阅读说明：本技术 利用费托合成重质馏分油制备表面活性剂的方法及其系统 (Method and system for preparing surfactant by using Fischer-Tropsch synthesis heavy distillate oil ) 是由 万会军 向忠权 杨强 李明 刘垒 陈晏杰 于 2019-10-15 设计创作，主要内容包括：本发明涉及一种利用费托合成重质馏分油制备直链表面活性剂和重质表面活性剂的方法,所述方法以费托合成重质馏分油为原料,经过馏分切割、碱洗、水洗、精馏以及烷基化处理等,得到直链表面活性剂和重质表面活性剂。本发明还涉及用于实施该方法的系统,该系统主要包括切割塔、碱洗罐、水洗塔、精馏塔以及烷基化单元。本发明的方法和系统能够以高的成本效益比得到直链表面活性剂和重质表面活性剂。(The invention relates to a method for preparing a linear chain surfactant and a heavy surfactant by Fischer-Tropsch synthesis heavy distillate oil. The invention also relates to a system for carrying out the method, which mainly comprises a cutting tower, an alkaline washing tank, a water washing tower, a rectifying tower and an alkylation unit. The process and system of the present invention enable the production of linear surfactants and heavy surfactants at a high cost-to-benefit ratio.)

1. A method for preparing a linear chain surfactant and a heavy surfactant by Fischer-Tropsch synthesis heavy distillate oil comprises the following steps:

(1) cutting fraction of Fischer-Tropsch synthesis heavy distillate to obtain C10^-A fraction section, a crude C10-C13 fraction section, a crude C14-C17 fraction section and C17⁺Fractionating;

(2) mixing the crude C10-C13 fraction segment and the crude C14-C17 fraction segment with alkali respectively to obtain corresponding mixtures, stirring the mixtures respectively, filtering and separating the mixtures respectively to remove alkali residues to obtain liquid phases, and washing the liquid phases with water respectively to obtain a primarily treated C10-C13 fraction segment and a primarily treated C14-C17 fraction segment;

(3) rectifying the preliminarily treated C10-C13 fraction segment and the preliminarily treated C14-C17 fraction segment respectively to obtain C10-C13 fraction hydrocarbon and C14-C17 fraction hydrocarbon; and

(4) respectively alkylating the C10-C13 fraction hydrocarbon and the C14-C17 fraction hydrocarbon to obtain the linear surfactant and the heavy surfactant.

2. The process of claim 1, wherein in step (1), the fischer-tropsch synthesis heavy fraction oil is cut with any one of the cutting towers selected from: (a) an atmospheric tower, a vacuum tower 1 and a vacuum tower 2; (b) a vacuum tower 1' + a vacuum tower 2' + a vacuum tower 3 '; (c) an atmospheric fractionating tower and/or a vacuum fractionating tower provided with two side stripping towers; and (d) a divided wall column;

preferably, before the fraction cutting, the temperature of the Fischer-Tropsch synthesis heavy distillate oil is raised to 100-200 ℃, preferably 100-150 ℃;

further preferably, the atmospheric tower, the vacuum tower 1 and the vacuum tower 2 are adopted to cut the fraction of the Fischer-Tropsch synthesis heavy distillate oil; preferably, the theoretical plate number of the normal pressure tower is 20-40, preferably 25-30, the tower top temperature is 120-160 ℃, preferably 150-160 ℃, the tower bottom temperature is 210-260 ℃, preferably 240-250 ℃, and the operation pressure is 0.1-0.2 MPa (A), preferably 0.10-0.15 MPa (A); the number of theoretical plates of the decompression tower 1 is 20-50, preferably 25-35, the temperature at the top of the tower is 140-180 ℃, preferably 155-165 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 230-250 ℃, and the operating pressure is 0.015-0.040 MPa (A), preferably 0.020-0.030 MPa (A); the number of theoretical plates of the decompression tower 2 is 20-50, preferably 20-30, the temperature at the top of the tower is 150-210 ℃, preferably 200-210 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 270-280 ℃, and the operating pressure is 0.005-0.03 MPa (A), preferably 0.010-0.020 MPa (A);

or, preferably, the fraction cutting is carried out on the Fischer-Tropsch synthesis heavy distillate oil by adopting a vacuum tower 1' + a vacuum tower 2' + a vacuum tower 3 '; preferably, the theoretical plate number of the decompression tower 1' is 20-40, preferably 25-30, the tower top temperature is 80-180 ℃, preferably 100-150 ℃, the tower bottom temperature is 150-300 ℃, preferably 180-250 ℃, and the operation pressure is 0.015-0.05 MPa (A); the number of theoretical plates of the decompression tower 2' is 20-50, preferably 25-35, the temperature at the top of the tower is 140-180 ℃, preferably 155-165 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 230-250 ℃, and the operating pressure is 0.015-0.040 MPa (A), preferably 0.020-0.030 MPa (A); the number of theoretical plates of the decompression tower 3' is 20-50, preferably 20-30, the temperature at the top of the tower is 150-210 ℃, preferably 200-210 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 270-280 ℃, and the operating pressure is 0.005-0.03 MPa (A), preferably 0.010-0.020 MPa (A);

or, preferably, the Fischer-Tropsch synthesis heavy distillate oil is subjected to distillate cutting by using a dividing wall tower; preferably, the dividing wall column operating conditions are: the temperature of the top of the main tower is 100-200 ℃, preferably 140-160 ℃, the temperature of the bottom of the main tower is 200-300 ℃, preferably 250-280 ℃, the operating pressure is 0.005-0.025 MPa (A), preferably 0.01-0.02 MPa (A), the number of public rectification section theoretical plates is 10-20, the number of public stripping section theoretical plates is 5-15, the number of side line extraction section tower plates is 20-30, and the number of pre-rectification section tower plates is 20-30;

or, preferably, an atmospheric fractionating tower and/or a vacuum fractionating tower which is provided with two side steam stripping towers is adopted to cut the fraction of the Fischer-Tropsch synthesis heavy distillate oil; preferably, a vacuum fractionating tower provided with two side steam stripping towers is adopted to cut fractions of the Fischer-Tropsch synthesis heavy distillate oil; further preferably, the theoretical plate number of the vacuum fractionating tower is 20-60, preferably 30-50, the tower top temperature is 80-110 ℃, preferably 90-100 ℃, the tower bottom temperature is 250-300 ℃, preferably 260-280 ℃, and the operation pressure is 0.005-0.025 MPa (A), preferably 0.01-0.02 MPa (A); the number of theoretical plates of the side stripping towers is 10-30, preferably 15-25, and the number of the theoretical plates of the two side stripping towers can be the same or different.

3. The method according to claim 1 or 2, wherein, in the step (2), the alkali is one of sodium hydroxide, potassium hydroxide and sodium carbonate or any combination thereof;

preferably, the mixture is stirred at the rotating speed of 10-100 r/min at the temperature of 30-60 ℃ respectively;

preferably, a 5-20 micron filter screen is adopted for filtering and separating;

preferably, the water washing is performed with 0.2 to 0.8 times the volume of the liquid phase, respectively.

4. The process according to any one of claims 1 to 3, wherein, in the step (3), the rectification is azeotropic rectification or extractive rectification.

5. The method of claim 4, wherein the azeotropic distillation can be carried out by a homogeneous azeotropic distillation process or a heterogeneous azeotropic distillation process;

further preferably, when the homogeneous azeotropic distillation process is adopted, 75-99.9 wt%, preferably 90-96 wt% of ethanol is selected as the entrainer; the solvent ratio of the entrainer calculated by the mass ratio of the ethanol in the entrainer to the raw material is 1-8;

in addition, preferably, when a heterogeneous azeotropic distillation process is adopted, a binary mixed solvent of ethanol and water is selected as an entrainer, wherein the mass concentration of the ethanol is 60-94%, preferably 80-90%; the azeotropic distillation solvent ratio is 0.5-5, preferably 1-2, calculated by the mass ratio of the ethanol in the entrainer to the raw material;

preferably, the azeotropic distillation comprises the steps of: enabling the preliminarily treated C10-C13 fraction and the preliminarily treated C14-C17 fraction to respectively enter respective azeotropic distillation towers, and respectively generating azeotropes at the tops of the azeotropic distillation towers; cooling the azeotrope, and then respectively entering respective tower top liquid separation tanks for standing and layering to obtain an oil phase; respectively feeding the oil phases into an entrainer recovery stripping tower, and respectively obtaining C10-C13 fraction hydrocarbons and C14-C17 fraction hydrocarbons at the bottom of the entrainer recovery stripping tower;

more preferably, the azeotropic distillation further comprises: withdrawing an oxygenate from the bottom of the azeotropic distillation column;

more preferably, the azeotropic agent is supplemented to the water phase obtained by standing and layering in the tower top liquid separating tank, and then the water phase is returned to the azeotropic distillation tower for recycling;

more preferably, the theoretical plate number of the azeotropic distillation tower is 20-40, and preferably 20-30;

alternatively, preferably, the extractive distillation is carried out in an atmospheric distillation column; preferably, the theoretical plate number of the atmospheric distillation tower is 50-70, and the reflux ratio is 5-15;

preferably, the extractive distillation comprises the following steps: feeding the primarily treated C10-C13 fraction segment and the primarily treated C14-C17 fraction segment into respective extractive distillation columns as feed streams; adding an extracting agent into the extractive distillation tower, wherein the volume flow ratio of the extracting agent to the feed material flow is 0.5-5: 1, and preferably 0.5-2: 1; respectively producing C10-C13 fraction hydrocarbon and C14-C17 fraction hydrocarbon at the top of each extractive distillation column;

further preferably, the material flows generated at the bottom and the bottom of the extractive distillation tower enter an extractant recovery tower to be treated, and a regenerated extractant material flow is obtained at the bottom of the extractant recovery tower;

further preferably, the extractive distillation is carried out with one or more extractants selected from the group consisting of: ethylene glycol, dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide, preferably N-methylpyrrolidone.

6. The method according to any one of claims 1 to 5, wherein in the step (4), the alkylation is any one selected from HF alkylation and Total alkylation; preferably, HF alkylation;

preferably, the alkylation is HF alkylation, operating conditions of which are: the ratio of the benzene to the olefin is 5-12: 1, preferably 8-10: 1, the reaction temperature is 30-50 ℃, preferably 35-40 ℃, the reaction pressure is 0.5-2 MPaG, preferably 0.5-1 MPaG, and the volume ratio of HF to hydrocarbon is (1.0-2.5): 1, preferably (1.5-2.0): 1;

alternatively, preferably, the alkylation is a digital alkylation, the operating conditions of the digital alkylation being: benzene to olefin ratioThe molar ratio is (10-20): 1, preferably 12-18: 1, the reaction temperature is 100-180 ℃, preferably 140-160 ℃, the reaction pressure is 2.5-4.0 MPaG, preferably 3.0-4.0 MPaG, and the catalyst is a Lewis acid catalyst taking synthetic zeolite as a carrier, such as a silicon-aluminum fluoride catalyst or a SiO₂-Al₂O₃A solid acid catalyst.

7. The method of any one of claims 1-6, wherein said C10 is administered^-The distillate is sent to a hydrofining unit in sections for refining treatment;

it is also preferred that said C17⁺The distillate is sent to a hydrofining unit for refining treatment.

8. A system for implementing the method of any one of claims 1-7, wherein the system comprises:

a cutting tower;

a caustic wash tank connected in fluid communication to the cutter tower;

a filter connected in fluid communication to the caustic wash tank;

a water wash column connected in fluid communication to the filter;

a rectification unit connected in fluid communication to the water wash column; and

an alkylation unit coupled in fluid communication to the rectification column.

9. The system of claim 8, wherein the cutting tower is any one selected from the group consisting of: (a) an atmospheric tower, a vacuum tower 1 and a vacuum tower 2; (b) a vacuum tower 1' + a vacuum tower 2' + a vacuum tower 3 '; (c) an atmospheric fractionating tower and/or a vacuum fractionating tower provided with two side stripping towers; and (d) a divided wall column;

preferably, the theoretical plate number of the atmospheric tower is 20-40, preferably 25-30; the number of theoretical plates of the decompression tower 1 is 20-50, preferably 25-35; the number of theoretical plates of the decompression tower 2 is 20-50, and preferably 20-30;

preferably, the theoretical plate number of the decompression tower 1' is 20-40, preferably 25-30; the theoretical plate number of the decompression tower 2' is 20-50, preferably 25-35; the theoretical plate number of the decompression tower 3' is 20-50, preferably 20-30;

preferably, the number of theoretical plates of the vacuum fractionating tower provided with the two side strippers is 20-60, preferably 30-50; the number of theoretical plates of the side stripper is 10-30, preferably 15-25, and the number of the theoretical plates of the two side strippers can be the same or different;

preferably, the divided wall column comprises the following parts: the system comprises a pre-distillation section, a common rectification section, a common stripping section and a side draw-off section; preferably, the number of the pre-distillation section trays is 20-30, the number of the public distillation section theoretical plates is 10-20, the number of the public stripping section theoretical plates is 5-15, and the number of the side line extraction section trays is 20-30.

10. The system of claim 8 or 9, wherein the rectification unit comprises an azeotropic rectification column or an extractive rectification column;

preferably, the rectification unit is any one selected from the group consisting of: (1) an azeotropic distillation tower, an azeotropic distillation tower top liquid separation tank and an entrainer recovery stripping tower which are connected in a fluid communication manner; or (2) an extractive distillation column and an extractant recovery column connected in fluid communication.

Technical Field

The invention relates to the field of Fischer-Tropsch synthesis, in particular to a method for preparing a linear chain surfactant and a heavy surfactant by utilizing Fischer-Tropsch synthesis heavy distillate oil and a system for implementing the method.

Background

Because of the energy crisis and the continuous rise of the crude oil price, the Fischer-Tropsch synthetic oil product obtained by the coal indirect liquefaction technology is one of the most realistic and feasible ways to realize the basic self-supply of oil products in China and guarantee the economic and social sustainable development in China. As the development of the Fischer-Tropsch synthesis technology in China becomes mature day by day, the production of fine chemicals by Fischer-Tropsch synthesis oil products gradually goes to commercialization.

As the Fischer-Tropsch synthesis oil product has the characteristics of no sulfur and no aromatic hydrocarbon, high linear α -olefin content (accounting for 60-70%) of heavy distillate oil in the Fischer-Tropsch synthesis oil product, and the like, the high-content α -olefin is utilized to produce high-added-value linear surfactant and heavy surfactant products, so that the economic benefit of the indirect coal liquefaction device is obviously improved.

Linear surfactants and heavy surfactants are used as main raw materials of industrial and domestic detergents, have superior cost performance and biodegradability compared to other surfactants, and thus are widely used worldwide for a long period of time. With the continuous and rapid development of national economy, the domestic demand for linear surfactants is increasing day by day. Meanwhile, the branched-chain surfactant has the defects of poor biodegradability and great harm to the environment, and the demand of the branched-chain surfactant is gradually reduced along with the increasingly strict requirement on environmental protection in China, so that the demand of the market for the linear-chain surfactant is correspondingly expanded.

CN 108341735A discloses a method for producing linear alkylbenzene, wherein the raw material is normal alkane containing 2-20 carbon atoms in Fischer-Tropsch synthetic oil. The method comprises the steps of cutting Fischer-Tropsch synthetic oil by a dividing wall tower to obtain C10-C13 fractions; then methanol is used as an extracting agent to remove oxygen-containing compounds, and finally HF acid is used for alkylation to produce linear alkylbenzene. The method does not involve the treatment of the C14-C17 fraction; meanwhile, the fischer-tropsch oil product contains organic acid and oxygen-containing compounds such as alcohol, aldehyde, ketone, ester and the like besides hydrocarbon components, so that the separation effect of methanol on the oxygen-containing compounds (such as heavy alcohols, aldehydes and acid compounds) in the fischer-tropsch oil product is not obvious. Since the organic acid cannot be separated from the extractant of the organic alcohol system, solvent recovery becomes difficult if the organic alcohol system is used to separate the hydrocarbons and oxygenates to remove the acid and oxygenates. In addition, inner Mongolia Anderson chemical industry Co., Ltd proposes that heavy distillate oil which is an intermediate product of an Italy fine chemical device is extracted to remove impurity components, light solvent oil and reaction raw materials are separated, the reaction raw materials react with aromatic hydrocarbon (benzene) in the presence of HF and sulfuric acid to generate a linear chain surfactant and a heavy surfactant, and light alkane and heavy alkane are separated simultaneously. However, the process does not cut heavy distillate, and the fraction of olefins less than C10 and olefins greater than C17 are also alkylated, so that on the one hand the HF consumption is high and on the other hand the purity of the linear and heavy surfactants is not high. In addition, the process adopts methanol to extract oxygen-containing compounds (such as heavy alcohols, aldehydes and acid compounds) in the Fischer-Tropsch synthesis oil product, and the Fischer-Tropsch synthesis oil product contains a large amount of oxygen-containing compounds such as heavy alcohols and heavy acids, which have weaker polarity and poorer dissolving capacity and selectivity of the methanol, the heavy alcohols and the heavy acids, so the extraction and separation effect by using the methanol is not obvious. In addition, since the organic acid cannot be separated from the extractant of the organic alcohol system, if the organic alcohol system is used to separate the hydrocarbons and oxygenates to remove the acid and oxygenates, solvent recovery becomes difficult.

Therefore, there is still a need in the art to develop different methods for preparing linear surfactants and heavy surfactants using fischer-tropsch synthesized heavy distillate to better produce linear surfactants and heavy surfactants on an industrial scale.

Disclosure of Invention

Through research, the inventor develops a method for preparing a linear surfactant and a heavy surfactant by using Fischer-Tropsch synthesis heavy distillate oil, which is different from the prior art. The method comprises the steps of taking Fischer-Tropsch synthesis heavy distillate oil as a raw material, respectively obtaining a C10-C13 distillation section and a C14-C17 distillation section through fraction cutting, removing oxygen-containing compounds through alkali washing, water washing and rectification (azeotropic rectification and/or extractive rectification), and then obtaining a linear chain surfactant and a heavy surfactant through alkylation.

One object of the present invention is to provide a method for preparing linear surfactants and heavy surfactants by using Fischer-Tropsch synthesis heavy distillate oil, wherein the method comprises the following steps:

(1) cutting fraction of Fischer-Tropsch synthesis heavy distillate to obtain C10^-A fraction section, a crude C10-C13 fraction section, a crude C14-C17 fraction section and C17⁺Fractionating;

(2) mixing the crude C10-C13 fraction segment and the crude C14-C17 fraction segment with alkali respectively to obtain corresponding mixtures, stirring the mixtures respectively, filtering and separating the mixtures respectively to remove alkali residues to obtain liquid phases, and washing the liquid phases with water respectively to obtain a primarily treated C10-C13 fraction segment and a primarily treated C14-C17 fraction segment;

(3) rectifying the preliminarily treated C10-C13 fraction segment and the preliminarily treated C14-C17 fraction segment respectively to obtain C10-C13 fraction hydrocarbon and C14-C17 fraction hydrocarbon; and

(4) respectively alkylating the C10-C13 fraction hydrocarbon and the C14-C17 fraction hydrocarbon to obtain the linear surfactant and the heavy surfactant.

It is another object of the present invention to provide a system for implementing the above method, wherein the system comprises:

a cutting tower;

a caustic wash tank connected in fluid communication to the cutter tower;

a filter connected in fluid communication to the caustic wash tank;

a water wash column connected in fluid communication to the filter;

a rectification unit connected in fluid communication to the water wash column; and

an alkylation unit coupled in fluid communication to the rectification column.

The preparation method of the invention utilizes the characteristic that heavy distillate oil as Fischer-Tropsch synthesis product is rich in α olefin with high content, and obtains the linear chain surfactant and the heavy chain surfactant by fraction cutting, alkali washing, water washing and rectification (azeotropic rectification or extractive rectification), and then alkylation.

Drawings

FIG. 1 is a schematic diagram of a process flow for producing linear surfactants and heavy surfactants using Fischer-Tropsch synthesis of heavy distillate according to an exemplary embodiment.

FIG. 2 is a schematic illustration of a process flow for producing linear surfactants and heavy surfactants using Fischer-Tropsch synthesis of heavy distillate according to another exemplary embodiment.

FIG. 3 is a schematic illustration of a process flow for producing linear surfactants and heavy surfactants using Fischer-Tropsch synthesis of heavy distillate according to yet another exemplary embodiment.

Figure 4 is a schematic of the procedure for the preparation of linear surfactants and heavy surfactants as described in example 6.

Wherein each reference numeral denotes the following equipment and streams, respectively:

101 is a Fischer-Tropsch synthesis heavy distillate oil stream, 102 is C10^-The cut stream, 103, is C10 and C10⁺The distillate stream 104 is crude C10-C13 distillate stream 105 is crude C13⁺A fraction stream 106 which is a crude C14-C17 fraction stream, 107 which is a C10-C13 fraction stream containing trace alkali and alcohol and containing caustic sludge, 108 which is a C10-C13 fraction stream containing trace alkali and alcohol, 109 which is a caustic sludge stream, 110 which is a preliminarily treated C10-C13 fraction stream containing no acid and alkali but containing trace alcohol, 111 which is a stream mainly containing alkali and water, 112 which is desalted water, 113 which is a cooled C10-C13 fraction stream containing no acid and no oxygen compound but containing an entrainer, 114 which is a fraction stream mainly containing an oxygen compound and a small amount of C10-C13, 115 which is a stream mainly containing an entrainer and water after settling and stratification, 116 which is a stream containing a C10-C13 fraction hydrocarbon and an entrainer, 117 which is a fraction mainly containing an entrainer and a small amount of C10-C13, 118 which is a fresh fraction stream, 119 which is a C13-C582 fraction stream containing no entrainer and no entrainer, 120 is benzene and 121 is a linear surfactant; 122 is C17⁺A fraction section stream 137 is a C14-C17 fraction section stream containing trace alkali and alcohol and containing caustic sludge, 138 is a C14-C17 fraction section stream containing trace alkali and alcohol, 139 is a caustic sludge stream, 140 is a preliminary treated C14-C17 fraction section stream containing no acid and alkali but containing trace alcohol, 141 is a stream mainly containing alkali and water, 142 is desalted water, 143 is a cooled C14-C17 fraction hydrocarbon stream containing no acid and no oxygen compound but containing an entrainer, 144 is a stream mainly containing oxygen compound and a small amount of C14-C17 fraction hydrocarbon, 145 is a stream mainly containing entrainer and water after settling and stratification, 146 is a stream containing C14-C17 fraction hydrocarbon and an entrainer, 147 is a stream mainly containing an entrainer and a small amount of C14-C17 fraction hydrocarbon, 148 is a fresh entrainer material, 149 is a C14-C86525 fraction stream containing no entrainer and no alcohol, and a heavy surface active benzene fraction 17, 180 and 181 are both 30% NaOH lye, 123 is a C10-C13 cut hydrocarbon stream free of extractant, acid and alcohol, 153 is a C14-C17 cut hydrocarbon stream free of extractant, acid and alcohol, 124 is a C10 cut hydrocarbon stream containing primarily extractant and trace alcohol and trace C10-C13 distillate hydrocarbon stream, 154 is a stream comprising mainly extractant and containing traces of alcohol and C14-C17 distillate hydrocarbons, 125 is a stream comprising mainly alcohol and containing traces of C10-C13 distillate hydrocarbons, 155 is a stream comprising mainly alcohol and containing traces of C14-C17 distillate hydrocarbons, 126 is an extractant stream, 156 is an extractant stream, 127 is a fresh extractant stream, 157 is a fresh extractant stream.

A is an atmospheric pressure lightness-removing tower, B is a decompression C10-C13 cutting tower, C is a decompression C14-C17 cutting tower, D is a C10-C13 alkaline washing tank, E is a C10-C13 filter, F is a C10-C13 water washing tower, G is a C10-C13 azeotropic rectifying tower, H is a C10-C13 azeotropic rectifying tower top liquid separating tank, I is a C10-C13 azeotropic agent recovery stripping tower, J is a C10-C13 alkylation unit, N is a C14-C17 alkaline washing tank, O is a C17-C17 filter, P is a C17-C17 water washing tower, Q is a C17-C17 rectification tower, R is a C17-C17 azeotropic rectifying tower top separation tower, S is a C17-C17 recovery stripping tower, T is a C17-C17 alkyl side-C17 extractive distillation tower, R is a C17-C17 extractive side-C17 extractive distillation tower, and an extraction tower is provided with a C17-C17 extraction tower side-17, and an extraction tower side-17 extraction tower, two extraction tower side-17 extraction tower, y is a side stripper, and Z is a side stripper.

Detailed Description

In this context, unless otherwise stated, the term "Fischer-Tropsch heavy distillate" means a fraction oil mainly containing C7-C30 in Fischer-Tropsch oils.

Herein, unless otherwise specified, the term "ambient temperature", also referred to as room temperature or ambient temperature, means a temperature in the range of 20 to 35 ℃; the term "atmospheric pressure" means about 1 atmosphere.

In one embodiment, the present invention relates to a process for the preparation of linear surfactants and heavy surfactants using fischer-tropsch synthesized heavy distillate, wherein the process comprises the steps of:

(1) cutting fraction of Fischer-Tropsch synthesis heavy distillate to obtain C10^-A fraction section, a crude C10-C13 fraction section, a crude C14-C17 fraction section and C17⁺Fractionating;

(2) mixing the crude C10-C13 fraction segment and the crude C14-C17 fraction segment with alkali respectively to obtain corresponding mixtures, stirring the mixtures respectively, filtering and separating the mixtures respectively to remove alkali residues to obtain liquid phases, and washing the liquid phases with water respectively to obtain a primarily treated C10-C13 fraction segment and a primarily treated C14-C17 fraction segment;

(3) rectifying the preliminarily treated C10-C13 fraction segment and the preliminarily treated C14-C17 fraction segment respectively to obtain C10-C13 fraction hydrocarbon and C14-C17 fraction hydrocarbon; and

(4) respectively alkylating the C10-C13 fraction hydrocarbon and the C14-C17 fraction hydrocarbon to obtain the linear surfactant and the heavy surfactant.

In a preferred embodiment, in the step (1), the fischer-tropsch synthesis heavy fraction oil is cut using any one of the cutting towers selected from the group consisting of: (a) an atmospheric tower, a vacuum tower 1 and a vacuum tower 2; (b) a vacuum tower 1' + a vacuum tower 2' + a vacuum tower 3 '; (c) an atmospheric fractionating tower and/or a vacuum fractionating tower provided with two side stripping towers; and (d) a divided wall column.

In a further preferred embodiment, in the step (1), the temperature of the fischer-tropsch synthesis heavy fraction oil is raised to 100 to 200 ℃, preferably 100 to 150 ℃ before the cut is performed.

In a further preferred embodiment, in the step (1), the fischer-tropsch synthesis heavy fraction oil is cut by using an atmospheric tower + a vacuum tower 1+ a vacuum tower 2, preferably, the number of theoretical plates of the atmospheric tower (also referred to as "atmospheric light-ends removal tower" herein) is 20 to 40, preferably 25 to 30, the tower top temperature is 120 to 160 ℃, preferably 150 to 160 ℃, the tower bottom temperature is 210 to 260 ℃, preferably 240 to 250 ℃, and the operating pressure is 0.1 to 0.2mpa (a), preferably 0.10 to 0.15mpa (a); the decompression tower 1 (also referred to as a decompression C10-C13 cutting tower) has the theoretical plate number of 20-50, preferably 25-35, the tower top temperature of 140-180 ℃, preferably 155-165 ℃, the tower bottom temperature of 220-280 ℃, preferably 230-250 ℃, and the operating pressure of 0.015-0.040 MPa (A), preferably 0.020-0.030 MPa (A); the decompression column 2 (also referred to herein as a "decompression C14-C17 cut column") has a theoretical plate number of 20-50, preferably 20-30, a top temperature of 150-210 ℃, preferably 200-210 ℃, a bottom temperature of 220-280 ℃, preferably 270-280 ℃, and an operating pressure of 0.005-0.03 MPa (A), preferably 0.010-0.020 MPa (A).

In a further preferred embodiment, in the step (1) above, the fischer-tropsch synthesis heavy distillate is cut with a divided wall column, preferably operating conditions of the divided wall column are: the temperature of the top of the main tower is 100-200 ℃, preferably 140-160 ℃ (for example 150 ℃), the temperature of the bottom of the tower is 200-300 ℃, preferably 250-280 ℃ (for example 270 ℃), the operating pressure is 0.005-0.025 MPa (A), preferably 0.01-0.02 MPa (A) (for example 0.015MPa (A)), the number of theoretical plates of a common rectification section is 10-20 (for example 15), the number of theoretical plates of a common stripping section is 5-15 (for example 8), the number of plates of a side line extraction section is 20-30 (for example 25), and the number of plates of a pre-rectification section is 20-30 (for example 25).

In a further preferred embodiment, in the step (1), the fischer-tropsch synthesis heavy distillate oil is cut by a vacuum tower 1 '+ a vacuum tower 2' + a vacuum tower 3', preferably, the theoretical plate number of the vacuum tower 1' is 20 to 40, preferably 25 to 30 (for example, 28), the tower top temperature is 80 to 180 ℃, preferably 100 to 150 ℃ (for example 120 ℃), the tower bottom temperature is 150 to 300 ℃, preferably 180 to 250 ℃ (for example 200 ℃), and the operation pressure is 0.015 to 0.05mpa (a); the number of theoretical plates of the decompression tower 2' is 20-50, preferably 25-35, the temperature at the top of the tower is 140-180 ℃, preferably 155-165 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 230-250 ℃, and the operating pressure is 0.015-0.040 MPa (A), preferably 0.020-0.030 MPa (A); the number of theoretical plates of the decompression tower 3' is 20-50, preferably 20-30, the temperature at the top of the tower is 150-210 ℃, preferably 200-210 ℃, the temperature at the bottom of the tower is 220-280 ℃, preferably 270-280 ℃, and the operating pressure is 0.005-0.03 MPa (A), preferably 0.010-0.020 MPa (A).

In a further preferred embodiment, in the step (1), the fischer-tropsch synthesis heavy fraction oil is cut by using an atmospheric fractionating tower and/or a vacuum fractionating tower provided with two side strippers, and preferably, the fischer-tropsch synthesis heavy fraction oil is cut by using a vacuum fractionating tower provided with two side strippers. Further preferably, the number of theoretical plates of the vacuum fractionation column is 20 to 60, preferably 30 to 50 (e.g., 40), the column top temperature is 80 to 110 ℃, preferably 90 to 100 ℃ (e.g., 95 ℃), the column bottom temperature is 250 ℃ to 300 ℃, preferably 260 to 280 ℃ (e.g., 270 ℃), and the operating pressure is 0.005 to 0.025MPa (A), preferably 0.01 to 0.02MPa (A) (e.g., 0.015MPa (A)); the number of theoretical plates of the side stripper is 10 to 30, preferably 15 to 25 (e.g., 20), and the number of theoretical plates of the two side strippers may be the same or different.

The C10-C13 fraction and the C14-C17 fraction obtained by cutting the Fischer-Tropsch synthesis heavy distillate oil contain olefin, alkane, organic acid and other organic oxygen-containing compounds. The present inventors have noticed that organic acids cause corrosion of equipment and therefore need to be removed as early as possible. In view of this consideration, the present inventors have specifically designed the flow scheme of the process of the present invention so that the organic acids and a part of other organic oxygen-containing compounds in the C10 to C13 fraction and the C14 to C17 fraction are removed in the (2) th step of the production process of the present invention.

In a preferred embodiment, in the step (2) above, the base is one of sodium hydroxide, potassium hydroxide and sodium carbonate or any combination thereof.

In a preferred embodiment, in the step (2), the mixture is stirred at a rotation speed of 10 to 100r/min at 30 to 60 ℃, for example, at 50r/min at 40 ℃.

In a preferred embodiment, in the step (2), a 5-20 micron filter screen, for example, a 10 micron filter screen is used for the filtration separation.

In a preferred embodiment, in the step (2), the water washing is performed with 0.2 to 0.8 times the volume of the liquid phase. In the step (2), the liquid phases are washed with water in the respective corresponding water washing towers.

It should be noted that the caustic washing operations of the crude C10-C13 fraction and the crude C14-C17 fraction are carried out spatially separately (either simultaneously or not), and the conditions of the caustic washing operations of the two simultaneously carried out may be the same or different. Likewise, the washing operations of the liquid phases obtained from the two are also carried out spatially separated (either simultaneously or not), and the conditions of the washing operations of the liquid phases carried out simultaneously may be identical or different.

In the above step (3), the rectification is performed in order to remove the remaining oxygen-containing compounds. In a preferred embodiment, the rectification is azeotropic rectification or extractive rectification.

In a preferred embodiment, the azeotropic distillation may employ a homogeneous azeotropic distillation process or a heterogeneous azeotropic distillation process. When a homogeneous azeotropic distillation process is adopted, 75-99.9 wt%, preferably 90-96 wt% of ethanol is selected as an entrainer; the solvent ratio of the entrainer, in terms of the mass ratio of ethanol to the raw material in the entrainer, is 1 to 8, for example 2. When a heterogeneous azeotropic distillation process is adopted, a binary mixed solvent of ethanol and water is selected as an entrainer, wherein the mass concentration of the ethanol is 60-94%, preferably 80-90% (such as 86%); the azeotropic distillation solvent ratio is 0.5 to 5, preferably 1 to 2 (for example, 1.5) in terms of the mass ratio of the ethanol to the raw material in the azeotropic agent.

In a further preferred embodiment, the azeotropic distillation comprises the steps of: enabling the preliminarily treated C10-C13 fraction and the preliminarily treated C14-C17 fraction to respectively enter respective azeotropic distillation towers, and respectively generating azeotropes at the tops of the azeotropic distillation towers; cooling the azeotrope, and then respectively entering respective tower top liquid separation tanks for standing and layering to obtain an oil phase; and respectively feeding the oil phases into an entrainer recovery stripping tower, and respectively obtaining C10-C13 fraction hydrocarbons and C14-C17 fraction hydrocarbons at the bottom of the entrainer recovery stripping tower. In a still further preferred embodiment, further comprising withdrawing oxygenate from the bottom of the azeotropic distillation column. In another preferred embodiment, the azeotropic agent is supplemented into the aqueous phase obtained by standing and layering in the tower top liquid separating tank, and then the aqueous phase is returned to the azeotropic distillation tower for recycling. In yet a further preferred embodiment, the number of theoretical plates of the azeotropic distillation column is 20 to 40, preferably 20 to 30 (e.g., 26).

In a preferred embodiment, the extractive distillation is carried out in an atmospheric distillation column; preferably, the theoretical plate number of the atmospheric distillation tower is 50-70 (such as 60) and the reflux ratio is 5-15 (such as 10).

In a preferred embodiment, the extractive distillation comprises the steps of: feeding the primarily treated C10-C13 fraction segment and the primarily treated C14-C17 fraction segment into respective extractive distillation columns as feed streams; adding an extracting agent into the extractive distillation column, wherein the volume flow ratio of the extracting agent to the feed material flow is 0.5-5: 1, preferably 0.5-2: 1 (such as 1: 1); respectively producing C10-C13 fraction hydrocarbon and C14-C17 fraction hydrocarbon at the top of the extractive distillation tower. Further preferably, the material flows generated at the bottom and the bottom of the extractive distillation tower enter an extractant recovery tower for treatment, and a regenerated extractant material flow is obtained at the bottom of the extractant recovery tower.

In a preferred embodiment, the extractive distillation is carried out with one or more extractants selected from the group consisting of: ethylene glycol, dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide, preferably N-methylpyrrolidone.

It should be noted that the rectification (i.e., azeotropic rectification and/or extractive rectification) of the preliminary treated C10-C13 fraction and the preliminary treated C14-C17 fraction is carried out spatially separately (either simultaneously or not), and the rectification conditions for the two simultaneously carried out may be the same or different.

In a preferred embodiment, in the above step (4), the alkylation is any one selected from HF alkylation and fractional alkylation; preferably, HF alkylation.

In a preferred embodiment, the alkylation is HF alkylation, operating conditions of which are: the ratio of the benzene to the olefin is 5-12: 1, preferably 8-10: 1, the reaction temperature is 30-50 ℃, preferably 35-40 ℃ (for example 38 ℃), the reaction pressure is 0.5-2 MPaG, preferably 0.5-1 MPaG (for example 0.8MPaG), and the volume ratio of HF to hydrocarbon is (1.0-2.5): 1, preferably (1.5-2.0): 1 (for example 1.8: 1).

In a preferred embodiment, the alkylation is a digital alkylation, the operating conditions of the digital alkylation being: the benzene-olefin ratio is (10-20): 1, preferably 12-18: 1, the reaction temperature is 100-180 ℃, preferably 140-160 ℃, the reaction pressure is 2.5-4.0 MPaG, preferably 3.0-4.0 MPaG, and the catalyst can be a Lewis acid catalyst taking synthetic zeolite as a carrier, such as a silicon-aluminum fluoride catalyst, a SiO silicon catalyst and the like₂-Al₂O₃A solid acid catalyst.

It should be noted that the alkylation of the C10-C13 fraction and the C14-C17 fraction is carried out spatially separately (either simultaneously or not), and that the type of alkylation of both simultaneously carried out may be the same or different, for example, the C10-C13 fraction is alkylated with HF and the C14-C17 fraction is alkylated with Deltal.

In a preferred embodiment, C10 is^-The distillate is sent to a hydrofining unit for refining treatment.

In a preferred embodiment, C17 is⁺The distillate is sent to a hydrofining unit for refining treatment.

The linear chain surfactant and the heavy surfactant prepared by the Fischer-Tropsch synthesis heavy distillate oil by the preparation method can meet the following performance index requirements:

table 1: main performance index of linear surfactant

Table 2: main performance index of heavy surfactant

In one embodiment, the present invention relates to a system for implementing the above method of the present invention, wherein the system comprises:

a cutting tower;

a caustic wash tank connected in fluid communication to the cutter tower;

a filter connected in fluid communication to the caustic wash tank;

a water wash column connected in fluid communication to the filter;

a rectification unit connected in fluid communication to the water wash column; and

an alkylation unit coupled in fluid communication to the rectification column.

In a preferred embodiment, the cutting tower is any one selected from the group consisting of: (a) an atmospheric tower, a vacuum tower 1 and a vacuum tower 2; (b) a vacuum tower 1' + a vacuum tower 2' + a vacuum tower 3 '; (c) an atmospheric fractionating tower and/or a vacuum fractionating tower provided with two side stripping towers; and (d) a divided wall column.

In a further preferred embodiment, the number of theoretical plates of the atmospheric tower is 20 to 40, preferably 25 to 30; the number of theoretical plates of the decompression tower 1 is 20-50, preferably 25-35; the number of theoretical plates of the decompression tower 2 is 20-50, preferably 20-30.

In a further preferred embodiment, the number of theoretical plates of the vacuum column 1' is 20 to 40, preferably 25 to 30; the theoretical plate number of the decompression tower 2' is 20-50, preferably 25-35; the number of theoretical plates of the decompression tower 3' is 20-50, preferably 20-30.

In a further preferred embodiment, the number of theoretical plates of the vacuum fractionation tower provided with two side strippers is 20 to 60, preferably 30 to 50; the number of theoretical plates of the side stripping towers is 10-30, preferably 15-25, and the number of the theoretical plates of the two side stripping towers can be the same or different.

In a further preferred embodiment, the divided wall column comprises the following sections: a pre-fractionation section, a common rectification section, a common stripping section and a side draw section. Preferably, the number of the pre-distillation section trays is 20-30, the number of the public distillation section theoretical plates is 10-20, the number of the public stripping section theoretical plates is 5-15, and the number of the side line extraction section trays is 20-30.

In a preferred embodiment, the rectification unit comprises an azeotropic rectification column or an extractive rectification column. In a further preferred embodiment, the rectification unit is any one selected from the group consisting of: the azeotropic distillation tower comprises (1) an azeotropic distillation tower, an azeotropic distillation tower top liquid separation tank and an azeotropic agent recovery stripping tower which are connected in a fluid communication mode; or (2) an extractive distillation column and an extractant recovery column connected in fluid communication.

By placing the caustic wash tank downstream of the cutter tower, organic acids that can cause corrosion to the system can be removed as early as possible.

The process of the present invention is further described below with reference to fig. 1-4, but the scope of the present invention is not limited thereto.