SOME C H IN ESE CLAYS AS ADSORBING AGENTS. 183
G.CLAY PER 20 M L.RAPESEED OIL
Fig. 3.
Ta b le I I I .
Decolorization o f Rape-seed Oils.
Clay. Oil.* T em p.,
° C.
% Colour U n rem o v ed a fte r T rea tin g , g. C lay p er 20 m l. Oil.
0-2. 0-5. 1-0. 1-5. 2-0. 3-0.
I R - l 110 ___ 75 65 __ 55 __
I R - l 200 — — 77 — 68 62
I I R - l 110 75 61 44 —- 25 10
I I R - l 180 —- 74 56 — 33 19
I I I R - l 30 84 — 60 — 45 39
I I I R - l 110 — 69 46 —. 26 14
I I I R - l 180 85 67 51 — 35 25
I I I R -2 110 — 60 48 33 28 16
I I I R -2 180 — 62 44 35 26 16
IV R - l 110 80 67 49 — 30 13
IV R - l 180 — 67 48 — 25 15
V R -I 180 — 84 72 — 57 46
V I R -2 110 — 63 42 31 25 15
V I R -2 180 — 55 35 22 18 11
* Colour o f b o th th e original oils in A .S.T.M . colour n u m b ers is 3 J m inus.
184 STIEN AND YAO : Ta b l e IV .
Decolorization o f Lubricating Oils.
Clay. Oil.* T em p .,
° C.
% C olour U n rem o v ed a f te r T re a tin g , g. C lay p e r 20 m l. Oil.
0-5. 1-0. 1-5. 2-0. 3-0.
I I L -l 200 59 49 — 39 35
I I I L -l 110 75 67 — 60 59
I I I L -l 180 77 64 — 50 46
I I I L -l 200 64 53 — 43 41
I I I L-2 110 68 60 48 43 30
I I I L-2 180 67 53 44 38 27
V L -l 180 70 60 — 53 52
V I L-2 110 65 51 41 35 26
V I L-2 180 58 40 30 22 16
* C olour o f th e o rig in al oils in A .S.T.M . co lo u r n u m b e r : L - l, 8 m in u s ; L-2, 4£ m in u s.
De g t t m m in g o f Ga s o l i n e.
T he procedure for degum m ing te sts was a m odification of th e vapour- phase tre a tm e n t m eth o d previously described.7 A 500-ml. ro u n d -b o tto m flask was fitted w ith a P yrex-glass colum n of 35 m m . inside diam eter and a b o u t 30 cm. high, which in tu r n was fitted w ith a th erm o m eter an d connected to a condenser. T he outside of th e colum n was w ound w ith one or tw o layers of asbestos tw ine to p rev e n t excessive h e a t loss. One h u n d red gram s of th e clay u n d er investigation were packed in th e column, covering a d e p th of ab o u t 14 cm.
T he clay packings in th e colum n were in th e form of eith er ta b le ts or granules. As th e acid -treate d collyrite d isin teg rated com pletely to a fine pow der, it was pressed into ta b le ts ab o u t 12 m m. diam eter an d 4-5 mm.
dep th . T he u n tre a te d clays were sim ply broken in to granules an d screened.
T he 3-4-m esh size was used for packing. T he halloysite granules firmly retain ed th e ir form , w ith o u t an y disintegration afte r long use. T h e colly
rite a n d cim olite granules, however, w ere n o t v ery strong. T h ey form ed an appreciable am o u n t of sm all particles during th e tim e of use, an d m ight cause some tro u b le b y clogging up th e colum n. T his fa c t m ay be of considerable im portance from th e engineering p o in t of view.
T he gasoline sam ples em ployed were v ery low -grade p ro d u cts obtained in th e p la n t by cracking of tu n g oil. T h ey contained considerably more higher-boiling fractions th a n are com m only included in gasolines. A 200-ml. po rtio n was used in each d istillatio n over th e clay. O nly the fractions boiling u p to 200° C. were collected. T he residue, in average am ounting to a b o u t 20 per cent, of th e charge, was discarded before the n e x t 200-ml. gasoline sam ple was distilled. E ach d istillatio n to o k about 20-30 m inutes. T he clay -treated distillate was w ashed w ith alkali and w ater an d its gum co n ten t determ ined b y th e copper-dish m eth o d .9 B lank te sts w ith th e colum n packed w ith th e sam e volum e o f b roken porcelain were also carried out. D uring th e tre a tm e n t th e clays grad u ally blackened, indicating th a t chem ical reactions were tak in g place.
T he sta b ility of th e clay -treated gasolines was also te sted . Com posite
SOME C H IN E SE CLAYS AS ADSORBING AGENTS. 185 sam ples were stored in glass bottles and placed in th e dark. T he colour intensity, acid num ber, and gum content of these samples were determ ined from tim e to tim e.
The experim ental results are given in Tables V and VI.
Ta b l e V .
G um Contents o f Clay-treated Gasolines (mg. per 100 m l.).
N o. o f C ut. C lay I. C lay I I . C lay V. C lay VT.
G asoline . G-3 G-3 G-3 G-4
B lan k 285 285 285 189
1st 277 35 53 —
2n d 257 54 — 1
3 rd 282 63 45 —
4 th . . 222 _ — 13
5 th 239 27 56 —.
6 th — 65 __ 22
7 th . . — 52 66 .—.
8 th . . — 134(?) — 36
9 th . . — .59 67 —
10th — 126 59 30
11th — 99 _ .__
12th — 139 45 26
13th — 290 45 —
1 4th — .—. —. 32
15th — — 40 .—.
16th — .— — 31
17th — — 63 —
18th — —. .— 21
19th — — 121 .—.
20 th — — 100 23
22nd .—. — — 13
24 th — .—. —. 16
2 6 th .— — — 15
28 th — — .—. 29
3 0th — — — 36
Ta b l e V T .
S ta b ility o f Clay-treated Gasolines.
T im e A fter T reatin g .
G asoline G-3 T re a te d w ith Clay V.
G asoline G-4 T re a te d w ith C lay V I.
Colour. * A cid No. G u m .f Colour.* A cid No. G u m .f
F re s h . 2-5 _ 64 0-2 _ 36
1 w eek 3-3 —. 30 0-3 0-24 31
2 w eeks — — .—. 0-3 0-14 29
1 m o n th 4-2 0-40 60 0-4 0-19 •36
1J m o n th s . .— — — 0-5 0-35 16
3 m o n th s — — — 0-7 0-30 49
7 m o n th s 14-2 0-26 180 —■ — —
* Colour in te n s ity is t h a t e q u iv a len t to % K 2Cr20 , solu tio n X 103.
t G um c o n te n t in m g. p e r 100 c.c., d e te rm in ed b y copper-dish m eth o d .
186 S U EN AND YAO : Di s c u s s i o n.
The various clay sam ples showed different degrees of effectiveness in th e individual treatm e n ts. I n général, th e T sunyi halloysite sta n d s o u t as th e m ost active am ong all th e clay sam ples studied. I ts gum -reducing capacity is p artic u larly im pressive. As show n in T able V, afte r th ir ty distillations it was still useful. T he experim ents were discontinued only because th e gasoline sam ple in use was ex h au sted . T he cim olite is effective as a gum -reducing agent, b u t its decolorizing pow er is poor.
T he u n tre a te d collyrite is hard ly useful, an d becomes active only b y acid tre a tm e n t. T he different processes o f tre a tin g th e collyrite bring ab o u t v ery slight variations in th e decolorizing power. T he choice o f sulphuric acid or hydrochloric acid is therefore inconsequential, an d th e a d d itio n of salts shows no beneficial effect.
T he acid tre a tm e n t of clay is a tedious process. I n th e p resen t cir
cum stances it is n o t advisable to carry it o u t on a large scale. F o r this reason no a tte m p t was m ade to a c id -tre at th e cim olite a n d halloysite.
Among th e oil sam ples investigated, th e resistance to bleaching varies w ith th e individual oil sam ples, as shown in T ables I I to IV . T he effect of tem p eratu re during th e decolorization is q uite noticeable, th e optim um te m p eratu re of tre a tm e n t being different in different cases. F o r th e gasolines, m oderate tem p eratu res seem to be suitable. F o r th e rape-seed oils, 110° C. gives b e tte r results in m ost cases. F o r th e lu b ricatin g oils, tem p eratu res of 180-200° C. ap p ear to be m ore advan tag eo u s th a n lower tem peratures.
I t is som etim es considered t h a t a clay w ith a higher ra tio of silica to alum ina has a greater adsorbing pow er.5 This does n o t agree w ith th e d a ta o btained here. T he halloysite has a m uch lower ra tio of silica to alum ina th a n th e cimolite, b u t shows a fa r g reater a c tiv ity .
As a gum -reducing agent th e halloysite m ay be a dvantageously applied industrially. W ith th e d a ta given in T able V, a sim ple calculation shows th a t 1 to n of clay will yield a t least 12,000 gallons of gasoline w ith a copper-dish gum content below 30 mg. per 100 m l., stab le a t le ast for a few m onths, which is quite perm issible for o rd in ary uses. A t th e p re
vailing prices of th e item s involved, th e cost of clay tre a tm e n t of th e gasoline is estim ated to be only a fractio n of 1 per cent, o f th e to ta l cost.
Moreover, according to th e experience of th e U niversal Oil P ro d u cts Com
p an y of Chicago, w hen converting th e yield o f gasoline per u n it q u a n tity of clay from th e lab o rato ry -test d a ta to p la n t scale a facto r of a t least 10 should be m ultiplied.8 I f th is is also tru e in th e presen t case, th e cost of tre a tin g w ith clay could be fu rth e r reduced.
Ac k n o w l e d g m e n t.
T he au th o rs wish to express th e ir g ra titu d e to Mr. M. C. W ang of these L aboratories for analysing some of th e clays. T h ey are also in d e b ted to th e Ceramics D ivision of th e C entral B ureau for In d u stria l R esearch for supplying th e cimolite sam ple, to g eth e r w ith its chem ical analysis, an d to Prof. S. C. Liang, of th e D e p a rtm e n t of C hem istry, N atio n al Chungking U niversity, for th e loan o f th e K le tt colorim eter used.
SOME C H IN E SE CLAYS AS ADSORBING AGENTS. 187 Literature Cited.
A .S.T.M . D esig n atio n D 155-39T .
D a n a , “ T h e S y ste m o f M ineralogy o f J . D. D a n a ,” 6 th E d ., p p . 634-697, J o h n W iley & Sons, N ew Y o rk . 1920.
N u ttin g , O il db Gas J ., 1933, 32 (26), 17.
P a n a n d P ’eng, B u ll. Geological S u rvey Szechuan, 1939, N o. 2, p. 81.
S tag n er, “ Science o f P e tro le u m ,” Vol. I l l , pp. 1699-1705, O xford U n iv e rsity P ress, L o n d o n , 1938.
Su, Y . P ., P r iv a te c o m m u n icatio n , F eb . 1943.
Suen a n d W an g , J . Chinese Chem. Soc., 1941, 7, 93.
‘‘ U .O .P . L a b o r a to r y T e s t M ethods for P e tro le u m a n d I t s P ro d u c ts ,” p. 184, U n iv e rsa l Oil P ro d u c ts Co., Chicago, 1937.
Ib id ., p. 213.
188