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UDC 547212:66.092.14
MATHEMATICAL MODELLING AND OPTIMIZATION OF INDUSTRIAL PYROLYSIS PROCESS OF ETHANE TOGETHER WITH BUTANE-BUTYLENE FRACTION (BBF) TAKING INTO ACCOUNT OF FEEDBACK
Z.A.Mammadov
SOCAR "Azerikimya " PU zakirA.mammadov@socar.az Received 12.12.2016
The mathematical model of pyrolysis process (ethane+BBF) taking into account feedback has been developed. On the basis of the model there has been carried out the optimization of unrecirculating process, as a result of which the scheme of control of the pyrolysis process of (ethane+BBF) depending on totality of the controlled parameters has been composed. Three variants of carrying out the pyrolysis process of (ethane+BBF) with recirculation at various compositions and quantities of recirculant have been considered. The advantages of the process realization with recirculation in comparison with unre-circulating process have been shown.
Keywords: pyrolysis process, thermal decomposition, dehydrogenation reactions, ethane decomposition, recirculation fraction, purposeful products.
The pyrolysis process of petrol at the Sumgait plant "Ethylene-Polyethylene" is accompanied by a number of series-parallel conversions, as a result of which a large quantity of products (including hydrocarbon fraction C4) is formed. However, due to reconstruction, the plant could not operate at full capacity, and the fraction of BBF obtained by pyrolysis could not find further rational application and was simply sent for storage. Therefore, in order to improve the process we have carried out an industrial experiment: to gas furnace BBF (C3 - 6.2%, n-C4H10 - 25.7%, a-C4Hg - 42.4%, cis-C^g -13.9% and trans-C4H8 - 11.8%) was simultaneously given with ethane. This fraction has been also used as raw material for pyrolysis with the aim of additional preparation of purposeful products (ethylene+propylene).
The process of thermal decomposition of hydrocarbons consists of quite a number of elementary reactions proceeding in two stages. Firstly, the primary thermal splitting reactions of alkanes proceed with formation of olefins, diole-fins and alkanes with less numbers of carbon and hydrogen atoms than initial one. In the second stage, the formed olefins and diolefins as well as alkanes are subjected to dehydrogenation reactions, further splitting and condensation with formation of methane, acetylene, benzene and carbon. The carbon to be adsorbed on the surface
of the reactor forms the pyrolysis coke.
When composing the stoichiometric scheme of pyrolysis process of the mixture (ethane+BBF), we have used the previously proposed scheme of ethane and propane decomposition, including the equation 9 and 7 respectively. We have added the stoichiometric equations of BBF decomposition fraction to them:
kR
— C2H4 + C2H6, C3H + CH4,
И-С4Н10 n-C4Hi0
kB3 V
n-C4Hi0 ( ' » a-C4Hg + H2, a-C4H8 OObO— 2C2H4,
k
4H8
a-C4H8 -c/s-C4H8 trans-C4H8
(1)
> CH4 + C3H4 (PD), C2H2 + C2H6,
>C3H4 (МА) + CH4,
kB8
a-C4H8 + C2H4 C6H12
B9
a-C4H8 + C3H6 10) a-C4H8 + C3H6 _biO
^ C7H14, > C4H6 + H2,
where C3H4 (PD) - propadiene, C3H4 (MA) -methylacetylene (propyne), cis-C4H8 - cis-2-bu-tylene, trans-C4H8 - trans-2-butylene, C6H12 -1-hexene, C7H14 - 1-heptene, a-C4H8 - normal butylene. The kinetic model corresponding to this scheme has the form:
dnC2^ /dl = (-^-^+^3+^5+^1+^6)-^
dnC2H4 / dl = (r1-r2-r3-r4-r5-r6-r7+rp1+rp5+rp6 +rB1+2rB4-rB8>F
d%2 /dl = (r1-2r2+r3/8+r4+r5+2r6+93r7/150+r9+r8+rp2-rp3-rp6+rB3+rB10)F
dncH / dl = (2r2+rp1+rp3+rp6 +7b2+7B5+7B7>F
dnC^ / dl = (7-3/4 +rB10)F
dncH / dl = (-3/8+r B3-7 B4—7 B5—r B8—r B9—r B10)F
dnC
dn
/ dl = (73/8—-B1—-B2—-B3)^F
C6H6/d/ = (74/3)^F dn^^ / dl = (-5+-B6)^F
dnc /dl = (2-6—-8)F
dn^H / dl = (143-7/150+rp2—rp6+7B2—7B9)F dn^H / d = (57r7/150—rp1—rp2—rp3—rp5)F dnco /dl = (r8—r9)F dnCC)2/dl = r9F d«H20/d/=(-r8-r9)F
(2)
dn.
trans - C+fijj
/¿L r-
(-rB7)F
dnC3H4 (PD) = rB5F dnc3H4 (MA)/d/ = VB7-F dnC6H12 /dl = rB8 F
dnn
/ dl = -b9'F,
where r1^r9 — reaction rates for case of ethane propane pyrolysis [2], rB1^rB10 — reaction rate pyrolysis [1], rp1^r p7 — reaction rates for case of for case of (ethane + BBF) pyrolysis, equal to
ri = k
r2 = k2
C2H6
(1/K,1)
n^ tt
P / RT V n,
2 ¿—t 1
p/ RT V n
Hl
C2H4
r3 = k3nC2H4 pRT Vn r4 = k4nC2H4 pRT V n
r5 = k5nC2H4 pRT V"1
r6 = k6nC2H4 pRT V ^
• p/RTVn |-(i/K,2)n
CH4
P/RT V n
r7 = k7 nC2H6 nC2H4
PRT V n
r8 = k8nCnH2O
p/RT V n
2
Г9 - k9nCOnHO
P/RT X n,
rpl - kpinC3H8 PRTX n
'p2
= kp2nC3H8 P/RTX П
rp3 - kp3nc3Hg nH2 ^pRTX n,
V = kp4nC2H PRTXП
rp5 - kp5nC3Hg nCH4
rp6 - kp6nC3H6 ПН2
pRT X n P/RT X n 1
rp7 - kp7nC2H6 nHH2 ^pRTX П J
rBi - kBinC4H10 pRTX n, ГВ2 - ^B2nC4H10 ^^X Пг
pRT X n
ГВ5 - kB5na-C4Hg pRTX П rB6 - ^B6nH2o ^^X n,
ГВ7 - kB7Пцис-С4H8 P/RTX П
P/RT X n
ГВ4 - kB4na-C4Hf
—
8na-C4Hg nC2H4
P/RT^n, -K,
кВ9По.-С4шПсъЩ PjPTYs^ ~kl
rB10 - ^B10na-C4H8 P/RTX ni ,
8^C6H12
В9ИС7Н14
¡'1'^Ъъ
P/RT^n,
where ki-k9 - reaction rate constants for ethane the propane decomposition occurs, therefore its pyrolysis, kp1-k р7 - reaction rate constants for decomposition rate is also taken into account.
propane pyrolysis, kBi- kltU) - reaction rate constants for (ethane + BBF) pyrolysis, £B3, £B8,
To obtain a complete mathematical model of the pyrolysis process (ethane + BBF) pro-
kw - reverse reaction rate constants for equations ceedinë with feedback t0 kinetic model (2)Jt is
0 0 0 ^ added the equation of recycle streams (3), ther-3, 8, 9 system (1). M ^ .
In this case, during (ethane+BBF) pyrolysis mal balance (4) and hydrodynamics (5):
2
2
3
ff = f0i (1 " aR ) + fR,aR f = fpri (1 - aR ) + fRi aR
dT dl = ^dH q— X r AHr7
(3)
1/(1—aR )XXa;+XM c
dP/ dl = —0.50962-10—13 [ 1 + (¥ dj L )]^fi
X« Ii
X Soi —
a,,
(4)
(5)
Here n - current number of moles of i-component of mixture, kmol-h-1; Ani - number of moles of i-component changed as a result of reaction, kmol-h-1; l - current reactor length, m; P -current pressure, atm; T - current temperature, K; L0 - straight pipe length, m; M - average molecular weight of pyrogas, kg kmol-1; R - gas constant,
3 11
m atm kmol- deg- ; a' - molar fraction of i-component of the mixture flowing to the pyrolysis mixture o/p; aR - recirculate fraction, o/p; de,
dn - external and internal diameter of the pipe, m;
2 1
q - heat intensity of radiant pipes, kcal m h-; y -coefficient considering influence of local resistance, o/p; - coefficient of friction, o/p; f0, f0\, ffei, f, fnPi - mass fractions of i-component in total and fresh reactor loading, in recirculate, in the stream at the outlet of the reactor and in stream runoff from the reactor, o/p; c„i - heat capacity of i-component, Kcal Kmol-1 deg-; g0i - quantity of i-component in the fresh loading, kg h-1.
In Table 1 the kinetic constants values calculated on industry data from EP-300 installation of Sumgait "Ethylene-polyethylene" plant.
The average deviations from experimental data on the base components of the process were: H2 - 3.3%; CH4 - 9.3%; C2H - 7.1%; C2H4 -4.0%; C3H8 - 6.9%; C3H - 10.9%; C4H - 9.6%; ZC4 (BIF) - 6.6%; EC6 - 10.4%, indicating the adequacy of mathematical model.
Based on the developed mathematical model there has been carried out the optimization of unrecirculation (aR=0) pyrolysis process (ethane+ BBF) in variation of set of parameters (ethane loading g02H<5, BIF loading g^, the ratio of water
vapor: raw material and temperature at the inlet of the reactor t0) in the following intervals of their changes: g^ - (2500-3500) kg/h, gBBF- (10002000) kg/h, the ratio of water vapor: raw material:
g^o : gC2H - K^M2^ inlet temperature t0 -(775^850)°C.
Table 1. Kinetic parameters of model
Reaction rate constant of the pyrolysis process (ethane+BBF)* Equilibrium constant of the pyrolysis process (ethane+BBF)**
kB1 =exp(22.32887-14364.44/RT)
kB2 =exp(22.20580-18896.23/RT)
J kB3 =exp(17.13610-28247.47/RT) A"pB3=exp(-7.61371-11063.91/RT)
\ &B3 =exp(24.74981-17183.56/RT)
kB4 =exp(15.99420-24022.26/RT)
kB5 =exp(13.86064-21699.26/RT)
kB6 =exp(9.96850-21562.30/RT)
kB7 =exp(11.85635-28582.35/RT)
[kB8 =exp(21.53001-17392.60/RT) A"pB8=exp(3.37799+10365.05/R7)
\kBS =exp(18.15202-27757.65/RT)
f kB9 =exp(13.94265-28966.15/RT) A"pB9=exp(0.22467-1208.50/R7)
|&B9 =exp(13.71798-26578.76/RT)
kB10 =exp(10.12543-28378.49/RT)
-t-—1-T—T-
* Dimension of the reaction rate constant: I order - s- ; II order - m kmol - s** Dimension of the equilibrium constant [A"pB3] = kmol-m- ; [A"pB8], [A"pB9] = m3 kmol-1
The yields of purposeful products (ethy-lene+propylene) obtained as a result of this optimization were compared with yields of purposeful products during use of pure ethane as raw material. The last ones are taken from previously published papers on ethane pyrolysis [3].
In Table 2 the differences in yields of purposeful products A in use of mixture (ethane + BBF) and just pure ethane as raw material under same loads, at ratio water vapour: raw material and inlet temperatures from above-mentioned intervals changes are presented.
As is seen from Table 2, at ratio of water vapour: raw 1:1 an addition of gBBF = 1000 kg/h to ethane for all loads in the interval of (25003500) kg/h and all inlet temperature in the interval (775-850)0С gives negative values of difference of yields, i.e. an addition of BBF fraction in these cases is inadvisable in comparison with case of pure ethane. The same yield for gBBF = 1000 kg/h can be done in relation to 3000 and 3500 kg/h loads and the ratio of water vapor: raw material 1.5:1 is in the temperature intervals (775-850)0С.
Thus, in these cases there is no need to add BBF fraction, i.e. one can obtain the best yields of purposeful products using pure ethane as raw material. Therefore, the cases with negative differences in yields are discarded, and from remaining data array presented in Table 2, are selected the data corresponding to the greatest difference of purposeful products for both considered cases of used raw materials (ethane + BBF) and ethane), i.e. the most advisable ones for carrying out the process (framed). They are summarized in final Table 3, from which one can see what quantity of BBF should be added to this ethane load, at what ratio of water vapour: raw material and at what temperature at the inlet to the reactor it is necessary to carry out the process to obtain the best yields of purposeful products.
In Table 3 there are presented the conversions of ethane and BBF corresponding to each case, as well as the total selectivity of the process, equal to:
X2 —
^ —
gC2H4
gC,H4 X gBBFX2
— BBF conversion,
- total selectivity,
X1 —
gç2Hi gC2H gC2H¡
- ethane conversion,
where g^ , gBBF, &е2и4 - current vdues BBF и С2Н4.
Thus, Table 3 is a guidance to the operator in the management of the unrecirculating process at pyrolysis installation (ethane + BBF).
The variants of combinations of the parameters taken into account (shown in Table 3) have been used during optimization of the pyrolysis process (ethane + BIF) with feedback.
In order to compare the results of carrying out of unrecirculating process of the unconverted raw materials with recirculating process presented in Table 3 three variants were considered: 1) a case of recirculation of only unconverted raw materials (ethane + BBF); 2) a case of return of whole composition of the reaction mixture at the outlet from reactor and 3) an intermediate case, in which the composition of recirculate includes besides (ethane + BBF), selectively chosen methane-hydrogen and propane-propylene fraction and a sum of hydrocarbons С5-С7.
The best variants of yields of purposeful products of the unrecirculating process have been taken as a basis in calculation of recirculation process (Table 3): =3500 kg/h, gBBF -
2000 kg/h, a ratio of water vapor:raw materials -(1:1) and (1.5:1) and fo = 8500С.
For completeness of the investigation, let's consider these variants over the whole variation interval of inlet temperature - (775-850)0С. Variation interval of recirculate fraction is equal to: aR = (0.05-0.95) for all above-mentioned cases of the recirculating process. The results of the comparison of purposeful products yield during carrying out pyrolysis process (ethane + BBF) with or without recirculation are presented in Table 4.
о
Table 3. Recommended optimum variants of combination ethane and BBF loads, ratios of water vapour:raw material and inlet temperatures^________
gC2H , Kg/h gBBF , Kg/h gH2o • gc2H t0, 0С X1 X2 ^CH+OH) (ethane+BBF), Kg/h (ethane), Kg/h д, Kg/h
2500 1000 1.5:1 775 0.625 0.849 0.400 1097.03 997.62 99.41
2500 1000 2:1 800 0.554 0.840 0.462 1149.13 997.80 151.33
2500 1500 1:1 775 0.661 0.850 0.347 1214.45 958.69 255.76
2500 1500 1.5:1 775 0.515 0.841 0.465 1352.35 997.62 354.73
2500 1500 2:1 850 0.443 0.808 0.526 1353.41 950.64 402.77
2500 2000 1:1 850 0.550 0.849 0.535 1645.55 834.48 811.07
2500 2000 1.5:1 850 0.421 0.827 0.614 1662.59 905.44 757.15
2500 2000 2:1 850 0.333 0.751 0.676 1575.85 950.64 625.21
3000 1000 1.5:1 775 0.533 0.843 0.485 1307.07 1297.64 9.43
3000 1000 2:1 800 0.472 0.818 0.540 1316.74 1270.58 46.16
3000 1500 1:1 775 0.571 0.848 0.432 1478.19 1326.40 151.79
3000 1500 1.5:1 775 0.443 0.824 0.534 1524.16 1297.64 226.52
3000 1500 2:1 850 0.452 0.807 0.533 1530.19 1271.42 258.77
3000 2000 1:1 850 0.523 0.848 0.558 1821.72 1281.63 540.09
3000 2000 1.5:1 850 0.400 0.815 0.636 1801.46 1282.56 518.90
3000 2000 2:1 850 0.315 0.718 0.699 1663.81 1271.42 392.39
3500 1000 1.5:1 775 0.463 0.830 0.548 1456.18 1452.67 3.51
3500 1000 2:1 825 0.441 0.801 0.573 1454.23 1432.26 21.97
3500 1500 1:1 775 0.500 0.845 0.496 1668.81 1519.68 148.63
3500 1500 1.5:1 800 0.424 0.813 0.557 1665.24 1472.53 192.71
3500 1500 2:1 850 0.393 0.767 0.591 1644.79 1450.58 194.21
3500 2000 1:1 850 0.497 0.846 0.578 1983.71 1551.21 432.50
3500 2000 1.5:1 850 0.378 0.800 0.657 1920.75 1501.96 418.79
3500 2000 2:1 850 0.299 0.693 0.715 1738.08 1450.58 287.50
As can be seen, carrying out the process with recirculation of unconverted (ethane+ BBF) gives significantly higher yields of purposeful products g(C2H4+C3H6)with recirc over the whole variation interval of inlet temperatures - [775-850]0C and in all aR values in comparison with unrecirculating process g'(C2H4+C3H6)unrecircul and with increase of temperature at the inlet of the reactor, as well as with rise of aR for each temperature a difference in yields A' increases both at ratio of water vapour : raw material 1:1, and at 1.5:1. However, an increase of this ratio leads to a decrease of purposeful product yields in both cases, as well as to the difference between yields for recirculating and unrecirculating processes due to the fact that with increase of quantity of water vapour a volume rate of raw material is increased, which leads to decrease of contact time and conversion of ethylene and BBF, respectively. In spite of this, the yields of the purposeful products in this case remain also higher than in the unrecirculating process.
Thus, in case of return of unreacted raw materials (ethane+BBF) is more advantageous to carry out the process at a ratio of water va-pour:raw material 1:1 and at large values of aR.
For case of recirculation of all obtained composition at the outlet of the reactor at a ratio of water vapour: raw material 1:1 the yields of purposeful products are higher than in the unre-circulating process only for the inlet temperature in the interval of [775-825]0C and aR = 0.95, that's why other variants is not worth to consider (A'<0) and to carry out the process without recirculation, not spending means for pumping the reaction mass back into the reactor.
To carry out the process with recirculation at ratio of water vapor:raw material 1.5:1 is advisable for all values of aR at 775 and 8000C, as well as at t0 = 825 and 8500C, but only at value of aR =
0.95 (A'>0).
If compare the yield values of purposeful products in both considered cases (cases 1 and 2), it turns out that much better results are obtained at recirculation of only unreacted (ethane + BBF),
1.e. in a case of the same compositions of raw materials and recirculate, for all values of aR, in this case with increase of recirculation share the yields of purposeful products are increased, i.e. it is more profitable to work at large values of aR.
In consideration of a case intermediate between these two variants (case 3) it turns out that at ratio of water vapor: raw material 1:1 to carry out the process with recirculation is not advisable for all t0 and all aR excepting t0 = 7750C and aR = 0.05; 0.35 and t0 = 8000C and aR = 0.05 (all other A' are negative).
At ratio of water vapor: 1.5:1 the picture is changed, and to work with recirculation becomes profitable for t0 = 775 and 8000C for all aR and up to aR = 0.65 and 0.35, respectively for t0 = 825 and 8500C. It is clear from obtained results that the work with recirculation gives clear advantages in comparison with carrying out unrecirculating processes, however, the choice of composition and quantity of recirculation will depend on the specific assigned task, because if on the one hand, the yields of purposeful products are increased with increase of a quantity of recirculate, on the other hand, an increase of a quantity of recirculate may involve an increase of expenditure for division of reaction mass and pumping it into the reactor. In
this case, a work on smaller recirculation share can be more economically beneficial.
This problem can be solved only by taking into account all controlled parameters related to process.
References
1. Алиев A.M., Бабаев А.И., Гусейнова A.M., Ис-маилов Н.Р. Моделирование и исследование процесса пиролиза этана с обратной связью // XXII Международная научная конференция "Математические методы в технике и технологиях - ММТТ-22". 2009. Т. 3. С. 150-153.
2. Алиев A.M., Taиров А.З., Гусейнова A.M., Ка-лаушина ЯМ., Шахтахтинский Т.Н. Применение методики оптимального проектирования процессов пиролиза парафиновых углеводородов к процессу пиролиза пропана // ТОХТ. 2004. Т. 38. № 6. С. 654.
3. Бабаев A.K, Алиев A.M., Taиров A.3., Гусейнова A.M., Исмаилов Н.Р. Моделирование и оптимизация процесса пиролиза этана с обратной связью. Часть 1. Моделирование и исследование процесса // Азерб. хим. журн. 2008. № 3. С. 16.
OKS RABÎTONÎ NOZORO ALMAQLA ETANIN BUTAN-BUTiLEN FRAKSiYASI (BBF) iLO BiRGO PiROLiZi SONAYE PROSESiNiN RiYAZi MODELLO^DÎRlLMOSi VO OPTÏMALLA§DIRILMASI
Z.A.Mamm3dov
Oks rabitani nazara almaqla piroliz (etan+BBF) prosesinin riyazi modeli qurulmuçdur. Model asasinda prosesin resirkulyasiyasiz optimallaçdirilmasi apanlmiç va naticada idaraetma parametrlarinin qiymatlarindan asili olaraq piroliz prosesinin optimal idara edilmasi sxemi içlanmiçdir. Optimallaçdirma masalasinin hallina resirkulyatin muxtalif miqdari va tarkibi ila ич variantda baxilmiçdir. Gôstarilmiçdir ki, prosesin resirkulyasiya ila aparilmasi daha boyuk ustunluklara malikdir.
Açar sozlzr: pirolz prosesi, termiki parçalanma, dehidrogenh§m3 reaksiyasi, etanin parçalanmasi, resirkulyatin payi, maqsadli mahsullar.
МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ И ОПТИМИЗАЦИЯ ПРОМЫШЛЕННОГО ПРОЦЕССА ПИРОЛИЗА ЭТАНА СОВМЕСТНО С БУТАН-БУТИЛЕНОВОЙ ФРАКЦИЕЙ (ББФ)
С УЧЕТОМ ОБРАТНОЙ СВЯЗИ
З.А.Мамедов
Pa3pa6oTarn математическая мoдель npo^cca пирoлиза (этан+ББФ) с учетом oбратнoй связи. На ocHoBe мoдели прoведенa oптимизaция безрециркуляциoннoгo прoцессa, в результате кoтoрoй сoстaвленa схема управления npo^ccoM пирoлизa (этан+ББФ) в зaвисимoсти oт сoвoкупнoсти управляемых пaрaметрoв. Рaссмoтрены три варианта прoведения прoцессa пирoлизa (этан+ББФ) с рециркуляцией при разных уставах и кoличествax ре-циркулята. Пoкaзaны преимущества oсуществления прoцессa с рециркуляцией no сравнению с безрециркуля-цдонным прoцессoм.
Ключевые слова: процесс пиролиза, термическое разложение, реакции дегидрирования, разложение этана, доля рециркулята, целевые продукты.
Table 2. Difference of purposeful product yields in use of ethane +BBF mixture and pure ethane as a raw material at the same load for both cases, at ratios of water vapour: raw material and inlet temperatures_
g^H -2500 kg/h; gH2o : g^ -1:1 gCU -2500 kg/h; gH2o : g^ -1.5:1 gCU -2500 kg/h; gH2o : g^ -2:1
Sebf Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C
775 800 825 850 775 800 825 850 775 800 825 850
1000 -28.12 -53.99 -78.74 -100.59 1000 99.41 85.36 67.35 46.48 1000 147.38 151.33 149.13 141.51
1500 255.76 229.79 200.42 169.4 1500 354.73 352.22 342.31 326.08 1500 348.15 375.33 393.38 402.77
2000 523.62 503.71 476.52 811.07 2000 572.52 590.79 597.55 757.15 2000 479.55 536.15 582.86 625.21
gCU -3000 kg/h; gH2o : g^ -1:1 gCU -3000 kg/h; gH2o : g^ -1.5:1 gCU -3000 kg/h; gH2o : g^ -2:1
Sbbf Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C
775 800 825 850 775 800 825 850 775 800 825 850
1000 -105.30 146.88 -191.53 -236.86 1000 9.43 -8.57 -95.72 -61.38 1000 39.98 46.16 45.24 37.82
1500 151.79 116.54 73.28 29.11 1500 226.52 224.36 213.51 195.24 1500 192.55 222.86 244.87 258.77
2000 385.64 286.80 328.37 540.09 2000 403.09 424.16 433.96 518.90 2000 278.61 333.57 390.96 392.39
gCU -3500 kg/h; gH2o : g^ -1:1 gCU -3500 kg/h; gH2o : g^ -1.5:1 gCU -3500 kg/h; gH2o : g^ -2:1
Sbbf Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C gBBF Difference in yields a, kg/h at t0, 0C
775 800 825 850 775 800 825 850 775 800 825 850
1000 -77.71 -121.73 -173.04 -230.35 1000 3.51 -11.04 -33.61 -63.48 1000 4.85 17.1 21.97 19.63
1500 148.63 113.07 72.31 20.32 1500 189.15 192.71 186.17 170.30 1500 115.97 149.72 175.94 194.21
2000 364.19 335.72 307.60 432.50 2000 332.56 359.34 374.80 418.79 2000 158.27 280.11 272.20 287.50
where A - g(C2H4+C3H6Xethane +BBF)- g^^+Q^H^ethane
o o 1. Return of unreacted (ethane+BBF) 2. Return of all composition of reaction mixture 3. Return of unreacted (ethane +BBF) and selectively chosen part of reaction mixture
g°2H =3500 kg/h; g^BF =2000 kg/h gC2H =3500 kg/h; gBBF =2000 kg/h g°2H =3500 kg/h; g£BF =2000 kg/h
gH20 : gC2H6 1:1 gH20 : gC2H6 1,5:1 gH20 : gC2H6 1:1 gH20 : gC2H6 1,5:1 gH20 : gC2H6 1:1 gH20 : gC2H6 1,5:1
.c re ut 1 is ffi Sg + 4 H4 (C2 aR .c re £ S )6 K Ck +k 4 H4 2 (C2 a', kg/h .c re ut 1 is ffi sg + 4 H4 (C2 aR .c re £ S )6 K Ck +k 4 H4 2 (C2 a', kg/h .c re ut ithou wi H /g C3 kg + 4 H4 (C2 aR .c re £ wi )6 K rt m Ck +k 4 H4 2 (C2 a', kg/h .c re ut ithou wi 3s + 4 H4 (C2 aR .c re £ wi )6 K Ck +k 4 H4 2 (C2 a', kg/h .c re ut ithou wi + 4 H4 (C2 aR .c re rith wi )6 Ck +k 4 H4 2 (C2 a', kg/h .c re ut ithou wi + 4 H4 (C2 aR .c re rith wi )6 rt Sg Ck +k 4 H4 2 (C2 a', kg/h
ff- 1925.0 0.05 1928.4 3.4 1689.4 0.05 1692.3 2.9 1925.0 0.05 1921.0 -4.0 1689.4 0.05 1698.1 8.7 1925.0 0.05 1928.5 3.5 1689.4 0.05 1701.2 11.8
0.35 1948.8 23.8 0.35 1709.6 20.2 0.35 1875.0 -50.0 0.35 1729.9 40.5 0.35 1925.9 0.9 0.35 1751.6 62.2
0.65 1969.1 44.1 0.65 1726.8 37.4 0.65 1787.3 -137.7 0.65 1719.7 30.3 0.65 1898.3 -26.7 0.65 1771.4 82.0
0.95 1989.1 64.1 0.95 1744.0 54.6 0.95 2094.4 169.4 0.95 1985.7 296.3 0.95 1861.7 -63.3 0.95 1771.1 81.7
o o 00 1973.1 0.05 1977.3 4.2 1790.8 0.05 1794.2 3.4 1973.1 0.05 1961.5 -11.6 1790.8 0.05 1794.0 3.2 1973.1 0.05 1973.3 0.2 1790.8 0.05 1800.3 9.5
0.35 2002.6 29.5 0.35 1814.8 24.0 0.35 1874.5 -98.6 0.35 1792.5 1.7 0.35 1954.1 -19.0 0.35 1834.5 34.2
0.65 2027.6 54.5 0.65 1835.3 44.5 0.65 1754.0 -219.1 0.65 1791.9 1.1 0.65 1916.1 -57.0 0.65 1837.5 46.7
0.95 2052.4 79.3 0.95 1855.7 64.9 0.95 2058.1 85.0 0.95 2021.7 230.9 0.95 1873.1 -100.0 0.95 1823.2 32.4
<N 00 1991.4 0.05 1996.6 5.2 1868.2 0.05 1872.3 4.1 1991.4 0.05 1973.0 -18.4 1868.2 0.05 1865.3 -2.9 1991.4 0.05 1989.1 -2.3 1868.2 0.05 1874.9 6.7
0.35 2028.0 36.6 0.35 1896.4 28.2 0.35 1850.4 -14.1 0.35 1826.8 -41.4 0.35 1958.8 -32.6 0.35 1891.5 23.3
0.65 2059.2 67.8 0.65 1920.5 52.3 0.65 1702.5 -288.9 0.65 1748.6 -119.6 0.65 1914.7 -76.7 0.65 1879.6 11.4
0.95 2090.1 98.7 0.95 1944.4 76.2 0.95 1997.7 6.3 0.95 2023.9 155.7 0.95 1868.3 -123.1 0.95 1854.7 -13.5
o 00 1983.7 0.05 1990.2 6.5 1920.7 0.05 1925.5 4.8 1983.7 0.05 1958.9 -23.9 1920.7 0.05 1911.3 -9.4 1983.7 0.05 1980.0 -3.7 1920.7 0.05 1924.5 3.8
0.35 2028.9 45.2 0.35 1953.9 33.2 0.35 1808.6 -175.1 0.35 1835.6 -85.1 0.35 1943.8 -39.9 0.35 1924.9 4.2
0.65 2067.3 83.6 0.65 1982.1 61.4 0.65 1639.0 -344.7 0.65 1724.6 -196.1 0.65 1896.9 -86.8 0.65 1901.5 -19.2
0.95 2105.4 121.7 0.95 2010.2 89.5 0.95 1921.2 -62.5 0.95 1999.2 78.5 0.95 1849.4 -134.3 0.95 1869.9 -50.8
where a' = g^H+QH^ith rec. -g(C2H4+C3H6) without r
