Clathrate-Based Recovery of Sulfuric Acid from Spent A cid

Abstract

Recently, the applications of hydrate phenomena in industrial processes have been increasing. A clathrate or hydrate is a solid, ice-like compound that forms when water/guest is mixed under certain conditions. Hydrogen water molecules bond with the guest molecules to form a crystal lattice. Different guests can form the Clathrate (e.g., gases or liquids). Dilute Sulfuric acid is usually generated at different industrial plants, and these dilute acids are considered waste because they cannot be reused again. Many treatment processes handle this environmental problem, like electrochemistry, precipitation, adsorption, membrane filtration, and ion exchange. Although such processes have significant operational advantages, their disadvantage is that many of the high costs of the treatment process and the generated products of treatment are considered toxic pollutants. This work utilized clathrate phenomena experiments to re-concentrate dilute sulfuric acid. The selected clathrate guest was Cyclopentane. Each experiment s consists of a mixture of Cyclopentane and dilute sulfuric acids. The volume ratios of dilute sulfuric acid to Cyclopentane were (6:1, 4: 1, 3:1, and 2:1) with different initial concentrations (12.5%, 10%, 7.5%, 5%, 2.5%) of acid. It was found that the clathrate method was effective in re-concentrate dilute sulfuric acids with a maximum efficiency of 94% at the ratio of acid /cyclopentane (6:1) at 12.5% concentration. It can be concluded that the increase in dilute sulfuric acid /cyclopentane volume ratio leads increasing in removal efficiency while reducing the yield percentage and enriched Factor.

Keywords

• acid extraction
• clathrate hydrate
• hydrate formation
• sulfuric acid (h2so4)
• solvent extraction