Processing unconventional and opportunity crude oils using zeolites

Abstract

The disclosed process removes or reduces impurities such as asphaltenes, solids (especially solid fines), sulfur, metals, chlorides, water, salts, and acids from bitumen, oil sands, and crude oils with a wide range of gravities. A crude source composition is contacted with one or more zeolite materials to remove asphaltenes, solids, sulfur, NSO, metals, chlorides, water, salts, and / or acids from the composition. The crude source is typically diluted with a hydrocarbon solvent such as naphtha before contacting the zeolite(s). The disclosed processes represent an improvement over prior and presently available processes because the disclosed processes are capable of processing emulsions.

Description

BACKGROUND [0001] 1. Field of the Invention [0002] The invention relates to separation processes and systems to remove or reduce impurities from unconventional and opportunity petroleum resources. [0003] 2. Description of the Related Art [0004] Opportunity petroleum resources such as acidic crude oil, extra heavy oil, heavy oil, high salinity crudes, acidic residuum, gas oils, oil sand, diluted bitumen, and undiluted bitumen are typically treated to remove impurities such as asphaltenes, solids, sulfur, NSO, metals, chlorides, water, salts, and acids before sending the resource upstream for additional processing. One currently available treatment is solvent deasphalting (SDA). This process takes advantage of the fact that maltenes are more soluble in light paraffinic solvents than asphaltenes. This solubility increases with solvent molecular weight and decreases with temperature. There are constraints with respect to how deep a SDA unit can cut into the residue or how much deasphalt...

AI Technical Summary

Benefits of technology

[0026] An aspect of the disclosure provides a process for removing one or more impurities from a petroleum composition. Such impurities can include asphaltenes, solids (especially solid fines), sulfur, metals, chlorides, water, salts, and acids. Petroleum compositions can include opportunity crude oil sources such as bitumen, oil sands, and crude oils with a wide range of gravities. An aspect of the process is that it does not require a catalytic chemical process to remove one or more impurities. However, such chemical processes can be implemented in conjunction, i.e., upstream or downstream, with the disclosed process. An advantage of the disclosed process is that it represents an improvement over presently available technologies for treating opportunity petroleum sources because the disclosed process is capable of processing emulsions.

Problems solved by technology

There are constraints with respect to how deep a SDA unit can cut into the residue or how much deasphalted oil (DAO) can be produced.

These constraints are typically due to the DAO quality specifications required by downstream conversion units; and the final high-sulfur residual fuel oil stability and quality.

The disadvantages of the process are that it performs no conversion, produces a very high-viscosity byproduct pitch, and where high quality DAO is required, SDA is limited in the quality of feedstock that can be economically processed.

The disadvantages of delayed coking are that it is a thermal cracking process and it is a more expensive process than SDA although still less expensive than other conversion processes on heavier crudes.

One common misconception of delayed coking is that the product coke is a disadvantage.

In addition, in thermally cracking this material to extinction, a significant portion will convert to coke.

However, SAGD requires large amounts of steam and is quite energy intensive.

This process produces less environmental pollution than the other two processes but consumes large amounts of energy.

The disadvantages of the solvent extraction process are: environmental pollution due to the loss of solvent; storage of solvent inventories; large quantities of water are required to remove the solvent from the sand after extraction; and difficulties in process scale up.

However, various problems exist in the extraction and separation steps, which may lead to ineffective separation of the bitumen, solids, and water that may result in: large quantities of water usage and disposal in the tailings pond; environmental pollution; high energy consumption; unacceptable bitumen quality.

Available extraction and separation processes are encumbered with several problems.

One problem is low bitumen extraction rate due to the existence of asphaltenes, salts, acids, and extra fine particles at the silica-water interface, and water-oil interface, the bitumen strongly adheres to the sand particles.

The displacement efficiency of removing bitumen from the sand is low by hot water extraction alone.

The remaining bitumen in the oil sand tailings is not only an issue with regard to bitumen yield, but also may be an environmental problem.

Emulsions present another problem.

The emulsion is difficult to break by the conventional separation techniques in the existing process and will be either disposed of in the tailings pond or carried over in the bitumen product.

The emulsion that is carried over may cause serious problems in the downstream processes, such as corrosion, fouling, catalyst deactivation, and decreased operating efficiency.

Likewise, suspended fine particles smaller than 10 microns are very difficult to remove by flotation, gravity separation, or centrifugation.

The fine particles are also responsible in part for formation and stabilization of emulsions, and will cause plugging problems in downstream processes.

Asphaltenes have a higher molecular weight as compared with lighter petroleum fractions, and are the most difficult portion of the feedstock to upgrade.

Heavy metals may deteriorate catalyst activity in downstream operations, and may cause serious environmental problems if handled improperly.

However, the processes discussed above typically do not to remove the heavy metals or NSO contained in asphaltenes and resins.

These acids may also cause serious environmental pollution if released with water.

The current hot water extraction and separation process is not designed for naphthenic acid removal, except as salts which may contribute to emulsion stabilization.

The above problems are characteristic deficiencies of the current hot water extraction technology.

This was referred to as desalter instability and can lead to shorter run lengths.

Stable emulsions and asphaltenes cause serious problems for oil refiners.

Emulsions complicate refinery operations and lead to operational upsets and production losses.

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