A process for producing rosin oil

Abstract

The present disclosure relates to a process for producing rosin oils from a renewable material comprising rosin acid such as from a feedstock comprising crude tall oil. According to the process, rosin acid present in the renewable material is separated (101), and a stream comprising at least part of the separated rosin acid is subjected to thermal decarboxylation reaction (102) to produce a stream comprising formed rosin oil, and recovering (103) rosin oil from the stream. The disclosure also relates to a system for carrying out the process, as well as to uses of the rosin oil obtainable by the process as renewable feedstock in co-processing with fossil feedstock for increasing renewable content of fossil transportation fuels and / or chemical and in co-processing with other renewable feedstocks for production of renewable fuels and / or chemicals, or components thereto. The disclosure also relates to a rosin oil product obtainable by the process.

Description

[0001] A PROCESS FOR PRODUCING ROSIN OIL

[0002] FIELD

[0003] The present disclosure relates to a process for producing rosin oil from renewable materials comprising rosin acid, such as from crude tall oil. The process includes thermal decarboxylation of rosin acid to produce a stream comprising rosin oil, and separating rosin oil from the stream. The disclosure also relates to systems and arrangements for carrying out the process, uses of the rosin oil obtainable by the process, and to a rosin oil product obtainable by the process.

[0004] BACKGROUND

[0005] Rosin is a solid resinous material that occurs naturally in pine trees. There are three major sources of rosin: gum rosin from the oleoresin extrudate of the living pine tree; wood rosin from the oleoresin contained in the aged stumps; and tall oil rosin from the waste liquor recovered as a by-product in the Kraft paper industry. Rosin is an ingredient in printing inks, photocopying and laser printing paper, varnishes, adhesives, soap, paper sizing, soda, soldering fluxes, and sealing wax.

[0006] Rosin comprises predominantly rosin acids. Rosin acids are tricyclic diterpenoids comprising two chemically reactive centres, namely double bonds, and carboxyl groups.

[0007] Rosin acids can be decarboxylated either by a thermal or an oxidative reaction. The decarboxylation reaction has often been regarded as an undesired side reaction.

[0008] EP0149958 discloses that rosin acid decarboxylation can be accelerated by performing the decarboxylation reaction in the presence of one or more accelerators such as high sulphur tall oil rosin, fatty acids, and organic and inorganic sulphides. The thermal oils produced were used in rubber formulation.

[0009] EP3838998 discloses biorenewable rosin derived hydrocarbon compositions and their uses.

[0010] Sundqvist et al (Can. J. Chem. Engineering, 77, 1999, pp. 465-472) have realized that the decarboxylation reaction helps increasing resinate concentration in a Ca- resinate reaction since it allows one to control the solution viscosity increase to the desired level for the resinate to be used as an ink vehicle. Bernas et al (Top Catal, 2012, 55, pp. 673-679; DOI 10.1007 / s11244-012-9846-7) discloses a process for producing aliphatic hydrocarbons from tall oil rosin. Also, use of the aliphatic hydrocarbons obtained as fuel additives is suggested.

[0011] Raw materials of biological origin, such as by-products in the Kraft paper industry, are also potential sources for various renewable fuels and renewable fuel components, and for renewable chemicals. These raw materials can be converted into renewable fuels by directing them through a catalytic reactor and contacting simultaneously with gaseous hydrogen. The resulting product can be refined further, and finally fractionated to form the desired renewable fuels, renewable fuel components and / or renewable chemicals.

[0012] However, the quality of the renewable raw material is not always on the required level for the catalytic step to be able to function in the most effective way. Highly acidic renewable raw materials, such as those derived from crude tall oil, may cause significant corrosion issues. Moreover, low impurity feeds are desired both for coprocessing and for the renewables production especially when the renewable raw material is co-processed in a fossil refinery. There is also a need to refine lower value side streams, such as crude tall oil (CTO) fractionation side streams, into higher value products. Sometimes market fluctuations create bottlenecks, and a versatile use of side products, such as rosin acid, for refined end products is advantageous or necessary.

[0013] SUMMARY

[0014] It is an aspect of the present disclosure to provide a specific process for producing rosin oil, the process comprises the steps of: a) providing renewable material comprising rosin acid; b) separating at least part of the rosin acid from the renewable material, c) subjecting a stream comprising at least part of the separated rosin acid to a thermal decarboxylation reaction to form rosin oil at a temperature from more than 280 °C to 360 °C, for a period of time sufficient to provide a conversion of the rosin acid of at least 90 %, and continuously removing a stream comprising the formed rosin oil from the thermal decarboxylation reaction; and d) recovering the formed rosin oil. According to another aspect, the present disclosure relates to the use of a rosin oil obtained from the process of claim 1 as renewable feedstock in co-processing with fossil feedstock for increasing renewable content of fossil transportation fuels and / or fossil chemicals.

[0015] According to yet another aspect, the present disclosure relates to the use of rosin oil obtained from the process of claim 1 in co-processing with other renewable feedstocks for production of renewable fuels and / or renewable chemicals, or components thereto.

[0016] According to still another aspect, the present disclosure relates to a system for carrying out a process for producing rosin oil from a renewable feedstock comprising crude tall oil, the system comprising

[0017] - dehydration equipment configured to remove at least water from the feedstock;

[0018] - a depitching equipment configured to separate tall oil pitch from the dehydrated feedstock to produce a fraction comprising tall oil pitch and a fraction comprising depitched tall oil;

[0019] - separating means configured to separate depitched tall oil to a fatty acid depleted stream comprising rosin acids and a fatty acid containing stream;

[0020] - a decarboxylation reactor configured to carry out a decarboxylation reaction of the fatty acid depleted stream comprising rosin acids to obtain a stream comprising formed rosin oil; and

[0021] - separating means configured to separate rosin oil from the stream comprising formed rosin oil to obtain rosin oil and a rosin oil depleted stream; and

[0022] - recycling means configured to return at least part of the rosin oil depleted stream to the decarboxylation reactor.

[0023] According to still another aspect, the present disclosure concerns an arrangement comprising

[0024] - a continuous flow reactor configured to carry out a thermal decarboxylation reaction of a stream comprising rosin acid and to obtain a stream comprising formed rosin oil; - separating means configured separate at least rosin oil from the stream comprising formed rosin oil to obtain recovered rosin oil and a rosin oil depleted stream; and

[0025] - recycling means configured to return at least part of the rosin oil depleted stream to the continuous flow reactor.

[0026] According to still another aspect, the present disclosure concerns a rosin oil product comprising: more than 85 wt.-%, preferably more than 90 wt.-%, more preferably more than 95 wt.-%, most preferably more than 97 wt.-% of rosin oil;

[0027] 0.1 -10 wt.-%, preferably 0.1-5 wt.-%, more preferably 0.1 -2 wt.-%, most preferably 0.5-2 wt.-% of rosin acid;

[0028] 0-5 wt.-%, such as 0.1-5 wt.-%, of other neutral components;

[0029] 0-5 wt.-%, such as 0.1-5 wt.-%, of light acids; and

[0030] 0-3 wt.-%, such as 0.1-3 wt.-%, of heavy (C20+) compounds.

[0031] A number of exemplifying and non-limiting embodiments of the invention are described in accompanied dependent claims.

[0032] Metal content of rosin oil is advantageously low when majority or all of the used feeds to the decarboxylation unit are obtained by evaporating CTO. Moreover, rosin oil obtained by the present process mixes well with e.g. fossil feed. The process of the present disclosure enables additional value creation for the side streams of the CTO separation. The separations may further be optimised for increasing lower grade rosin acid streams and simultaneously produce even better rosin products. If the present process is combined with a CTO separation plant, the rosin is already hot, and energy is saved for the processing.

[0033] Additionally, the process can be switched from producing rosin acid to a process for producing rosin oil depending on the market situation. Rosin oil may further be stored at lower temperature, providing thus flexibility in logistics.

[0034] Various exemplifying and non-limiting embodiments of the invention together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in connection with the accompanying figures. The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e., a singular form, throughout this document does not exclude a plurality.

[0035] BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 shows an exemplary non-limiting schematic overview of production of rosin oil according to an embodiment of the present disclosure.

[0037] Figure 2 shows an exemplary system of the present disclosure for producing rosin oil from a feedstock comprising crude tall oil.

[0038] Figure 3 shows an arrangement 300 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 301 configured to carry out a thermal decarboxylation reaction of a stream comprising rosin acid A and to obtain streams comprising formed rosin oil B ( / ,g), a separating means 302 comprising an evaporator 303 and a condenser 304 for recovering rosin oil, and a recycling means 305 for returning at least part of a rosin oil depleted stream D to the reactor.

[0039] Figure 4 shows an arrangement 400 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 401 configured to carry out a thermal decarboxylation reaction of a stream comprising rosin acid A and to obtain streams comprising formed rosin oil B ( / ,g), a separating means 402 comprising an evaporator 403 and a distillation column 404 for separating the streams B (l,g) to rosin oil and to a rosin oil depleted stream D, recovering means 406 for separating rosin acid E from the rosin oil depleted stream, and recycling means 405 for returning at least part of the rosin oil depleted stream and / or the recovered rosin to the reactor. The reactor and the distillation column are configured to operate at the same pressure.

[0040] Figure 5 shows an arrangement 500 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 501 for converting a stream comprising rosin acid A to streams comprising rosin oil B ( / ,g), a separating means 502 comprising an evaporator 503 and a distillation column 504 for separating the streams B to rosin oil and to a rosin oil depleted stream D, recovering means 506 for separating rosin acid E from the rosin oil depleted stream, and recycling means 505 for returning at least part of the rosin oil depleted stream and / or the recovered rosin acid to the reactor. The reactor and the distillation column are configured to operate at different pressures.

[0041] Figure 6 shows an arrangement 600 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 601 for converting a stream comprising rosin acid A to streams comprising rosin oil B (l,g), a separating means 602 comprising an evaporator 603, a condenser 610, and a distillation column 604 for separating the streams B ( / ,g), to rosin oil and to a rosin oil depleted stream D, recovering means 606 for separating rosin acid E from the rosin oil depleted stream, and recycling means 605 for returning at least part of the rosin oil depleted stream and / or the recovered rosin to the reactor. The reactor and the distillation column are configured to operate at the same pressure.

[0042] Figure 7 shows an arrangement 700 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 701 for converting a stream comprising rosin acid A to streams comprising rosin oil B (l,g), a separating means 702 comprising an evaporator 703 and a distillation column 704 for separating the streams B (l,g) to rosin oil and to a rosin oil depleted stream D, recovering means 706 for separating rosin acid E from the rosin oil depleted stream, and recycling means 705 for returning at least part of the rosin oil depleted stream and / or the recovered rosin to the reactor. The reactor and the distillation column are configured to operate at the same pressure.

[0043] Figure 8 shows an arrangement 800 of an exemplary non-limiting embodiment of the present disclosure comprising a continuous flow reactor 801 for converting a stream comprising rosin acid A to streams comprising rosin oil B (l,g), a separating means 802 comprising an evaporator 803 and a distillation column 804 integrated to the reactor for separating the stream B (l,g) to rosin oil and to a rosin oil depleted stream D, recovering means 806 for separating rosin acid E from the rosin oil depleted stream, and recycling means 805 for returning at least part of the rosin oil depleted stream and / or the recovered rosin to the reactor.

[0044] Figure 9 shows exemplary evaporator configurations 907a, b for allowing feeding a stripping gas such as carbon dioxide to the arrangements of figures 4-8. DESCRIPTION

[0045] Figure 1 shows an exemplary process of the present disclosure for production of rosin oil. In the figure reference numbers and arrows illustrate reactions and streams, respectively.

[0046] Accordingly, the process comprises the following steps. a) providing renewable material A comprising rosin acid; b) separating 101 at least part of the rosin acid from the renewable material; c) subjecting 102 a stream comprising at least part of the separated rosin acid to thermal decarboxylation reaction to form rosin oil at a temperature from more than 280 °C to 360 °C for a period of time sufficient to provide a conversion of the rosin acid of at least 90%, and continuously removing a stream comprising the formed rosin oil from the thermal decarboxylation reaction; and d) recovering 103 the formed rosin oil.

[0047] Rosin acid is a tricyclic diterpenoid comprising a carboxylic acid group at the tertiary 4-carbon of the A ring. Exemplary rosin acids suitable for the present disclosure are abietic acid (CAS No. 514-10-3), isopimaric acid (CAS No. 5835-26-7), levopimaric acid (CAS No. 79-54-9), neoabietic acid (CAS No. 471-77-2), palustric acid (CAS No. 1945-53-5), pimaric acid (CAS No. 127-27-5), sandaracopimaric acid (CAS No. 471 -74-9), dehydroabietic acid (1740-19-8), and mixtures thereof.

[0048] Rosin acids decarboxylate at high temperatures to rosin oils, meaning that the rosin acid molecules degrade into lighter neutral rosin oils by losing their acid group and releasing carbon dioxide. Accordingly, rosin oils are the decarboxylation reaction products of rosin acids. Decarboxylation of abietic acid is shown below as an illustrative example.

[0049] Abietic acid Rosin oii The renewable character of carbon-containing compositions, such as feedstocks and products of biological origin i.e. renewable material, can be determined by comparing the14C-isotope content of the feedstock to the14C-isotope content in the air in 1950. The14C-isotope content can be used as evidence of the renewable origin of the feedstock or product. Carbon atoms of renewable material comprise a higher number of unstable radiocarbon (14C) atoms compared to carbon atoms of fossil origin. Therefore, it is possible to distinguish between carbon compounds derived from biological sources, and carbon compounds derived from fossil sources by analysing the ratio of12C and14C isotopes. Thus, a particular ratio of said isotopes can be used to identify and quantify renewable carbon compounds and differentiate those from non-renewable i.e. fossil carbon compounds. The isotope ratio does not change in the course of chemical reactions. Examples of a suitable method for analysing the content of carbon from biological sources is ASTM D6866 (2020). An example of how to apply ASTM D6866 to determine the renewable content in fuels is provided in the article of Dijs et al., Radiocarbon, 48(3), 2006, pp 315-323. For the purpose of the present invention, a carbon-containing material, such as a feedstock or product is considered to be of renewable origin if it contains 90% or more modern carbon, such as 100% modern carbon, as measured using ASTM D6866.

[0050] The renewable material of the present disclosure comprises typically at least 20 wt.- % rosin acid, preferably at least 90 wt.-% rosin acid. The renewable material may include in addition to rosin acid further renewable components, such as fatty acids, aldehydes, ketones, alcohols, terpenes, ethers and / or sterols.

[0051] Exemplary renewable materials suitable for the present process comprise crude tall oil, tall oil, tall oil pitch, depitched tall oil, distilled tall oil (DTO) and tall oil rosin, which all contain rosin acids. Also other rosin acid containing renewable materials, such as gum-resins, can be used.

[0052] In an exemplary embodiment the renewable material comprises crude tall oil. Content of CTO in the renewable material is preferably at least 10 wt.-% CTO, more preferably at least 50 wt.-% CTO, even more preferably at least 90 wt.-% CTO.

[0053] In an embodiment the renewable material contains less than 300 ppm, more preferably less than 150 ppm, most preferably less than 130, such as less than 100 ppm, less than 80 ppm or even less than 50 ppm, sulphur by weight. The low sulphur content is preferable when the product of the present process i.e. rosin oil is coprocessed with oxygen containing renewable materials.

[0054] In a particular embodiment the renewable material for decarboxylation is rosin acid originated from CTO. In this embodiment the process comprises, prior to thermal decarboxylation, the following steps: i) dehydrating the renewable material to produce dehydrated renewable material; ii) depitching the dehydrated renewable material to produce a fraction containing tall oil pitch, and a fraction containing depitched tall oil; and iii) subjecting the fraction containing depitched tall oil to separation to produce a stream containing fatty acids, and a fatty acid depleted stream containing the separated rosin acid.

[0055] The dehydration step removes e.g. water and turpentine from the renewable material. Dehydration takes place typically in a moderate vacuum, between 120-200 °C. Exemplary dehydration conditions include rapid heating up to 200 °C in reduced pressure, such as at 5 kPa. The dehydrated renewable material contains fatty acids such as TOFA, rosin acids, and tall oil pitch.

[0056] The dehydrated renewable material is typically subjected to depitching to separate pitch compounds from the dehydrated renewable material. Exemplary depitching conditions include temperature of about 300 °C and a pressure of about 1 kPa. The short depitching time, such as few seconds, e.g. 1 -5 s, is preferred to avoid premature decarboxylation of the rosin acids present in the dehydrated renewable material.

[0057] The depitched renewable material contains fatty acids and rosin acids, which are separated e.g. by distillation prior to subjecting the rosin acids to thermal decarboxylation.

[0058] Dehydration and depitching of CTO is disclosed in more detail in e.g. by L.-H. Norlin in Encyclopaedia of Industrial Chemistry, 2005, Chapter Tall Oil, pp. 1-14 incorporated here by reference.

[0059] According to the present process most of the fatty acids are separated from the renewable material prior to thermal decarboxylation to produce a fatty acid containing stream and a fatty acid depleted stream containing the rosin acid.

[0060] The fatty acid depleted stream containing rosin acid is used for producing rosin oil.

[0061] The fatty acid depleted stream contains typically less than 40 wt.-%, preferably less than 10 wt.-%, more preferably less than 5 wt.-%, most preferably less than 1 wt.-% fatty acids.

[0062] In an embodiment, the fatty acid depleted stream contains tall oil pitch and rosin acid. The fatty acid depleted stream containing tall oil pitch and rosin acid can be subjected to the thermal decarboxylation reaction. The decarboxylation reaction conditions are as disclosed below.

[0063] The stream containing fatty acids may still include rosin acids which can be used in the present process. Accordingly, it is preferable to utilize the remaining rosin acids in the process, as well.

[0064] Thus, in a preferred embodiment, the fatty acid containing stream is subjected to distillation to produce a. a fraction comprising the fatty acid, and b. one or more fractions comprising rosin acid.

[0065] The one or more fractions comprising rosin acid can be subjected to decarboxylation to increase the overall yield of the rosin oil. The decarboxylation reaction conditions are as disclosed below.

[0066] In another embodiment at least part of the fatty acid depleted stream containing rosin acid is separated into at least one of the following fractions prior to decarboxylation: a. a first rosin acid fraction which is gaseous at the processing condition, such as temperature 150 °C or more, preferably from 150 °C to 250 °C, such as from 150 °C to 200 °C and pressure about 2 kPa, b. a second rosin acid fraction which is liquid at the processing conditions, and c. a third rosin acid fraction which is solid at the processing conditions, provided that the first rosin acid fraction is condensed prior to the subjecting to thermal decarboxylation. According to this embodiment at least one, preferably two of the fractions, more preferably the first rosin acid fraction and the second rosin acid fraction are decarboxylated. The decarboxylation reaction conditions are as disclosed below.

[0067] In an embodiment, the decarboxylation process includes subjecting at least part, preferably all, of the fatty acid depleted streams to thermal decarboxylation reaction.

[0068] The decarboxylation is performed at a temperature from more than 280 °C to 360 °C for a period of time sufficient to provide a conversion of the rosin acid to rosin oil of at least 90 %, preferably at least 95 %. The reaction time, i.e. the period of time the material stays in the decarboxylation reactor to give at least 90% conversion is typically between 3-12 hours, such as 8-12 hours. By the term “conversion” is herein meant the overall conversion of the rosin acid in the decarboxylation. The conversion depends on several parameters, such as the reactor size, reaction time, temperature and the like. A single pass conversion in a reactor may be adjusted to be low, such as 30-50 %, depending on the dimensioning of the reactor set up. The conversion i.e. the overall conversion may be enhanced by recycling efficiently the reactants, such as rosin acid. Preferably, the different streams, especially the formed rosin oil depleted streams, are recycled back to the thermal decarboxylation reaction and to the rosin oil separation units to enhance the conversion of the rosin acid and to increase the yield of rosin oil. Moreover, residence time for the reactants may be adjusted by altering the WHSV (weight hourly space velocity) of the rosin acid feed into the decarboxylation reactor.

[0069] Pressure of the decarboxylation reaction is typically at 0.1 - 110 kPa.

[0070] In an embodiment the decarboxylation reaction takes place at a low pressure, from 0.1 to less than 20 kPa, such as from 0.5 to less than 20 kPa. The pressure can be thus from 0.1 , 0.5, 1 , 2, 3, 4, 5, 7, 9, 10, 12, 15, or 17 kPa up to 7, 9, 10, 12, 15, 17, 18.5, 19, less than 20 kPa.

[0071] The use of low pressure assists vaporization of rosin oil and thus also removal of rosin oil from the decarboxylation reaction.

[0072] In an embodiment the decarboxylation reaction takes place at a high pressure, from 20 to 110 kPa. The pressure can be thus from 20, 30, 40, 50, 60 or 70 kPa up to 40, 50, 60, 0, 80, 90, 100, 110 kPa.

[0073] Depending on the desired production capacity, the decarboxylation reactor may be quite a large vessel. The risk of corrosion may require using high-grade stainless- steel materials, and especially making the low-pressure equipment vacuum proof, e.g. needing thick walls, will increase economic burden.

[0074] An advantage in atmospheric operation is the simplicity of handling the CO2 purge stream as CO2 is produced in the decarboxylation reaction and must be let out of the reactor continuously. CO2 purge stream catches volatile organic compounds with it. At reduced pressure operation CO2 will carry more organics out of the reactor than in the atmospheric case. In both cases the organics may be recovered to increase production yield and to lower potential environmental impacts.

[0075] When operating at a high pressure or near atmospheric pressure, recovery of high boiling organics from CO2 can be accomplished more comprehensively than at a low pressure resulting in smaller losses. Moreover, smaller size basic type of condensers can be applied at higher pressures saving the equipment costs.

[0076] The decarboxylation of rosin acids does not require decarboxylation catalysts when the decarboxylation reaction is performed under conditions disclosed above. Accordingly, no decarboxylation catalysts are added to the decarboxylation reaction. However, a feedstock comprising CTO may include components which may catalyse decarboxylation such as sulphur compounds. When the term “decarboxylation” is used, it is meant that the amount of the compounds having carboxylic groups is reduced, not necessarily that all carboxylic groups are removed. Preferably, at least 95% of the carboxylic groups of the rosin acids of the feed are removed in the decarboxylation step.

[0077] The stream comprising formed rosin oil may still contain material boiling above and / or below rosin oil such as non-condensables and a high boiling residue comprising neutral components such as sitosterol and esters thereof, remaining rosin acid, and acids heavier than rosin acid such as C(20+) fatty acids. The amount of material other than rosin oil depends on the decarboxylation reaction conditions and on the quality of the stream comprising rosin acid fed to the decarboxylation reaction.

[0078] In an embodiment the process further comprises after step c) and before step d) the steps: i. separating from the stream comprising the formed rosin oil, said formed rosin oil and a rosin oil depleted stream; and ii. recycling at least part of the rosin oil depleted stream to the thermal decarboxylation reaction of step c).

[0079] Depending on the decarboxylation reaction conditions, the stream comprising the formed rosin oil may contain a liquid phase and / or a gaseous phase.

[0080] In an embodiment the stream comprising the formed rosin oil contains a liquid phase and a gaseous phase, and the process comprises separating the formed rosin oil from at least one of the phases.

[0081] In an embodiment the separating of the formed rosin oil from the liquid phase comprises a. directing the liquid phase to a first evaporator operating at 260 °C or above, preferably at 300 °C or above, to produce a rosin oil vapor containing stream and a rosin oil depleted stream; and b. distilling and / or condensing the rosin oil containing stream thereby providing purified rosin oil.

[0082] In one embodiment the separating of the formed rosin oil from the gaseous phase comprises condensing and / or distilling rosin oil from the gaseous phase thereby providing purified rosin oil.

[0083] In an embodiment the process comprises directing a non-condensable gas, such as carbon dioxide, steam, or nitrogen, to the separating of step i. to enhance stripping. Preferably the carbon dioxide is the carbon dioxide formed in the decarboxylation reaction.

[0084] In an embodiment, part of the CO2 formed in the decarboxylation reaction is withdrawn from the reaction and recovered and used elsewhere.

[0085] In an embodiment the decarboxylation reaction produces a stream comprising rosin oil vapour, which is continuously removed from the decarboxylation reactor. In this embodiment the separating comprises condensing the rosin oil vapour formed and preferably also distilling the condensed stream for separating fractions boiling above and / or below rosin oil thereby providing purified rosin oil and one or more rosin oil depleted streams.

[0086] In an embodiment the formed rosin oil of step i. is at least in part in form of rosin oil vapor, and the separating of step i. comprises a. condensing the rosin oil vapor formed; and b. distilling the condensed rosin oil for separating fractions boiling above and / or below rosin oil thereby providing purified rosin oil.

[0087] In another embodiment the separating of step i. comprises subjecting the stream comprising the formed rosin oil to distillation thereby providing purified rosin oil and a rosin oil depleted stream.

[0088] The rosin oil depleted stream may comprise one or more of the above-mentioned compounds, typically at least remaining rosin acid. In an embodiment at least part of the rosin oil depleted stream is recycled to the thermal decarboxylation reaction of step c). Preferably, at least part of the rosin oil depleted stream is withdrawn from the process to avoid accumulation of heavy components such as C(20+) fatty acids, sitosterol and esters thereof.

[0089] In an embodiment separating of step i. comprises a. directing a liquid stream of step c) to a first evaporator operating at 260 °C or above, preferably at 300 °C or above, to produce a rosin oil vapor containing stream and a rosin oil depleted stream; and b. condensing the rosin oil vapor to provide rosin oil and a rosin oil depleted stream.

[0090] In this embodiment at least part of the rosin oil depleted stream is recycled to the thermal decarboxylation reaction of step c). Preferably, at least part of the rosin oil depleted stream is withdrawn from the process to avoid accumulation of heavy (C20+) compounds, such as fatty acids, esters, and alcohols, such as sitosterol, and esters and derivatives thereof.

[0091] In another embodiment the separating of step i. comprises a. directing the stream of step c) to a first evaporator operating at 260 °C or above, preferably at 300 °C or above to produce a stream comprising rosin oil vapor and a rosin oil depleted stream; b. directing the stream comprising rosin oil vapor and rosin oil depleted stream to a distillation column to separate at least rosin oil from the stream comprising rosin oil vapor thereby producing purified rosin oil.

[0092] In this embodiment at least part of the rosin oil depleted stream is recycled to the thermal decarboxylation reaction of step c). Preferably, at least part of rosin oil depleted stream is withdrawn from the process to avoid accumulation of heavy (C20+) compounds.

[0093] In an embodiment the process comprises recovering rosin acid from the rosin oil depleted stream and recycling at least part of the recovered rosin acid to the decarboxylation reaction of step c). This embodiment typically comprises directing at least part of the rosin oil depleted stream to a second evaporator operating at 260 °C or above, preferably at 300 °C or above to produce a stream comprising rosin acid and a rosin acid depleted stream, and recycling as least part of the stream comprising rosin acid to the thermal decarboxylation reaction. Preferably, at least part of the rosin acid depleted stream is withdrawn from the process to avoid accumulation of heavy components such as C(20+) fatty acids, sitosterol and esters thereof.

[0094] In an embodiment the thermal decarboxylation reaction of step c) and the separating of step i. are performed at the same pressure.

[0095] In an embodiment the thermal decarboxylation reaction of step c) and the separating of step i. are performed at different pressures.

[0096] In an embodiment the thermal decarboxylation reaction is at 0.5-20 kPa(a).

[0097] In another embodiment the thermal decarboxylation reaction is at atmospheric pressure i.e. 101 kPa(a) or above.

[0098] In an exemplary embodiment the thermal decarboxylation reaction is performed at 110 kPa(a) at 325 °C, and the separating comprises heating the rosin oil containing stream to 330 °C and distilling it at 10 kPa(a).

[0099] Recovering the organic material from the formed CO2 is easiest done by condensation, i.e. by cooling the CO2 rich gas to a condensate including liquified organic material. When operating at or close to atmospheric pressure (e.g. about 101 kPa(a)) this can be accomplished more comprehensively than in reduced pressure resulting in smaller losses of rosin oil, rosin acid and other organic materials. The atmospheric pressure operation also allows for use of basic type of condensers, such as shell and tube condensers or plate condensers, thus avoiding the use of more costly condensers required in vacuum operation. In an embodiment the organic liquid recovered by condensation is directed for refining in the distillation column while the organics depleted CO2 stream will be, depending on its final composition, led to further treatment or purged as such.

[0100] The present process thus relates to controlled and enhanced decarboxylation of rosin acids aiming at a larger portion of feedstock comprising rosin acid, in particular CTO, to be available for renewable transportation fuel and / or renewable chemicals production and other downstream processes.

[0101] As rosin acid is decarboxylated, it degrades into a lighter neutral component, losing its acid group and releasing carbon dioxide. This will provide a reaction product having a clearly reduced acidity, or TAN (total acid number), and a decreased corrosiveness compared to the rosin acid. The low acidity is particularly important when the rosin oil is used as renewable feedstock in co-processing with a fossil feedstock for increasing renewable content of fossil transportation fuels and / or fossil chemicals.

[0102] In an embodiment, the rosin oil product has TAN of less than 30 mg KOH / g, preferably less than 10 mg KOH / g, more preferably less than 2.5 mg KOH / g.

[0103] The sulphur content of the rosin acid may be high depending on the process for manufacturing. A high sulphur content rosin oil product may be used per se as feedstock for fossil fuel refining. However, for production of renewable fuels and renewable chemicals a sulphur removal process for this type of feedstock may be necessary.

[0104] In an embodiment, the rosin acid contains less than 700 ppm, preferably less than 600 ppm, more preferably less than 500 ppm, such as less than 400 ppm of sulphur by weight.

[0105] In an embodiment, the rosin oil product contains less than 300 ppm, preferably less than 150 ppm, more preferably less than 130, most preferably less than 100 ppm, such as less than 80 or even less than 50 ppm, sulphur by weight. The low sulphur content is preferred when the rosin oil is co-processed with oxygen containing renewable feedstocks for production of renewable fuels and / or renewable chemicals, or components thereto. Exemplary oxygen containing renewable feedstocks are plant oils / fats and animal oils / fats, and they preferably include waste and residue materials originating from animal fat / oil, plant fat / oil or fish fat / oil. These feedstocks comprise oxygenated hydrocarbons such as fatty acids and triglycerides which must be converted to aliphatic hydrocarbons by hydrodeoxygenation (HDO). For example, 50 wt-ppm of sulphur is enough for sulfidation of certain HDO catalyst such as NiMo and CoMo; higher sulphur content just consumes hydrogen needed for the hydrodeoxygenation reaction. Low sulphur rosin oil even allows for using noble metal-based HDO catalysts.

[0106] The present process for producing rosin oil from rosin acid is a continuous process. A continuously operated process benefits from hot infeeds, whereby energy savings are achieved by using an infeed already preheated by the previous processing step, such as in the case of using a side product directly from the CTO fractionation or distillation, or a product obtained directly from the refinery feedstock pretreatment. Moreover, continuous withdrawal of the rosin oil product from the decarboxylation reaction enhances reaction rate as the concentration of the reaction products decreases. The removal of the formed rosin oil from the rather harsh decarboxylation reaction conditions also limits its exposure to possible side reactions. Furthermore, a continuous process decreases the need for larger processing equipment and thus mitigates investment costs. Thus, the process comprises continuously removing formed rosin oil from the decarboxylation reaction and separating the formed rosin oil.

[0107] The rosin oil containing stream removed from the decarboxylation reaction may still include unreacted rosin acid. In an embodiment, at least part of a rosin oil depleted stream is recycled back to the decarboxylation reaction allowing for increased overall yield of rosin oil. The recycled rosin acid depleted stream may also heat up the liquid content of the decarboxylation reactor. This will cover at least part of the energy required to keep the reactor at the desired temperature. In a preferred embodiment, the recycled rosin acid depleted stream will cover the energy input to the decarboxylation reactor up to 80 %, such as 90% or even 100%.

[0108] According to another aspect, the present disclosure concerns a system for carrying out the process described above. An exemplary system 200 suitable for producing rosin oil from a feedstock comprising CTO is shown in figure 2. The system 200 comprises - a dehydration equipment 201 configured to remove at least water and turpentine from the renewable feedstock comprising rosin acid A to provide a dehydrated feedstock B;

[0109] - a depitching equipment 202 such as an agitated film evaporator, a thin film evaporator and / or a distillation column configured to separate tall oil pitch C from the dehydrated feedstock to produce a stream containing depitched tall oil containing rosin acid D and fatty acid E,

[0110] - a distillation column 203, such as a rosin column configured to separate the stream comprising depitched feedstock at least into a fatty acid depleted stream containing rosin acid D, and a fatty acid containing stream E,

[0111] - a decarboxylation reactor 204 configured to out a thermal decarboxylation reaction of at least the fatty acid depleted stream containing rosin acid to obtain a stream comprising the formed rosin oil F;

[0112] - separating means 205 configured to separate rosin oil from the stream comprising formed rosin oil to obtain rosin oil and a rosin oil depleted stream; and

[0113] - recycling means 212 configured to return at least part of the rosin oil depleted stream to the decarboxylation reactor.

[0114] In one embodiment the stream comprising formed rosin oil comprises rosin oil vapour, and the separating means 205 is configured to condense rosin oil vapor into rosin oil. In a preferable embodiment the system comprises a distillation column 205’ for separating fractions boiling above and / or below rosin oil to provide purified rosin oil.

[0115] In another embodiment the separating means 205 comprises an evaporator (not shown in figure 2) such as a thin film evaporator operating at 260 °C or above, preferably at 300 °C or above for converting the stream comprising formed rosin oil to a stream comprising rosin oil vapor and to a rosin oil depleted stream, and a condenser configured to condense rosin oil vapour into rosin oil.

[0116] In another embodiment the separating means 205 comprises an evaporator (not shown in figure 2) such as a thin film evaporator operating at 260 °C or above, preferably at 300 °C or above for converting the stream comprising formed rosin oil to a stream comprising rosin oil vapor and to a rosin oil depleted stream, and a distillation column 205’, wherein fractions boiling above and / or below the rosin oil are separated to provide purified rosin oil.

[0117] The system 200 also includes a recycling means 213 configured to return at least part of the rosin oil depleted stream d’ to the decarboxylation reactor.

[0118] In an embodiment the recycling means comprises one or more lines from the separating means to the decarboxylation reactor. The lines may be equipped with heaters, such as reboilers, electrical heaters, shell and tube heat exchangers or evaporators, for heating the rosin oil depleted stream.

[0119] Typically, TAN of the stream comprising rosin oil exiting the decarboxylation reactor is at least 70% lower, preferably at least 85 % lower, more preferably at least 90% lower, most preferably at least 95% lower, than TAN of rosin acid containing stream entering the reactor. Thus, TAN of the rosin oil obtainable by the method of the present disclosure is typically 50 or less, preferably 30 or less, more preferably 25 or less, even more preferably 15 or less, still even more preferably 10 or less, most preferably 5 or less depending on the amount of residues in the final product. The final rosin oil product may be further purified by distillation for reducing TAN further.

[0120] An optional residue G may be withdrawn from the decarboxylation. It has an increased value as it may provide a lower TAN feedstock to e.g. renewable fuels / renewable chemical production or co-processing due to mainly containing heavier neutrals and less rosin acids.

[0121] The system 200 may further comprise one or more further distillation columns such as a heads column 206 for separating volatiles, such as low boiling fatty acids from the stream containing high-boiling fatty acids, and a fatty acid separation column 207 for separating the high-boiling fatty acids, in particular TOFA, and for producing one or more fractions comprising remaining rosin acid d.

[0122] The tall oil pitch C and the fatty acid containing fraction E may still include reasonable amounts of rosin acids d. To improve overall yield of the rosin oil, the system includes preferably means 208 for feeding the tall oil pitch C comprising remaining rosin acid d to the thermal decarboxylation reactor, and / or means 209 for feeding the one of more fractions comprising remaining rosin acid d from the fatty acid separation column into the thermal decarboxylation reactor. The system may further include means 210 for feeding rosin acid d from the distillation column 203 into the decarboxylation reactor 204.

[0123] The thermal decarboxylation reactor is preferably equipped with a heater 211 for maintaining or increasing temperature of the thermal decarboxylation reactor. An exemplary heater comprises hot oil (t > 300 °C) which is circulated in the jacket or in the coil of the thermal decarboxylation reactor.

[0124] The system naturally also comprises any connections, ducts, valves etc. for carrying out the process, as is known to a person skilled in the art. The various equipment also comprise any suitable inlets and outlets, including outlets for any light gases that are formed during the stages of the process.

[0125] In one embodiment, the amount of rosin acid D separated from the dehydrated feedstock B in the depitching equipment 202 is reduced, thus more rosin acid is left in the tall oil pitch C. This may give rise one of more of the following benefits:

[0126] - possible capacity bottleneck of depitching can be overcome while still recovering the rosin acid for decarboxylation.

[0127] - overall process throughput is increased.

[0128] - less energy is needed for depitching 202 and rosin distillation 203.

[0129] - the distilled rosin acid is of better quality since the amount of heavy neutrals evaporated together with rosin acid in depitching is limited.

[0130] In another embodiment, at least part of the distilled rosin acid is withdrawn from the process as a high-quality rosin acid product D’. Accordingly, the amount of rosin acid d fed to the reactor 204 through route 210 is simultaneously increased. This in turn allows division of production of rosin acid and rosin oil against market demand. Furthermore, less energy is used in the rosin distillation because the amount of D is decreased. This is because D is taken from the column 203 as a vapor whereas d taken from the column as liquid. Less energy input to 203 also means lower pressure drop in the column which benefits the quality and / or yield of fatty acid in the fraction E.

[0131] In still another embodiment, the system includes means 212 for feeding rosin D” to the decarboxylation reactor.

[0132] CTO fractionators may wish to produce rosin packed in drums. As drums are normally stored in ambient temperature, rosin normally gets crystallized in the drums. The use of crystalline rosin is rather difficult as it needs to be molten before further use requiring high temperature and additional energy input. Melting is an extra processing step for the conventional rosin users necessitating more production hardware.

[0133] In the process and system shown in figure 2 crystalline rosin D” can be fed to the reactor 204 in solid form, preferably as crushed, or as a slurry or in liquid form. The feed can be led to the reactor 204 as a stream of its own or mixed with one or more of the other feed streams. This embodiment opens an opportunity to use solid rosin in the process thus widening the potential feedstock mix of the decarboxylation process. Feeding rosin to the decarboxylation reactor may be beneficial to address logistical and / or market restrictions.

[0134] Until now, decarboxylation of rosin acids has been considered undesirable, and the existing crude tall oil processes have been designed to avoid decarboxylation because it dilutes the rosin product, and the created CO2 increases the vapour load of vacuum systems. The resulting rise in pressure increases temperature and accelerates all side reactions. In the present process however, controlled decarboxylation of rosin acids originating e.g. from crude tall oil is desired, as this leads to valuable new renewable feedstock. Rosin oil is indeed a renewable feedstock having a low amount of impurities and a low level of oxygen desired for renewable fuel manufacturing. Rosin oil has thus the benefit of being (almost) oxygen free and thus attractive for co-processing in cases where oxygen typically creates difficulties. On the other hand, rosin oil has a lower hydrogen to carbon ratio than for example TOFA due to its multicyclic structure, leading to a higher hydrogen consumption. This can be alleviated by co-processing. Furthermore, rosin acid decarboxylation can help the use of this kind of feedstock especially in fossil refinery (co-processing), where the total acid number (TAN) is strictly restricted to less than 0.5. This means that there essentially cannot be free fatty acids or any other acids in the feed. The use of the present product in co-processing also helps avoiding corrosion issues in the system and downstream processing equipments.

[0135] According to yet another aspect, the present disclosure concerns an arrangement suitable for producing rosin oil from a stream comprising rosin acid, i.e. for carrying out the steps of c)- d) of the process.

[0136] The arrangement comprises - a continuous flow reactor configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid to a stream comprising formed rosin oil;

[0137] - a separating means configured to separate at least rosin oil from the stream comprising formed rosin oil to produce rosin oil and a rosin oil depleted stream; and

[0138] - recycling means configured to return at least part of the rosin oil depleted stream to the continuous flow reactor.

[0139] The continuous flow reactor is typically a thermal decarboxylation reactor configured to operate at more than 280 °C to 360 °C. The decarboxylation reaction produces rosin oil and carbon dioxide. Typically, the rosin oil containing stream includes not only rosin oil and carbon dioxide, but also other compounds such as light acids, rosin acid, and a heavy residue. The rosin oil is separated from the stream by condensation and / or by distillation, whereas at least part of the rosin oil depleted stream is returned to the decarboxylation reactor. Exemplary non-limiting arrangements suitable for the process are shown in figures 3-8.

[0140] In an embodiment shown in figure 3 the arrangement 300 comprises

[0141] - a continuous flow reactor 301 configured to carry out a decarboxylation reaction to convert a stream A comprising rosin acid to a stream comprising the formed rosin oil;

[0142] - separating means 302 configured to separate the stream comprising the formed rosin oil to a gaseous part B (g) and to a liquid part B ( / ), the separating means further comprising o a first evaporator 303 such as a thin film evaporator or a falling film evaporator configured to convert the liquid part of the stream comprising formed rosin oil to a rosin oil vapor containing stream C (g) and a rosin oil depleted stream D; o a condenser 304 configured separate at least rosin oil from the rosin oil vapor containing stream to obtain rosin oil; and

[0143] - recycling means 305 configured to return at least part of the rosin oil depleted stream to the decarboxylation reactor.

[0144] Using the arrangement of figure 3, a stream comprising rosin acid A is fed to the thermal decarboxylation reactor 301 to produce a stream comprising formed rosin oil. A gaseous stream comprising rosin oil B (g) and a liquid stream comprising rosin oil B ( / ) are removed from the reactor. The liquid stream B (I) is directed from the reactor to an evaporator 303 such as a thin film evaporator or a falling film evaporator. The evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream B (I) and the evaporates at least rosin oil of the stream. Accordingly, a rosin oil vapor containing stream C (g), and a rosin oil depleted liquid stream D ( / ) is formed. The gaseous streams C (g) and B (g) are directed to the condenser 304 thereby producing rosin oil, whereas at least part of the rosin oil depleted liquid stream is returned to the thermal decarboxylation reactor. Preferably at least part of the rosin oil depleted stream is withdrawn from the circulation to avoid accumulation of heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement. The gaseous stream comprising rosin oil B (g) is also directed to the condenser for removing light off gas.

[0145] In an embodiment shown in figure 4 the arrangement 400 comprises

[0146] - a continuous flow reactor 401 configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid A to streams comprising formed rosin oil B;

[0147] - separating means 402 comprising o a first evaporator 403 such as a thin film evaporator or a falling film evaporator configured to convert the stream comprising formed rosin oil to a rosin oil vapor containing stream C (g) and to a rosin oil depleted stream D; o a distillation column 404 configured separate at least rosin oil from the rosin oil vapor containing stream to obtain purified rosin oil;

[0148] - recycling means 405 configured to return at least part of the rosin oil depleted stream to the decarboxylation reactor; and

[0149] - optional recovering means 406 configured to separate rosin acid from the rosin oil depleted stream D and to recycle the recovered rosin acid E to the thermal decarboxylation reactor.

[0150] The continuous flow reactor 401 and the distillation column 404 are configured to operate at the same pressure.

[0151] Using the arrangement of figure 4, a stream comprising rosin acid A is fed to the thermal decarboxylation reactor 401 to produce stream comprising rosin oil. A gaseous stream comprising rosin oil B (g) and a liquid stream comprising rosin oil B ( / ) are removed from the reactor. The stream B ( / ) is directed from the reactor 401 to the first evaporator 403 such as a thin film evaporator or a falling film evaporator. The first evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream B ( / ) and evaporates at least rosin oil of the stream. Accordingly, a stream comprising a rosin oil vapor C (g), and a rosin oil depleted liquid stream D is formed. The streams are directed to the distillation column 404 thereby producing purified rosin oil, whereas at least part of the rosin oil depleted stream D is returned from the distillation column to the decarboxylation reactor and / or directed to an optional second evaporator 407 such as a thin film evaporator or a falling film evaporator of the recovering means. The second evaporator operating at 260 °C or above, preferably at 300 °C or above recovers rosin acid from the rosin oil depleted stream D thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The stream comprising recovered rosin acid is recycled to the decarboxylation reactor, whereas at least part of the rosin acid depleted stream is withdrawn from the circulation to avoid accumulation heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement.

[0152] The decarboxylation reactor 401 also includes an outlet 408 for the gaseous stream comprising rosin oil B (g) including light off gas but also remaining rosin oil c (g) which can be directed to the distillation column (marked by dotted lines in the figure 4).

[0153] In an embodiment at least part of the stream B ( / ) is directed from the decarboxylation reactor 401 to the bottom of the distillation column 404 prior to directing to the first evaporator 403 (not shown in the figure). Since at least part of the stream B ( / ) evaporates in the distillation column, less vapor is formed in the evaporator. This in turn, improves the gas-liquid separation in the evaporator.

[0154] The arrangement shown in figure 4 is more complicated than the arrangement of figure 3 but it allows for more efficient recovery of residual rosin acid, and more efficient rosin oil purification by distillation. It also allows for separation of other components such as light acids such as saturated and unsaturated C3-C18 carboxylic acids by distillation if desired.

[0155] In an embodiment shown in figure 5 the arrangement 500 comprises - a continuous flow reactor 501 configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid A to a stream comprising formed rosin oil B;

[0156] - separating means 502 comprising o a first evaporator 503 such as a thin film evaporator or a falling film evaporator configured to convert the stream comprising formed rosin oil to a rosin oil vapor containing stream C (g) and a rosin oil depleted stream D; o a distillation column 504 configured separate at least rosin oil from the rosin oil vapor containing stream to obtain purified rosin oil;

[0157] - recycling means 505 configured to return at least part of the rosin oil depleted stream D to the thermal decarboxylation reactor; and

[0158] - optional recovering means 506 configured to separate rosin acid from the rosin oil depleted stream and to recycle the recovered rosin acid E to the thermal decarboxylation reactor.

[0159] Using the arrangement of figure 5, a stream comprising rosin acid A is fed to the thermal decarboxylation reactor 501 to produce stream comprising rosin oil. A gaseous stream comprising rosin oil B (g) and a liquid stream comprising rosin oil B ( / ) are removed from the reactor. The liquid stream comprising rosin oil B ( / ) is directed from the decarboxylation reactor 501 to a first evaporator 503 such as a thin film evaporator or a falling film evaporator. The evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream and evaporates at least rosin oil of the stream. Accordingly, a stream comprising a rosin oil vapor C (g) and a rosin oil depleted liquid D is formed. The stream is directed to the distillation column 504 thereby producing purified rosin oil, whereas at least part of the rosin oil depleted stream D directed from the distillation column to the decarboxylation reactor 501 and / or to the optional second evaporator 507 such as a thin film evaporator or a falling film evaporator of the optional recovering means 506. The second evaporator operating at 260 °C or above, preferably at 300 °C or above recovers rosin acid from the rosin oil depleted stream D thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The stream comprising rosin acid is recycled to the thermal decarboxylation reactor, whereas at least part of the rosin acid depleted residue is withdrawn from the circulation to avoid accumulation of heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement.

[0160] The gaseous stream B (g) is also directed to the distillation column since it may include some rosin oil vapour c (g).

[0161] The arrangement of figure 5 resembles the arrangement of figure 4 but the thermal decarboxylation reactor 501 is configured to operate at higher pressure than the distillation column 504. Thus, the arrangement 500 also includes means for allowing decreasing and increasing pressure between the decarboxylation reactor and the recovering means such as a pressure reducing means 508, a flash tank 509, and a pump 511 . The purpose of the flash tank is to let the liquid evaporate in a controlled manner prior to leading it to the distillation column. The arrangement also includes an optional line 512 for directing evaporated stream comprising rosin oil B (g) from the flash tank to the distillation column. Typically, the recycling means 505 also includes at least one further heating means 513, such as reboilers, electrical heaters, shell and tube heat exchangers or evaporators, for heating material configured to be returned to the decarboxylation reactor.

[0162] The use of higher pressure in the thermal decarboxylation reactor than in the distillation column avoids evaporation of materials from the decarboxylation reactor.

[0163] The arrangement 600 shown in figure 6 comprises

[0164] - a continuous flow reactor 601 configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid A to a stream comprising formed rosin oil B, the continuous flow reactor comprising o a first outlet 608 for a gaseous stream comprising rosin oil B (g); o a second outlet 609 for a liquid stream comprising rosin oil B ( / );

[0165] - a separating means 602 comprising o a first evaporator 603 such as a thin film evaporator or a falling film evaporator configured to convert the liquid stream comprising rosin oil B ( / ) to a rosin oil vapor containing stream C (g) and a rosin oil depleted stream D; o a condenser 610 configured to produce a liquid stream comprising rosin oil C ( / ) and for removing light off gas; o a distillation column 604 configured separate at least rosin oil from the rosin oil containing streams to obtain purified rosin oil and a rosin oil depleted stream D;

[0166] - recycling means 605 configured to return at least part of the rosin oil depleted stream D to the thermal decarboxylation reactor; and

[0167] - optional recovering means 606 configured to separate rosin acid from the rosin oil depleted stream D and to recycle the recovered rosin acid E to the decarboxylation reactor.

[0168] Using the arrangement of figure 6, a stream comprising rosin acid A is fed to the thermal decarboxylation reactor 601 to produce stream comprising rosin oil. A gaseous stream comprising rosin oil B (g) and a liquid stream comprising rosin oil B ( / ) are removed from the reactor.

[0169] The liquid stream comprising rosin oil is directed from the reactor 601 via the outlet 609 to a first evaporator 603 such as a thin film evaporator or a falling film evaporator. The evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream and evaporates at least rosin oil of the stream. Accordingly, a stream comprising a rosin oil vapor C (g) and a rosin oil depleted liquid D is formed.

[0170] The gaseous stream comprising rosin oil B (g) is directed from the reactor via the outlet 608 to the condenser to remove light off gas and to produce a liquid stream comprising rosin oil C ( / ).

[0171] The streams C ( / ), C (g) and D are directed to the distillation column 604 thereby producing purified rosin oil, whereas at least part of the rosin oil depleted stream D is directed from the distillation column either via the recycling means 605 back to the decarboxylation reactor or to the optional second evaporator 607 such as a thin film evaporator or a falling film evaporator of the recovering means 606. The second evaporator operating at 260 °C or above, preferably at 300 °C or above separates rosin acid from the rosin oil depleted stream D thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The stream comprising rosin acid is recycled to the decarboxylation reactor, whereas the rosin acid depleted residue is withdrawn from the circulation to avoid accumulation of heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement. The second outlet is preferably directed toward bottom part of the distillation column (not shown in the figure)

[0172] The decarboxylation reactor 601 is configured to operate at a different pressure than the distillation column 604. Thus, the arrangement also includes means for allowing decreasing and increasing pressure between the decarboxylation reactor and the separating means such as one or more pressure regulating means 611 , 612, and pumps 613. The arrangement also includes a condenser 610 for removing light of gas from the rosin oil vapor containing stream B (g) and to produce a liquid stream comprising rosin oil C ( / ). The arrangement also includes a heating means 614 such as a boiler for heating the rosin oil depleted stream D and / or the stream comprising recovered rosin oil E, and a heating jacket 615 for heating the reactor. In an embodiment the heating means 614 is a third evaporator operating at 260 °C or above, preferably at 300 °C or above configured to separate rosin acid from the rosin oil depleted stream D directed from the distillation column towards the decarboxylation reactor, thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The rosin acid containing stream is returned to the decarboxylation reactor whereas the rosin acid depleted stream d which still may include rosin acid is returned to the distillation column.

[0173] The arrangement 700 shown in figure 7 comprises

[0174] - a continuous flow reactor 701 configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid A to a stream comprising formed rosin oil B, the continuous flow reactor comprising o a first outlet 708 for a gaseous stream comprising rosin oil B (g); o a second outlet 709 for a liquid stream comprising rosin oil B ( / );

[0175] - a separating means 702 comprising o a first evaporator 703 such as a thin film evaporator or a falling film evaporator configured to convert the liquid stream comprising rosin oil B ( / ) to a rosin oil vapor containing stream C (g) and a rosin oil depleted stream D; o a distillation column 704 configured separate at least rosin oil from the rosin oil vapor containing stream C (g) and from the gaseous stream comprising rosin oil B (g) to obtain purified rosin oil and a rosin oil depleted stream; - recycling means 705 configured to return at least part of the rosin oil depleted stream D to the thermal decarboxylation reactor; and

[0176] - optionally recovering means 706 configured to separate rosin acid from the rosin oil depleted stream D and to recycle the recovered rosin acid E to the decarboxylation reactor.

[0177] Using the arrangement of figure 7, a stream comprising rosin acid A is fed to the thermal decarboxylation reactor 701 to produce a stream comprising rosin oil. A gaseous stream comprising rosin oil B (g) and a liquid stream comprising rosin oil B ( / ) are removed from the reactor via outlets 708 and 709, respectively.

[0178] The liquid stream B ( / ) may include heavy residues accumulated in the bottom of the reactor whereas the gaseous stream B (g) comprises light off gas.

[0179] The liquid stream comprising rosin oil is directed from the reactor 701 to a first evaporator 703 such as a thin film evaporator or a falling film evaporator. The evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream and evaporates at least rosin oil of the stream. Accordingly, a stream comprising a rosin oil vapor C (g) and a rosin oil depleted liquid D is formed.

[0180] The streams C (g), B (g), and D are directed to the distillation column 704 thereby producing purified rosin oil, whereas at least part of the rosin oil depleted stream D is directed from the distillation column either via the recycling means 705 back to the decarboxylation reactor and / or to the optional second evaporator 707 such as a thin film evaporator or a falling film evaporator of the recovering means 706. The optional second evaporator operating at 260 °C or above, preferably at 300 °C or above or above separates rosin acid from the rosin oil depleted stream D thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The stream comprising recovered rosin acid is recycled to the thermal decarboxylation reactor, whereas the rosin acid depleted residue is withdrawn from the circulation to avoid accumulation of heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement.

[0181] The arrangement 700 resembles the arrangement 600 but the thermal decarboxylation reactor 701 and the distillation column 703 are configured to operate at same pressures. The arrangement also includes at least one heating means 710 for heating the streams for recycling to the decarboxylation reactor and a heating jacket 711 for heating the reactor. In contrast to the arrangement of figure 6, the arrangement 700 allows effective stripping of rosin oil and rosin acid by the CO2 formed in the reaction improving yield of rosin oil. In an embodiment the heating means 710 is a third evaporator operating at 260 °C or above, preferably at 300 °C or above configured to separate rosin acid from the rosin oil depleted stream D directed from the distillation column towards the decarboxylation reactor, thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The rosin acid containing stream is returned to the decarboxylation reactor whereas the rosin acid depleted stream d which still may include rosin acid is returned to the distillation column.

[0182] Figure 8 shows still another arrangement suitable for producing rosin oil from a stream comprising rosin acid. The arrangement resembles the arrangement of figure 7, but the distillation column 804 of the separating means 802 is positioned above the decarboxylation reactor 801 when the arrangement is at its operational position. Accordingly, the arrangement 800 comprises

[0183] - a continuous flow reactor 801 configured to carry out a decarboxylation reaction to convert a stream comprising rosin acid A to a stream comprising formed rosin oil B;

[0184] - separating means 802 comprising a distillation column 804 integrated to the continuous flow reactor, the distillation column configured separate at least rosin oil from the stream comprising formed rosin oil;

[0185] - recycling means 805 configured to return at least part of rosin oil depleted stream to the decarboxylation reactor;

[0186] - optional recovering means 806 configured to separate rosin acid from the rosin oil depleted stream to obtain a stream comprising recovered rosin acid and a rosin acid depleted stream and to return at least part of the stream comprising rosin acid to the thermal decarboxylation reactor.

[0187] Using the arrangement 800, a rosin oil containing gaseous stream B (g) including carbon dioxide flows from the decarboxylation reactor directly upwards to the distillation column 804 to recover rosin oil. Rosin oil containing liquid stream B ( / ) is directed from bottom of the decarboxylation reactor to a first evaporator 803 such as a thin film evaporator or a falling film evaporator. The evaporator operating at 260 °C or above, preferably at 300 °C or above reheats the stream and evaporates at least rosin oil of the stream. Accordingly, a stream comprising a rosin oil vapor C (g), and a rosin oil depleted liquid D is formed. The stream C (g) is directed to the distillation column 804 thereby producing purified rosin oil, whereas at least part of the rosin oil depleted stream D is directed from the first evaporator either via the recycling means 805 back to the decarboxylation reactor and / or to the optional second evaporator 807 such as a thin film evaporator or a falling film evaporator of the recovering means 806. The optional second evaporator operating at 260 °C or above, preferably at 300 °C or above separates rosin acid from the rosin oil depleted stream D thereby producing a stream comprising rosin acid E and a rosin acid depleted residue. The stream comprising recovered rosin acid is recycled to the thermal decarboxylation reactor, whereas at least part of the rosin acid depleted residue is withdrawn from the circulation to avoid accumulation of heavy residues including components such as C(20+) fatty acids, sitosterol and esters thereof into the arrangement.

[0188] The integration reduces the footprint and requires less pumps and interconnecting piping.

[0189] In an embodiment the arrangement comprises means for introducing noncondensable stripping gas such as carbon dioxide, steam, or nitrogen, preferably carbon dioxide formed in the decarboxylation reaction, to the distillation column of the arrangement. Non-limiting examples are shown in figure 9. In the embodiment shown in figure 9A, the arrangement comprises an ejector 908 upstream of a second evaporator 907a for feeding the stripping. The ejected carbon stripping gas reduces operation pressure of the evaporator so that it is lower than in the distillation column (e.g. 5 kPa(a) vs. 10 kPa(a)). Also stripping in the distillation column is enhanced.

[0190] In the embodiment of figure 9B, stripping gas is fed to the second evaporator 907b via an inlet 909. Pressure of the stripping carbon dioxide is the same as the pressure of the arrangement. Since the amount of stripping gas in the arrangement is increased, also the recovery of rosin oil is enhanced.

[0191] The arrangements of the present disclosure such as those disclosed in figures 4-7 can also be used for producing rosin acid of high purity by directing a rosin acid containing stream A to a distillation column 404, 504, 604 i.e. by passing the decarboxylation reactor 401 , 501 , 601 (marked with dotted lines in the figures). Accordingly, the arrangements are suitable for producing rosin oil and rosin acid, e.g. depending on the market needs.

[0192] According to another aspect the present disclosure concerns a rosin oil product obtainable by the process disclosed above. The rosin oil product comprises: more than 85 wt.-%, preferably more than 90 wt.-%, more preferably more than 95 wt.-%, most preferably more than 97 wt.-% of rosin oil;

[0193] 0.1 -10 wt.-%, preferably 0.1-5 wt.-%, more preferably 0.1 -2 wt.-%, most preferably 0.5-2 wt.-% of rosin acid;

[0194] 0-5 wt.-%, such as 0.1-5 wt.-%, of other neutral components;

[0195] 0-5 wt.-%, such as 0.1-5 wt.-%, of light acids; and

[0196] 0-3 wt.-%, such as 0.1-3 wt.-%, of heavy (C20+) compounds.

[0197] In an embodiment, the other neutral components comprise alcohols, esters, ethers, aldehydes, ketones, or other than rosin oil hydrocarbons, such as turpentine and derivatives thereof.

[0198] In an embodiment, the light acids comprise saturated or unsaturated C3-C18 carboxylic acids.

[0199] In an embodiment, the heavy (C20+) compounds comprise fatty acids, esters, and alcohols, such as sitosterol, and esters and derivatives thereof

[0200] In an embodiment the rosin oil product comprises 85-97 wt.-%, such as 90-97 wt.- % or 95-97 wt.-% decarboxylation reaction product of at least one tricyclic diterpenoid, such as at least one of abietic acid (CAS No. 514-10-3), isopimaric acid (CAS No. 5835-26-7), levopimaric acid (CAS No. 79-54-9), neoabietic acid (CAS No. 471 -77-2), palustric acid (CAS No. 1945-53-5), pimaric acid (CAS No. 127-27- 5), sandaracopimaric acid (CAS No. 471 -74-9), and dehydroabietic acid (CAS No. 1740-19-8).

[0201] In an embodiment the rosin oil product has TAN of less than 30 mg KOH / g, preferably less than 20 mg KOH / g, more preferably less than 10 mg KOH / g, most preferably less than 2.5 mg KOH / g. In an embodiment, the TAN of the rosin oil product is between 0.51-30 mg KOH / g , such as 12-10 mg KOH / g, or even 1 .5- 2.5 mg KOH / g. Using a low TAN rosin oil product as feedstock for downstream processing reduces corrosion of the equipment and enables decreasing the overall TAN of the feedstock. In an embodiment the total amount of metallic impurities, such as Al, As, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, V, Zn of the rosin oil product is less than 20 wt-ppm. In view of downstream processing, it is desirable to have a low metal impurity content for the rosin oil product. In an embodiment the sulphur content of the rosin oil product is less than 300 ppm, preferably less than 150 ppm, most preferably less than 130, such as less than 100 ppm, less than 80, or even less than 50 ppm, determined as elemental sulphur. Depending on the origin of the rosin acid used in manufacturing the rosin oil product, the product may have a very low S content, such as from 0.1 to 30 ppm, or even from 0.1 to 10 ppm. The rosin oil product may even be essentially sulphur-free.

[0202] Considering the use of the rosin oil product as a feed for downstream processing by e.g. catalytic hydroprocessing or catalytic hydrotreatment, low sulphur or sulphur- free feedstock enables the use of noble metal catalysts.

Claims

CLAIMS1 . A process for producing rosin oil, the process comprising the steps of: a) providing renewable material comprising rosin acid; b) separating at least part of the rosin acid from the renewable material; c) subjecting a stream comprising at least part of the separated rosin acid to a thermal decarboxylation reaction to form rosin oil at a temperature from more than 280 °C to 360 °C, for a period of time sufficient to provide a conversion of the rosin acid of at least 90 %, and continuously removing a stream comprising the formed rosin oil from the thermal decarboxylation reaction; and d) recovering the formed rosin oil.

2. The process according to claim 1 , wherein the process further comprises after step c) and before step d) the steps: i. separating from the stream comprising the formed rosin oil, said formed rosin oil and a rosin oil depleted stream; and ii. recycling at least part of the rosin oil depleted stream to the thermal decarboxylation reaction of step c).

3. The process according to claim 2, wherein the stream comprising the formed rosin oil contains a liquid phase and a gaseous phase and separating the formed rosin oil from at least one of the phases.

4. The process according to claim 3, wherein the recovering of the formed rosin oil from the liquid phase comprises a. directing the liquid phase to a first evaporator operating at 260 °C or above, preferably at 300 °C or above to produce a rosin oil vapor containing stream and a rosin oil depleted stream; and b. distilling and / or condensing the rosin oil containing stream thereby providing purified rosin oil.

5. The process according to claim 3 or 4, wherein the recovering of the formed rosin oil from the gaseous phase comprises condensing and / or distilling rosin oil from the gaseous phase thereby providing purified rosin oil.

6. The process according to any one of claims 2 to 5 comprising feeding a noncondensable gas such as carbon dioxide, steam or nitrogen, preferably carbon dioxide formed in the decarboxylation reaction, to the separating of step i.

7. The process according to any one of claims 2 to 6, wherein the subjecting to the thermal decarboxylation reaction of c) and the separating of step i. are at the same pressure.

8. The process according to any one of claims 2 to 6, wherein the subjecting to the thermal decarboxylation reaction of c) and the separating of step i. are at different pressures.

9. The process according to any one of claims 1 to 8, wherein the thermal decarboxylation reaction of step c) is from 0.1 to less than 20 kPa(a) such as from 0.5 to less than 20 kPa(a).

10. The process according to any of claims 1 to 9, wherein the thermal decarboxylation reaction of step c) is from 20 to 110 kPa(a).

11. The process according to any one of claims 1 to 10, wherein the renewable material comprises at least 20 wt.-% of rosin acid, preferably at least 90 wt.-% of rosin acid.

12. The process according to any one of claims 1 to 11 , wherein the renewable material comprises crude tall oil (CTO), tall oil pitch, distilled tall oil, tall oil rosin, or tall oil, preferably CTO.

13. The process according to any one of claims 1 to 12, wherein the renewable material comprises at least 50 wt.-% CTO, preferably at least 90 wt.-% CTO.

14. The process according to any one of claims 2 to 13 comprising a. recovering rosin acid from the rosin oil depleted stream thereby providing a rosin acid containing stream and a rosin acid depleted stream; and b. recycling at least part of the rosin acid containing stream to the decarboxylation reaction of step c).

15. The process according to any one of claims 1 to 14, wherein the renewable material comprises CTO, and wherein step b) comprises i) dehydrating at least part of the renewable material to produce dehydrated renewable material, ii) depitching the dehydrated renewable material to produce a. a fraction containing tall oil pitch, and b. a fraction containing depitched tall oil; iii) subjecting the fraction containing depitched tall oil to separation to producea. a stream containing fatty acids, and b. a fatty acid depleted stream containing the separated rosin acid.

16. The process according to claim 15, wherein the fraction containing tall oil pitch contains rosin acid, and the process comprises a. subjecting the fraction containing tall oil pitch to thermal decarboxylation reaction at a temperature from more than 280 °C to 360 °C for a period of time sufficient to provide a conversion of the rosin acid of at least 90 %, and continuously removing the formed rosin oil from the thermal decarboxylation reaction; and b. recovering the formed rosin oil.

17. The process according to claim 15 or 16, wherein the fatty acid containing stream comprises rosin acid, and the process comprises a. subjecting the fatty acid containing stream to distillation to produce i. a fraction comprising fatty acids and ii. one or more fractions comprising rosin acid, and b. subjecting at least part of the one or more fractions comprising rosin acid to the thermal decarboxylation reaction18. The process according to any one of claims 15 to 17, wherein the process comprises separating prior to step c) the fatty acid depleted stream containing rosin acid at least into one of a. a first rosin acid fraction which is in gas phase, b. a second rosin acid fraction which is in liquid phase, and c. a third rosin acid fraction which is in solid phase, in a temperature of 150 °C or more and at a pressure of about 2 kPa, provided that the first rosin acid fraction is condensed prior to the subjection of step c) and wherein at least one of the fractions is subjected to the thermal decarboxylation reaction.

19. The process according to any one of claims 1 to 18, wherein the residence time of the thermal decarboxylation reaction of step c) is from 3 h to 12 h, such as from 8 h to 12 h.

20. The process according to any one of claims 1 to 19, wherein TAN of the rosin oil is lowered at least 70%, preferably at least 85%, more preferably at least 90%, most preferably at least 95%, compared to the TAN of rosin acid.

21. Use of rosin oil obtained from the process of any one of claims 1 to 20 as renewable feedstock in co-processing with fossil feedstock for increasing renewable content of fossil transportation fuels and / or chemicals.

22. Use of rosin oil obtained from the process of any one of claims 1 to 20 in coprocessing with other renewable feedstocks for production of renewable fuels and / or chemicals, or components thereto.

23. A system (200) for carrying out the process of claim 2, wherein the renewable material comprises crude tall oil, the system comprising- dehydration equipment (201 ) configured to remove least water and turpentine from the feedstock;- a depitching equipment (202) configured to separate tall oil pitch from the dehydrated feedstock to produce a fraction comprising tall oil pitch and a fraction comprising depitched tall oil;- separating means (203) configured to separate depitched tall oil to a fatty acid depleted stream containing rosin acid and a fatty acid containing stream;- a decarboxylation reactor (204) configured to carry out a decarboxylation reaction of the fatty acid depleted stream containing rosin acid to obtain a stream comprising formed rosin oil;- separating means (205) configured to separate rosin oil from the stream comprising formed rosin oil to obtain rosin oil and a rosin oil depleted stream; and- recycling means configured to return at least part of the rosin oil depleted stream to the decarboxylation reactor.

24. The system according to claim 23, wherein a stream comprising formed rosin oil comprises rosin oil vapour, and wherein the separating means (205) is configured to condense rosin oil vapor into rosin oil.

25. The system according to claim 23 or 24 comprising a distillation column (205’) for separating fractions boiling above and / or below rosin oil to provide purified rosin oil.

26. The system according to any one of claims 23 to 25 comprising at least one separating means (207) configured to separate the fatty acid containing streaminto a distillate comprising fatty acid and one or more fractions comprising rosin acid.

27. The system according to any one of claims 23 to 26 comprising means (208) configured to feed the fraction comprising tall oil pitch into the decarboxylation reactor.

28. The system according to claim 26 or 27, comprising means (209) configured to feed the one or more fractions comprising rosin acid into the decarboxylation reactor.

29. The system according to any one of claims 23 to 28, wherein the decarboxylation reactor is equipped with a heater (211 ) for maintaining or increasing temperature of the decarboxylation reactor.

30. An arrangement for carrying out the process according steps c) - d) of claim 2, the arrangement comprising- a continuous flow reactor (301 , 401 , 501 , 601 , 701 , 801 ) configured to carry out a decarboxylation reaction of a stream comprising rosin acid and to obtain a stream comprising rosin oil;- separating means (302, 402, 502, 602, 702, 802) configured separate at least rosin oil from said stream comprising rosin oil to obtain a stream comprising formed rosin oil and a rosin oil depleted stream; and- recycling means (303, 403, 503, 603, 703, 803) configured to return at least part of the rosin oil depleted stream to the continuous flow reactor.

31. The arrangement according to claim 30 wherein the separating means (302) comprises a first evaporator (303) configured to operate at 260 °C or above, preferably at 300 °C or above to produce a stream comprising rosin oil vapor and a rosin oil depleted stream, and a condenser (304) configured to condense the rosin oil vapor.

32. The arrangement according to claim 30 wherein the separating means (402, 502, 602, 702), comprises a first evaporator (403, 503, 603, 703) configured to operate at 300 °C or above to produce a stream comprising rosin oil vapor and a rosin oil depleted stream, and a distillation column (404, 504, 604, 704) configured to separate at least rosin oil from the stream comprising rosin oil vapour.

33. The arrangement according to claim 30 wherein the separating means (802) comprises a distillation column (804) integrated to the thermal decarboxylation reactor (801 ) and configured to separate at least rosin oil form the rosin oil containing stream.

34. The arrangement according to any one of claims 30 to 33 wherein the recycling means comprises at least one heating means (513, 713, 803) configured to heat the rosin oil depleted stream to 260 °C or above, preferably to 300 °C or above.

35. The arrangement according to any one of claims 30 to 34 comprising a recovering means (406, 506, 606, 706, 806) configured to separate rosin acid from the rosin oil depleted stream to obtain a stream comprising recovered rosin acid and a rosin acid depleted stream, and to recycle at least part of the stream comprising recovered rosin acid to the thermal decarboxylation reactor.

36. The arrangement according to claim 35 wherein the recovering means comprises a second evaporator (407, 507, 607, 707, 807, 907a, b) configured to operate at 260 °C or above, preferably at 300 °C or above.

37. The arrangement according to 36 comprising an ejector (908) upstream to the second evaporator (907a) and configured to direct stripping gas to the separating means.

38. The arrangement according to claim 36 wherein the second evaporator (907b) comprises an inlet (909) for a stripping gas.

39. A rosin oil product obtainable by the process according to any one of claims 1 to 20 comprising: more than 85 wt.-%, preferably more than 90 wt.-%, more preferably more than 95 wt.-%, most preferably more than 97 wt.-% of rosin oil;0.1 -10 wt.-%, preferably 0.1-5 wt.-%, more preferably 0.1 -2 wt.-%, most preferably 0.5-2 wt.-% of rosin acid;0-5 wt.-%, such as 0.1-5 wt.-%, of other neutral components;0-5 wt.-%, such as 0.1-5 wt.-%, of light acids; and0-3 wt.-%, such as 0.1-3 wt.-%, of heavy (C20+) compounds.

40. The rosin oil product according to claim 39 comprising 85-97 wt.-%, such as 90-97 wt.-% or 95-97 wt.-% decarboxylation reaction product of at least one ofabietic acid, isopimaric acid, levopimaric acid, neoabietic acid, palustric acid, pimaric acid, sandaracopimaric acid, and dehydroabietic acid.41 . The rosin oil product according to claim 39 or 40, wherein the rosin oil product has TAN of less than 30 mg KOH / g, preferably less than 20 mg KOH / g, more preferably less than 10 mg KOH / g, most preferably less than 2.5 mg KOH / g. In an embodiment, the TAN of the rosin oil product is between 0.51 -30 mg KOH / g, such as 12-10 mg KOH / g, or even 1.5- 2.5 mg KOH / g.

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