UPGRADING OF CRUDES BY THERMAL TREATMENTS.

Ziel

TO IMPROVE KNOWLEDGE OF THE REACTIONS THAT TAKE PLACE DURING THERMAL TREATMENT OF HEAVY PETROLEUM CUTS WITH A VIEW TO ENHANCING THE STABILITY OF PRODUCTS
Extensive experimental work was carried out on 4 crudes, made up of 11 pilot plant runs and detailed inspections of all the products from both straight run and visbreaking runs.
On the basis of the experimental data obtained, some general considerations about the visbreaking process have been drawn and some correlations between feedstock features, process operating temperature, kinetic parameters and stability characteristics of the visbroken residues have been developed.

All the products from both straight and visbreaking runs were thoroughly inspected and the relevant characteristics carefully examined.
The total aromatic concentration and the content in sulphur and nitrogen compounds in the petroleum fractions increased with increasing boiling point and usually were higher in the visbreaking products than in the corresponding straight run ones. The visbreaking gasolines exhibited higher density, higher bromine number, higher maleyc anhydride value (MAV) and sulphur content than the corresponding straight run fractions.
The visbreaking gasoils exhibited higher density, aromatic content, sulphur content, nitrogen content bromine number and maleyc anhydride value, than the corresponding straight run fractions. Moreover, they were also unstable as they did not meet the stability specifications (2 mg per 100 cc of potential insoluble matter).
In comparison with the straight run corresponding fractions the visbreaking vacuum gas oils (VGO) exhibited a higher content in aromatic and polar compounds; furthermore, within the aromatic group, there was a shift from monocyclic to polycyclic compounds and within the saturates there was a shift from alkanes to polycyclic naphthenes. As a consequence they showed a higher density and lower K factor (higher aromatic content).
The visbroken atmospheric and vacuum residues exhibited higher density, generally higher asphaltene content and viscosity, higher nitrogen and metal content than the corresponding straight run factio ns.
TRADITIONAL TREATMENTS OF HEAVY RESIDUES SUCH AS COKING, THERMAL CRACKING AND VISBREAKING, RESULT IN GAS OILS AND VACUUM DISTILLATES OF MARKED INSTABILITY, AS IS SHOWN, FOR EXAMPLE, BY THE FORMATION OF INSOLUBLES IN THE FORMER AND BY VISCOSITY CHANGE AND PRECIPITATION OF ASPHALTENES IN THE LATTER. IN COMMERCIAL PLANTS, REDUCING THE SEVERITY AND USING SUITABLE SOLVENTS ARE THE COMMONEST WAYS OF MINIMIZING THESE PHENOMENA. IT IS INTENTED TO GAIN A BETTER INSIGHT INTO THE UNDERLYING REACTIONS AND DEVICE NEW MEANS OF MANAGING THEM THROUGH A COLLABORATIVE RESEARCH PROGRAMME INVOLVING SEPARATE CONTRACTS WITH AGIP PETROLI, SELM AND ERG SPA (SEE EN3C004600-I (A) AND EN3C004700 (A)). AGIP PETROLI'S CONTRIBUTION WILL CONCERN THE FOLLOWING POINTS:
- DEVELOPMENT OF ANALYSIS METHODS: BESIDES CONVENTIONAL ANALYTICAL TECHNIQUES, GEL-PERMEATION, NMR AND TGA WILL BE USED. COMPARISON OF THE RESULTS OBTAINED BY THE COLLABORATING CONTRACTORS, TOGETHER WITH STANDARDIZATION OF METHODS, WILL MAKE FOR SAFE USE OF THE ANALYTICAL DATA.
- PILOT PLANT VISBREAKING RUNS WILL BE PERFORMED AT 3 OR MORE TEMPERATURES IN THE RANGE 460-500 CELSIUS DEGREES ON ATMOSPHERIC AND VACUUM DISTILLATION RESIDUES OBTAINED FROM 4 TYPICAL CRUDES. EACH CRUDE WILL BE SEPARATED INTO PSEUDOCOMPONENTS ACCORDING TO THE BOILING POINT. EVERY POSSIBLE ANALYTICAL CHARACTERIZATION WILL BE PERFORMED ON THEM, AS WELL AS ON THE CORRESPONDING ONES FROM VISBREAKING PRODUCTS. THE RESULTS OF THIS COMPARISON AND THOSE CONCERNING THE STABILITY BEHAVIOUR OF ATMOSPHERIC GO AND VACUUM GO BEFORE AND AFTER REACTION SHOULD SERVE TO SHED LIGHT ON THE ORIGIN OF PRODUCT INSTABILITY.
- A KINETIC MODEL WILL POSSIBLY BE CONSTRUCTED FOR THE PURPOSE OF FORECASTING THE BEHAVIOUR OF A FEEDSTOCK AS A FUNCTION OF ITS COMPOSITION AND OF VISBREAKING SEVERITY.

Wissenschaftliches Gebiet

Programm/Programme

FP1-ENNONUC 3C - Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988

Thema/Themen

Data not available

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

CSC - Cost-sharing contracts

Koordinator

Euron SpA

EU-Beitrag

Keine Daten

Adresse

Via Felice Maritano 26
20097 San Donato Milanese
Italien

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