阅读说明：本技术 在蒸汽裂解焦油的改质过程中维持再循环溶剂的高溶解力的方法 (Method for maintaining high solubility of recycled solvent in upgrading process of steam cracked tar ) 是由 K·坎德尔 徐腾 G·A·希特 F·C-Y·王 A·S·蒙尼托 D·T·菲卢赫利 K·J 于 2019-08-20 设计创作，主要内容包括：提供了用于改进烃原料相容性的方法。更具体地,制备液体烃产物的方法包括热浸泡焦油料流以产生减小反应性的焦油,并共混减小反应性的焦油与包含再循环溶剂的工作流体以产生较低粘度、减小反应性的焦油。所述方法还包括在大于350℃的温度下加氢处理较低粘度、减小反应性的焦油以产生含有液体烃产物和再循环溶剂的总液体产物。所述方法还包括从总液体产物分离再循环溶剂并使再循环溶剂流向减小反应性的焦油用于共混以产生较低粘度、减小反应性的焦油,其中再循环溶剂具有的S-(BN)为大于110。(A process for improving the compatibility of a hydrocarbon feedstock is provided. More specifically, the method of producing a liquid hydrocarbon product includes heat soaking a tar stream to produce a reduced reactivity tar, and blending the reduced reactivity tar with a working fluid including a recycled solvent to produce a lower viscosity, reduced reactivity tar. The process also includes hydrotreating the lower viscosity, reduced reactivity tar at a temperature greater than 350 ℃ to produce a total liquid product containing liquid hydrocarbon product and recycled solvent. The method further includes separating the recycle solvent from the total liquid product and flowing the recycle solvent to the reduced reactivity tar for blending to produce a lower viscosity, reduced reactivity tar, wherein the recycle solvent has S BN Is greater than 110.)

1. A process for producing a liquid hydrocarbon product comprising:

providing a reduced reactivity tar;

blending the reduced reactivity tar with a working fluid to produce a lower viscosity, reduced reactivity tar;

hydrotreating a lower viscosity, reduced reactivity tar at a temperature greater than 350 ℃ to produce a Total Liquid Product (TLP) comprising liquid hydrocarbon products and recycled solvent;

separating recycled solvent from the TLP, wherein the recycled solvent has a solubility blend value (S) greater than 110_BN) (ii) a And

the recycled solvent is flowed to the reduced reactivity tar for blending to produce a lower viscosity, reduced reactivity tar.

2. The process of claim 1, if recycling S of solvent_BNLess than 115, the method further comprising increasing the temperature of the lower viscosity, reduced reactivity tar during hydrotreating.

3. The method of claim 1 or 2, wherein the lower viscosity, reduced reactivity tar is hydrotreated at a temperature of greater than 350 ℃ to about 500 ℃.

4. The method of any of claims 1-3, wherein the lower viscosity, reduced reactivity tar is hydrotreated at a temperature of about 400 ℃ to about 450 ℃.

5. The method of any one of claims 1-4, wherein the working fluid comprises a recycled solvent, and wherein S of the recycled solvent_BNFrom greater than 110 to about 160.

6. The method of any one of claims 1-5, wherein S of solvent is recycled_BNFrom greater than 120 to about 150.

7. The method of any one of claims 1-6, wherein S of solvent is recycled_BNFrom about 130 to about 150.

8. The method of any of claims 1-7, further comprising treating the lower viscosity, reduced reactivity tar to remove solids therefrom prior to hydrotreating.

9. The method of any of claims 1-8, further comprising centrifuging the lower viscosity, reduced reactivity tar to remove substantially all solids having a size greater than 25 μ ι η.

10. The method of any one of claims 1-9, wherein the working fluid comprises a 2-ring aromatic, a 3-ring aromatic, a 4-ring aromatic, or any combination thereof.

11. The method of any one of claims 1-10, wherein the working fluid comprises a solvent selected from the group consisting of: benzene, ethylbenzene, trimethylbenzene, xylene, toluene, naphthalene, alkylnaphthalenes, tetralins, alkyltetralins, and any combination thereof.

12. The method of any of claims 1-11, wherein hydrotreating a lower viscosity, reduced reactivity tar further comprises:

heating the lower viscosity, reduced reactivity tar in a hydrogen-containing preconditioner to a temperature of from about 260 ℃ to about 300 ℃; then the

Heating the lower viscosity, reduced reactivity tar in a first reactor containing hydrogen to a temperature of about 325 ℃ to about 375 ℃; then the

The lower viscosity, reduced reactivity tar is heated in a second reactor containing hydrogen to a temperature of about 360 ℃ to about 450 ℃.

13. A process for producing a liquid hydrocarbon product comprising:

heat soaking the tar stream to produce reduced reactivity tar;

blending the reduced reactivity tar with a working fluid to produce a lower viscosity, reduced reactivity tar;

centrifuging the lower viscosity, reduced reactivity tar to remove solids therefrom; then the

Hydrotreating a lower viscosity, reduced reactivity tar at a temperature greater than 350 ℃ to produce a Total Liquid Product (TLP) comprising liquid hydrocarbon products and recycled solvent;

separating recycled solvent from the TLP, wherein the recycled solvent has a solubility blend value (S) greater than 115_BN) (ii) a And

the recycled solvent is flowed to the reduced reactivity tar for blending to produce a lower viscosity, reduced reactivity tar.

14. The process of claim 13 if recycling S of solvent_BNLess than 120, the method further comprising increasing the temperature of the lower viscosity, reduced reactivity tar during hydrotreating.

15. The method of claim 13 or 14, wherein the lower viscosity, reduced reactivity tar is hydrotreated at a temperature of greater than 350 ℃ to about 500 ℃.

16. The method of claim 15, wherein the temperature is from about 400 ℃ to about 450 ℃.

17. The method of any one of claims 13-16, wherein the working fluid comprises a recycled solvent, and wherein S of the recycled solvent_BNFrom greater than 120 to about 150.

18. The method of claim 17, wherein S of the solvent is recycled_BNFrom about 130 to about 150.

19. The method of any of claims 13-16, wherein the lower viscosity, reduced reactivity tar is substantially free of solids having a size greater than 25 μ ι η after centrifugation.

20. The method of any one of claims 13-16, wherein the working fluid comprises a 2-ring aromatic, a 3-ring aromatic, a 4-ring aromatic, or any combination thereof.

21. The method of any one of claims 13-16, wherein the working fluid comprises a solvent selected from the group consisting of: benzene, ethylbenzene, trimethylbenzene, xylene, toluene, naphthalene, alkylnaphthalenes, tetralins, alkyltetralins, and any combination thereof.

22. A process for producing a liquid hydrocarbon product comprising:

heat soaking the tar stream to produce reduced reactivity tar;

blending the reduced reactivity tar with a working fluid to produce a lower viscosity, reduced reactivity tar;

hydrotreating a lower viscosity, reduced reactivity tar at a temperature greater than 350 ℃ to produce a Total Liquid Product (TLP) comprising liquid hydrocarbon products and recycled solvent;

separating the recycled solvent from the TLP;

measurement of solubility blending value (S) of recycled solvent_BN)；

If recycling S of the solvent_BNLess than 115, increasing the temperature of the lower viscosity, reduced reactivity tar during hydrotreating; and

the recycled solvent is flowed to the reduced reactivity tar for blending to produce a lower viscosity, reduced reactivity tar.

23. The method of claim 22, wherein the temperature of the lower viscosity, reduced reactivity tar is from about 400 ℃ to about 450 ℃.

24. The method of claim 22 or 23, wherein the working fluid comprises a recycled solvent, and wherein S of the recycled solvent_BNFrom about 130 to about 150.

25. A process for producing a liquid hydrocarbon product comprising:

heat soaking the tar stream to produce a first process stream comprising reduced reactivity tars;

blending the first process stream with a working fluid to reduce the viscosity of the first process stream and produce a second process stream comprising solids and reduced-reactivity, lower-viscosity tars;

centrifuging the second process stream to produce a third process stream comprising reduced reactivity, lower viscosity tars and having a solids concentration less than the second process stream;

hydrotreating the third process stream at a temperature of greater than 350 ℃ to about 450 ℃ to produce a fourth stream comprising liquid hydrocarbon product and recycle solvent;

separating the recycled solvent from the fourth stream, wherein the recycled solvent has a solubility blend value (S) of about 130 to about 150_BN) (ii) a And

the recycled solvent is flowed to the first process stream for blending to produce a second process stream.

26. A process for producing hydrotreated tar, the process comprising:

(a) providing a process stream comprising reduced reactivity tars;

(b) mixing a process stream with a blend value (S) having solubility_BN)<110 to produce a tar-fluid mixture;

(c) catalytically hydroprocessing the tar-fluid mixture to produce a Total Liquid Product (TLP) comprising liquid hydrocarbon products and a working fluid;

(d) separating a recycle solvent and a hydroprocessed tar from the TLP, wherein the recycle solvent has a true boiling point range substantially the same as the true boiling point range of the working fluid and has a solubility blend value (S)_BN) More than or equal to 110; and

(e) replacing the working fluid in step (b) with at least a portion of the recycled solvent.

FIELD

Background

Pyrolysis tar is a form of tar produced from the pyrolysis of hydrocarbons. One form of pyrolysis tar, steam cracker tar ("SCT"), contains a variety of component materials, including high molecular weight molecules such as asphaltenes that are produced during the pyrolysis process and that typically boil above 560 ° F. These asphaltene molecules have a low H/C and a high sulphur content, which contributes to the high viscosity and high density of SCT.

Solvent Assisted Tar Conversion (SATC) is an SCT upgrading process that involves mixing SCT with a working fluid and upgrading the mixture to a less viscous and less dense product that includes hydrotreated tar and solvent. At least a portion of the solvent may be recovered and recycled to the process, and the working fluid may comprise recycled solvent. Upgrading may include cracking and hydrotreating, such as one or more of thermal cracking, hydrocracking, and hydrogenation. The process is typically carried out under pressure and weight hourly space velocity ("WHSV") conditions selected to optimize one or more of SCT conversion, hydrotreated tar yield/quality, and solvent yield/and quality. The operating temperature is also an important process parameter that can be adjusted to maintain the desired solvent quality. Although hydrogenation of aromatic molecules is favored when hydrotreating at lower temperatures (e.g., about 300 ℃), less cracking occurs. This will increase the partially and/or fully hydrogenated molecules in the product, which will eventually be present in the recycled solvent after distillation. The increase in the amount of hydrogenated molecules in the recycled solvent reduces the solvency of the recycled solvent, which in turn reduces the ability of the recycled solvent to dissolve tar components. Another feature of SATC is the recycling of fractions from the product formed as solvent. The amount of recycled solvent used as the working fluid is typically from about 20% to about 60% by weight, for example about 40% by weight. The solvent recovered from the SATC process typically has a desirably high solvency, such as a significant solubility blending value (S) of the solvent_BN) As indicated. If S of the solvent is recovered_BNLess than 100, e.g., about 80 or about 90, the recycled solvent has a reduced tar dissolving capacityAnd is therefore less desirable for use as a working fluid or working fluid component.

Additional conditions such as start-up at lower temperatures (fresh catalyst) and adjustments (slower feed rates) can also lead to accumulation of hydrogenated/naphthenic molecules in the solvent of the middle distillate recycle. In addition, entrainment of smaller naphthenic molecules in the recycled solvent due to less efficient distillation can also affect solvent quality.

There remains a need to further improve the hydroprocessing of pyrolysis tars while improving the quality of the recycled solvent, for example by reducing the accumulation of hydrogenated molecules in the recycled solvent.

SUMMARY

Brief description of the drawings

FIG. 1 depicts an exemplary process flow of a tar disposal method according to one or more embodiments.

FIG. 2 depicts a more specific illustration of a tar treatment process according to one or more embodiments.

FIG. 3 depicts an alternative cold tar recycling arrangement that may be used to heat soak a tar feed, where tars produced by two different upstream processes may be treated, according to one or more embodiments.

FIG. 4 depicts a configuration of a preconditioner and several reactors that may be used in a hydroprocessing process according to one or more embodiments.

Detailed description of the invention

Embodiments are generally directed to improving hydrocarbon feedstock compatibility. More particularly, embodiments relate to processes that include combining a hydrocarbon feed and a working fluid comprising a recycle solvent to separate components of the feed into separable fractions, to hydrocarbon products of such processes, and to apparatus useful in such processes.