Химия и химические технологии / 6.Органическая химия.

Tanashev S.T., Karabaev Zh.A., Musakhanov O.M.

M.Auezov South Kazakhstan State University, Kazakhstan

Production of winter diesel fuel from a mixture of little paraffin amangeldy gascondensate and high paraffin kumkol oil

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, 2].

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 [3]. 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 (Table 1).

The study was conducted on the diesel cloud point fractions obtained from a mixture of paraffins and little field Amangeldy gas condensate and highly paraffin Kumkol oil’s 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 oil
Indicators	of little paraffin Amangeldy gas condensate				of high paraffin Kumkol oil
	180-350°С	200-350^oС	220-350°С	240-350^оС	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. s.	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
b. e.	345	343	346	347	348	352	352
Viscosity at 20 °С, mm^2/s	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 de waxy 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 (Table 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 (Table 3).

Table 2

Indicators	Fractions of oil
	of little paraffin Amangeldy 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. s.	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
b. e.	342	341	342	343	345	352	353
Viscosity at 20 °С, mm^2/s	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	Paraffins from fraction
	of little paraffin Amangeldy 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. s.	241	246	242	244
10%	253	257	254	257
50%	274	277	289	291
90%	320	320	335	338
95%	335	331	338	346
b. e.	343	343	346	348
Temperature, ° C
crystallization	13	13	18	20
pour	11,5	11,5	17	17
Aromatic content, % (wt.)	0.53	0.52	0.4	0.44
Out of the potential, % (wt.)	74.1	86.7	80.0	87.0
Content paraffin hydrocarbons,%	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
Initial fuel	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 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 de waxy 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 de waxe raw materials with a simultaneous increase in output of winter diesel fuel.

References

1. Tanashev S.T., Shalataev S.Sh., Iskendirov B.J., Karabaev Zh.A. Intensification of process atmospheric and vacuum distillation Kumkol oil // NPK. Ufim State University of Economics and servis. Innovational development of science. – Russia, Ufa, 2013. – P. 32-33.

2. Kapustin V.M. Basis of design refineries and petrochemical plants. Russian State University of Oil and Gas. I.M. Gubkin.- M.: Chemistry, 2012.- 440 p.

3. Kapustin V.M., Rudin M.G., Chemistry and oil refining technology. -M.: Chemistry, 2013.-496 р.