Wasson Chromatography Corner 18

Significance of Hydrocarbon Analysis in Reforming Processes

Accurate monitoring of reforming reactions and refinery streams is essential to optimize yields, ensure product quality and meet environmental regulations. Comprehensive hydrocarbon profiling at trace levels supports process control in fuel reforming, isomerization, and sulfur removal steps.

Objectives and Overview

This newsletter issue describes three analytical challenges addressed by Wasson-ECE: comprehensive hydrocarbon fuel reforming analysis, online monitoring of reflux and isomerate streams, and sulfur speciation using chemiluminescence detection. The goal is to demonstrate turnkey GC solutions that deliver sensitive, reproducible measurements for both permanent gases and complex hydrocarbon mixtures.

Methodology and Instrumentation

Two complementary methods were implemented on a single Agilent gas chromatograph:

• FID-based analysis for methane, propane, methanol and ethanol down to 10 ppm.
• Dual TCD (summed) analysis for permanent gases including H₂, CO₂, O₂/Ar, N₂, CO, NH₃ and H₂O at 100–400 ppm.

Online analysis of refinery distillates employed a three-part system: an Agilent GC with FID, a precision sampling subsystem capable of ambient or sub-ambient aliquot delivery, and an automated control computer. Special double block and bleed valves prevented cross-contamination. A single 70 minute FID run resolved C₂–C₈ alkanes, cycloalkanes and aromatics at 400 ppm detection limits. Sulfur chemiluminescence detection (SCD) was detailed, illustrating oxidation to SO/SO₂ under partial vacuum, photon emission and equimolar response.

Main Results and Discussion

The combined FID/TCD configuration achieved an eleven-minute total runtime for reforming gas streams, enabling high throughput. Online reflux/isomerate monitoring delivered unattended, accurate quantitation of over 20 hydrocarbon components. The SCD method provided sub-ppm sulfur speciation with straightforward calibration but required precise air-H₂ ratio control.

Benefits and Practical Applications

• Single-system analysis of complex gas mixtures reduces capital and maintenance costs.
• Automated online sampling improves throughput and reproducibility in refinery QA/QC.
• Equimolar, species-specific sulfur detection supports compliance with tightening regulations.

Future Trends and Application Potential

Advances in multi-detector GC configurations and data processing software will further shorten run times and enhance peak identification. Integration with continuous process analytics and machine learning can enable predictive maintenance and dynamic process optimization.

Conclusion

Wasson-ECE’s tailored GC solutions demonstrate robust performance for fuel reforming, reflux/isomerate analysis and sulfur speciation. The combination of FID, dual TCD and SCD technologies on a single platform offers comprehensive, reliable data essential for modern refinery and environmental laboratories.

Used Instrumentation

• Agilent Technologies Gas Chromatograph with FID and dual TCD detectors
• Sampling subsystem with double block and bleed valves
• Chemiluminescence sulfur detector (SCD)