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Reaction between and dioxide under high Title

Author(s) Kiyama, Ryo; Minomura, Shigeru

Citation The Review of Physical of (1951), 21: 1-8

Issue Date 1951

URL http://hdl.handle.net/2433/46661


Type Departmental Bulletin Paper

Textversion publisher

Kyoto University The Review of Physical Chemistry of Japan Vol. 21 No. 1 (1950)


By Rro I:rva~ln and Sntc>:rc ltirxoxcRn.


Generally a under high pressure is performed in the vessel up to date and the reaction mechanism is explained by the changes of the pressure, volcm^, temperature or yield, etc, and any consideration of the mechanism contains the hypothesis. The authors studied the reaction between ammonia ar.d carbon dioxide in the glass vessel under the conditions of the temperature -20-~-IOO C, the total pressure 1~?0 cmHg and the temperahu~c SO^~-`100'C,the total pressure 'I+300 atm. From the inflexion of the curve of the pressure-volume-temper:ariu'e relation obtained acd the observation of the rrtction process with the naked eye, the process of the reaction between ammonia and carbon dioxide is discnsserl.


(1) Materials. The prepemtiou of ammonia: Ammo:ria. is evaporated 6om am monia in a bomb, dried by passing through , kaliem bydroxide and over metallic natrium, pentoxide successively. finally distillated and presserved oa phosphorus pentoside in a flask for abort a month. The prelalration of carbon dioxide : Carbon dioxide is evaporated from liquid .carbon dioxin-le in a bomb, or prepared from heating in a Terex tube fitted with glass n•ool plug to catch solid , dried by passing through sulphuric and over , finally distilled and preserved as in the case of rmmonia.

(2) The experimental apparatus and operation at low temperature and pressure. The experimental apparatus is shown in Fig. 1. 11ir_;, are mano- meters and R is a b_vette and the gas pressure can be controlled by nl_. ~" is a reaction vessel and F, _, thermostats. The gas mixture of ammo-ria and carbon dioxide is led in Band the ratio is detc.mincd by Dl, ar.d the volume change of the gas mist:rc nb The Review of Physical Chemistry of Japan Vol. 21 No. 1 (1950)

$ R 611'A\(A and 5. 3QIQ0\fURA

In }3 IS trleasnred at the YOtel prCSSnre TO of 1.-20 cmI}g,at the temperaturespas renrr°ufvoirr pezom.ierez om.ier 7uToPpump of 0, 10, IS, 30'C and at the inteu•al -F1 8 ~~ IlV of:30minctes. (1n the other hard, F/BF~ tlV ~-F1 the gas mixture is led in V and Yhc ~v pmtial pressure ratio is determined by \'I, and the total pressure change o~a v M is measuredh}' n1, at -18~100'C M1Mi 3 M37 v M:Mt an(1 at the interval of 30 minutes. Fig. l (3) The experimental apparatus and operation at high temperature and pressure. The appar:~hrs" and the procedures°r for sampling in the piezometer are the same as the rc}xnts of this Journal 7~he total volume of the glass piezometer is S+7 cc, in which the gas mixture of ammonia and calbal dioxide of the con- stant paltial pressure ratio is sealed. The measured volume of the capillar}' of the piezometer is about 120 nun', the inner and outer diameter are about 0,8 and 8 mm respectively. L1 the experiment two sets of furnace must be set ou the part and the bomb containing the swelling part of the piezometer, to keep a desired temperature of the reaction and to deconllwse - 6anlate perfectly before the compressing plocedr:re begins. The total voh:nle oC the gas mixture iu the measured volume of the glass capillary is measured under pressure 1:300 atm at the interval of }0 minctes.

Experimental results. (1) The react[on at low temperature and pressure. (a) The ieotberme. The pressurexvoh:me-pressure (PV-P) cwves, under the conditions of the tem(lelahuc, 0~.30'C, the total pressure 1-.20 cmHg and the paltial pressure ratio \H,:CO.-2:1, arc shoran in Fig. 2. rvery• isotherm has ml inflexion point and the gas mixture (roes not react till it reaches the point and after the point starts to react. \Ghite solid appears on the wall of the reaction vessel lrith increasing pressure alter the point and disappears lvith decreasing pressure. The position of the point shifts to the high pressure at high

]) R. Kiymm~mrd K. Su:uki, TIr%rJounnel, 21, 50 (1951) R. Kiyanmand K. inooe,ibnl., 21, i3 (1951) R Kiyamn,'C. Ikegami and I:. moue, rb%rt., 21, u8 (1951) 2) R Kiyamnmul ti. Kiacshim,tbiC., 19, d3 (19A,^.) 2

The Review of Physical Chemistry of Japan Vol. 21 No. 1 (1950)


//. oo

A~ ~o~~ ..-z ..~i ~,1 9.00 ~-

,~ /8 /o .~ 1p 'o ~i~ °/0 TI \'. ~7.00 V0 O B~ 8

0. S. 00 00 I I. I / V 2 o s fo /s ~o ).oo).GD -zo_~ o ao ro toa PrrnHg 7=~

Fig.: NfIa: CO.,-:: 1. Curve 1 is the case Pig.r• ~~. 3 YIh:CO_:--^:1. Cure I is the cvse of the wixlnrc dried hp passing Ihmugh and of.,r then~~ mixture dried 1•y passing through and preserving nn the drying materials. Curve is preservingpresen nn the drying materials. Cun~e3 is the case of the mixture dried only by passing the cssees of the mixture dried only' by passing thrnugL the drying materials. IhmughIhrnug the drying nulerinls.

temperature. (h) The isoeores. 'I he reaction under thetl'. conditions of the temperature, -~O~.I00'C, the total pressure about 10 cmHcmHg and the partial pressure ratio NHa:C0,=4:1 is shown by the pressure-temperatureire-tem (P-T) diagram in Fig. 3. 1'he gas mixture does not react on curve F1A, b.it reacts on Curve B, and the pressure change of trove $ is larger withth decreasingdecree temperature. "1"hedissocia- tion of the product is plotted on carve C. The crosses on curve A shown the P- T relation of an inncrt gas, air,

(c) The in8neuce of the partial preesuipressure. The apparent }'field derived from the p:essme change at -13'C off the gasga mixtures of three kinds of the partial pressure ratios is shown in Tablee 1.t. TheT Table 1 excess of ammonia gives the higher yield than in thet r Pactial pressure ratio fieldofthe casepartial pressure ratio AH ,:CO,=2:COQ=2 1, rrrl, , cp: ;o though the excess of carbon dioxide indicatesdicates thet 2.05: t.00 55 same yield at the constant intervals o[ time. ime. SO.Ib 1.00 90 r vapor (d) The inFlnence of the vapour, Loo 7.73 55 Th e ,taming points of the reaction in thehe case of the dried only by passing through the drying materials are shown on curve

I : 1, are except in not (ound

I The Reviewof PhysicalChemistry of Japan Vol.21 No. 1 (1950) I

t R. 1:I1'A\f4 and S. \ffNOnTl7RA

2 in Pig. 2. The position of curve ~ is loner by several centimeters :rt the same temperature than in the case of the gases dried 6y passing through the drying materi:ds and preserving on phosphorus pentoxidc, curve I. Similarly in Pitt. 3, in the case of the gases dried only by passing through the drying materials, stove 2, the pressure change is obsen•ed even at higher temperature by 20~ 0'C th:m in the case of the gases dried b}' panning through and pre- serving on the dq•im~ materials, curve 1.

('L) The reaction at high temperature and pressure. (a) The isotherms. "I•Le I'V-P wn•es, order the conditions of the tear perahoc ti0-'200'C, the total pressure / 8 1-100 ahn surd the partial pressure ratio \I-I,,: C(l,_•3; I, arc shorn in /.7 ?~~~. Pig. 4. livery isotherm has an in- ~B~o Oexion lwint which indicates the re- l.b /aJ C C action starts and the position of ~J~ e the lxrint appears at high pressure 1.S ~? With inaeasingtennenture. At1'_'9L .+ 9 °~, the crave is nearly monotonous. II 1.6 4 13clou~ 1°9'C the white solid F r 3 'oo, begins to appear at the conditions of n ~ the tengterat~ue and pressure of the o r.1 inflcxinn point and disappear when 0 d~ Qo the pressure is decreased at the same 1 r ~. tempcraturc. Alxwe l-3~'C thu «•lfolc space of the rcac[ioa vessel is occupi- L0 \ ed only «ith the gas phase and the reaction dues nol p:a:eed eo acaua- tely revcrsib;e at the cona,ut inter- 0.8 vals of time as in the case below 1•>9'l . 0.7 'fh c 1'V-P staves, under the 0 20 40 60 80 /oo conditions ~~f the temperatttes 1°9, P etm li;0 and 165'C, the tot d pressure L -•If0 ahu and the partial pressure ratios NH,: CO_=3 : 1, 3 : I and shown in Pigs, ii, f, and 7. Lvei}' isotherm has hvo inllcxio,t l:oints Fig. i, in which the second inHexiou point is (ound only at 12`t°Cand 0.F I,i

i The Review of Physical Chemistry of Japan Vol. 21 No. 1 (1950)


tr ~Qt\ LI1 so ~S r e ~ f 1_] t.a ~rl /'C _~~ ~.~ .\ 1.4 ' .. i.a t•:1 f 0 r i,. = 1""~ r ~.t 1.1 ..,J~ 3 1s ~JO• _~ o. I,0 ° I, II Q• ~.~~ G o .r9, > 'i 0.g > 4 L4 ' S ti

0.:1 n.~ 1:1 ^

0Q_7 7 6 1.90

n,fi ~_~ i --' 0 90 -Ill 6u s0 IW lJn I•III P ,'U •10 fU SU l00 1911140 P aim 1' :um Fig. +r NIh:Cn_-:: I. Fig. fi Cavre=I, 9:uu1 .^,; Nlly:tlf),_^; I. Pig. i (:anres-/, b mot G, NlIa: CO,=1:1. TLe unlinalesu( Digs.F and i :ue shua'u by the rigid ;uul left respectively.

at l:~ and I6a'C until :1ODatrn and the point: shift to the side of high pressure with increasing temperature. The whole =pace of the vessel is occulricd o;,ly tr•ilh the gas Irhase till the second inflexion point and after that produces a fog. "phe fog become.. droplets and the droplets enlarge with increasing pressure and finally the column of liquid appears on the head of mm'cuiy. From the isotherms of Figs. ~, (i and i, in the case of excess ammonia. the first inflexion point is foand to appear at somerehat luacr pressure and the second point at considerably Lru'cr pressure.:unl the production velocity of the liquid phase is larger. (lr) The inllueoce of the pressure. 7•he rel:tlion between the reaction time and the apparent yield dclived (Irom the volume change under the conditions of the temperature lix)'C, the total pressure 90-300 atnt and the partial pressure ratios NIL,:CO,-2: l and 3: I, is shown in 1'ig. S, 'fhc apparent yield becomes larger such as aba_t 5, 13 and IG~o respcctivel}- in GO minutes and the time t.rken to reach equilibrium becomes shorter with increasing pressure from 110 [o li>U and 3UU atm in the case of the partial pressure ratio NH~:CO.=2; L On lbe other h:urd, the apparent yield becomes about JJOO in Ii0 minutes at 90 arm i

The Review of Physical Chemistry of Japan Vol. 21 No. 1 (1950)

6 R. 6r1':\NA mul S. VISr)31 t"F:1

in the case u( the partial pressure ratio ee -2 \II,:CO,=3;1 and reaches equilibrium to eithin about ti miuraes at I:iO arm and w indicates tL'c higher v.rlue than at 90 atm T° JO atul the velocity'o( the volume change is JO too first to drag the quantitative change of 3 IQ 4 the diagram of the J field. 5 0 (e) The influence of the water vapour. 0 ~p 10 )0 t0 SO ~0 ]O f0 The PV-P curves; when the gas mixture T.m. m,p r~~;. s. contains slightly the water vapour as men- l'airvc 1; I~H~:C(L=%:I, Ib0°C., 150 ahn. tioned in Exp. (L): (d), under the condi- l'arvc :: Nki~:C(t.=3:1, 150°C, ;p ahn. Curve S \fI;:C0.=__°: 1, I50°C, 3110 anu. tions of the temperature IGir'C, the total ('un~e {; Hllz:f.(1_=°;1, I+tO°(', I:A ahn. Cun'c 5; SlIp:COr=::1, 150°C, 110 ~tne pressure I--IGO ahn and the partial pressure ratios \TIh:CO.,=:3: I, S; 1 and I : 1, show the sank' first and second inflexion

'mar I,fi i 1.6 \r

l.u j 1,5 n. 1 L{ Ls 1;1 ~C l.fi La A1.3 0 - l ,_^ t,~ ~1 ~. .. 2 'II 1;3e ],1 i s„ '~ ii 0 1.0 1.. 1:5~ _c > 0.9 I,1 La 3 _~ 0,8 LG is ° 0 0,7 o,o 1.^.~ 4 5 c. 0.6 os 1.1

U SO 40 fi0 9f1 loll 1`.'A 1~IU 1110 o ro ao sa loo Lo lao lso P atm P atm

Pig. 9 Curves 1 and 9: Nii~:0O.=3:1, IGS°C. Fig. 11 Curves 1 and °; NI4~:C0.=1:I, IG5°CL Pig. 10 Curves 3 and 9; Nltya?0:=9:1, IG5°lL Fig. IS Curves 8, 4 and :r; NIia:Cn_=J:1, IfiO°C. Curves land 3 are the cases of the mislures dried Curves I and .^, are the vises of the mia ores dried by passirg through and preserving nn the dging In' passing through and preserving ou the drying materials. Carve _ is Ore vase of the mice ore .I rial nulerinls. Cures 7 and ~ are the cvscs of the mly Lv Ixising ilun~gh the dryitrg nra~crials. mislnres dried only by Lassing Ihra~.gh the drr-ing Cures 4 and d arc the e~scs of the mislwes added u~llerinls. The oNinnl rs of Figs. 0 and 10 are the wnlcr vapour 0.8 and tJ$£ respGa ivcly. The shown by the left and rigid resparively. vrdinaics of Figs. 11 and IS are shown by the left and right respectively. The Review of Physical Chemistry of Japan Vol. 21 No.-1 (1950)

RISACTIONBIiT\\9iC:N A\I\tON1A ANU C.IRBUN 11IfrXIDE UNDIiR IITCfI PRESSIrRF. 7 points at about GO and 110 atm. The comparison beriveen the 1'V-P carves of the gas mixture dried perfectly and the above mentioned awes is shown by Fig.<. 9, 10 and II. In the curves of the gas mixtures arc not found the difference betwectt perfect and intpei(ect dryiicss till the first inflexion point appears, b t the gas dried intpcifectly ir,dic:itcs the first inflexion point at sour=what lower presure and the second inflexion point at considerably lower pressure, and after the points larger volume change occurs than the gas dried yerfectly wept is the case of the partial pressure ratio Nh1,: Cfl_=3: I, Fig. 9. The 1'V-P rchition, in the rtscs of the adcLtion of 0,8 and ago water vapa.ir to the gas mixture of the partial ptes-swe ratio ArH:;:COa=1:1 at li>n'C, is shown in Fig. 13. The liquid phase is not (oand at 3it0 a4n in the cases of the dry gas mizb.ue and the addition of 0.3 go water valxrtr, but (omtd at Il0 :,tm in the case of ago water v.gro.ir.


\\rhen the monotonous cwve is inflected in the I'V-Y diagram of the gas mix- huc, the mixture begins either to react, or to condense under the condition of the inflexion point in the coarse of the compression. As shown in Fig. 4, it is considered that the white solid phase produced- from the gas mishrre under the condition of the inflexion point below 1?~'C is ammonium carbnmate. The yie.d of ammonium caib:anlte becomes small \vith increasing temperat .ne and in the case of 129'C the solid phase is scarcely found even rafter the inflexion point appears and Yte PV-1' curve is a nwst monotonous. At the condition of the in- flexion point above 129'C it is considered that the gas mixQire produces and ]voter in the gas state until it reaches sattu:rtion. The comparison beriveen the , at which the mixttres produce the liquid phase as shown in Figs. 5 and G, and the calculated vapour pressures of ammonium '1 at the snore tens- Table 3 peratureis shownin fable?. 1'hepres- I Pressurenun soresof the secondinflexion point are \Cnn.iiiion NH;:C01 ~\~''Ording to Aa»rA.of independentthe c alculated vapour •1•e,,,. ~ auumrs ratligan txraure °\ 1a 9:1 °:1 pressures of anunonium carbamate. Ac- t°_9 -a ss 99 cording;a, it can be considereJ that the too ac uo of gas mixture does not start to pwdace only the liquid phase of ammonium car- 1Gi ioe ~a.. ~a

d) l:. P. I:gan, J, li. Ports mtd f.. I/. Pons, /ar/, ' TheReview of Physical Chemistry of Japan Vol . 21 No.1 (1950) i

S - P.. KI1'A\Laxnd 5. AI]NCiTII~RA

bamate at the second inflexion point, but the wen and wabs in the gas Mate produced from the gas roixhtre after the first inflexion point ::hove I•2~'C,reach srkrtation noel start to condense.

Conclusion. ]Below the nornnl tcmperab.ire and pressure, the PV-Y diagr:un of the gas mixture cf ammonia and carbon dioxide indicates an inflexion point and the position shifts to the side of high pressure with increasing tcmpcrahu'c and after the point the mixture prod~ccs ammonium rub:unate. The Iowcr the tempera- tare and the more excessive :unmoiia is, the large: the yleid is at the con_tant intervals of time. The reactio.t is remnrlcab'.y influenced by the e'. to vapour slightly Contained. At high tempentt,.rre and pressure, the P\%-P curve of the gas mixture shows an inflexion point be:ow 1.29'C at:d hco inflexion pouts above I•39'C and the Fositio:t shifts to the side of high pressure tcith increasing temperature. Ile:ow It?p=C the gas mixture prahces :mmonirm c;ubamate and above 14!1'Cat.uts the urea fonuation in the gas state at the first inflexion point. 'This indic:aes that the gas phase exist till the second inflexion point and begins to condense at the second point. The po::ition of the condensation in the PV-I' rliagnm is remarl:ab;y in0~ieitced by the total pre~serc, partial pressure ratio and water vapour. '1'l :c :uutltoa expre,.c hcvly thank to the nliris4y of I{d ce.tion (ur the Scientiti_ liescarch Grant

T/tt Lrrbora'ory of P/rysical Cluwtislr}', hj•ola Uai.~n•sity.