The present invention relates to a normal paraffin composition and a process to prepare the normal paraffin composition.
Normal paraffins may be obtained by various processes. EP2655565 disclose a method for deriving paraffins from crude oil. Also, paraffins may be obtained using the so called Fischer-Tropsch process. An example of such process is disclosed in WO2014095814 and WO2016107864.
WO2016107864 discloses a process to prepare paraffins and waxes. In WO2016107864 a Fischer-Tropsch product stream comprising paraffins having from 10 to 300 carbon atoms is subjected to a hydrogenation step followed by separation of the hydrogenated Fischer-Tropsch product to obtain at least a fraction comprising 10 to 17 carbon atoms.
A problem of the process disclosed in WO2016107864 is that the hydrocarbon chain length distribution of the normal paraffin composition fraction comprising 10 to 17 carbon is such that the ratio between fraction having from 10 to 13 carbon atoms and the fraction of normal paraffin having from 14 to 17 carbon atoms in the normal paraffin composition is about 1. The fraction of normal paraffins having from 14 to 17 carbon atoms, however, is a less favorable product than the fraction of normal paraffin having from 10 to 13 carbon atoms. The demand for linear alkyl benzene sulphonate (LAS) comprising the normal paraffin fraction having from 10 to 13 carbon atoms is much higher than the demand for paraffin sulphonates and chloroparaffins, both comprising the normal paraffin fraction having from 14 to 17 carbon atoms.
It is an object of the invention to solve or minimize at least one of the above problems. It is a further object of the present invention to provide a normal paraffin composition which can be advantageously used in the manufacture of linear alkyl benzene (LAB), an intermediate for the production of LAS, the most widely used surfactants in the detergent industry.
Moreover, an object of the present invention is to provide an a more efficient and simple method to prepare normal paraffins having a higher amount of the fraction comprising 10 to 13 carbon atoms on a smaller scale.
One of the above or other objects may be achieved according to the present invention by providing a normal paraffin composition comprising from 45 to 60 wt. % of a fraction of normal paraffin having from 10 to 13 carbon atoms and from 40 to 55 wt. % of a fraction of normal paraffin having from 14 to 18 carbon atoms.
It has been found according to the present invention that the normal paraffin composition may be advantageously used for the production of surfactants in the detergent industry.
In another embodiment of the present invention there is provided a process to prepare normal paraffin compositions.
An advantage of the process according to the present invention is that the process line-up has been simplified and that there is less risk of corrosion of the distillation columns, heat exchanger and additional equipment.
A further advantage is that by selecting the light wax stream the equipment size gets smaller and the separation easier. In this way the production of normal paraffins is also attractive on smaller scale. Yet a further advantage is that less energy is required for the heating and distillation.
Another advantage is that the composition of the normal paraffins can be influenced such that the normal paraffins composition will be lighter because the heavier molecules reside in the heavy wax.
The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.
According to the present invention, a normal paraffin composition comprises from 45 to 60 wt. % of a fraction of normal paraffin having from 10 to 13 carbon atoms and from 40 to 55 wt. % of a fraction of normal paraffin having from 14 to 18 carbon atoms.
Normal paraffin compositions are known and described for example in WO2014095814 and WO2016107864.
Suitably, the normal paraffin composition according to the present invention comprises 49 wt. % of the fraction of normal paraffin having from 10 to 13 carbon atoms and 51 wt. % of a fraction of normal paraffin having from 14 to 18 carbon atoms based on the total amount of the normal paraffin composition.
Preferably, the normal paraffin composition according to the present invention comprises a fraction of normal paraffin having from 10 to 13 carbon atoms comprises 10 carbon atoms in the range of from 10 to 11 wt. %, 11 carbon atoms in the range of from 30 to 32 wt. %, 12 carbon atoms in a range of from 30 to 32 wt. % and 13 carbon atoms in a range of from 23 to 26 wt. % based on the amount of the normal paraffin having from 10 to 13 carbon atoms.
Also, the normal paraffin composition according to the present invention comprises the fraction of normal paraffin having from 14 to 18 carbon atoms comprises 14 carbon atoms in a range of from 25 to 27 wt. %, 15 carbon atoms in a range of from 24 to 26 wt. %, 16 carbon atoms in a range of from 22 to 23 wt. %, 17 carbon atoms in a range of from 18 to 20 wt. % and 18 carbon atoms in a range of from 4 to 6 wt. % based on the amount of the normal paraffin having from 14 to 18 carbon atoms.
It is preferred that the normal paraffin composition according to the present invention is a Fischer-Tropsch derived normal paraffin composition.
The Fischer-Tropsch derived normal paraffin composition is derived from a Fischer-Tropsch process. Fischer-Tropsch product stream is known in the art. By the term “Fischer-Tropsch derived” is meant a paraffin wax is, or is derived from a Fischer-Tropsch process. A Fischer-Tropsch derived normal paraffin composition may also be referred to a GTL (Gas-to-Liquids) product. An example of a Fischer-Tropsch process is given in WO2002/102941, EP 1 498 469 and WO2004/009739, the teaching of which is incorporated by reference.
The Fischer-Tropsch derived normal paraffin composition comprises paraffins, primarily n-paraffins. Preferably, the Fischer-Tropsch derived normal paraffin composition comprises more than 85 wt. % of n-paraffins, preferably more than 90 wt. % of n-paraffins.
In a further aspect, the present invention provides a process to prepare a Fischer-Tropsch derived normal paraffin composition, the process at least comprising the following steps:
The normal paraffin comprising from 10 to 13 carbon atoms is also known as light detergent fraction (LDF) and the normal paraffin comprising from 14 to 18 carbon atoms is also known as heavy detergent fraction (HDF).
Preferably, the normal paraffin fraction comprising 10 to 13 carbon atoms has a flashpoint according to ASTM D93 between 70 and 80° C., more preferably between 70 and 75° C. and most preferably a flashpoint of 74° C. Also the kinematic viscosity according to ASTM D445 of the normal paraffin fraction comprising 10 to 13 carbon atoms at 40° C. is between 1.30 and 1.45 cSt, preferably between 1.30 and 1.40 cSt, most preferably the kinematic viscosity at 40° C. of LDF is 1.36 cSt.
The pour point of the normal paraffin fraction comprising 10 to 13 carbon atoms according to ASTM D97 is below 0° C., preferably below −15° C., more preferably below −20° C. and most preferably below −21° C.
The density of the normal paraffin fraction comprising 10 to 13 carbon atoms according to ASTM D1298 is between 700 and 800 kg/m3, preferably between 700 and 750 kg/m3.
Preferably, the normal paraffin fraction comprising 14 to 18 carbon atoms has a flashpoint between 100 and 130° C., more preferably between 110 and 125° C. and most preferably a flashpoint of 122° C. Also the kinematic viscosity of the normal paraffin fraction comprising 14 to 18 carbon atoms according to ASTM D445 at 40° C. is between 2.00 and 3.00 cSt, preferably between 2.50 and 2.70 cSt, most preferably the kinematic viscosity at 40° C. of the normal paraffin fraction comprising 14 to 18 carbon atoms is 2.66 cSt.
The pour point of the normal paraffin fraction comprising 14 to 18 carbon atoms according to ASTM D97 is below 20° C., preferably below 15° C., more preferably below 12° C.
The density of the normal paraffin fraction comprising 14 to 18 carbon atoms according to ASTM D1298 is between 700 and 800 kg/m3, preferably between 750 and 780 kg/m3.
Suitably, the normal paraffin fraction comprising 10 to 13 carbon atoms has a flashpoint between 70 and 80° C., a kinematic viscosity according to ASTM D445 at 40° C. between 1.30 and 1.45 cSt, a pour point according to ASTM D97 below −21° C., and a density according to ASTM D1298 between 700 and 800 kg/m3.
In addition, the normal paraffin fraction comprising 14 to 18 carbon atoms has a flashpoint between 100 and 130° C., a kinematic viscosity according to ASTM D445 at 40° C. between 2.00 and 3.00 cSt, a pour point according to ASTM D97 is below 12° C., and a density according to ASTM D1298 between 700 and 800 kg/m3.
In another aspect, the present invention provides a process to prepare linear alkyl-benzene sulphonate using a normal paraffin fraction comprising 10 to 13 carbon atoms as obtained according to the process of the present invention.
For the purpose of this description, a single reference number will be assigned to a line as well as a stream carried in that line.
The process scheme is generally referred to with reference numeral 1.
In a Fischer-Tropsch process reactor 2 a Fischer-Tropsch product stream is obtained. Separation into a first gaseous hydrocarbon stream 10 and a first liquid fraction 20 is accomplished in the reactor itself.
The gaseous hydrocarbon stream 10 is fed to a cooling unit 3 wherein the gaseous hydrocarbon stream is cooled and separated to obtain a second gaseous hydrocarbon stream 30 and a second liquid fraction 40. The gaseous hydrocarbon stream 30 is fed to another cooling unit 4 wherein the gaseous hydrocarbon stream 30 is cooled and separated to obtain a third gaseous hydrocarbon stream 50 and a third liquid fraction 60. The second liquid fraction 40 and the third liquid fraction 60 are fed to a hydrogenation reactor 5 to obtain a hydrogenated liquid hydrocarbon stream 70. The hydrogenated liquid hydrocarbon stream 70 is distilled in one or more atmospheric distillation columns 6 to recover a hydrogenated normal paraffin fraction 80 comprising 5 to 9 carbon atoms, a fraction 90 comprising 10 to 13 carbon atoms, a fraction 100 comprising 14 to 18 carbon atoms and a fraction 110 comprising 19 to 35 carbon atoms.
The invention is illustrated by the following non-limiting examples.
The invention is illustrated by the following non-limiting examples.
Product Distribution of the First, Second and Third Liquid Hydrocarbon Streams
In Table 1 the flows of molecules with indicated chain length in three liquid hydrocarbon streams is given, with full distribution of the streams depicted in
Process to Prepare Normal Paraffins
In the comparative example 2 all the liquid hydrocarbon streams are combined and after hydrogenation used for the production of normal paraffins. The case according to the invention is represented by example 3. In Table 2 the total size of the hydrocarbon streams is indicated as well as the split in C10−, target range of normal paraffins and C18+. Comparison of example 3 (according to the invention) with comparative example 2 it can be seen that the paraffin total yields were only 16% lower. However, for the comparative example the amount of feed could be reduced with as much as 76%. This enables to build the Hydrogenation Reactor and it's surrounding equipment 4 times smaller. This brings a very significant reduction in cost to build the equipment and is combined with lower energy consumption for operation. On top of that, the very low amount of heavier hydrocarbons in example 3 enables to do the final distillation at atmospheric conditions, whereas an expensive vacuum distillation operation in combination with an atmospheric distillation (to remove the lighter components) is required for the comparative example. Hence the situation as per invention in example 2 is much more attractive as the expensive vacuum distillation that requires high energy loads, could be eliminated.
Process to Prepare C10 to 13 and C14 to 18 Normal Paraffins
The recovered paraffins will need further distillation to meet the product specification of the lighter C10-C13 normal paraffins and C14-C18 normal paraffins final products. The resulting compositions are given in Table 3 and Table 4. It can be seen that the compositions according to the invention are lighter compared to the comparative example.
In Table 5 the normal paraffin final product weight fractions are given. It can be seen that in example 3 according to the invention almost the same amount of LDF is obtained, with a lower amount of HDF. The LDF content out of the NP products increases hence from 44 to 49%.
It is advantaged to have a larger amount of LDF, because this stream can be used very well for the production of LAB. The NP consumption for LAB production is significant and the NP has a good premium compared to kerosene.
Number | Date | Country | Kind |
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16197552.9 | Nov 2016 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2017/077996 | 11/2/2017 | WO | 00 |