The long-term plan for the economic development of the country provided extensive development of petrochemical synthesis.
In this regard, it becomes necessary to increase the production of highly liquid paraffin feedstock for petrochemical synthesis purity [1, p. 32]. As you know, in the process of dewaxing fuel alcohol-aqueous urea solution to the gravitational phase separation obtained with paraffin content of aromatic hydrocarbons of not more than 0.5% (mass) that meets the requirements of technical specifications for production of paraffin for BVK. For these paraffins dewaxed product after separation of the complex is washed with a light fraction boiling end temperature of 180-200 °C. Upon decomposition of the complex the remainder of the extraction fraction passes into paraffins. It is separated from the paraffins by distillation, while it is carried away with an easy portion of the paraffins. As a result, the potential output target paraffins-aromatics 0.5% significantly reduced [2, p. 46]. Therefore, an important factor affecting the desired purity paraffins, are conditions for extraction of the remainder of the fuel out of the complex.
The purpose of this study – to develop a method to increase the yield potential of normal paraffins urea dewaxing of diesel fractions little paraffin Amangeldy gas condensate and oil from the Kumkol high paraffin.
First and foremost it was selected conditions of complexation to ensure complete extraction of deparaffin fraction of normal paraffins.
Reduction of losses paraffins intended to achieve an increase in the gap between the end of the boiling temperatures of the wash fraction and the initial boiling deparaffin product. Diesel fractions from raw samples were prepared, differing initial boiling point (Tab. 1).
The study was conducted on the diesel cloud point fractions obtained from a mixture of paraffins and little field condensate and highly Amangeldi Kumkol paraffin oils containing hydrocarbons complexing respectively 15-17 and 34-37% (wt) they varied from 4 to 14 °C, and the temperature pour point of -1 to -18 °C.
Table 1
Fractions of petroleum |
|||||||
Indicators |
of little paraffin Amangeldy gas condensate |
of high paraffin Kumkol oil |
|||||
180-350°С |
200-350oС |
220-350°С |
240-350оС |
180-350°С |
200-350°С |
230-350°С |
|
Density |
0.8250 |
0.8279 |
0.8305 |
0.8322 |
0.8065 |
0.8075 |
0.8160 |
Fractional composition, ° C | |||||||
b. b. |
182 |
198 |
224 |
239 |
178 |
203 |
231 |
10% |
217 |
225 |
240 |
251 |
205 |
226 |
252 |
50% |
258 |
263 |
268 |
271 |
271 |
263 |
284 |
90% |
316 |
312 |
315 |
315 |
333 |
320 |
337 |
95% |
327 |
329 |
335 |
332 |
343 |
345 |
346 |
k. k. |
345 |
343 |
346 |
347 |
348 |
352 |
352 |
Viscosity at 20 °С, mm2/с |
3.62 |
4.05 |
4.6 |
5.08 |
3.82 |
4.0 |
5.53 |
Temperature, ° C | |||||||
cloud |
-14 |
-12 |
-10 |
-9,5 |
-1 |
0 |
+4 |
pour |
-18 |
-16 |
-14 |
-12,5 |
-5 |
-4 |
-1 |
flash
(Closed Cup) |
70 |
78 |
96 |
105 |
70 |
80 |
90 |
Complexing hydrocarbon content,% (wt.) |
15.1 |
15.8 |
16.3 |
16.96 |
34,1 |
36,6 |
37,1 |
To each mixture were chosen dewaxing conditions. Depending on the fractional composition of the product deparafiniruemogo chelation reaction was performed under the following conditions: urea solution saturation temperature – 50-55 ° C; ratio of hydrocarbon solutions of urea and – from 2.5: 1 to 4.5: 1 (by volume); complexation temperature – 60-30 ° C; contacting duration – 40 minutes, the last 10 min – holding at final temperature (30 ° C); stirrer speed – 1200 rev / min. In these circumstances provided a complete extraction of n-paraffins – the content of complexing dewaxed hydrocarbon fractions equal to zero (Tab.2), Cloud point – below -35 ° C, pour point – below -65 ° C.
When used as a starting material diesel fuel fractions with different initial boiling point of the potential yield of paraffins (content in the feed hydrocarbons complexing) changes (Tab. 3).
Table 2
Indicators |
Fractions of oil |
||||||
of little paraffinAmangeldy gas condensate |
of high paraffin Kumkol oil |
||||||
180-350°С |
200-350°С |
220-350°С |
240-350°С |
180-350°С |
200-350°С |
230-350°С |
|
Density |
0,8431 |
0,8357 |
0,8379 |
0,8414 |
0,8286 |
0,8295 |
0,8367 |
Fractional composition, ° C | |||||||
b. b. |
182 |
198 |
224 |
237 |
180 |
206 |
232 |
10% |
215 |
222 |
236 |
249 . |
201 |
224 |
252 |
50% |
257 |
261 |
268 |
270 |
265 |
263 |
291 |
90% |
315 |
309 |
312 |
324 |
331 |
329 |
341 |
95% |
323 |
327 |
333 |
333 |
340 |
345 |
349 |
k. k. |
342 |
341 |
342 |
343 |
345 |
352 |
353 |
Viscosity at 20 °С, mm2/с° |
3,72 |
4,12 |
4,87 |
5,22 |
4,06 |
4,16 |
6,97 |
Temperature, ° C | |||||||
cloud |
<-35 |
<-35 |
<-35 |
<-35 |
<-35 |
<-35 |
<-35 |
pour |
<-65 |
<-65 |
<-65 |
<-65 |
<-65 |
<-65 |
<-65 |
Complexing hydrocarbon content,% (wt.) |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Table 3
Indicators |
Paraffin faction |
|||
of little paraffinAmangeldy gas condensate |
of high paraffin Kumkol oil |
|||
180-350°С |
240-350°С |
180-350°С |
230-350°С |
|
Density |
0,7739 |
0,7749 |
0,7781 |
0,7798 |
Fractional composition, ° C | ||||
b. b. |
241 |
246 |
242 |
244 |
10% |
253 |
257 |
254 |
257 |
50% |
274 |
277 |
289 |
291 |
90% |
320 |
320 |
335 |
338 |
95% |
335 |
331 |
338 |
346 |
к. к. |
343 |
343 |
346 |
348 |
Temperature, ° C | ||||
crystallization |
13 |
13 |
18 |
20 |
pour |
11,5 |
11,5 |
17 |
17 |
Aromaticcontent,% (wt.) |
0,53 |
0,52 |
0,4 |
0,44 |
Out of the potential,% (wt.) |
74,1 |
86,7 |
80,0 |
87,0 |
Content,%
paraffins |
1,13 |
1,88 |
0,8 |
1,65 |
Table 4
The fractions, which were included in the compound |
Yield winter diesel fuel (wt.%) of raw materials |
|
of little paraffin Amangeldy gas condensate |
of high paraffin Kumkol oil |
|
Initialfuel |
79,7 |
64,4 |
180-200°С |
80,1 |
65,35 |
200-350°С |
82,4 |
- |
180-220°С |
- |
67,5 |
220-350°С |
83,7 |
- |
Thus, when dewaxing complexing fractions containing hydrocarbons 14-17% (wt), with an increase in their boiling onset temperature of 180 to 240 ° C on the potential yield of paraffins is increased from 74.1 to 86.7% of the fractions containing hydrocarbons complexing paraffin 34-37% yield is increased from 80 to 87% (wt). Despite the rise in temperature starts boiling products deparafiniruemyh 50-60 ° C, the characteristics obtained are similar paraffins. This is due, as stated, together with the stripping wash fraction dewaxing fractions with initial boiling point lower portion of light paraffins.
In the common, to increase the yield of the desired paraffin oil dewaxing process in alcoholic-aqueous solution of urea as the starting product is advisable to use a fraction with initial boiling point 230-240 ° C. This will increase the yield of paraffins and decrease in raw material amount of intermediate fraction obtained during the distillation of the wash fraction paraffins. However, when dewaxing dewaxed fuel fractions yield decreases with high initial boiling point, and its fractional composition does not meet the necessary requirements.
We have studied the possibility of dewaxed product that meets the requirements of state standard on diesel fuel, by compounding the dewaxed high-boiling component with a light fuel fraction, which has not been subjected to dewaxing.
Data output winter diesel fuels after compounding are presented in Table 4. As can be seen, after compounding with the light fraction dewaxed product yield winter diesel fuel that meets the requirements of state standard increases.
The proposed version of the dewaxing has the following advantages: increased yield of liquid paraffin (the potential for the capture of raw materials); increased yield of winter diesel fuel; reduces the number of intermediate fractions. The possibility of increasing the yield of normal alkanes from potential content deparafiniruemom raw materials with a simultaneous increase in output of winter diesel fuel.
References
- Tanashev S.T., Shalataev S.Sh., Iskendirov B.J., Karabaev J.A., Intensification of atmospheric-vacuum distillation of Kumkol oil. NPK. Ufim State University of Economics and servis. Innovational development of science-Russia-2013 .-. Ufa.
- Kapustin V.M., Basics of design of oil refining and petrochemical enterprises. Russian State University of Oil and Gas. I.M.Gubkina.- M .: Chemistry, 2012.- 440 p.
- Kapustin V.M., Rudin M.G., Chemistry and technology of oil refining. M .: Chemistry, 2013.-496р.
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