EN
The demand for high-purity BTX aromatics for the synthesis of petrochemical products is steadily increasing.
New catalysts enable performance improvements in the reformers (platformer, aromizer) and thus higher selectivities and yields of BTX aromatics.
Reformer products, the so called reformate gasolines, are used as feedstock for BTX aromatics extraction.
A final distillation of the aromatic fractions purifies the BTX aromatics for further use in a synthesis unit.
The purpose of a BTX extraction unit is to produce high purity aromatics from a feed stream of aromatic and non-aromatic components. For most BTX extraction units, the recovery of aromatics occurs in a liquid-liquid extractor column while the purification takes place in an extractive distillation column. Steam stripping is used to remove the aromatics from the solvent.
BTX extraction units use solvents of different polarity, such as sulfolane (high polarity) and diethylene glycol (DEG) / triethylene glycol (TEG) (low polarity).
BTX extraction technologies can produce CH-grade benzene and TDI-grade toluene. Typical recovery of benzene, toluene and xylenes is at least 99 %, 97 % and 91 %, respectively. Higher recoveries require slightly more energy.
The selection of the solvent is often based on some fundamental property such as solvency and selectivity. The more polar solvents have the highest solvency at a given selectivity. A solvent with high solvency would require a lower solvent circulation rate and, therefore, need a lower capital budget for extractor and extractive distillation columns. However, the solvent recovery would require additional equipment, since solvents with high solvency are more difficult to remove from the products.
Energy consumption & heat integration
The optimization of a BTX extraction unit in terms of energy consumption and the heat integration in conjunction with the separation of the BTX aromatics by distillation is integral part of the design process.
ISBL Cost estimate
Indicative ISBL costs of a BTX extraction unit for the production of high purity aromatic products with an assumed capacity of 10,000 BPD of reformate feed:
EDL together with its partner offer the following scope of services:
EDL is a specialized and innovative service provider for the process industry in Germany and internationally, with its main focus on refinery, chemical, petrochemical and gas sector clients as well as special-purpose technologies (business areas).
EDL has built a first-rate reputation in the process industry, as a reliable and competent partner for the planning and construction of complete plants and plant units. In the last few years EDL has demonstrated its expertise in refinery revamps with over 40 large-scale projects.
