FI20215788A1 - A tall oil residue composition, method and use - Google Patents

Abstract

The present disclosure relates to a tall oil residue composition (40) and to controlling temperature in a process for production of biofuels, wherein the tall oil residue composition (40) comprises tall oil residue (20) and bio diluent (30) and the temperature of the tall oil residue is controlled by adding bio-diluent (30) to the tall oil residue (20). The present disclosure further concerns use of the tall oil residue composition (40).

Description

A TALL OIL RESIDUE COMPOSITION, METHOD AND USE

FIELD OF THE DISCLOSURE

The present disclosure relates to a tall oil residue composition and to controlling temperature in a process for production of biofuels, wherein the tall oil residue composition comprises tall oil residue and bio-diluent and the temperature of the tall oil residue is controlled by adding bio-diluent to the tall oil residue. The present disclosure further concerns a tall oil residue composition obtained by the method and use thereof.

BACKGROUND OF THE DISCLOSURE

Biomass is increasingly recognized as a valuable feedstock to be used as an alternative to petroleum for the production of hydrocarbons, suitable as fuels or fuel components.

There is an increasing interest in alternative feedstocks for replacing at least partly crude oil, in the production of for example as transportation fuels or components compatible with fuels.

Renewable energy sources represent the potential fuel alternatives to overcome the global energy crises in a sustainable and eco-friendly manner. In future, biofuels may replenish the conventional non-renewable energy resources due to their renewability and several other advantages.

Biofuels are typically manufactured from feedstock originating from renewable sources including oils and fats obtained from plants, animals, algal materials, fish, and various waste streams, side streams and sewage sludge. These feedstocks, particularly the various waste streams and side streams, contain varying amounts of contaminants, such as gums, phospholipids and other phosphorus compounds, metals and metal compounds, which are, for example, deleterious to converting catalysts. One of these sources is crude tall oil (CTO) obtained as a by-product of the kraft process of wood pulp manufacture. = 25 Crude tall oil is a mixture of components with different boiling points and thus a multistage

N process is usually needed in order to overcome the challenges of handling this complex 5 feedstock in manufacturing processes.

S Despite the ongoing research and development of processes for processing biomass,

E especially crude tall oil, there is still a need to provide an improved process for production o 30 of biofuels. 5

N BRIEF DESCRIPTION OF THE DISCLOSURE

N An object of the present disclosure is to provide a tall oil residue composition wherein the bio-diluent to tall oil residue ratio is 1:10 to 4:10 and a method of controlling temperature in a process for production of biofuels, such as biogasoline, biodiesel and/or components thereof. The temperature of the tall oil residue fraction is controlled by adding bio-diluent to the tall oil residue fraction.

The disclosure is based on the idea of providing a tall oil residue composition having an acid value below 35 mg/KOH/g. This is achieved by combining a tall oil residue, comprising below 10 w-% fatty acids, below 10 w-% resin acids, and over 80 w-% neutrals, with a bio- diluent having a viscosity below 50 mm?/s measured by EN ISO 3104, CTO 50 °C and a boiling point below 300 °C. The bio-diluent is also substantially free of water. The tall oil residue composition with low acidity is especially beneficial due to its low corrosivity in the processes where it is utilized.

The disclosure is further based on the idea of controlling temperature in a tall oil residue tank by adding bio-diluent to tall oil residue. Tall oil residue, which is recovered from pre- treatment of a feedstock of tall oil material, such as crude tall oil, is combined with a bio- diluent in order to overcome the challenges of enhanced temperatures in the process for production of biofuels. Since the treated tall oil residue, recovered from the process, is a tall oil residue composition with enhanced properties, which is usable in other processes, the method of the disclosure makes good use of the resources, i.e. all parts of the tall oil material feedstock.

An advantage of the product and method of the disclosure is the possibility to diminish or eliminate the use of components in the process which are not derived from biomass.

Further advantages are obtained if all the compositions recovered from the process are entirely derived from biomass, i.e. are of biological origin.

Further advantages of the product and method of the disclosure are the enhanced properties of the obtained tall oil residue composition, which enables utilizing a greater part — 25 of the renewable feedstock. Typically, the obtained tall oil residue composition has lowered

O viscosity and better pumpability as well as lower levels of metals, sulphur and/or nitrogen.

N A lowered viscosity also impacts positively on the cleanliness of the eguipment. Especially © beneficial is that the acid value of the tall oil residue composition is below 35 mg/KOH/qg, 7 preferably below 25 mg/KOH/g.

Ao

N 30 The object of the disclosure is achieved by the product, method and use which are

S characterized by what is stated in the independent claims. The preferred embodiments of

N the disclosure are disclosed in the dependent claims.

N

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

Figure 1 is a schematic flow diagram representing one embodiment of the purification process;

Figure 2 shows a distillation curve of the boiling temperatures of a bio-diluent.

DETAILED DESCRIPTION OF THE DISCLOSURE

An advantageous tall oil residue composition as well as an industrially effective and sustainable method is provided for controlling process conditions in a sustainable way. In the process relating to the production of hydrocarbons suitable as fuels or fuel components, a valuable composition for use in other processes is provided thereby utilizing more completely the renewable source used as feedstock.

The disclosure relates to a tall oil residue composition which comprises tall oil residue and bio-diluent and wherein the tall oil residue comprises below 10 w-% fatty acids, below 10 w-% resin acids, and over 80 w-% neutrals. Typically, the bio-diluent viscosity is below 50 mm?/s measured by EN ISO 3104, CTO 50 °C, less than 10 w-% of bio-diluent components has a boiling temperature below 300 °C and/or the bio-diluent is substantially free of water.

In embodiments of the disclosure the bio-diluent to tall oil residue ratio is 1:10 to 4:10 by weight and the acid value of the tall oil residue composition is below 25 mg/KOH/g. The disclosure further relates to a method of controlling temperature in a process for production of biofuels from tall oil material, wherein the temperature of the obtained tall oil residue is controlled by adding a bio-diluent to the tall oil residue and by recirculating part of the obtained tall oil composition via a cooler back to the tall oil residue tank. The cooler is preferably a heat exchanger using cooling oil as cooling media, Preferably, bio-diluent is = 25 added in a ratio of 1:10 to 4:10, preferably 1.5:10 to 3.5:10, more preferably 2:10 to 3:10

N of bio-diluent to tall oil residue, i.e. so that the amount of bio-diluent in the composition is 5 between 10 w-% and 40 w-%.

S The process of the method of the disclosure typically comprises evaporating tall oil material

E in a multistage evaporation, comprising two or more evaporators; recovering a fraction of © 30 tall oil residue; adding bio-diluent to the tall oil residue before it reaches a tall oil residue 5 tank; adding bio-diluent to the tall oil residue in the tall oil residue tank; recirculating at least

N part of the obtained tall oil residue composition to the tall oil residue tank and/or recovering

N a tall oil residue composition. When the process is started up, all tall oil residue composition is recirculated to the tall oil residue tank.

The disclosure also relates to a product obtained by the method of the disclosure.

The disclosure further relates to the use of a tall oil residue composition of the disclosure or obtained by the method of the disclosure, in a chemical pulping process, as biofuel in a power plant and/or as raw material in chemical and construction industry. Typically, the tall oil residue composition has a viscosity below 1000 cpoise (mPa-s), preferably between 200 and 900 cpoise, more preferably between 500 and 700 cpoise, or any value between any of the two of 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 and 1000 cpoise measured according to ASTM D2196-99 or measured according to EN ISO 3104 (50 °C) a viscosity below 1000 mm?/s, preferably between 200 and 900 mm?/s, more preferably between 500 and 700 mm?/s, or any value between any of the two of 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 and 1000 mm?/s. The ash content of the tall oil residue composition is typically below 1 w-%, preferably below 0.6 w-%, more preferably below 0.5 w-%, most preferably below 0.3 w- % measured according to SCAN-T 11 and/or the sulphur content of the tall oil residue composition is typically below 0.5 w-%, preferably below 0.3 w-%, more preferably below 0.2 w-%, most preferably below 0.1 w-% measured according to ASTM D 4239 - 00.

In the present specification and claims, the following terms have the meanings defined below.

The term “tall oil material” in connection with the present invention refers to a by-product of Kraft pulping of wood, especially coniferous wood. The tall oil material is a mixture of fatty acids, resin acids, neutral compounds and turpentine components originating from wood, for example a sole crude tall oil or a mixture of different crude tall oils. The turpentine components of tall oil are substantially composed of CioHi6 terpenes.

The term “tall oil residue” refers to the residue fraction obtained when purifying tall oil — 25 material, such as crude tall oil. Light neutral components can be separated to be processed

O to raw materials for valuable transportation fuel products and the remaining residue or

N leftover fraction is the tall oil residue. Methods for purifying and/or fractioning tall oil © material are for example different kinds of distillation and/or evaporation, such as 7 multistage evaporation. Typically, the tall oil residue consists of high boiling neutrals as

E 30 well as some leftover resin acids and fatty acids. 2 The term “neutrals” refers here to esters, unsaponifiables (monomeric neutrals such as

N sterols and alcohols) as well as polymeric neutrals (polymers).

N The term “unsaponifiables” refers here to substances which lack the ability to form soaps, i.e. cannot be saponified by caustic treatment. Typical unsaponifiables are higher aliphatic alcohols, sterols, and hydrocarbons, particularly fatty alcohols (C20-C24), sterols (C30) and carotenes, and various other alkyl- and cycloalkyl hydrocarbon derivatives (C10-C30).

The term “bio-diluent” refers here to a sustainable bioliguid with low viscosity, high boiling point, and which is substantially free of water. 5 The feedstock of the embodiments of the disclosure either comprises tall oil material feedstock or consists of tall oil material feedstock. In embodiments of the disclosure, the tall oil material is a by-product of Kraft pulping of wood, preferably coniferous wood.

Typically, the tall oil material is selected from crude tall oil (CTO) and mixtures thereof.

CTO refers to the processed mixture of naturally-occurring compounds extracted from wood species like pine, spruce and aspen. It is obtained from the acidulation of crude tall oil soap from Kraft and sulphite pulping processes used in paper making. Crude tall oil (CTO) generally contains both saturated and unsaturated oxygen-containing organic compounds such as resin acids (mainly abietic acid and isomers thereof), fatty acids (mainly linoleic acid, oleic acid and linolenic acid), neutral substances, fatty alcohols, sterols and other alkyl hydrocarbon derivatives, as well as inorganic impurities (alkaline metal compounds, sulphur, silicon, phosphorus, calcium and iron compounds). Preferably the tall oil material is a sole crude tall oil or a mixture of different crude tall oils.

According to the embodiments of the disclosure, the tall oil material used for the feed or part thereof may comprise purified CTO. For example, washing and/or distilling may be used for the purification of CTO.

In embodiments of the method of the disclosure the process for production of biofuels, comprises treating or pre-treating the tall oil material used as feedstock. Preferably, the feedstock comprising tall oil material is treated by multistage evaporation, which may comprise two, three, four or more evaporators. Examples of suitable evaporation methods — 25 are those utilizing thin film evaporation technology. The evaporators in the evaporation

O methods can thus be selected from the group consisting of thin film evaporators, falling

N film evaporators, short path evaporators, plate molecular stills and any other evaporators © using thin film evaporation technology. The evaporators can be either of the same type or - different type and are selected independently from the above listed evaporators. The & 30 evaporators are suitably arranged in series and the temperature is typically increased & successively from the first to the second and subsequent evaporators. 5 Having more than one evaporators, provides the advantage that the boiling in the

N evaporators following the first evaporator takes place in a more controlled manner because low boiling light components do not cause so much “carry over”, i.e. migrating of the impurities to the vapour.

Using a multi-stage evaporation for purifying tall oil material, such as crude tall oil, is a very efficient method for removing impurities from light neutral components which are separated to be processed to raw materials for valuable transportation fuel products, while the amount of the residue fraction, the tall oil residue, is minimized.

Typically, the pretreatment of the feedstock comprising tall oil material comprises the following steps (a) evaporating the tall oil material in a first evaporator to produce a first fraction comprising light hydrocarbons and water and a second fraction comprising fatty acids, resin acids, neutral substances and residue components, (b) evaporating said second fraction in at least one further evaporator to produce a third fraction comprising fatty acids, resin acids and light neutral substances, and a residue fraction, and (c) recovering said first fraction, third fraction and residue fraction.

The apparatus used for purifying tall oil material used as feedstock in the method of disclosure typically comprises - a first evaporator arranged to evaporate said tall oil material and to produce a first fraction comprising light hydrocarbons and water and a second fraction comprising fatty acids, resin acids, neutral substances and residue components, - at least one further evaporator arranged to evaporate said second fraction and to produce a third fraction comprising fatty acids, resin acids and light neutral substances and a residue fraction,

N - a first connection arranged to feed the second fraction to said at least one further

N 25 evaporator, and

NN

O

© - optionally one or more further connections between said further evaporators.

O

I In embodiments of the method of the disclosure, the process further comprises an * additional pretreatment step of storing the tall oil material in a storage tank before the first 00

O evaporator.

LO

N 30 In some embodiments of the method of the disclosure, the pretreatment of the feedstock

N comprising tall oil material is performed by using a heater and evaporator combination.

Suitably said heater and evaporator combination comprises a heater and a series of evaporators. Suitably a combination of a heater and three evaporators is used.

According to one embodiment, the present invention relates to a process for purifying biological feed material, comprising the steps of - subjecting the biological feed material to treatment in a heater to produce a first fraction comprising water and light components, and a second fraction comprising heavier components and residues, - evaporating said second fraction in a first evaporator to produce a third fraction comprising water and low boiling light hydrocarbon and a fourth fraction comprising heavier components and residues, - evaporating said fourth fraction in a second evaporator to produce a fifth fraction comprising mainly fatty acids and a sixth fraction comprising heavier components and residues, evaporating said sixth fraction in a third evaporator to produce a seventh fraction comprising mainly fatty acids and an eight fraction comprising heavy residues, and - recovering the fifth and/or seventh fractions.

The heater may be a conventional heater or a falling film evaporator (falling film tube evaporator) or a plate molecular still or a thin film evaporator, suitably a falling film evaporator (FFE) or plate molecular still is used, particularly suitably a FFE is used. The conventional heater refers here to any heat exchanger - flashing apparatus combination or the like, suitable for rapid heating and condensing of the separated gaseous phase. The biological feed material is heated in the heater at a temperature from 80 to 150°C, suitably from 90 to 120°C. The heating is carried out under a pressure from 40 to 80 mbar, suitably from 45 to 65 mbar. A first fraction comprising water and some light components is separated and the second fraction comprising the heavier components and residues, such

N 25 as fatty acids, resin acids, neutral substances etc. is directed to a series of evaporators. . The falling film evaporator removes effectively a major amount of water present in the feed <Q material, typically more than 50 % by weight. The second fraction from the heater,

S containing the remaining components, is directed to the first evaporator in the series of

E evaporators. & 30 In the series of evaporators, the first evaporator is a thin film evaporator or a short-path

O evaporator or a plate molecular still, suitably a thin film evaporator is used. The first

O evaporator operates at a temperature from 180 to 250°C, suitably from 190 to 220°C. A pressure of 40 to 80 mbar, suitably from 45 to 65 mbar is used. A third fraction containing water and low boiling light hydrocarbon components, said fraction having boiling point of

100 — 210°C, suitably 100 — 170°C at a normal pressure, is removed and the fourth fraction (from the first evaporator) is directed to the second evaporator. When CTO is used as feed material, Crude Sulfate Turpentine (CST) is removed in the third fraction with water.

Particularly suitably the heater and the first evaporator are operated under the same pressure. Suitably the same pressure vessel or pressure line is used. The liquid phase (fraction) from the first evaporator is led to a second evaporator. A thin film evaporator or plate molecular still or short path evaporator can be used, suitably the second evaporator is a short path evaporator. The second evaporator typically operates at a temperature of 200 to 350°C, suitably from 250 to 300°C. A pressure of 0.01 to 50 mbar, suitably 0.5 to 10 mbar, more suitably 1 to 5 mbar and particularly 2 to 3 mbar is used in the second evaporator. A fifth fraction comprising mainly (more than 50 % by weight) fatty acids is separated and fed to a reactor feed tank and the sixth fraction (liquid phase) is led to a third evaporator.

The third evaporator may be a short path evaporator or a plate molecular still, suitably a short path evaporator is used. Typical operating conditions include a temperature of 250 to 400°C, suitably from 290 to 360°C. A pressure of 0.01 to 10 mbar, suitably 0.01 to 5 mbar, more suitably 0.1 to 2 mbar is used. From the third evaporator, the seventh fraction (distillate) and fed to the reactor feed tank. The eight fraction (the residual, very viscous fraction), amounting typically about 5 % by weight from the original feed is the tall oil residue used in the method.

Optionally the feed material may be subjected to additional flashing prior to feeding to the heater, and/or the liquid material obtained from the heater is subjected to flashing prior to feeding into the first evaporator. Flashing may be carried out using any suitable manner, for example using heat-exchanger-expansion vessels where volatile components are released.

N The light hydrocarbons, fatty acids, resin acids and light neutral substances obtained in . accordance with the process can be used for the production of biofuels and components

P thereof and especially it relates to the use of the light hydrocarbons for the production of

S gasoline, naphtha, jet fuel, diesel and fuel gases and/or to the use of the fatty acids, resin = 30 acids and light neutral substances for the production of diesel, jet fuel, gasoline, naphtha 2 and fuel gases. Typically, the process comprises upgrading by hydroprocessing for

L example using a reactor system for catalytic treatment.

O The characterization of tall oil residue recovered after multistage evaporation of tall oil material is presented in Table 1 below, where typical concentrations of total neutrals, resin acids and fatty acids as well as unsaponifiables are shown.

Table 1 Characteristics of tall oil residue obtained by multistage evaporation

Tall oil sn

Pensa fre ja

Fa EA [ee

Typically, the tall oil residue comprises or consists of below 10 w-%, preferably below 9 w- %, more preferably up to 8 w-% fatty acids; below 10 w-%, preferably below 9 w-%, more preferably below 8 w-%, most preferably below 7 w-% resin acids; and over 80 w-% neutrals, preferably over 82 w-%, more preferably over 85 w-%. Typically, the amount of unsaponifiables is 10 - 35 w-%, preferably 15 - 30 w-%, more preferably 20 — 25 w-%.

In preferable embodiments of the disclosure, the recovered fraction of tall oil residue has an acid value below 50 mg/KOH/g, preferably below 40 mg/KOH/g, more preferably below 30 mg/KOH/g.

The temperature of the tall oil residue added according to the method of the disclosure is typically between 250 °C and 400 °C, preferably between 290 °C and 360 °C, more preferably between 300 °C and 320 °C.

According to the embodiments of the disclosure, the bio-diluent is a sustainable bioliguid such as a first generation distilling residue. Typically, the viscosity of the bio-diluent is below 50 mm?/s measured by EN ISO 3104, CTO 50 °C; the boiling point of the bio-diluent is above 300 °C and the bio-diluent is substantially free of water. Typically, that the bio-

N diluent is substantially free of water, which means that the bio-diluent comprises below 1

N w-% water, preferably below 0.5 w-%. The boiling point of the bio-diluent is above 300 °C,

S which typically means that below 10 w-% of the bio-diluent components has a boiling point

S 20 below 300 °C, preferably below 5 w-% of the bio-diluent components has a boiling point

E below 300 °C. 00 5

Table 2 Characteristics of a typical bio-diluent

Unit Method Bio- diluent

Acid value CTO mg/KOH/g | SCAN-T 11

Neutral substances | w-% 88,6

CTO, calculated

Fatty acids CTO, | w-% 11,1 calculated

Water, K-F | w-% PCTM 4B 0,28 coulometric, CTO

Viscosity, CTO 50 °C EN ISO 3104 | 18,81

Typically, the bio-diluent comprises or consists of below 15 w-%, preferably below 12 w- % fatty acids; below 2 w-%, preferably below 1 w-%, more preferably below 0.5 w-% resin acids; and over 80 w-%, preferably over 82 w-%, more preferably over 85 w-% neutrals.

In preferable embodiments of the disclosure, the bio-diluent has an acid value below 50 mg/KOH/g, preferably below 40 mg/KOH/g, more preferably below 30 mg/KOH/g, most preferably below 20 mg/KOH/g or even below 10 mg/KOH/g.

The temperature of the bio-diluent added according to the method of the disclosure is typically between 30 °C and 80 °C, preferably between 40 °C and 60 °C.

According to the embodiments of the product of the disclosure typically comprises over 90

N w-% of tall oil residue and bio-diluent, preferably the tall oil residue composition comprises

O

N and/or consists of 100 % of tall oil residue and bio-diluent.

N

2 The tall oil residue composition recovered from the tall oil residue tank, obtained by the © 15 embodiments of the method of the disclosure and comprising or consisting of tall oil

I a. residue and bio-diluent , is typically directed to a tall oil residue cooler and thereafter at 2 least partly recirculated back to the tall oil residue tank and/or lead to a tall oil residue

Lo composition storage tank. With the method of the disclosure it is possible to control the

O temperature of the tall oil residue so that the temperature of tall oil residue composition directed to the tall oil residue composition storage tank is kept between 120 *C and 190 °C, preferably below 180 °C. The valves controlling the amount of tall oil residue composition recirculated and the amount of tall oil residue composition directed to the tall oil residue composition storage tank is steered by the temperature of the tall oil residue composition after leaving the cooler and/or the fluid level in the tall oil residue tank.

Typically, the fluid level of the tall oil residue tank is kept between 30 vol-% and 80 vol-% of the tank volume. At the same time the viscosity of the tall oil residue composition is typically lowered. The viscosity of the tall oil composition of the disclosure is typically below 1000 mm?/s, preferably between 200 and 900 mm?/s, more preferably between 500 and 700 mm?/s.

In preferable embodiments of the disclosure, the tall oil residue composition has an acid value below 35 mg/KOH/g, preferably below 30 mg/KOH/g, more preferably below 25 mg/KOH/g, preferably the acid value is a value between 10 and 35 mg/KOH/g, more preferably between 10 and 30 mg/KOH/g, most preferably between 10 and 25 mg/KOH/qg.

In Figure 1 crude tall oil (tall oil material) (10) is fed to a pretreatment unit (100) to obtain fraction(s) of light hydrocarbons, fatty acids, resin acids and light neutral substances (21, 22) and a residue fraction of tall oil residue (20). A bio-diluent (30) is added to the tall oil residue (20) and the obtained tall oil residue composition (40) is directed to a tall oil residue tank (110). At least part (41) of the tall oil residue composition (40) is recirculated to the tall oil residue tank (110) via a tall oil residue cooler (120) and the rest of the tall oil residue composition (42) is directed to a tall oil residue composition storage tank (130). The other fraction(s) (21, 22) obtained from the pretreatment unit (100) are optionally subjected to fractionation in a fractionation step (not shown) and/or optionally converted catalytically in the hydroprocessing step (not shown) in the presence of hydrogen.

EXAMPLES

In the following examples, the tall oil residue fraction was obtained from a multistage — 25 evaporation. The characteristics of the tall oil residue are shown in Table 1. The tall oil

O material was crude tall oil. 5 Analysis methods used in the Examples

S The analysis methods used for measuring viscosity were CTO 50 °C EN ISO 3104 and

E ASTM D2196-99 at 50 *C. The acid value was measured by SCAN-T 11. & 30 Example 1 — Comparative

O A new tall oil residue cooler was installed to the refinery's tall oil residue tank. The viscosity

O of the tall oil residue obtained from the pretreatment unit and the viscosity of the tall oil residue composition obtained from the tall oil residue tank was measured in order to see if the process could be run without using an external thinner. The viscosity was measured by EN ISO 3104 (CTO 50 °C).

The tall oil residue composition was directed from the tall oil residue tank to a tall oil residue cooler and part of the cooled down composition was recirculated back to the tall oil residue tank.

Table 3 Viscosity measurements of tall oil residue composition in tall oil residue tank

Viscosity in tall oil residue tank mm%/s

Day 11 1846

Day 12 1969

As can be seen from the results in Table 3, viscosity increased significantly. Further, the cooling capacity of the tall oil residue cooler decreased. The use of the external thinner was continued after the trial.

Example 2

A tall oil residue was obtained from multistage evaporation using crude tall oil (tall oil — material) as feedstock. The temperature of the tall oil residue was 310 *C. About 10 w-%

QA

S 15 of 15 generation distilling residue (bio-diluent) was added to about 80 w-% of tall oil residue

N and the obtained tall oil residue composition was directed to the tall oil residue tank. The © ratio of bio-diluent to tall oil residue was 2:10 by weight. The temperature of the bio-diluent

I was about 50 °C and the characteristics of the bio-diluent are shown in Table 2. a a © As shown in Figure 2, less than 10 w-% of the distilling residue components (the bio-diluent components) have a boiling temperature below 300 °C.

S The tall oil residue composition was directed from the tall oil residue tank to a heat

N exchanger used as the tall oil residue cooler and part of the cooled down composition was recirculated back to the tall oil residue tank with tall oil residue composition based on the fluid level of the tall oil residue tank and the temperature of the tall oil residue composition after cooling. The rest of the tall oil residue composition was directed to a tall oil residue composition storage tank. The temperature of the tall oil residue composition directed to the tall oil residue composition storage tank was kept below 180°C and the fluid level in the tall oil residue tank was kept below 80 % by volume. The other fraction(s) obtained from the multistage evaporation were upgraded by hydroprocessing.

The characteristics of the recovered tall oil residue composition directed to the tall oil residue composition storage tank are shown in Table 4.

Table 4 Characteristics of the recovered tall oil residue composition

Acid number CTO mg/KOH/g | SCAN-T 11

Ash 625°C (tall oil) SCAN-T 4

Water, K-F volumetric, CTO PCTM 4C

Water, K-F coulometric, CTO PCTM 4B

Viscosity, CTO 50 °C EN ISO 3104 [819.3

Carbon, C (Flash) ASTM D5291 |78.77

Hydrogen, H (Flash) ASTM D5291 | 11.03

As shown in Table 5, the viscosity varies based on the amount of bio-diluent added to the tall oil residue. The viscosity was measured by EN ISO 3104 (CTO 50 °C). — Table 5 Viscosity of tall oil residue composition based on tall oil residue and bio-diluent

QA

S ratio.

S Viscosity

O W-% mm?2/s - Tall oil residue 1962 a

N Tall oil residue / bio-diluent 90/10 00 5 Tall oil residue / bio-diluent 80/20

N

S Tall oil residue / bio-diluent 70/30

Claims (18)

1. A tall oil residue composition, characterized in that the composition comprises tall oil residue and bio-diluent, wherein the tall oil residue comprises below 10 w-% fatty acids, below 10 w-% resin acids, and over 80 w-% neutrals; viscosity of the bio-diluent is below 50 mm?/s measured by EN ISO 3104, CTO 50 °C; less than 10 w-% of bio-diluent components has a boiling point below 300 °C; and the bio-diluent is substantially free of water; and wherein the bio-diluent to tall oil residue ratio is 1:10 to 4:10 by weight and acid value of the tall oil residue composition is below 35 mg/KOH/g.

2. The tall oil residue composition of claim 1, characterized in that the bio-diluent to tall oil residue ratio is 1.5:10 to 3.5:10, preferably 2:10 to 3:10.

3. The tall oil residue composition of any of the preceding claims, characterized in that the acid value of the tall oil residue composition is between 10 mg/KOH/g and below 35 mg/KOH/g, more preferably between 10 mg/KOH/g and 30 mg/KOH/g, most preferably between 10 mg/KOH/g and 25 mg/KOH/g.

4. The tall oil residue composition of any of the preceding claims, characterized in that the tall oil residue has an acid value below 50 mg/KOH/qg, preferably below 40 mg/KOH/g, more preferably below 30 mg/KOH/g.

5. The tall oil residue composition of any of the preceding claims, characterized in that the bio-diluent comprises below 1 w-% water, preferably below 0.5 w-

%

6. The tall oil residue composition of any of the preceding claims, characterized N in that less than 5 w-% of the bio-diluent components has a boiling point below N 300 °C. S O 25

7. A method of controlling temperature in a process for production of biofuels from z tall oil material, characterized in that the temperature of tall oil residue is > controlled by adding bio-diluent to tall oil residue in a ratio of 1:10 to 4:10 by 2 weight, preferably 1.5:10 to 3.5:10, more preferably 2:10 to 3:10 of bio-diluent 3 to tall oil residue.

8. The method of claim 7, characterized in that the process further comprises the following steps

(a) evaporating tall oil material in two or more evaporators; (b) recovering a fraction of tall oil residue.

9. The method according to any of claims 7 to 8, characterized in that the recovered fraction of tall oil residue has an acid value below 50 mg/KOH/qg, preferably below 40 mg/KOH/g, more preferably below 30 mg/KOH/g.

10. The method according to any of claims 7 to 9, characterized in that the process comprises further steps of adding bio-diluent to the tall oil residue before a tall oil residue tank, adding bio-diluent to the tall oil residue in the tall oil residue tank; recirculating tall oil residue composition obtained by adding bio-diluent to the tall oil residue and/or recovering the tall oil residue composition by directing part of the tall oil residue composition to a tall oil residue composition storage tank.

11. The method according to any of claims 7 to 10, characterized in that the recirculating is controlled by keeping tall oil residue tank fluid level between 30 vol-% and 80 vol-% of the tank volume and/or keeping the temperature of the tall oil residue composition directed to the tall oil residue composition storage tank between 120 °C and 190 °C, preferably below 180 °C .

12. The method according to any of claims 7 to 11, characterized in that the tall oil material is a by-product of Kraft pulping of wood, preferably coniferous wood.

13. The process according to any of claims 7 to 12, characterized in that the tall oil material is selected from crude tall oil (CTO) and mixtures thereof. —

14. The method according to any of claims 7 to 13, characterized in that the QA < viscosity of the bio-diluent is below 50 mm?/s measured by EN ISO 3104, CTO N 50 °C; the boiling point of the bio-diluent is above 300 °C, the bio-diluent is O 25 substantially free of water. I =

15. The method according to any of claims 7 to 14, characterized in that the x viscosity of the tall oil composition is below 1000 mm?/s , between 200 and 900 MN Lo mm?/s , more preferably between 500 and 700 mm%/s . S N

16. A product obtained by the method of any of claims 7 to 15.

17. Use of a tall oil residue composition of any of claims 1 to 6 or claim 16 in a chemical pulping process, as biofuel in a power plant and/or as raw material in chemical and construction industry.

18. The use according to claim 17, characterized in that ash content of the tall oil residue composition is below 1 w-%, preferably below 0.6 w-%, more preferably below 0.5 w-%, most preferably below 0.3 w-% measured according SCAN-T 11 and/or the sulphur content of the tall oil residue composition is below 0.5 w- %, preferably below 0.3 w-%, more preferably below 0.2 w-%, most preferably below 0.1 w-%. N O N K <Q O O I a a 00 00 N LO N O N