Total Sulfur Analyzer

Sulfur content in Liquefied Petroleum Gas (LPG) is tested to optimise the catalytic hydrodesulfurization process. Its traceability is also crucial due to the emissions of sulphur dioxide as atmospheric pollution. Very low sulfur detection in LPG samples is increasingly crucial to ensure the accurate monitoring of total organic sulfur thus reducing corrosion, avoiding catalyst poisoning and meeting product quality specifications. One analyzer with the sample introduction system for LPG samples and built in standard gas blend generator offers a new and cost effective solution to these monitoring needs.

 

Total Sulfur Monitoring in Liquified Petroleum Gas

Liquified petroleum gas (LPG) is one of the key products of any refinery. LPG is usually sold to a processing facility to be further refined. This refinement often requires the use of expensive catalysts.

Sulfur compounds, naturally found in petroleum products, act as poisons to noble metal catalysts used in the processes employed in converting feedstock to useable intermediate and end products. Because of this, sulfur compounds are removed entirely from the LPG at a point prior to a vulnerable process or prior to sale to a processor or end-user. Analyses are made at a point directly downstream from the sulfur removal step and are used as a check on sulfur scrubbing efficiency. The sulfur removal process can typically be hydrotreatment (over a non-sulfur-sensitive catalyst) or scrubbing with some (solid or liquid) material that reacts with and removes the sulfur compounds.

Total Sulfur Monitoring in Ethylene and Propylene Refining

One principle activity at most large refineries is the refining of ethylene and propylene from crude oil and its derivatives. Sulfur and sulfur compounds are present to some extent in almost all crude oil reserves in the western hemisphere. Ethylene and propylene are primarily used as raw materials in the manufacturing of plastics; these process streams are sold to chemical processing plants where they are polymerized.

Sulfur compounds poison the polymerization process employed in converting ethylene and propylene to polyethylene and polypropylene, respectively. Very expensive catalyst chemicals are destroyed as a result of the “poisoning”. Because of this, sulfur compounds are scrubbed from ethylene and propylene process streams, normally at the refinery prior to sale to the processor. Lead oxide (PbO) scrubber beds are used as sulfur scavengers. Similar to an automobile catalytic converter, the scrubber bed consists of a large reactor vessel filled with millions of ceramic balls, which are coated with lead oxide.

Lead oxide has a tremendous affinity for absorbing many different sulfur compounds but, eventually, reaches a saturation point, when reactivity drops and no more sulfur can be absorbed. When this point is reached, the scrubber bed must be regenerated. Usually, scrubber beds are operated in parallel, enabling one bed to be regenerated while the other remains on-line. Without a sensitive, specific, on-line sulfur analyzer, the beds are regenerated every four to seven days as a safeguard (whether it is needed or not). Bringing in a C.I. Analytics Total Sulfur analyzer can virtually eliminate the need to perform unnecessary regeneration of the scrubber bed.

 

  C.I.Analytics offers 2010L analyzer that can detect Total Arsenic, Total Chlorides, Total Nitrogen and Total Sulfur in addition to elemental impurities analysis with high levels of accuracy, speed and high degree of automation. Until recently, separate analyzers were required to measure total compounds in hydrocarbon stream which was expensive. Now, one analyzer can perform both these detections from low PPB levels to high ppm levels. With this analyzer payback is fast, due to decreased reprocessing time and maximized product output. 

 

Note: Houston Atlas replacement