Process Technologies

Isomerization with De-isohexanizer (DIH)

For still higher RON isomerate, a deisohexanizer can be added downstream from the reaction section. The higher octane and more volatile iso-hexanes (dimethylbutanes) are removed by distillation together with the C₅’s. The distillate is combined with the de-isohexanizer bottom to become the final isomerate product. A side-stream from the bottom half of the column, concentrated in lower octane species such as methylpentanes (MPs) and the unconverted n-hexane, is recycled to the reactor.

De-isopentanizer (DIP)

To improve the octane boosting effect of the isomerization process, a deisopentanizer column can be integrated upstream of the isomerization unit. The advantages of this scheme are the following:

• having a new separate base with a high MON to be blended into the gasoline pool: isopentane
• sending a low isopentane-containing feed to the isomerization unit, so that the net isopentane production is larger

A further step to increase the octane pool is to split the reformate into two cuts. A light reformate is thus obtained including C₅ and C₆ components. This cut can be isomerized after separating the isopentane. This can be achieved by blending the light reformate with the straight run light naphtha and processing them simultaneously.

Once-through C₅/C₆ isomerization

The scheme of once-through C₅/C₆ Isomerization is based on a permutable reactors design; that is, either reactor can be used in the lead or lag position or it can be operated independently during catalyst servicing. This insures an ultra-high on-stream service.

Benfree® RD

The Benfree® RD integrates an external fixed bed hydrogenation reactor with the reformate splitter column, therefore reducing equipment and associated costs to save capital cost and plot area. The light reformate product is withdrawn as a side draw of the column for RVP control. Operating conditions are adjusted to minimize the toluene carry-over to the hydrogenation reactor thus minimizing the octane loss.

Benfree® C

When limiting the benzene formation in the reformer is not sufficient to meet gasoline pool specifications, Benfree® C engineering design services will provide a reliable solution to adjust the benzene saturation to requirement. The conventional option consists of a hydrogenation unit downstream of a reformate splitter to saturate the benzene contained in the light reformate stream. The unit utilizes a highly active catalyst that is operated in the liquid phase under mild conditions to minimize investment cost.

Semi-Regenerative Catalytic Reforming

Semi-Regenerative Catalytic Reforming completes Axens portfolio for lower capacities units. Axens has a long experience in conventional fixed bed reformers with over 50 references. Axens offer is related to the use of our Symphony solution of multi-promoted catalysts for semi-reg units.

Octanizing™ and Aromizing™

The Octanizing™ and Aromizing™ technology offers unrivaled product yields, low investment and operating costs and an exceptional on-stream factor for the production of gasoline and aromatics. Axens has an extensive experience in capacity and severity with over 130 licenses awarded worldwide.