Clausstekniikka

Clausstekniikka refers to the Claus process, a chemical engineering technology primarily used for the recovery of elemental sulfur from hydrogen sulfide (H2S) found in raw natural gas and refinery gas streams. This process is crucial in industrial settings for environmental protection and resource recovery, as hydrogen sulfide is a toxic and corrosive gas.

The Claus process typically operates in two main stages. The first stage involves the thermal decomposition of hydrogen sulfide in a high-temperature furnace, producing sulfur dioxide (SO2) and water. This reaction can be represented as 2 H2S + 3 O2 -> 2 SO2 + 2 H2O. The second stage utilizes catalytic converters where the sulfur dioxide reacts with the remaining hydrogen sulfide to produce elemental sulfur and water. This is an equilibrium reaction: 2 H2S + SO2 <=> 3 S + 2 H2O. This stage is usually carried out in multiple steps with cooling and reheating between each catalytic bed to maximize sulfur recovery.

Various modifications and enhancements to the basic Claus process exist, such as the "Rich" Claus process, which incorporates an acid gas enrichment step, and "Tail Gas Treatment" (TGT) units, which further process the tail gas (residual sulfur compounds) to achieve very high overall sulfur recovery efficiencies, often exceeding 99%. These TGT units can employ technologies like the SCOT (Shell Claus Off-gas Treatment) process or other catalytic hydrogenation and hydrolysis methods. The elemental sulfur produced is typically in molten form and is then solidified into prills or blocks for transportation and sale.