Material behavior study in corrosive environments reflecting biorefineries and biogas installations

Many studies present biorefineries as strategic tools for the future bioeconomy. The development of new processes in integrated biorefineries and related (although so far limited to 1G biorefineries) experience in the domain would militate for accessing updated knowledge to put corrosion economic impact under control and thus optimize CAPEX and OPEX of such production facilities. To identify biorefinery induced specific corrosion issues innovative experimental approaches are proposed in the ECORBIO project. We proposed to measure in laboratory the effects of industrial products such as organics acids and by-products (molasses, vinasses, condensates, digestates) on steel and stainless steel samples, in corrosive environments reflecting as far as we know biorefineries and biogas installations. Corrosion tests on selected S235, 3CR12, 316L metal samples were carried out in corrosive environments reflected by liquid and vapour phases of solutions of succinic acid, citric acid, lactic acid and acetic acid. Sulfuric acid and water are chos~n as references solutions in the study. Laboratory reflux apparatus was used in the order to stabilize the system to 100°C. Anaerobic fermentation tests on S235, 3CR12, 316L were also carried out in digestates with or without glycerol. An incubator apparatus was used in the order to stabilize system to 32 °C and 160 rpm. Corrosion kinetics was assessed in a first approach by visuals observations of samples and by mass loss data analysis. S235 steel samples are the most damaged and have the greatest mass loss (Fig.1 and 2). During the corrosion tests, 3CR12 steels have damages and mass loss higher than 316L steels, which are practically unchanged (Fig.1 and 2). By contrast, during anaerobic fermentation tests, 3CR12 steel samples show substantially more resistance to corrosion in the test environment than for 316L steel (Fig.1 and 2). Thereafter, metal concentrations in aggressive solutions will be assessed and related to mass loss, in the order to establish a metals extracting model