A review of incident trends reveals ways to reduce risks to production
FAILURE of an amine system to reliably treat process streams can have a devastating effect on production, the environment, and (sadly) an engineer’s bonus. The intention of this article is to use the empirical trends from amine system failure investigations to focus attention on where risks to production can be significantly reduced.
Amine is a widely-used solvent for removing carbon dioxide (CO2), hydrogen sulfide (H2S) and occasionally other acidic species from process streams. It is used in the oil, gas, steel, ammonia, hydrogen, biogas and carbon-capture industries. The process stream is mixed with a circulating aqueous amine solvent in a vertical column (contactor or absorber) where the bulk of the species is removed. The loaded amine solution needs to be regenerated for reuse, which occurs in another column (stripper, still, or regenerator) by decreasing the pressure and adding heat, which releases the acidic species from the amine solution. The liberated species, H2S and CO2 for example, may be processed further, reinjected, or appropriately incinerated.
For this study, we constructed a database containing 375 cases of severe production failures (for incidents costing US$250,000–250m in lost production). We included only well-documented cases where an in-depth, technically sound, investigation had been conducted by an Amine Experts consultant (272 incidents), or a paper’s author (103 incidents).
Severe amine system failures fall into five categories (see Figure 1): Off-specification product; corrosion; foaming; flooding; and extensive amine loss (solvent degradation or leaks). The three most frequent failure areas – foaming, product quality, and corrosion – are discussed here in more detail.