Premium
Computational fluid dynamics investigation for austenitic AISI 904L stainless steel corrosion in a biodiesel stream piping
Author(s) -
Ferreira D. J. O.,
Torres C. E. A. S.,
Lins V. F. C.,
Park S. W.
Publication year - 2018
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201709727
Subject(s) - piping , hydrochloric acid , materials science , corrosion , methanol , biodiesel , austenitic stainless steel , austenite , refinery , metallurgy , chemistry , organic chemistry , catalysis , environmental science , environmental engineering , microstructure
A Brazilian biodiesel plant uses the transesterification of soybean oils with the methanol and sodium methoxide catalyst excess to convert these oils into alkyl esters and glycerin. Hydrochloric acid solution is injected in the piping to neutralize free NaOH and reduce saponification of oils. After the hydrochloric acid solution, several failures of pipelines of AISI 316L and 904L steels were registered. The objective of this work is to study the austenitic stainless steel corrosion observed in the downstream piping the hydrochloric acid injection, applying computational fluid dynamics and to evaluate pH and chloride profiles using different geometries for the acid solution injection in order to avoid or mitigate the corrosive attack. The obtained results showed a good agreement with in situ observations of the pipe degradation. All the studied geometries presented evidence of a weak mixture between the polar and non‐polar species, even under turbulent flow. The elbow geometry is more effective to reduce the local corrosive attack compared to two other simulated geometries.