Process for the production of renewable base oil, diesel and naphtha

Patent metadata

Field	Value
Publication number	US-11142701-B2
Application number	US-201816623306-A
Country	US
Kind code	B2
Filing date	Jun 15, 2018
Priority date	Jun 19, 2017
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

Hydrotreatment of biological oil is disclosed for producing renewable base oil and a diesel oil from low value biological oils. Low value biological oils containing free fatty acids and fatty acid esters can be processed into a renewable base oil and a renewable diesel oil in an efficient manner by first separating at least part of the free fatty acids from the feedstock and then processing separately this free acid feed in a ketonisation reaction followed by hydrodeoxygenation and hydroisomerisation reactions to yield a renewable base oil stream. The remaining free fatty acid depleted feed is processed in a separate hydrodeoxygenation and hydroisomerisation step to yield a renewable diesel stream.

First claim

The invention claimed is:

1. A method for producing a renewable base oil and a diesel fuel from a feedstock of biological origin, the method comprising:
a) providing a feedstock, the feedstock containing 2-95 wt % of a mixture of free fatty acids; 5-98 wt % fatty acid glycerols selected from mono-glycerides, di-glycerides and tri-glycerides of fatty acids; and 0-50 wt % of one or more compounds selected from a list consisting of: fatty acid esters of the non-glycerol compound, fatty amides, and fatty alcohols; wherein at least 50 wt % of the feedstock is made up of the mixture of free fatty acids and fatty acid glycerols;
b) separating the feedstock into at least:
a free fatty acid feed having a higher concentration of free fatty acids than the feedstock, the free fatty acids containing C 10 -C 24 fatty acids; and
one or more free fatty acid depleted feed(s) having higher concentration of the compounds selected from mono-glycerides, di-glycerides and tri-glycerides of fatty acids, and having a higher boiling point than the free fatty acid feed;

c) subjecting the free fatty acid feed to ketonisation reaction conditions where two fatty acids react to yield a ketone stream, the ketone stream containing as a major part saturated ketones;
d) subjecting the ketone stream to both hydrodeoxygenation reaction conditions and to hydroisomerisation reaction conditions, simultaneously or in sequence, to yield a deoxygenated and isomerised base oil stream containing the renewable base oil; and
e) transforming the one or more free fatty acid depleted feed(s) into a diesel fuel.

2. The method according to claim 1 , comprising:
prior to step a), pre-treating an initial feedstock containing fatty acid esters in at least a hydrolysis step thereby producing the feedstock, where a ratio of free fatty acids to fatty acid esters has been increased compared to the initial feedstock.

3. The method according to claim 1 , wherein the free fatty acid feed contains C 14 -C 22 fatty acids.

4. The method according to claim 1 , comprising:
distilling the deoxygenated and isomerised base oil stream of step d) to obtain a distilled renewable base oil.

5. The method according to claim 1 , comprising:
f) where the one or more free fatty acid depleted feed(s) is transformed into a diesel product by subjecting the one or more free fatty acid depleted feed(s) to both hydrodeoxygenation reaction conditions and to hydroisomerisation reaction conditions, simultaneously or in sequence, to yield a deoxygenated and isomerised diesel stream containing the diesel fuel; and
distilling the deoxygenated and isomerised diesel stream obtained from step f) to obtain a distilled diesel fuel.

6. The method according to claim 4 , comprising:
f) where the one or more free fatty acid depleted feed(s) is transformed into a diesel product by subjecting the one or more free fatty acid depleted feed(s) to both hydrodeoxygenation reaction conditions and to hydroisomerisation reaction conditions, simultaneously or in sequence, to yield a deoxygenated and isomerised diesel stream containing the diesel fuel; and
g) distilling the deoxygenated and isomerised diesel stream obtained from step f) to obtain a distilled diesel fuel.

7. The method according to claim 6 , additionally for producing a naphtha fuel, where the naphtha fuel is obtained from distillation of both the deoxygenated and isomerised base oil stream of step d) and from the distillation of a deoxygenated and isomerised diesel fuel of step e).

8. The method according to claim 6 , wherein no pre-treatment by hydrogenation or by hydrolysis is made in or in-between steps a)-c).

9. The method according to claim 6 , where the hydrodeoxygenation and hydroisomerisation of step d) take place in sequence, and where in-between the hydrodeoxygenation and hydroisomerisation there is a stripping step, where gasses are separated from liquids in a high temperature and high pressure separation step at a temperature between 300-330° C. and pressure between 40-50 barg.

10. The method according claim 6 , wherein between steps d) and e) there is a stripping step, where gasses are separated from liquids, at a temperature between 320-350° C. and pressure between 3-6 barg.

11. The method according to claim 6 , wherein the free fatty acid feed contains more than 90 wt % saturated fatty acid or C 16 fatty acids.

12. The method according to claim 6 , wherein the feedstock is palm oil fatty acid distillate (PFAD).

13. The method according to claim 6 , wherein the ketonisation reaction conditions include a temperature in a range from 300 to 400° C., a pressure in a range from 5 to 30 barg and a WHSV in a range from 0.25-3 h −1 , in a presence of a ketonisation catalyst, the ketonisation catalyst containing a metal oxide catalyst, in a presence of a gas in a range from 0.1-1.5 gas/feed ratio (w/w), the gas being selected from one or more of: CO 2 , H 2 , N 2 , CH 4 , and H 2 O.

14. The method according to claim 6 , wherein the ketonisation reaction conditions ensure liquid phase ketonisation;
wherein the ketonisation catalyst is a metal oxide catalyst selected from a list to contain metal consisting of one or more of: Ti, Mn, Mg, Ca, and Zr.

15. The method according to claim 6 , wherein the ketonisation catalyst is TiO 2 in anatase form having an average pore diameter of 80-160 Å, and/or a BET area of 40-140 m 2 /g, and/or porosity of 0.1-0.3 cm 3 /g.

16. The method according to claim 14 , wherein the ketonisation catalyst is TiO 2 , on a support, wherein a content of elements manganese, magnesium, calcium and potassium, are 0.05 wt % or less compared to a total catalyst weight as measured using X-ray diffraction.

17. The method according to claim 14 , wherein the ketonisation catalyst is TiO 2 on a support, wherein a content of the element potassium, is 0.05 wt % or less compared to a total catalyst weight as measured using X-ray diffraction.

18. The method according to claim 14 , wherein the hydrodeoxygenation reaction conditions of step d) and/or step f) include a temperature in a range from 250 to 400° C., a pressure in a range from 20 to 80 barg, a WHSV in a range from 0.5-3 h −1 , and a H 2 flow of 350-900 nl H 2 /l feed, in a presence of a hydrodeoxygenation catalyst NiMo on an alumina support.

19. The method according to claim 6 , wherein the hydroisomerization reaction conditions of step d) and/or step f) include a temperature in a range from 250 to 400° C., a pressure in a range from 10 to 60 barg, a WHSV in a range from 0.5-3 h −1 , and a H 2 flow of 100-800 nl H 2 /l feed, in a presence of an isomerisation catalyst including a Group VIII metal and a molecular sieve, on an alumina and/or silica support.

20. The method according to claim 6 , wherein the hydrodeoxygenation catalyst and isomerisation catalyst are the same; and
wherein more than 50 wt % of the feedstock is the mixture of free fatty acids and fatty acid glycerols.

21. The method according to claim 6 , wherein the feedstock comprises:
at least 10 wt % and below 90 wt % free fatty acids.

22. The method according to claim 6 , wherein the feedstock comprises:
at least 10 wt % and below 90 wt % fatty acid esters.

23. The method according to claim 6 , wherein the feedstock comprises:
at least 10 wt % and below 90 wt % free fatty acids and at least 10 wt % and below 90 wt % fatty acid esters, and wherein more than 70 wt % of the feedstock is said mixture of free fatty acids and fatty acid glycero

Assignees

• Neste Oyj

Inventors

• Myllyoja Jukka
• Nurmi Pekka
• Kanervo Jaana
• Toppinen Sami
• Makkonen Jaana
• Kettunen Mika

Classifications

• C11C1/10

  by distillation · CPC title

• C11C1/04

  by hydrolysis · CPC title

• C10N2030/74

  Noack Volatility · CPC title

• C10N2030/43

  Sulfur free or low sulfur content compositions · CPC title

• C10N2030/16

  Antiseptic; {(micro)} biocidal {or bactericidal} · CPC title