Title Reaction between ammonia and carbon dioxide under highpressure

Author(s) Kiyama, Ryo; Minomura, Shigeru

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

Issue Date 1951

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

Right

Type Departmental Bulletin Paper

Textversion publisher

Kyoto University

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

REACTION BETWEEN AMMONIA AND CARBON DIOXIDE

UNDER HIGH PRESSURE.

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

Introduction.

Generally a chemical reaction under high pressure is performed in the iron

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.

Experimentals.

(1) Materials. The prepemtiou of ammonia: Ammo:ria.gas is evaporated 6om liquid am

monia in a bomb, dried by passing through calcium oxide, kaliem bydroxide

and over metallic natrium, phosphorus 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 sodium bicarbonate

in a Terex tube fitted with glass n•ool plug to catch solid particles, dried by

passing through sulphuric acid and over phosphorus pentoxide, 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 mercury 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 partial

pressure ratio is detc.mincd by Dl, ar.d the volume change of the gas mist:rc

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 temperatures pas renrr°uf p ezom.ier To pump of 0, 10, IS, 30'C and at the inteu•al of :30 minctes. (1n the other hard, B tl V ~-F1

F/ the gas mixture is led in V and Yhc

pmtial pressure ratio is determined by \'I, and the total pressure change a

v M is measured h}' n1, at -18~100'C M1 3 7

v M: 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 capillary part and the bomb containing the swelling part of the piezometer,

to keep a desired temperature of the reaction and to deconllwse ammonium car-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:uk i, TIr%r Jounnel, 21, 50 (1951) R. Kiyanm and K. inooe, ibnl., 21, i3 (1951)

R Kiyamn, 'C. Ikegami and I:. moue, rb%rt., 21, u8 (1951) 2) R Kiyamn mul ti. Kiacshim, tbiC., 19, d3 (19A,^.)

voirr p ezom.ier 7u P

8 ~~ IlV-F1

M3

F~

o~

n

~v

Mi 3

b

Mt

REACTION RETR'l?RN ADfJ10NIA AND

The Review of Physical Chemistry of Japan Vol. 21 No.

CAP.BON DIOXIDE UNDF.A IIIGA PRESi[IRE 3

//. oo

9.00

~7. 00

S. 00

).GD _~

r• ~~.

.,r n~~

presen

the es

Ihrnug

under tl'.

10 cmH

ire-tem

curve F1

th decree

C. The

preesui

f the ga

e t. T

than in t

COQ=2

dicates t

ime.

r vapor

he case

1 (1950)

,~

°/0

V 0 O

0.

00

~o~~ ..-z ..~i

/8

/o

'o

.~ 1p TI \'.

~-

B~

A~

8

2

~,1

~i~

I I. I / V 2 o s fo /s ~o ).oo -zo o ao ro

PrrnHg 7=~

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

temperature.

(h) The isoeores. 'I he reaction under the conditions of the temperature, -~O~.I00'C, the total pressure about 10 cmHg and the partial pressure ratio

NHa:C0,=4:1 is shown by the pressure-temperature (P-T) diagram in Fig. 3. 1'he gas mixture does not react on curve A, b.it reacts on Curve B, and the

pressure change of trove $ is larger with decreasing temperature. "1"he dissocia-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 pressure. The apparent }'field derived from the p:essme change at -13'C of the gas mixtures of three kinds of the

partial pressure ratios is shown in Table 1. The Table 1 excess of ammonia gives the higher yield than in the

r Pactial pressure ratio field case of the partial pressure ratio AH,:CO,=2: 1, rrrl, , cp: ;o though the excess of carbon dioxide indicates the 2.05: t.00 55 same yield at the constant intervals o[ time.

SO.Ib 1.00 90 (d) The inFlnence of the water vapour, Loo 7.73 55 The ,taming points of the reaction in the case of

the gases dried only by passing through the drying materials are shown on curve

toa

I

I

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

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

action starts and the position of

the lxrint appears at high pressure

With inaeasingtennenture. At1'_'9L

the crave is nearly monotonous.

13clou~ 1°9'C the white solid phase

begins to appear at the conditions of

the tengterat~ue and pressure of the

inflcxinn point and disappear when

the pressure is decreased at the same

tempcraturc. Alxwe l-3~'C thu «•lfolc

space of the rcac[ioa vessel is occupi-

ed only «ith the gas phase and the

reaction dues nol p:a:eed eo acaua-

tely revcrsib;e at the cona,ut inter-

vals of time as in the case below

1•>9'l . 'fh

c 1'V-P staves, under the

conditions ~~f the temperatttes 1°9,

li;0 and 165'C, the tot d pressure L

-•If0 ahu and the partial pressure

shown in Pigs, ii, f, and 7. Lvei}'

Fig. i, in which the second inHexiou

C ~J~ e

1.S ~?

9 ° .+ ~,

II 1.6

4

F r 3 'oo , n ~

o r.1

0 ~ Qo d 1 r ~.

L0 \

0.8

0.7 0 20 40 60

P etm

ratios NH,: CO_=3 : 1, 3 : I and

isotherm has hvo inllcxio,t l:oi nts

point is (ound only at 12`t°C and

80 /oo

I : 1, are

except in

not (ound

tr

t.a

~.~

i.a 0

i,.

r ~.t

Q• ~.~~ G

'i 0.g

n.~

Q_7

n,fi

REAC7lON nE1lVY:1•:N .Uf\iONU1 AND

~Qt\ ~S

~ f

~rl _ ~~

.\' ..

' S ti

0.:1 1:1 ^

0 7 6 1.9 0

i

0.F I,i

~_~ i --' 0 90 -Ill 6u s0 IW lJn I•III P ,'U •10 fU SU l00 1911 140

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 unlinales u( Digs. F and i :ue shua'u by the

rigid ;uul left respectively.

at l:~ and I6a'C until :1OD atrn 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

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

CARBCIN DIO.l"IDE I?N DI:K IfiCll PP.IiSSCRk: 5

LI1 so

r e 1_]

/'C

1.4

t•:1 f

r = 1 ""~ 1.1 ..,J~ 3 1s ~JO• _~

o. I,0 ° I, II o .r9, >

> 4 L4

i

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

6 R. 6r1':\NA mul S.

in the case u( the partial pressure ratio

\II,:CO,=3;1 and reaches equilibrium

eithin about ti miuraes at I:iO arm and

indicates tL'c higher v.rlue than at 90 atm

atul the velocity'o( the volume change is

too first to drag the quantitative change of

the diagram of the J field.

(e) The influence of the water vapour.

The PV-P curves; when the gas mixture

contains slightly the water vapour as men-

tioned in Exp. (L): (d), under the condi-

tions of the temperature IGir'C, the total

pressure I--IGO ahn and the partial pressure ratios \TIh:CO.,=:3: I, S; 1 and I : 1, show

VISr)31 t"F:1

ee

to

w

JO

JO

IQ

0

T°

-2

3 4 5

0 ~p 10 )0 t0 SO ~0 ]O f0

T.m. m,p

r~~;. s. l'airvc 1; I~H~:C(L=%:I, Ib0°C., 150 ahn.

l'arvc :: Nki~:C(t.=3:1, 150°C, ;p ahn. Curve S \fI;:C0.=__°: 1, I50°C, 3110 anu. ('un~e {; Hllz:f.(1_=°;1, I+tO°(', I:A ahn. Cun'c 5; SlIp:COr=::1, 150°C, 110 ~tne

the sank' first and second inflexion

1.6

l.u

L{

A 1.3 - l ,_^

'II

0 1.0 c_

> 0.9

0,8

0,7

0.6

'mar

~C

~.

Ls

l.fi 0

t,~

1;3 e

1..

I,1

LG

o,o

os

U SO 40 fi0 9f1 loll 1`.'A 1~IU 1110 P atm

Pig. 9 Curves 1 and 9: Nii~:0O.=3:1, IGS°C.

Pig. 10 Curves 3 and 9; Nltya?0:=9:1, IG5°lL

Curves land 3 are the cases of the mislures dried

by passirg through and preserving nn the dging

nulerinls. Cures 7 and ~ are the cvscs of the

mislnres dried only by Lassing Ihra~.gh the drr-ing

u~llerinls. The oNinnl rs of Figs. 0 and 10 are

shown by the left and rigid resparively.

I,fi

j 1,5 n.

1;1

La

~1 ..

],1

i

\r

'~

1

2

3

4 5

i s„

ii 1:5~

La _~

is ° 0

1.^.~ c.

1.1

o ro ao sa loo Lo lao lso

P atm

Fig. 11 Curves 1 and °; NI4~:C0.=1:I, IG5°CL

Fig. IS Curves 8, 4 and :r; NIia:Cn_=J:1, IfiO°C.

Curves I and .^, are the vises of the mia ores dried In' passing through and preserving ou the drying materials. Carve _ is Ore vase of the mice ore .I rial mly Lv Ixising ilun~gh the dryitrg nra~crials.

Cures 4 and d arc the e~scs of the mislwes added the wnlcr vapour 0.8 and tJ$£ respGa ivcly. The 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)

RISACTION BIiT\\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.

Consideration:

\\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 urea

and ]voter in the gas state until it reaches sattu:rtion.

The comparison beriveen the pressures, at which the mixttres produce the

liquid phase as shown in Figs. 5 and G, and the calculated vapour pressures of

ammonium carbamate'1 at the snore tens- Table 3

perature is shown in fable ?. 1'he pres- I Pressure nun sores of the second inflexion point are \Cnn.iiiion

NH;:C01 ~\~''Ording to Aa»rA. independent of the calculated vapour •1•e,,,. ~ auumrs rat ligan

txraure °\ 1a 9:1 °:1pressures of anunonium carbamate. Ac-

cording;a, it can be considereJ that the

gas mixture does not start to pwdace

only the liquid phase of ammonium car-

d) l:. P. I:gan, J, li. Ports mtd f.. I/. Pons, /ar/,

t°_9

too

1Gi

-a ss 99

ac

ioe

uo

~a..

of

~a

i

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

S - P.. KI1'A\La xnd 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'C at.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.