements were taken using an ultrasonic thickness meter at 5 locations on the sulfolan pipe. At each point, measurements were taken four times at different angles. Based on these measurements, the minimum thickness of the sulfolan pipe is only 3.45 mm. Thickness analysis is performed using two approaches, namely fluid and structural loads. The minimum thickness required to accommodate fluid loads based on ASME standard B31.3 is 1.9 mm. While based on the structural approach based on API recommended practice 574 criteria, the minimum required thickness is 3.3 mm. Therefore, the pipe thickness is only 0.15 mm left until the material must be replaced. To obtain the residual life of the sulfolane pipe, the corrosion rate was calculated based on the minimum thickness found during the inspection. The corrosion rate was found to be 0.16 mm/year, so the life of the sulfolane pipe is only 11 months. The corrosion damage mechanisms in sulfolane pipes include uniform corrosion, corrosion under insulation, and atmospheric corrosion. Measures to replace the sulfolane pipe material must be prepared immediately so that structural failure can be prevented as early as possible to avoid disrupting the primary process in petroleum processing activities.

Keywords: corrosion, refinery, residual life, sulfolane, thickness decline

Topic: Engineering