Process for evaluating fouling caused by refinery feedstocks

1. A process for evaluating the fouling caused by a refinery feedstock on one or more refinery processes, said process comprising:

(i) providing a plurality of refinery feedstocks and/or a plurality of fractions of one or more refinery feedstocks,

(ii) providing an array comprising a plurality of metal samples representative of metallurgy present in a refinery,

(iii) contacting each of the plurality of metal samples with one or more of said refinery feedstocks or fractions under non-static conditions, wherein each of the refinery feedstocks or fractions is contacted with one of said metal samples in an essentially parallel manner, and

(iv) determining the fouling caused by said refinery feedstock or fraction thereof, the determination of each metal sample being carried out in parallel.

2. A process as claimed in claim 1 wherein the refinery feedstock to be evaluated is a crude oil, a synthetic crude, a biocomponent, an intermediate stream, or a blend of one or more of said components.

3. A process as claimed in claim 1 , wherein the plurality of metal samples comprises at least 20 metal samples.

4. A process as claimed in claim 1 , wherein the metal samples are in the form of a microfabricated array.

5. A process as claimed in claim 1 , wherein all or some of the metal samples have been treated with surface coatings believed to reduce fouling.

6. A process as claimed in claim 1 , wherein each refinery feedstock or fraction thereof is representative of (i) the refinery feedstock itself, (ii) the residue fraction obtained from a crude distillation unit (CDU) or blends of such fractions with other residue fractions or with a refinery feedstock, or (iii) vis-broken fractions.

7. A process as claimed in claim 1 , wherein the contacting of each of the plurality of metal samples with the refinery feedstock or a fraction thereof is under temperature, flow rate, and turbulence conditions representative of those to which the equivalent metallurgy would be exposed in the refinery.

8. A process as claimed in claim 1 , wherein the fouling is determined by visual analysis, ellipsometry or surface analysis using a suitable analytical technique, or by measurement of the mass accumulation on the metal samples.

9. A process as claimed in claim 1 , wherein the temperature of a feedstock or fraction thereof before and after contacting with a heated metal sample is measured to determine the degree of heating of the fluid by the metal sample.

10. A process as claimed in claim 1 , wherein the asphaltene or wax stability of a refinery feedstock and/or fraction thereof is measured.

11. A process as claimed in claim 1 , wherein the refinery feedstock to be evaluated is treated to produce a fraction thereof or a plurality of fractions thereof and the or each fraction is contacted with the plurality of metal samples.

12. A process as claimed in claim 11 , wherein the treatment comprises one or more of division, treatment in a microdistillation column or microfractionator, solvent extraction, membrane treatments, adsorption treatments and suitable chemical reactions.

13. A process as claimed in claim 1 , wherein the metal samples are in a form which has a non-negligible resistance, such as wires, thin sheets or meshes.

14. A process as claimed in claim 13 wherein fouling of the metal samples is measured by changes in resistance of the metal samples.