Method and device for separating asphaltenes from an asphaltene-containing fuel

Abstract

A method for separating asphaltenes from an asphaltene-containing fuel, wherein fuel is supplied to a separation unit in which a sub-stream with low-boiling fuel components of the fuel is separated. After separation of the sub-stream the fuel is supplied to a deasphalting unit in which asphaltenes contained in the fuel are separated by a solvent. After the separation of the asphaltenes from the fuel, the solvent is separated therefrom in a solvent recovery unit. The separated solvent is circulated back into the deasphalting unit, and a solvent fraction is obtained from the sub-stream that has been separated from the fuel, which is supplied to the deasphalting unit in addition to the solvent recirculated from the solvent recovery unit. A device is adapted for separating asphaltenes from an asphaltene-containing fuel.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2016 / 058850 filed Apr. 21, 2016, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 102015210256.4 filed Jun. 3, 2015. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention relates to a method for separating asphaltenes from an asphaltene-containing fuel. The invention further relates to a corresponding device for separating asphaltenes from an asphaltene-containing fuel.BACKGROUND OF INVENTION[0003]In energy production, crude and heavy oils are frequently used, which are available as economical fuels for power generation by gas turbines. However, such crude and heavy oils contain asphaltenes, which in turn contain chemically bound heavy metals. On combustion of the oils, heavy metals such as vanadium or nickel are released as metal oxides...

AI Technical Summary

Benefits of technology

The invention provides a method to efficiently and economically separate asphaltenes from fuel containing them and allow for the use of the fuel in a gas turbine process. Additionally, the invention provides a device to facilitate the implementation of this method.

Problems solved by technology

However, such crude and heavy oils contain asphaltenes, which in turn contain chemically bound heavy metals.

These solid asphalt particles can plug lines or fine nozzles of the burner used, causing a lasting detrimental effect on mixture formation in the turbines and thus reducing the efficiency of the turbines.

Light crude oils are only suitable to a limited degree for power generation in gas turbines, as modern high-performance turbines tolerate heavy metals such as nickel or vanadium in the fuel only up to limits that are below their concentration in most crude oils.

This reason alone is enough to make their use in heavy-metal-sensitive high-performance turbines unfeasible.

It is true that such gas turbines, which are operated at lower temperatures, show lower efficiency levels than heavy-metal-sensitive high-performance turbines.

In the use of magnesium salt, which is common as an inhibitor but costly, a high-melting magnesium vanadate forms instead of a low-melting vanadate.

In this case, however, there is the risk of crust formation on the turbine blades due to the deposition in layers of the magnesium vanadate.

More particularly, such cleaning involves shutting down the turbine for a period of several hours.

However, after deasphalting takes place, the short-chain alkanes preferably used as solvents (deasphalting agents) cannot be completely separated from the purified asphaltene-containing fuel and recirculated to the deasphalting process.

Common separation methods such as solvent evaporation in correspondingly applied processing units are generally accompanied by losses of the solvent to be separated, as complete separation is either impossible for technical reasons or extremely costly.

An undesirable solvent loss must therefore be accepted.

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