ANS:A - ethanolamine

H2S (hydrogen sulfide) present in naphtha reformed gas is commonly removed by absorption using a solvent such as ethanolamine. Ethanolamine, a common amine-based solvent, reacts with hydrogen sulfide to form a stable compound that can be easily separated from the gas stream. This process is known as amine gas treating or amine scrubbing. Ethanolamine is particularly effective for removing H2S from gas streams due to its high reactivity with hydrogen sulfide. While other chemicals like potassium carbonate (K2CO3) or hydrochloric acid (HCl) can also be used for H2S removal in different processes, they are not as commonly employed for this specific application in naphtha reformed gas. Vacuum gas oil is not typically used for H2S removal; rather, it's a type of feedstock used in various refining processes. Ethanolamine, also known as monoethanolamine (MEA), is a versatile chemical compound commonly used in various industrial applications, including gas purification, corrosion inhibition, surfactant production, and chemical synthesis. Here's an explanation of ethanolamine and its properties:

1. Chemical Structure: Ethanolamine has the chemical formula 𝐶2𝐻7𝑁𝑂C2​H7​NO and consists of a primary amine group (NH2) attached to a hydroxyl group (OH) on a two-carbon backbone. Its structure makes it a member of the amine family of organic compounds.
2. Reactivity: Ethanolamine is highly reactive due to the presence of both amine and alcohol functional groups. The primary amine group is capable of undergoing various chemical reactions, including acid-base reactions and nucleophilic substitutions. The hydroxyl group also contributes to its reactivity, allowing ethanolamine to participate in reactions such as esterification and ether formation.
3. Absorption Properties: One of the key applications of ethanolamine is in gas purification processes, particularly the removal of acidic gases such as carbon dioxide (CO2) and hydrogen sulfide (H2S) from natural gas and refinery gases. Ethanolamine reacts with acidic gases to form stable salts or complexes that can be easily separated from the gas stream. This absorption process, known as amine gas treating or scrubbing, relies on the high reactivity of ethanolamine with acidic gases to achieve efficient removal.
4. Corrosion Inhibition: Ethanolamine is also used as a corrosion inhibitor in various industries, including oil and gas production, water treatment, and metalworking. It forms a protective film on metal surfaces, preventing corrosion caused by exposure to corrosive environments such as acidic solutions or oxygen-containing atmospheres.
5. Surfactant Properties: Due to its amphiphilic nature (containing both hydrophilic and hydrophobic groups), ethanolamine can act as a surfactant or wetting agent. It is used in formulations for detergents, personal care products, and industrial cleaning agents to enhance their wetting, emulsifying, and foaming properties.
6. Chemical Synthesis: Ethanolamine serves as a building block in the synthesis of various organic compounds, including pharmaceuticals, herbicides, and plasticizers. Its functional groups make it a valuable intermediate in the production of diverse chemical products.

Overall, ethanolamine is a versatile chemical compound with a wide range of industrial applications, thanks to its reactivity, absorption properties, corrosion inhibition capabilities, and surfactant properties. Its ability to react with acidic gases makes it particularly valuable in gas purification processes, where it plays a crucial role in ensuring the quality and safety of industrial gases.