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Eshmetov Rasulbek Jumyazovich, Junior researcher scientist, Institute of General and Inorganic Chemistry of the Academy of Sciences of the Republic of Uzbekistan 77-a Mirzo Uiugbek str. 100170, Tashkent, Uzbekista
E-mail: [email protected] Adizov Bobir Zaripovich, PhD., in techniques, JSC "Uztransgas" Uzbekistan Republic Tashkent, Uzbekistan Salihanova Dilnoza Saidakbarovna, Doctor of Science, Institute of General and Inorganic Chemistry of the Academy of Sciences of the Republic of Uzbekistan
Tashkent, Uzbekistan Eshmetov Izzat Dusimbatovich, Doctor of Science, Institute of General and Inorganic Chemistry of the Academy of Sciences of the Republic of Uzbekistan
Tashkent, Uzbekistan Abdirahimov Saidakbar Abdurakhmanovich, Doctor of Science, professor, Institute of General and Inorganic Chemistry of the Academy of Sciences of the Republic of Uzbekistan
Tashkent, Uzbekistan
SYSTEMATIC ANALYSIS OF PRIMARY PREPARATION PROCESSES OF OIL FOR INDUSTRIAL REFINING
Abstract: In this article the process of initially preparation of oil refining in industry condition was analyzed system. Furthermore, systematic analysis of distillation oil devise (DOD) shows existing process line is insufficient, that is it contents the process of low parameter stability. It is confirmed by indicator of technological system integrity. Hence, development of the basic processes for separation of water and salts off oil in DOD allows increasing considerably technical and economic of operating benefits, as well as quality oil preparation for refining.
Keywords: demulsifier, emulsion, hydrophob, globule, gas condensate, oil, destruction, dehydration, desalination.
Introduction ly is carried out as a water-oil emulsions (WOE),
It is known, in Uzbekistan oil mining main- which subjected to initially preparation into DOD
with various output [1]. Equipments on oil preparation are as typical complex chemical technological systems to develop and optimize necessary application of modern ways of systematic analysis that solved by two stages: first, there are analysed
DOD quality properties, second, there are quantitative ones [2].
The systematic analysis of DOD assumes high rate of summary of studied processes scheme is presented in (Figure 1).
Figure 1. Structural diagram of the processes in DOD
As it is seen from Fig.1 on each level of system- tems namely A, B, C and D presenting in (Fig. 2).
atic analysis there are increased the specification Furthermore, the subsystems can be embodied into
rate. At the same time, correction and refinement different flowsheets differing each other on number of solution accepted previous levels. Flow chart of of elements and their compounds. DOD can be divided into four functional subsys-
Dosage of WOE
D
Degassing
WOE
Oil dehydrate Oil desalination
c B A
►
- _
Oil for processing
Figure 2. Coherence of goal attainment of subsystems in DOD
It is from (Fig. 2). A is oil refining in industrial condition, B is oil desalination, C is oil dehydration, A is degassing water-oil emulsion (WOE).
Thereby, the analysis of technological operation in DOD has shown that some processes can be implemented in two and more.
(Figure 3) illustrates flowsheet of installation for preparation of oil, which functioned as fol-
low [3]: crude oil from well feeds into oil-gas tank C-1 whence it directed to settler O-l. In that case, gas of high and medium pressure from the latter directed into booster compressor station (BCS). From the settler O-1 oil enters the reheating furnace (RF) whence it directed into second settler O-2. Before entering oil on RF it is mexed with demulsifier by block -doser D-1. However, the gas released from O-2 with
medium pressure feeds into BCS. Stratal and bottom water from settlers O-l and 0-2 directed into water-purification (WP) and subsequence into device to keep stratal pressure (SP) then the water flows in the strata. Form settler 0-2 oil feeds into second oil and gas tank C-2 and it can be fed into processing vessel reservoir water-oil suspension (RWOS № l). As a con-
As it is seen from Fig. 3 flowsheet of the equipment in order to prepare oil is compound chemical engineering object is being recirculation lines.
Absolutely, functioning efficiency of present set depends on the oscillation of oil composition, especially oil attendant that stabilize water-oil emulsion formation (pyrobitumen, paraffin, resin, mechanical impurities and etc.).
Yet, in industrial condition there is not possibility for maintenance of all oil attendants that explained continuous ingress of oil from multitude of wells. In addition, changing contents maintained above oil attendants, stratal water and mineral salts significantly impact on efficiency of marketable oil process. If development of DOD supposes some directions
sequence, water separated from the latter flows into drain capacity and then by pump it is directed in WP. After that, oil from reservoir RWOS № 1 enters the second one RWOS № 2, whence the oil via pump station as marketable oil enters in oil refinery (OR). Thus, low-grade oil (LGO) as a recycle returns in the manufacturing locating between O-l and RF.
gas pipeline -►
gaslift wells
commercial oil
at the OU Industrial Plant (OIP)
on improvement assessment of property wholeness (O) of the flowsheet will be important task.
Scientific basis of calculation of wholeness property of the flowsheet was stated in [4].
Evaluation of DOD wholeness consists of figures process stability belonging to the system. In that case, stable and "narrow" processes are revealed insufficiently that can be developed, intensified and
optimized.
Furthermore, we have been studied unity of DOD based on account of stability of its compound processes. For that, there were assorted the normal technological conditions indicated but it approved time limit on present set. Data collection was realized in 24 days through per two hours and they were treated according to [5].
Figure 3. flowsheet of installation for preparation of oil
Materials and Methods
Hence, residual moisture content in oil (wt.%) was used as a variable output parameter of RWOS № 1 while for RWOS № 2 it was residual salt, mg/l.
Based on processing data observations it was received the following equations of wholeness DOD:
N
DSVA
= 1d +1S/D +1V/S +1A/V - 3 =
(1)
= 0.81 + 0.73 + 0.76 + 0.87 - 3 = 0.17
It is noticeable from present equation stability of
the processes in DOD is low that linked mainly by considerable fluctuations of preparing oil composition.
Results and discussion
It is known that in oils, along with dissolved salts, there are various highly dispersed salts in the form of crystals, which are difficult to remove during traditional dehydration of NOE.
To extract them from dehydrated oil, a multiple washing with fresh water is used, which is expensive in commercial conditions.
Flushing with fresh water (without recirculation) can reduce the content of salts and clusters in it. At the same time, the fresh water consumption for oil flushing is calculated according to the formula.
qh2O = qW _ BKL - X Qo
0.8 X - BK
where QH2o is the flow rate of the washing water, m 3;
Q^ - the amount of formation water in the oil before the step esalination, m 3/m3; QFW = W1/(1-W1);
B - the amount of water in the oil at the outlet of the desalting stage, m 3/m 3;
B = W2/(1 - W2);
X - salt content in desalted oil, mg/l;
KL - salt content in formation water, mg/l;
K2 - salt content in washing water, mg/l;
Q0 - the amount of oil to be prepared, m 3;
0.8 - coefficient of mixing efficiency.
As can be seen from this equation (2), the consumption of fresh water during desalting of oil is significantly affected by the intensity of phase mixing, which can be increased through the use of ultrasonic action. This allows not only to reduce the frequency of oil flushing, but also the amount of fresh water consumed during oil flushing.
With a view to deeper removal of chloride salts from oil, we performed a two-fold flushing with the regimes noted in the previous experiment. Analyzes of the residual water content and the concentration of chloride salts were carried out according to the procedures.
The results are shown in Table 1
Table 1. - Indicators of preparation of local oils after the first and second washing using fresh water, ultrasonic treatment and without it
After the first wash After the second wash
Name of local oils Mass fraction of water,% Mass concentration of chloride salts, mg/dm 3 Mass fraction of water,% Mass concentration of chloride salts, mg/dm 3
Mingbulak (control) (x) 0,48 289 0,41 183
Mirshadi (control) (x) 0,67 364 0,57 215
Mingbulak 0,35 157 0,33 102
Mearshadi 0,38 230 0,35 184
Note: (x) without ultrasound (control)
From Table 1 it can be seen that double washing of oil with fresh water helps to reduce the content of chloride salts in it by about 1.6-2.0 times. In this case, the use of ultrasound also significantly reduces the residual content of chloride salts in oil.
Moreover, the use of the last bole effectively works during the first washing of oil with fresh water, in the second relatively less efficiently, which confirms the presence of hard-to-remove salts in oil.
Therefore, it is necessary to design approaches their increase including conventional ways of impact on water-oil system.
Low wholeness of DOD is consequence of unstable functioning of multiple processes in DOD.
Conclusion
To sum up, systematic analysis of DOD shows that present technological line is completed insuf-
ficiently, that is it contents processes of low stability of output parameters. It is confirmed also indicator of wholeness of the flowsheet. Therefore, working the main processes of water separation and mineral salts from oil in DOD allows to rise considerably technical and economic efficiency for its functioning, as well as quality of oil preparation to industrial processing.
References:
1. Levchenko D. N., Bergshteyn N. V., Hudyakova A. D., Nikolaeva N. M. Emulsion of oil with water and destruction method. - Moscow. Chemistry, - 1967. - 200 p.
2. Pozdnishev G. N. Stabilization and destruction of oil emulsion. - Moscow. Nedra, - 1982. - 221 p.
3. Chernojukov N. I. Purification of oil products. - Moscow. Chemistry, - 1978. -267 p.
4. Panfilov V. A. Scientific base of developing engineering line offood production. - Moscow. Agropromz-dat, - 1986. - 245 p.
5. Kafarov V. V., Dorohov I. N. Systematic analyses of chemical technological processes (strategies basis). -Moscow. Science, - 1976. - 500 p.
