Corrosion Control in the Paper Industry
It is a fact that corrosion has a significant economic impact on an industrial scale. As an example, the results of a study carried out in the USA showed that the estimated annual cost due to corrosion was $276 million, which is approximately 3.1% of the country's gross domestic product (GDP). It is logical then that, during the last decades, great efforts have been invested to face this problem and significantly improve corrosion management, offering better solutions, better equipment and new materials adapted for this purpose.
But what do we mean by "corrosion"? It can be defined in many ways, among the different meanings, we could say that corrosion can be the deterioration of materials by chemical interaction with their environment. Although the term corrosion is sometimes also applied to the degradation of plastics, concrete and wood, but in general it refers to metals.
The main problem is corrosion occurring in large industrial plants, such as power plants or chemical processing plants, where corrosion can even lead to plant shutdowns and/or production stoppages, with the economic consequences that this entails.
In particular, the paper industry is one of the industries most susceptible to this problem, which is why they invest in systems to reduce and control corrosion levels.
Project Description
BION has extensive experience in this sector and in recent years has improved the solutions suggested to avoid equipment failures due to corrosion. In the last 4 years Bioconservacion has supplied a mixture composed of BION ISORB and BION DOD to a pulp and paper plant located in Uruguay, specifically at the UPM plant in Fray Bentos. This plant is located on the banks of the Uruguay River, 4 km east of the city of Fray Bentos in the province of Rio Negro, and has a production capacity of 1.3 million tons per year of bleached eucalyptus short-fiber pulp for the manufacture of glossy paper and tissue paper.
PBS (Parallel Bed Scrubber) equipment was installed in this plant to prevent the deterioration of electrical components due to corrosion. The PBS equipment is a system similar to a SAH equipment, where the filter media are packed in bulk instead of using modules. This type of system can treat horizontal flows between 425 and 54,000 m3/h. On this occasion, the installed equipment is composed of two treatment stages, each with specific filter media in order to obtain maximum efficiency in the elimination of complex air emission.
After studying the composition of the main pollutants present in the installation, Bioconservacion suggested two filter media, which in combination can successfully remove most of the problematic compounds present in the stream. This specific mixture is composed of BION ISORB and BION DOD.
BION ISORB is designed to successfully attack a wide range of gases. It is especially recommended for the control of acid gases, nitrogen containing compounds, sulfur compounds and low molecular weight gases. BION ISORB uses a combination of two processes for contaminant removal. One of a physical nature, trapping the molecules inside the pellet due to its large internal surface area and a second by chemical oxidation. The oxidized gases are converted into harmless products. A particularity of BION ISORB is that it maintains its effectiveness even in the treatment of streams with relative humidity contents up to values above 95%.
This filter media is commonly used in applications such as wastewater treatment plants, pulp and paper plants, airports, chemical plants, refineries or laser cutting and engraving plants.
In turn, BION DOD is a high purity, high surface area, bi-impregnated activated carbon that effectively neutralizes acids.
BION DOD is a filter media widely used in water treatment plants, it has a very high H2S absorption capacity and is very useful for the treatment of mercaptans and other volatile organic compounds. It is a filter media especially suitable for neutralizing acidic compounds.
Evaluation
UPM Fray Bentos has been working with this PBS equipment and BION ISORB and BION DOD filter media to effectively prevent corrosion for 4 years. The client has been able to extend the life of its equipment and save costs due to maintenance shutdowns.
Bioconservacion also offers the service of performing an analysis of the remaining life of the filtering granulates, halfway through their estimated life, in order to re-optimize the replacement of the granulate mixture in the event that the actual working conditions differ from the initial conditions taken into account in the characterization.
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