Method for refining or upgrading hydrocarbons with analysis

• US 5,076,909 A
• Filed: 08/27/1990
• Issued: 12/31/1991
• Est. Priority Date: 05/14/1988
• Status: Expired due to Term

• Current Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Original Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Inventors: Robbins, Winston K., Haberman, Joel I., Overfield, Robert E.
• Primary Examiner(s): Therkorn, Ernest G.
• Application Number:
  US07/572,583
• Time in Patent Office: 491 Days
• Field of Search: 208/177, 208/178, 208/310 R, 585/828, 585/830, 436/139, 436/140, 436/143, 436/161, 210/656, 210/659, 210/198.2, 73/61.1 C, 250/301, 250/373
• US Class Current: 208/177
• CPC Class Codes: C10G 11/187 Controlling or regulating
• CPC Class Codes: C10G 21/30 Controlling or regulating
• CPC Class Codes: C10G 69/04 including at least one step of catalytic cracking in the absence of hydrogen
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 30/34 of fluid composition, e.g. gradient G01N30/36 takes precedence
• CPC Class Codes: G01N 30/74 Optical detectors measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J
• CPC Class Codes: G01N 30/8675 Evaluation, i.e. decoding of the signal into analytical information for analysis of specific compounds see also G01N30/88 and subgroups of G01N33/00; chemical libraries per se C40B
• CPC Class Codes: G01N 33/2829 Mixtures of fuels

Abstract

A sample of a hydrocarbon oil containing asphaltenes is chromatographically analyzed by forming a mixture of the oil with a weak solvent. The mixture is passed in contact with a column of a stationary phase of fine solid particles of fully functionalized material, followed by a weak solvent. The solvent, after recovery from the column, is analyzed for aromatics by UV-absorption of UV radiation in the range 200 to 400 nm. The absorbance of the UV light by the irradiated eluents across the UV wavelength range is monitored and the integral of absorbance is derived as a function of photon energy across the wavelength range. The magnitude of the derived integral in at least one time interval corresponding with aromatics in the eluent from the stationary phase is measured as an indication of the level of aromatics in the oil sample. The weak solvent may be followed by a strong solvent which, in turn, may be followed by a strong solvent which is modified by the addition of a hydrogen bonding solvent.

Claims

1. A process for refining or upgrading a petroleum hydrocarbon feed, in which samples of hydrocarbon oil produced in the process are each chromatographically analyzed to determine the level present of at least one component in the oil, and in which the operation of the process is controlled in dependence upon the determined level present of said at least one component, the analysis comprising the steps of:

(a) passing a mixture of the hydrocarbon oil and a carrier phase in contact with a first and second stationary phase over a time interval so as to retain the components of the hydrocarbon oil on the stationary phases wherein the first stationary phase comprises surface hydroxyl groups substantially all of which have been substantially fully functionalized with a charge transfer functionally selected from the group consisting of trinitroanilino propane, tetrachlorophthalimido propane, dinitrobenzoyl glycidyl propane, and tetranitrofluorenone and the second stationary phase comprises surface hydroxyl groups at least a portion of which have been substantially fully functionalized by a functionalilty selected from the group consisting of aminopropyl, cyanopropyl, nitropropyl, and a combination thereof;

(b) passing in contact with the first and second stationary phases a mobile phase of a weak solvent having a solubility parameter of 7.0 to 7.8 cal⁰.5 /cm¹.5 for a second time interval sufficient to elute saturates and mono aromatics from the first stationary phase;

(c) continuing passing the weak solvent to the second stationary phase for a third time interval sufficient to complete substantially the elution of mono aromatics;

(d) recovering solvent passed to the first and second stationary phases;

(e) monitoring solvents recovered in step (d) and detecting at least saturates, mono aromatics, and aromatics of two or more rings.

2. A process as claimed in claim 1, in which the control of the operation of the process is such as to oppose any rise in value of the level present of said at least one component above a predetermined value.

3. A process for refining or upgrading a petroleum hydrocarbon feed containing asphaltenic materials in which the feed is passed to a fractionation unit having a temperature and pressure gradient thereacross for separation into components according to the boiling ranges thereof, said components being recovered from respective regions of the fractionation unit and including a gas oil component boiling in a gas oil boiling range which is recovered from a gas oil recovery region of the unit, wherein discrete samples of gas oil fraction are taken from the recovered gas oil fraction at intervals and each analyzed, and wherein a signal representative of the amount of asphaltenic material present in each sample is generated and employed to modulate the operation of the fractionation unit so that the amount of polar component in the gas oil component is maintained below a predetermined amount, the analysis comprising quantifying the aromatic core content of the gas oil fraction by:

(a) passing the gas oil fraction and a carrier phase in contact with a chromatographic stationary phase over a first time interval so as to retain components of said gas oil fraction on said stationary phase;

(b) passing a mobile phase in contact with said stationary phase after step (a) over a second time interval, for eluting different retained components of said fraction from said stationary phase at different time intervals, and recovering the mobile phase which contacted the stationary phase together with the components eluted from said stationary phase;

(c) irradiating the gas oil fraction with UV light having a wavelength range of which at least a portion is within the range of about 200 nm to about 500 nm,

(d) measuring the absorbance of the UV light by the aromatic cores in recovered solution,

(e) deriving the integral of absorbance as a function of photon energy across the energy corresponding to the wavelength range, and

(f) comparing the absorbance integral to a predetermined value, thereby quantifying the aromatic core content.

4. A process for refining or upgrading a petroleum hydrocarbon feed in which the feed is passed to a catalytic cracking unit and converted to cracked products including upgraded hydrocarbon materials, wherein discrete samples of the feed passing to the catalytic cracking unit are taken at intervals and each analyzed, and a signal representative of the amounts of polar components and aromatic components having at least 3 rings ("3+-ring aromatics") is generated, and the feed is either blended with a higher quality feed or subjected to a catalytic hydrogenation treatment or both blended and catalytically hydrogenated if and/or when said signal corresponds to amounts of 3+-ring aromatic components and polar components in excess of predetermined amounts, the intensity of said catalytic hydrogenation treatment being increased and decreased with respective increases and decreases in the magnitude of the said signal, the analysis comprising quantifying the aromatic core content of the feed by:

(a) passing the feed and a carrier phase in contact with a chromatographic stationary phase over a first time interval so as to retain components of said feed on said stationary phase;

(b) passing a mobile phase in contact with said stationary phase after step (a) over a second time interval, for eluting different retained components of said feed from said stationary phase at different time intervals, and recovering the mobile phase which contacted the stationary phase together with the components eluted form said stationary phase;

(c) irradiating the feed with UV light having a wavelength range of which at least a portion is within the range of about 200 nm to about 500 nm,

(d) measuring the absorbance of the UV light by the aromatic cores in recovered solution,

(e) deriving the integral of absorbance as a function of photon energy across the energy corresponding to the wavelength range, and

(f) comparing the absorbance integral to a predetermined value, thereby quantifying the aromatic core content.

5. A process for refining and upgrading a petroleum hydrocarbon feed containing undesirable contaminating components selected from asphaltenic materials, aromatic components containing at least three conjugated aromatic rings ("3+aromatics"), polar components and mixtures comprising at least two of said contaminating components, comprising the steps of mixing a stream of a selective refining agent at selected mixture:

(i) a hydrocarbon raffinate stream having a reduced content of polar components and aromatic components; and

(ii) a stream of a mixture containing solvent and at least one of said contaminating components, wherein discrete samples of the raffinate stream are taken at intervals and each analyzed, and wherein a signal representative of the amount of contaminating component is derived, and employed directly or indirectly to vary the said refining conditions so as to maintain the amount of contaminating component in the raffinate below a selected amount, the analyses comprising quantifying the aromatic core content of the raffinate stream by;

(a) passing the raffinate stream and a carrier phase in contact with a chromatographic stationary phase over a first time interval so as to retain components of said raffinate stream on said stationary phase;

(b) passing a mobile phase in contact with said stationary phase after step (a) over a second time interval, for eluting different retained components of said raffinate stream from said stationary phase at different time intervals, and recovering the mobile phase which contacted the stationary phase together with the components eluted from said stationary phase;

(c) irradiating the raffinate stream with UV light having a wavelength range of which at least a portion is within the range of about 200 nm to about 500 nm,

(d) measuring the absorbance of the UV light by the aromatic cores in the recovered solution.

(e) deriving the integral of absorbance as a function of photon energy across the energy corresponding to the wavelength range, and

(f) comparing the absorbance integral to a predetermined value, thereby quantifying the aromatic core content.