FI130251B - Producing hydrocarbons from organic material of biological origin - Google Patents

Abstract

The present invention provided a process for producing hydrocarbons from a feedstock comprising organic material of biological origin, comprising a) providing a feedstock comprising organic material of biological origin, b) pre-treating the feedstock in one or more pre-treatment stages to obtain a purified feedstock, c) subjecting said purified feedstock to pre-hydrotreatment to obtain a stream of partly hydrotreated feed, d) subjecting the stream of partly hydrotreated feed to hydrotreatment to obtain a stream of hydrocarbons, e) distilling the stream of hydrocarbons to obtain at least two fractions, a first heavy bottom fraction, which is removed from the process and a second middle fraction, which is collected for further processing, and f) subjecting the collected middle fraction to isomerisation to obtain an isomerised stream of hydrocarbons.

Description

PRODUCING HYDROCARBONS FROM ORGANIC MATERIAL OF BIOLOGICAL

ORIGIN

The present invention relates to a process of producing hydrocarbons from organic material of biological origin, in particular organic material of biologi- cal origin comprising a high amount of impurities, such as nitrogen, silicon, chlo- ride and phosphorous containing compounds, as well as metals. The presented process is particularly suitable for challenging feedstock, which would typically not be introduced to a hydrogenation process using sensitive catalysts.

BACKGROUND OF THE INVENTION

Various oils and fats have been used as feedstock in production of mid- dle distillate components suitable as fuels especially for diesel engines. The pur- pose of using renewable and recycled organic material of biological origin in pro- duction of fuel components is mainly to reduce the use of fossil based feedstock and thereby to tackle global warming and other environmental issues. Hydrogen- ated vegetable oil (HVO) is a promising alternative to fossil based middle distillate fuels. Although HVO is mainly produced from vegetable oils, also other sources such as animal fats and algae oils can be used. There is still a need for alternative non-fossil based sources and processes to produce especially middle distillate fuels.

Many organic material sources that could be used to produce hydrocar- bon components, contain high amounts of impurities such as nitrogen, silicon, chlo- ride and phosphorous containing compounds and metals. These and other impuri- ties weaken the possibility of many organic materials to be used as feedstock or lowers the quality of the products.

Many previous methods have suggested various pre-treatment and pu- & rification processes for feedstock contain high amounts of impurities. There is also

N a need for new over all processes to handle feedstock with high amounts of impu-

O rities, as well as other feedstock.

N Patent publication W02007068800 describes a process based on oli-

E 30 — gomerization and deoxygenation for producing a hydrocarbon component, and

N partially for producing high-quality saturated base oil. Patent publication 3 W02021119610 relates to the production of renewable crude oil from renewable

N plant and animal-based resources. Patent publication W02010097519 discloses a

N method for preparing fuel components from crude tall oil. Patent publication

W02020016405 describes a method of purifying recycled or renewable organic material, in particular removing silicon from recycled ore renewable organic ma- terial comprising more than 1 ppm silicon as silicon compounds.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is thus to provide a method or pro- cess, which is particularly suitable for challenging feedstock that typically contain high amounts of impurities. Low-quality feedstock would typically not be intro- duced to a hydrogenation process using sensitive catalysts.

The objects of the invention are achieved by a method or process char- acterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a process for producing hydrocarbons from a feedstock comprising organic material of biological origin, the process com- prising a) providing a feedstock comprising organic material of biological origin, b) pre-treating the feedstock in one or more pre-treatment stages to ob- tain a purified feedstock, c) subjecting said purified feedstock to pre-hydrotreatment to obtain a stream of partly hydrotreated feed, d) subjecting the stream of partly hydrotreated feed to hydrotreatment to obtain a stream of hydrocarbons, e) distilling the stream of hydrocarbons to obtain at least two fractions, a first heavy bottom fraction, which is removed from the process and a second mid- & 25 dle fraction, which is collected for further processing, and

N f) subjecting the collected middle fraction to isomerisation to obtain an

O isomerised stream of hydrocarbons,

O wherein the pre-hydrotreatment is performed such that at least 80 =E wt.% of nitrogen, at least 90 wt.% of oxygen and at least 95 wt.% of phosphorous

N 30 is removed in the partly hydrotreated feed, and wherein in the collected middle

O fraction at least 90 % have a boiling point from 180 °C to 360 °C. = As used herein the term “organic material of biological origin” refers to organic material, i.e. material containing carbon. The organic material is of biolog- ical origin, i.e. from natural resource such as but not limited to plants, trees, algae, microbes but also animal sources are possible. Organic material of biological origin is here meant to exclude fossil based organic material. The organic material suita- ble in the present process typically contain organic compounds such as fatty acids, resin and rosin acids and other lipophilic compounds but also other organic com- pounds.

Particular examples of the feedstock comprising organic material of bi- ological origin of the present invention include, but are not limited to, animal based fats and oils, such as suet, tallow, blubber, lard, train oil, milk fat, fish oil, poultry oil, and poultry fat; plant based fats and oils, such as sludge palm oil, rape-seed oil, canola oil, colza oil, sunflower oil, soybean oil, hemp oil, olive oil, linseed oil, cot- tonseed oil, mustard oil, palm oil, arachis oil, castor oil, coconut oil, lignocellulosic pyrolysis liquid (LPL), HTL biocrude, crude tall oil (CTO), tall oil pitch (TOP), crude fatty acid (CFA), tall oil fatty acid (TOFA) and distilled tall oil (DTO); microbial oils; algal oils; recycled fats or various waste streams of the food industry, such as used cooking oil, yellow and brown greases; free fatty acids, any lipids containing phos- phorous and/or metals, oils originating from yeast or mold products, recycled ali- mentary fats; starting materials produced by genetic engineering, and any mixtures of said feedstocks.

In one embodiment of the current invention the feedstock comprising organic material of biological origin comprise pitch containing crude tall oil (CTO), residue and waste oils from palm oil production and/or recycled fats and oils.

In an embodiment of the present invention organic material of biologi- cal origin used as feedstock is selected from a group consisting of crude tall oil (CTO), tall oil pitch (TOP), tall oil fatty acid (TOFA), crude fatty acid (CFA), tall oil fatty acid (TOFA) and distilled tall oil (DTO); more particularly the organic material of biological origin is crude tall oil (CTO) or tall oil pitch (TOP). o In addition or as an alternative the organic material of biological origin

N can also be selected from acid oils, such as acidulated soapstock (ASK), technical = corn oil (TCO), plant oil from plants of the family Brassicaceae (carinata oil), palm 2 effluent sludge (PES), used cooking oil (UCO), gutter oil and brown grease (BG).

N 30 As defined herein crude tall oil (CTO, CAS Registry Number 8002-26-4)

E is most freguently obtained as a by-product of either Kraft or Sulphite pulping pro- © cesses and tall oil pitch (TOP, CAS number of 8016-81-7) is the residual bottom 2 fraction from crude tall oil distillation processes.

N Crude tall oil comprises resin acids, fatty acids, and unsaponifiables.

N 35 Resin acids are a mixture of organic acids derived from oxidation and polymeriza- tion reactions of terpenes. The main resin acid in crude tall oil is abietic acid but abietic derivatives and other acids, such as pimaric acid are also found. Fatty acids are long chain monocarboxylic acids and are found in hardwoods and softwoods.

The main fatty acids in crude tall oil are oleic, linoleic and palmitic acids. Unsapon- ifiables cannot be turned into soaps as they are neutral compounds which do not react with sodium hydroxide to form salts. They include sterols, higher alcohols and hydrocarbons. Sterols are steroids derivatives which also include a hydroxyl group.

Tall oil pitch (TOP) can be considered to be a UVCB substance (Sub- stances of Unknown or Variable composition, Complex reaction product or Biolog- ical materials) under the REACH definition. Composition of TOP according to

Holmbom (1978) is presented in Table 1. Tall oil pitch typically comprises from 34 to 51 wt.% free acids, from 23 to 37 wt.% esterified acids, and from 25 to 34 wt.% unsaponifiable neutral compounds of the total weight of the tall oil pitch. The free acids are typically selected from a group consisting of dehydroabietic acid, abietic and other resin acids. The esterified acids are typically selected from a group con- sisting of oleic and linoleic acids. The unsaponifiables neutral compounds are typ- ically selected from a group consisting of diterpene sterols, fatty alcohols, sterols, and dehydrated sterols.

Table 1. Component Group Composition of Tall Oil Pitch (wt.% of pitch)a osuus = jä [5 Jc [pe FP

Free acids, total 39.3 52.6 48.6 44.6 46.7 34.6

Fatty acids 1.4 1.8 1.3 0.8 1.3 2.4

Resin acids 10.6 125 |9.7 6.1 3.3 6.5

Other acids 27.3 37.3 |373 |37.7 42.1 25.7 & Esterified acids, total 30.6 23.2 | 233 | 268 27.9 37.8

DN Fatty acids 8.2 129 113.3 |15.2 13.8 12.4 o Resin acids 1.7 0.9 1.2 0.9 1.6 1.9

I Other acids 20.7 9.4 8.8 10.7 12.5 23.5

N Eguiv. weight for free | 648 591 716 642 873 719 rt PP

N a) Holmbom B, and Erä V, 1978. Composition of Tall oil pitch, Journal of the American oil

N chemistry society, 55, pp. 342-344.

The term “crude fatty acid (CFA)” refers to fatty acid-containing mate- rials obtainable by purification (e.g. distillation under reduced pressure, extrac- tion, and/or crystallization) of CTO. The term “tall oil fatty acid (TOFA)' refers to fatty acid rich fraction of crude tall oil (CTO) distillation processes. TOFA typically 5 comprises mainly fatty acids, typically at least 80 wt.% of the total weight of the

TOFA. Typically, TOFA comprises less than 10 wt.% rosin acids.

The term “distilled tall oil (DTO)” refers to resin acid rich fraction of crude tall oil (CTO) distillation processes. DTO typically comprises mainly fatty ac- ids, typically from 55 to 90 wt.%, and rosin acids, typically from 10 to 40 wt.% rosin — acids, of the total weight of the DTO. Typically, DTO comprises less than 10 wt.% unsaponifiable neutral compounds of the total weight of the distilled tall oil.

Acid oils refers to by-products of alkali or physical refining of crude oils and fats. One example of acid oils are oils obtained by acidulation of soapstock (ASK), which contains free fatty acids, acylglycerols and other lipophilic com- pounds.

The term “technical corn oil” TCO refers to corn oil extracted through a dry milling process. In the dry milling process, corn grains are cleaned and ground directly to obtain a fine corn flour. This flour is then mixed with water, enzymes and other ingredients (cooking and liquefaction) to convert starch into simple sug- — ars, then into glucose (saccharification). This glucose is fermented to produce eth- anol, which is then removed by distillation and purified by dehydration. The re- maining stillage (called distillers grain) is then processed further to expel technical corn oil (generally called “distillers corn oil” in the United States) through centrif- ugation. De-emulsifiers can be used to enhance separation of the TCO from the rest of the stillage. n The organic material can also comprise plant oil originating from a plant

N of the family Brassicaceae (carinata oil). The plant of the family Brassicaceae is se- = lected from Brassica juncea (brown mustard), Brassica carinata (Ethiopian mus- ? tard), Brassica nigra (black mustard), Brassica rapa, Brassica rapa subsp. oleifera

AN 30 (field mustard), Brassica elongate (elongated mustard), Brassica nariosa (broad-

E baked mustard), Brassica rupestris (brown mustard), Brassica tournefortii (Asian © mustard), Brassica napus, Brassica napus el, Sinapis hirta (mustard), Sinapis alba 3 (white mustard), Sinapis arvensis, Nasturtium floridanum, Nasturtium gambel-

N lium, Nasturtium gronlandicum, Nasturtium microfullum, nasturtium officinale,

N 35 Nasturtium sordidum and combinations thereof. Preferably the plant is Brassica carinata.

The term “palm effluent sludge” (PES), also commonly referred to, as palm oil mill effluent (POME) here refers to the voluminous liquid waste that comes from the sterilisation and clarification processes in milling oil palm. The raw efflu- ent contains 90-95% water and includes residual oil, soil particles and suspended solids.

The term “used cooking oil” (UCO) refers to oils and fats that have been used for cooking or frying in the food processing industry, restaurants, fast foods and at consumer level, in households.

Gutter oil is a general term for oil that has been recycled. It can be used to describe the practice of restaurants re-using cooking oil that has already been fried before.

Brown grease (BG) means an emulsion of fat, oil, grease, solids, and wa- ter separated from wastewater in a grease interceptor (grease trap) and collected for use as feedstock.

In one embodiment the organic material of biological origin comprises crude tall oil (CTO) optionally including tall oil pitch (TOP), tall oil pitch (TOP), brown grease (BG), acidulated soapstock (ASK), technical corn oil (TCO), low qual- ity animal fat (AF), Brassica carinata (BC), palm effluent sludge (PES) or any com- bination thereof. In one embodiment the feedstock comprises crude tall oil (CTO), tall oil pitch (TOP), brown grease (BG) and acidulated soapstock (ASK).

The process of the present invention further comprises a step of pre- treating the feedstock in one or more pre-treatment stages. The pre-treatment stages vary and are selected based on the feedstock and especially on the amount and type of impurities in the feedstock. The pre-treatment stages can be selected from heat treatment optionally followed by evaporation of volatiles; heat treat-

NN ment with adsorbent (HTA) optionally followed by flash evaporation; degumming;

O bleaching or any combination thereof. The pre-treatment also typically comprises 2 a step of removing impurities from the feedstock, including any suitable removal ? of solids from a liguid, including filtration, centrifugation and sedimentation; and

AN 30 removing volatiles from liquid, e.g. by evaporation. In the pre-treatment the feed-

E stock comprising organic material of biological origin, as previously defined, is pu- 0 rified and a purified feedstock is obtained. 3 In one embodiment the pre-treatment is selected from heat treatment

N optionally followed by evaporation of volatiles, whereby the feedstock is heated at

N 35 atemperature of from 80 °C to 325 °C, preferably 180 °C to 300 °C, more preferably 200 °C to 280 °C, in a residence time from 1 to 300 min. The heat treatment can follow by an evaporation step, where especially silicon and phosphorous contain- ing compounds are removed. An example of heat treatment of a feedstock compris- ing organic material can be found in WO 2020/016405. Heat treatment can also be followed by filtration as an addition or an alternative to evaporation. When the feedstock comprises brown grease or acidulated soapstock the pre-treatment com- prising heat treatment with or without filter-aid (adsorbent) followed by filtration and possible bleaching.

In one embodiment the pre-treatment is selected from heat treatment with adsorbent (HTA) optionally followed by flash evaporation. HTA as pre-treat- mentis especially suitable when the feedstock comprises CTO and/or TOP, but also for other feedstock. Heat treatment with adsorbent (HTA) can be performed in a temperature from 180 °C to 325 °C, preferably from 200 °C to 300 °C, more prefer- ably from 240 °C to 280 °C, optionally in the presence of an acid. The adsorbent can be selected from alumina silicate, silica gel and mixtures thereof and is typically added in an amount of 0.1 wt.% to 10 wt.%, such as 0.5 wt.%. An example of HTA can be found in WO 2020/016410.

In one embodiment the pre-treatment is selected from bleaching.

Bleaching can be conducted by acid addition in an amount of from 500 to 5000 ppm based on feed. The bleaching treatment can be performed in a temperature from 60 °C to 90 °C and including a drying step in 110 °C to 130 °C. The bleaching is finished by a filtration step to remove formed solids and possible filter aids. In one example bleaching includes the following sequence (1) acid addition 1000-4000 ppm citric acid (50% water) 85 °C, 10 min; (2) adsorbent/filter aid addition 0.1-1 wt.%, 85 °C, 800 mbar, 20 min; (3) drying 120 °C, 80 mbar, 25 min n (4) filtering 120 °C, 2.5bar.

N Both heat treatment (HT) and heat treatment with adsorbent (HTA) can = be performed under pressure, the pressure can be 500 to 5000 kPa. Also water can ? be added before or during HT and HTA to a level of up to 5 wt.%, such as 1 wt.% -

N 30 3 wt.%. The evaporation, e.g. performed by flashing can be performed after HT or

E HTA or any other pre-treatment stage and can be performed at about 160 °C, such 0 as from 150 °C to 225 °C, in a pressure of 10 to 100 mbar (0.1 to 5 kPa). 3 For a feedstock comprising palm oil effluent sludge (PES) the pre-treat-

N ment can comprise acid degumming followed by solid removal from the liquid, us-

N 35 ing filtration of centrifugation. The degumming process can further be followed by a bleaching step.

In one embodiment of the invention the pre-treatment, comprises heat treatment (HT) and bleaching.

In one embodiment of the invention the pre-treatment, comprises heat treatment (HT) with alkali addition and bleaching.

In one embodiment of the invention the pre-treatment, comprises heat treatment with adsorption (HTA) followed by flash (removal of light components comprising Si components etc. by evaporation) and bleaching,

In addition, the pre-treatment may or may not include additional steps such as removal of solids (using technologies such as centrifugation or filtration) before and/or after HT or HTA, water washing, degumming, hydrolysis, distillation, strong acid treatment, 2nd bleaching or any combination of the mentioned meth- ods.

The level and type of impurities vary with the organic material, but can also vary from one feedstock to another depending on source and how the organic — material have been treated. Typical impurity levels of the most significant impuri- ties are listed in Table 2 below.

Table 2. Typical impurities and ranges in different organic materials n TE TE (ppm) (ppm) (ppm) (ppm) (ppm) en

S n © Metals = Ca, Mg, Na, Fe; in total - 20 n. Different organic materials can be blended in the final feedstock to x avoid unwanted reactions. For example, if the feed Cl content is over 100 ppm and

O simultaneously N content is over 1000 ppm it is possible that ammonium chloride

O NHC! precipitation reaction takes place in pre-hydrotreatment step. In order to avoid this, organic material like BG, having a high Cl content and a high N content, are blended with organic material having a low Cl and/or N content, such as PES.

In one embodiment of the present invention the feedstock comprising organic material of biological origin comprises an impurity level of - nitrogen compounds from more than 30 ppm, preferably more than 50 ppm or 100 ppm, such as up to 5000 ppm; - silicon compounds from more than 1 ppm, preferably more than 5 ppm or more than 10 ppm or 30 ppm, up to 500 ppm; - phosphorous compounds from more than 5 ppm, preferably more than 10 ppm or 50 ppm, up to 3500 ppm; - chloride from more than 1 ppm, preferably more than 5 ppm or 10 ppm, up to 300 ppm; and/or - metals from more than 10 ppm, preferably more than 30 ppm or 50 ppm, up to 20000 ppm.

The amount of metals are given as the total sum of at least Ca, Mg, Na and Fe.

The process of the present invention further comprises a step of sub- jecting the purified feedstock to pre-hydrotreatment to obtain a stream of partly hydrotreated feed. The pre-hydrotreatment can also be called pre-hydrodeoxygen- ation or pre-HDO. The aim of the pre-hydrotreatment is to prepare the purified feed to the subsequent processes and also partly to function as a further purification step for the purified feedstock.

In one embodiment of the present invention, the pre-hydrotreatment is performed in conditions selected from: - a temperature range of 300 °C to 380 °C, preferably of 320 °C to 360 oC; - a pressure range of 40 to 80 bar, preferably 50 to 70 bar; o - a weight hourly space velocity (WHSV) of 0.25 1/h to 1.5 1/h, pref-

AN erably 0.3 1/h to 1 1/h; and = - a Hz/oil feed of 800 dm3/dm3 to 1200 dm3/dm3, preferably of 900 2 dm3/dm3 to 1100 dm3/dm3.

N 30 The catalyst used in the pre-hydrotreatment step is a typical hy-

E drotreating catalyst such as Ni, Co, Mo on a carrier such as alumina. Alternatively © or in addition the catalyst in pre-hydrotreatment can also be a typically hy- 2 drocracking catalyst such as NiW on acidic supports (ASA, Zeolites). In one embod-

N iment the catalyst in the pre-hydrotreatment is NiMo on alumina carrier. The pre-

N 35 treatment step is typically carried out in a reactor with one or more catalyst beds.

The extent of the pre-hydrotreatment depends on the organic material and level of impurities. The aim of the pre-treatment is to prepare the feed, e.g. to remove het- eroatoms and other impurities, to such a level that the hydrotreatment can remove the rest of the heteroatoms and impurities prior to the isomerization.

The pre-hydrotreatment step is meant to remove a major part of the heteroatoms and those other impurities still left after the pre-treatment. In the pre- sent invention the amount of nitrogen is removed by at least 80 wt.%, oxygen by at least 90 wt.% and phosphorous by at least 95 wt.% in the partly hydrotreated feed.

These high levels of removal of heteroatoms and impurities shows that major part of the removal takes place in pre-hydrotreatment compared to the hydrotreatment — step. Thereby, more adverse effect, such as formation of water and ammonia and catalyst de-activation, takes place in the pre-hydrotreatment step. The catalyst in the pre-hydrotreatment can be changed frequently, while the catalyst in the hy- drotreatment step stays fresh. Also, fresh hydrogen can be introduced to the hy- drotreatment step, which enable highly efficient conversion. Since major part of the conversion takes place in pre-hydrotreatment, the hydrotreatment step can be controlled such that the hydrotreated product is of high quality.

In the pre-hydrotreatment the partly hydrotreated feed withdrawn from the reactor, can be recycled in a relatively high ratio. The ratio of recycled partly hydrotreated feed to fresh purified feedstock in the pre-hydrotreatment step can be from 1:1 to 15:1, preferably 1:1 to 10:1 and more preferably 1:1 to 5:1.

One aim of the present process is therefore to lower the amount of het- eroatoms and impurities by a combination of pre-treatment and pre-hydrotreat- ment. Examples of levels of impurities before pre-treatment is given in Table 3, which also shows typical amounts of impurities still left in the feedstock prior to — the pre-hydrotreatment (pre-HDO) step. 0

N

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N 30

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N 35

Table 3. Examples of levels of impurities before pre-treatment and before pre-hy- drotreatment (pre-HDO) treat- ment Pre-HDO

It should be noted that ppm (part per million) corresponds to mg/kg.

The process of the present invention further comprises subjecting the partly hydrotreated feed to hydrotreatment to obtain a stream of hydrocarbons. In one embodiment of the present invention, the hydrotreatment is performed in con- ditions selected from: - atemperaturerange of 300 °C to 380 °C, preferably of 320 °C to 360 *C; - a pressure range of 40 to 80 bar, preferably 50 to 70 bar; - a weight hourly space velocity (WHSV) of 0.25 1/h to 1.5 1/h, pref- erably 0.3 1/h to 1 1/h; and & - a Hz/oil feed of 800 dm3/dm3 to 1200 dm3/dm3, preferably of 900 dm3/dm3 to 1100 dm3/dm3. > The catalyst used in the hydrotreatment step is a typical hydrotreating

N catalyst such as Ni, Co, Mo on a carrier such as alumina. Alternatively or in addition,

E the catalyst in the hydrotreatment can also be a typically hydrocracking catalyst © such as NiW on acidic supports (ASA, Zeolites). In one embodiment the catalyst in 3 20 the hydrotreatment is NiMo on alumina carrier. The treatment step is typically car-

N ried outin areactor with one or more catalyst beds.

N In the hydrotreatment the stream of hydrocarbon withdrawn from the reactor, is not or can be recycled back to the hydrotreatment, but typically in very low amount. A maximum of 10 wt.% of the stream of hydrocarbons can be recycled back to hydrotreatment. In one embodiment the hydrotreatment step does not contain any recycling.

The aim of the hydrotreatment is to essentially remove all impurities and heteroatoms from the feed, and the stream of hydrocarbons should therefore essentially only contain hydrocarbons.

The process of the present invention further comprises distilling the stream of hydrocarbons to obtain at least two fractions. The two fractions are a first heavy bottom fraction and a second middle fraction. The first heavy bottom frac- — tion is typically removed from the present process and the middle fraction is col- lected and subjected to further treatments. The first heavy bottom fraction can be characterized such that at least 90% of the components (compounds) of the first heavy bottom fraction have a boiling point of 360 °C or above. The second middle fraction can be characterized such that at least 90 % of the components (com- pounds) of the second middle fraction have a boiling point of from 180 °C to 360 °C. All boiling points are given in atmospheric pressure. The first heavy bottom fraction can be used as a product as such or subjected to other processes (not dis- closed here).

In one embodiment of the present invention the distillation is per- formed using the following conditions: a cut point target of 340 °C to 360 °C, vac- uum set point of 2 mbar, top column temperature of 180 °C, nitrogen feed rate of 2 1/h and feed rate of 0.24 1/h. These conditions are to be regarded as examples and a skilled person is able to operate the distillation such that the target fractions are obtained.

The process of the present invention further comprises a step of isom- o erization the collected middle fraction. In one embodiment of the current inven-

N tion, the isomerization of the collected middle fraction to obtain a stream of isom- = erized hydrocarbons is performed in conditions selected from: 2 - a temperature range of 300 °C to 360 °C, preferably 310 °C to 345

N 30 °C;

E - a pressure range of 35 bar to 60 bar, preferably 40 bar to 50 bar; 00 - a weight hourly space velocity (WHSV) of 1 1/h to 1.5 1/h. 3 The catalyst used in the isomerization of the stream of hydrocarbons is

N any typical isomerization catalyst, such as Pt or PI on a suitable support, preferably

N 35 the isomerization catalyst is Pt-SAPO11.

In one embodiment of the present invention the process further comprises a stripping step to remove gaseous compounds from a stream of the pro- cess. The stripping step can be performed after the pre-treatment step, the pre- hydrotreatment step, the hydrotreatment step, the isomerization step or any com- bination thereof. In one embodiment the stripping is performed after the pre-hy- drotreatment or hydrotreatment step to remove gaseous compounds before the distillation step. Gaseous compounds which can be removed in a stripping step in- clude sulphide (HzS), ammonia (NH3) and water. The stripping step can also be called a flash step or flash evaporation or flash distillation.

In the process of the present invention said feedstock comprising or- — ganic material of biological origin has prior to the pre-treatment step preferably not been distilled or evaporated, such that the gaseous fraction is collected for fur- ther processing steps and residue or liquid fraction is discarded.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The inven- tion and its embodiments are not limited to the examples described above but may vary within the scope of the claims. 0

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Claims (14)

Claims

1. A process for producing hydrocarbons from a feedstock compris- ing organic material of biological origin, the process comprising a) providing a feedstock comprising organic material of biological origin, b) pre-treating the feedstock in one or more pre-treatment stages to obtain a purified feedstock, c) subjecting said purified feedstock to pre-hydrotreatment to obtain a stream of partly hydrotreated feed, d) subjecting the stream of partly hydrotreated feed to hydrotreat- ment to obtain a stream of hydrocarbons, e) distilling the stream of hydrocarbons to obtain at least two frac- tions, a first heavy bottom fraction, which is removed from the process and a second middle fraction, which is collected for further processing, and f) subjecting the collected middle fraction to isomerisation to obtain an isomerised stream of hydrocarbons, wherein the pre-hydrotreatment is performed such that at least 80 wt.% of nitrogen, at least 90 wt.% of oxygen and at least 95 wt.% of phospho- rous is removed in the partly hydrotreated feed, and wherein in the collected middle fraction at least 90 % have a boiling point from 180 °C to 360 °C.

2. The process of claim 1, wherein the feedstock comprising organic material of biological origin comprises crude tall oil (CTO), tall oil pitch (TOP), tall oil fatty acid (TOFA), crude fatty acid (CFA), tall oil fatty acid (TOFA), dis- tilled tall oil (DTO), acid oils, such as acidulated soapstock (ASK), technical corn oil (TCO), plant oil from plants of the family Brassicaceae (carinata oil), & palm effluent sludge (PES), used cooking oil (UCO), gutter oil, brown grease N (BG) or any combination thereof.

2 3. The process of claim 1 or 2, wherein the feedstock comprising N organic material of biological origin comprises an impurity level of nitrogen E 30 compounds from more than 30 ppm, such as up to 5000 ppm; silicon com- © pounds from more than 1 ppm or 5 ppm, up to 500 ppm; phosphorous com- 3 pounds from more than 5 ppm, up to 3500 ppm; chloride from more than 1 N ppm or 5 ppm, up to 300 ppm and/or metals from more than 10 ppm or 30 N ppm, up to 20000 ppm.

4. The process of any preceding claim, wherein the pre-treatment stages of step b) comprises heat treatment (HT) optionally followed by evapo-

ration of volatiles; heat treatment with adsorbent (HTA) optionally followed by evaporation; degumming; bleaching or any combination thereof.

5. The process of any preceding claim, wherein the pre- hydrotreatment of step c) is carried out at a temperature of 300 °C to 380 °C, a pressure of 40 bar to 80 bar, a WHSV of 0.25 1/h to 1.5 1/h and in the pres- ence of a hydrotreatment or hydrocracking catalyst, preferably selected from Ni, Co, Mo and/or W, on a carrier such as alumina.

6. The process of any preceding claim, wherein the pre- hydrotreatment comprises recycling a part of the stream of partly hydrotreated feed back to the pre-hydrotreatment.

7. The process of claim 6, wherein the ratio of recycled partly hy- drotreated feed to fresh purified feedstock in the pre-hydrotreatment step is from 1:1 to 15:1, preferably from 1:1 to 10:1 and more preferably from 1:1 to

5:1.

8. The process of any preceding claim, wherein the hydrotreatment of the stream of partly hydrotreated feed of step d) is carried out at a tempera- ture of 300 °C to 380 °C, a pressure of 40 bar to 80 bar, a WHSV of 0.25 1/h to

1.5 1/h and in the presence of a hydrotreatment and/or hydrocracking catalyst, preferably selected from Ni, Co, Mo and/or W, on carrier such as alumina.

9. The process of any preceding claim, wherein the hydrotreatment comprises no recycling or at maximum recycling 10 % of the stream of hydro- carbons back to the hydrotreatment.

10. The process of any preceding claim, wherein the distilling of the stream of hydrocarbons of step e) is carried out such that at least 90% of the first heavy bottom fraction have a boiling point of 360 °C or above. n

11. The process of any preceding claim, wherein the isomerization AN of the collected middle fraction of step f) is carried out at a temperature of 300 = *C to 360 *C, preferably 310 *C to 345 *C, a pressure of 35 bar to 60 bar, 2 WHSV of 1.0 1/h to 1.5 1/h and in the presence of an isomerising catalyst se- N 30 lected from supported Pt or PI catalyst, preferably a Pt-SAPO11 catalyst. E

12. The process of any preceding claim, wherein the process further © comprises a stripping step to remove gaseous compounds from a stream of 2 the process, preferably the stripping step is performed after pre-treatment step N b), after pre-hydrotreatment step c), after hydrotreatment step d), after isomeri- N 35 sation step f) or any combination thereof.

13. The process of any preceding claim, wherein the pre- hydrotreatment step c) is carried out such that the level of nitrogen containing compounds is low and can be reduced to zero after hydrotreatment step d).

14. The process of any preceding claims, wherein said feedstock comprising organic material of biological origin has prior to the pre-treatment step not been distilled or evaporated, such that a gaseous fraction is collected for further processing steps and residue or liquid fraction is discarded. 0 QA O N S © N I a a 00 O 0 O N O N