BTX Extraction for Fuels, Additives and Chemicals

BTX Extraction ProcessMost fuel-additives and specialty chemicals have a BTX components for solvency or cleaning. The aromatic hydrocarbons benzene, toluene and xylene (BTX) are amongst the most important raw materials in the petrochemical industry. Apart from serving the petrochemical industry, where they are used in forming different chemicals such as styrene, caprolactum, phenol and other chemical compounds, they are also used in specialty chemicals and fuel additives as solvents and cleaning compounds. BTX hence plays a major role in sustaining everyday products.

The cracking of petroleum feedstocks in refineries and petrochemical plants yields streams rich in BTX. BTX is normally separated from hydrocarbon streams via liquid-liquid extraction. Many different polar solvents have been studied for aromatics extraction, but the first efficient method was the Udex process by Union Carbide based on a glycol solvent. Introduced in 1952, the process was superior at the time because, for the first time, a wide-boiling feed stock could be treated directly to yield high purity BTX products without expensive pre-fractionation. In 1959, Shell developed a new BTX aromatic extraction process based on ‘sulfolane’ solvent, (tetra hydro-thiophene 1,1- dioxide). Sulfolane has a higher polarity than glycols and is therefore a better solvent; however, glycols tend to be easier to separate from extract because of the lesser polarity. Other solvents such as n-methyl pyrolidone (NMP), dimethylsulfoxide (DMSO), dimethylformamide, morpholine, and carbonate derivatives have also been used or researched. Recently, ionic liquids have been garnering lots of attention.

The major solvent characteristics affecting the extraction process efficiency are the solvency and the selectivity. However, other characteristics must be taken into account such as the chemical stability, compatibility, availability, price, and environmental hazards.

With years of experience working on different BTX extraction units in petrochemical plants, PEC brings a diverse skillset in basic and detail engineering of BTX extraction processes. We offer the following scope of services:

  • Process simulation for individual columns of the BTX process as well as the entire BTX extraction unit
  • Analysis of current operation, troubleshooting and recommendations for process efficiency improvement (e.g. modification of flow rate, change of solvent, relative mass flowrates of lean solvent against the feed)

Process Engineering Consulting is a team of engineers with expertise in fuel and fuel additives, process engineering, chemical process design, techno-economic analysis, and tech due-diligence. Feel email us at info@processengineeringconsulting.com for more information or reach us directly at +1-825-365-1687.