SULFUR RECOVERY PLANTS
In sulfur plants,sulfur is recovered from hydrogen sulfide present in natural gas.There are several processes for this conversion,which is basically called the Claus process.

In 1940s, Du Pont developed a process to make ethylene glycol, or antifreeze, from hydroxyacetic (glycolic) acid. Over the next 30 years, the company developed other markets for glycolic acid, and in the mid-1970s, when more cost-effective methods of producing antifreeze had been discovered, the company opted to continue making the product for its growing list of new applications.

Zirconium is one of the few metals that resist attack by sulfuric acid at all concentrations to 70% and temperatures to boiling and above. These conditions are so corrosive to metals that most chemical processes are designed to circumvent them. In some cases, however, efficiency of operations and product yields dictate operating parameters that are in this envelope where sulfuric acid is extremely aggressive.

There are 3 main areas where sulfuric acid dewpoint temperature measurement can have major benefit:

• Process Control
• Thermal Efficiency
• Emissions Control

Zirconium and alloys of it, have found increased use in sulfuric acid service in media where many other engineering materials have fallen short.

Hydrogen embrittlement in boiler

Hydrogen embrittlement of mild steel boiler tubing occurs in high-pressure boilers (above 10 bars), when atomic hydrogen forms at the boiler tube surface as a result of corrosion.

Microbiologically induced corrosion of copper intrauterine devices “TCu380A” and “Nova T” by Enterobacter sp. in a synthetic intrauterine medium was investigated.

Potentially corrosive species produced by various types of bacteria include sulfuric acid, organic acids, enzymes and sulfur containing compounds. Given the right conditions, bacteria populations can undergo explosive growth, as can be illustrated in a simplistic growth model.

In the final repository, the canister must be protected against corrosion.  Above all oxygen and sulphide ions (S2-) of the substances, which are present in the groundwater, can cause corrosion of the canister. Oxygen can react with copper and form copper oxides. The sulphide ions form copper sulphide when they react with the copper.

In natural aquatic environments bacteria predominantly grow as multi-species communities called biofilms, attached to submerged surfaces. Better Knowledge of the development of biofilms is essential for studying their ecological role and also for devising effective strategies to control detrimental biofilms.

Biofilm is a microbially derived sessile community, attached to an interface, embedded in gelatinous matrix. Biofilm exhibits an altered phenotype with respect to growth, gene expression, and protein production. Attachment of microorganisms is the first step in biofilm formation on any surface.

Plate heat exchangers are used in Ocean Thermal Energy Conversion plants, dairy unit and lube oil cooling plants where a small D T is available for transfer in the system. They are widely preferred because of their compactness, surface area temperature approach upto 1° C. Absolute heat exchanger cleanliness is essential for the performance of these exchangers.

Numerous microscopic studies have described the development of biofilm on surfaces immersed in marine waters. The biofilm development begins with the adsorption of dissolved organic matter followed by the colonization, attachment and growth of microorganisms, and adsorption of particulate matter.

Various studies have indicated that multispecies biofilms have characteristic architecture and behave very much like 'quasi-tissues', exhibiting remarkable metabolic co-operativity among constituent microcolonies and a primitive type of homoeostasis.