close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2120227

код для вставки
Patented
June'14,
'
i
_
‘
l
I
_,
‘
UNITED STATES PATENT OFFICE‘ . ‘
PURIFICATION OF GLYOEROL
GilbertW. Brant, Buffalo, N. Y., assignor’to E. L
du Pont de Nemours & Company, Wilmington,
Del., a corporation of Delaware
.
No Drawing; , Application April 21, 1937.
_
Serial No..138,230
‘
16 Claims. .(Cl. zoo-156.5)
This invention relates to the puri?cation of
\
.
with the atmosphere or substances having a low ‘
glycerol, and more particularly, it relates to the
pH, or exposed to light for extended periods of
removal of odorous impurities as well as’ odor- ~ time, will develop an odor even- though it waswa
producing impurities from glycerol to render the
ter white and practically odorless when. freshly
5 same suitable for use inregenerated cellulose
structures.
''
prepared.
‘
5
This objectionable character of glycerol is no
The production of glycerol as it is known in the
art comprises the evaporation of impure, dilute,
a
doubt due to the fact that certain odor-develop
ing impurities are distilled over with vthe glycerol
water-glycerol mixtures to obtain crude glycerol
10 of about 80% concentration. Priorto thev evaporation, certain types of impurities are more or
even with those fractions distilled within care- '
fully chosen temperature ranges.
10
Whether or not these objectionable character'
less'completely removed by precipitation as the
istics'of glycerol have been known before, they
salts of heavy metals and ?ltration. The 80%
crude glycerol which is still very impure is steam5.4 G! distilled under ‘vacuum to obtain ‘a more or less
impure, once distilled glycerol of 95% concen-,
tration or higher. This once distilled glycerol is
then redistilled and decolorized to obtain glycerol
have been found to be especially obnoxious in the
production of . regenerated cellulose P61110185 in
which glycerol is used as a softening agent.
15.
vIn the manufacture of regenerated cellulose
?lm, large amounts of glycerol are required to
Produce properly‘?exlblllzed materialisuch ?lms
of C. P., U. S. P. and similar qualities. The color
20 is removed by treating the glycerol with a small
quantity of decolorizing or activated charcoal for
usually contain 10-20% or more of glycerol as '
a softener for the cellulose. When this glycerol ‘20
is not of the highest purity, the ?lms may'develop
a relativelyshort time, c. g. 10 to 60 minutes, at ' an obnoxious odor which makes it unsuitable for
a temperature of 75° to 80° 0. and ?ltering. Com- .many uses- The ?lm. fcrlnstance. has, wide an
mercial glycerol’ of c. P., U. s. P. and similar plicaticn in the wrapping and packaging of food- '
25 qualities contains impurities which are dependent stuffs. When obnoxious odors are developed in 25
} upon the quality .of crude glycerol used, the tem- such ?lm, not only is the package Objectionable,
perature to which the glycerol‘has been subjected , but the material wrapped acquires this obnoxious , .
during" distillation, the nature of the impurities
Odor ‘which persists lifter unwrapping, t0‘ the
originally present, and the care exercised in the detriment‘ of the value of the goods. Further
30 various processing steps. To obtain. glycerol or more, many of the products wrapped in this cel- ,30'
the highest commercial grades, only high grade, luloee ?lm'are Judged by their aroma, Such for
- crudes can be used. In some cases double dis-
example a6 tobacco Products, 018815 and (3188-
tillation and decolorization-of what are considered
to be high grade crudes-fail 'to yield glycerol of
35 sufficient purity for satisfactory use for purposes
in which odor is objectionable. Such glycerol may
be water-white and entirely satisfactory. in all
rettes, coil’ee, ,bakery products and perfumed
articles. Any variation in the fragrance of the
package or of the article contained therein will be 35
'most detrimental to the value of the article. A.
Serious feature 01 the Problem 18 the 810W develop
. respects except that it has an objectionable odor ' ment of the odor when the, glycerol. Or a regen
or develops such an odor under the conditions - erated cellulose ?lm containing the glycerol is
40 of its subsequent use. . '
.
v > Heretofore, only glycerol which, as commer-.
‘subjected to certain agencies or conditions. The. 40,‘
glycerol, as obtained from the manufacturer, may
cially produced, is sufficiently free from odorous - be and Very often is crystal 01681‘ and quite free
, or‘ odor-forming impurities to be acceptable for‘ from odor, but not from odor forming substances.
' these critical uses, could be so vused. In'most However,_after impregnation of the ?lm and sub
‘ 45 cases-additional distillation treatment does not
appreciably improve the glycerol in this respect.
It has been considered necessary. therefore, to
discard for these uses, all glycerols which, as
commercially produced, do not meet the rigid -'
‘,0 requirements of such uses ‘with respect to this~
characteristic.
7
>
"
'
sequent treatment‘required to ?nish the film; an- is
odor may be developed which makes the film ‘
quite valueless for the purpose for which it was
designed. Even’more seriousisthecaseinwhich
the recently manufactured .illm still has no de
tectable odor, but where such-an odor eventually 50
develops ~after“the him has been-used to wrap
‘It has been found that previously known glyc- > merchandise and prior to use of the merchandise.
erol of high grading, in some cases even so-call’ed~ - In such a case the loss in value{of the merchan-,
chemically pure glycerol, when used for
55 purposes where it will be maintained in contact
.disemayhe many times the Value. Of the ?lm; reference to the development of the odor, 55
2
2,120,227
In general, these objects are attained by add
ing to glycerol of inferior quality a‘ small amount
of powdered, activated carbon, preferably a car
bon of vegetable origin, mixing it thoroughly
therewith and maintaining it in contact with the‘
glycerol, preferably with continued agitation, for
a period of at least 6.and preferably 12 to 24
hours and then separating the ,carbon from the
it is often impossible to guard against such dif
ficulties, and it may'even be impossible to detect
such odors before the merchandise reaches the
consumer because such odors may not be detect
able except in con?ned spaces.
‘
The peculiar requirement in the production of
regenerated cellulose ?lm, therefore, is an ade
quate supply of glycerol of such puritylthat it
‘not only possesses no co1or‘,,nor odor, but will re
The activated charcoal to be used in accord 10
main colorless and odorless when subjected to
the severe conditions of heating and oxidation "ance with this invention should, be either an acid
encountered in the preparation of the .?lm, or charcoal or the charcoal-glycerol mixture should
when subjected to conditions that tend to develop‘ be slightly acidic. By the term "acid charcoal"
such an odor over a long period of time. It is is meant charcoal, the water extract of which is
15 necessary that glycerol for this purpose shall be distinctly acid in character. Ten grams of acid
of a purity in excess of thatheretofore required charcoal, when leached with 100 cc. of distilled
by U. S. P. or CJP. standards. The mere absence water will yield an acid extract having a pH
value of below 6, and preferably between 2 and
of odor in glycerol as obtained from the manu
facturer is not sufficient evidence that ?lm in 6. An acid charcoal of this type is found to have
_
glycerol.
.
.
su?lcient acidity to make a charcoal-glycerol
20 which it is used will have, or will develop no un- '
mixture slightly acid. When using a charcoal
desirable odor. The odor in‘ the ?lm is deter
mined by the following test applied to an un having a neutral or somewhat ‘alkaline character,
the charcoal-glycerol mixture should be adjusted
coated ?lm:‘ A sheet or ?lm measuring approx
imately 18 inches by 40 inches is tightly rolled. tohave a pH value less than '7.
In accordance with the preferred embodiment
26 The roll is cut into short sections which are
allowed to fall into a clean, dry glass bottle (dis- ' of this invention, the glycerol is simultaneously
carding the two end sections which have'been treated with an oxidizing agent, preferably hy
handled). The bottle is closed by a cardboard drogen peroxide, and an activated vegetable
cap lined with a layer of the same ?lm as that charcoal of the type above described, at a tem
30
30 being tested. After standing for a period of one perature below 50° C., and preferably below 40° C.
hour at room temperature, the cap is removed After the glycerol has remained in contact with
and the air inthe bottle is smelled to note if any the charcoal for a period of at least 6 hours and
preferably 12 to 24 hours or more, the latter is
_ odor can be detected.
It may readily be appreciated that once the ?ltered off at room temperature.
The following detailed. examples will serve to
35 glycerol is incorporated in the ?lm, and the ?lm
subsequently develops an objectionable odor be
illustrate several speci?c embodiments of the in- .
cause of the glycerol, it may then be too late to
vention, it being understood that the invention is
not to be speci?cally limited thereto.
take steps preventing the spoilage of ?lm by the
remainderv of that particular batch of glycerol,
Example 1‘
40 which by that time, may have been consumed.
40
The following. accelerated tests applied to a
Hydrogen peroxide (‘calculated at 100% H202)
sample of the glycerol will enable one to predict in quantity equal to 0.05% of the glycerol weight
accurately whether or not the glycerol to which ‘is mixed with 95% glycerol in a suitable mixer.
it is applied will be satisfactory when used in Finely powdered activated carbon, the water ex
45
45 ?lm: Ten cc. of glycerol and’ 10 cc. of distilled tract of which is distinctly acid, and which is
water are mixed in a 100 cc. beaker. Ten cc. of
known to the trade as Nuchar-WA, in quantity
0.5% sulfuric acid are added and the mixture equal to 2% of the glycerol weight, is then added
heated to 75° C. The glycerol is then allowed to and the whole agitated for 16 hours at room tem
cool to 55-65° C. and is tested for odor by smell
perature. The mixture is then passed through a
50 ing the same. Glycerol which develops no more ?lter press at room temperature, until a crystal r
than the slightest trace of odor in this test has clear product is obtained. The ?ltered glycerol,
been found to yield a perfectly satisfactory prod
when tested for developed odor with sulfuric acid
uct, when‘ used as a softener for regenerated cel
as'described above, is found to develop substan
lulose ?lm.
55
'
tially no odor.
been subjected to the usual distillation and decol
oration with charcoal, but which still develops an
odor under'the conditions of the above test may
a BI
Hydrogen peroxide (calculated at‘ 100% H202),
in quantity equal to 0.06% of the weight of the
glycerol, is mixed with 95% glycerol in a suit
be further puri?ed and thereby made quite satis
able mixing apparatus. 2.5% of ?nely powdered
factory for use in the manufacture of regener
ated cellulose ?lm.
'
Example II
It has now been found that glycerol which has
60
activated vegetable carbon,_the water extract of
_
which is distinctly acid, is added to the mixture.
Water is added to the mixture to bring the total
substantially free from odor-forming impurities. , strength of the glycerol to 85%. The whole mass
is slowly agitated for 14 hours at room tempera
It is another object of this invention to‘pro
65
ture to prevent the carbon from settling. The
‘duce glycerol that will remain substantially color
less and odorless after standing for an extended mixture isthenpassed through a ?lter_,press
period of time under conditions which cause the until it runs crystal clear, after which it is passed
It is therefore an object of this invention to
produce colorless andodorless glycerol which is
>
to a storage receiver. The ?ltered glycerol, un
duce glycerol that will remain substantially col
orless and odorless ,when used .in regenerated
clear for long periods of time without develop
development of odor in less pure glycerol.
70
_
der normal storage conditions remains crystal "
It is a further object of this invention to pro
cellulose structures.
.
‘
Other objects of the invention will be ap arent
76 from'the description that follows.
-
ing any noticeable odor. , The. ?ltered glycerol
_
may be used for softening of regenerated cellu
lose pellicles which will not develop any notice
able odor due to the glycerol present even ‘though 71
9,120,227
permitted to stand for a prolonged period of time
in-an enclosed space.
Example III
I
_
3
could be re?ned by the treatment of my inven-"
tion to make it suitable for the most critical uses
in which odorous glycerol is most objectionable.
'
-
Hydrogen. peroxide is obtained in 30%. aque
A quantity of 95% glycerol is- mixed with 2.5%
cus solution; at. the time of use, its condition as
‘of the weight of the glycerol of ?nely powdered > determined from analysis should approximate the
activated vegetable carbon, the water extract of speci?cations. It is well known that upon stand
which is distinctly acid, and which is known to the ing, some detericration‘results.
trade as Nuchar-W. The mixture is slowly agi
Although hydrogen peroxide is much superior
10 tated for a period of 16 hours at room tempera
to other similar oxygen yielding substances, it is 10
ture, after which it is passed through a ?lter also possible to employ, in lieu of a solution of
press. - The glycerol which ?rst passes through hydrogen peroxide,‘ such as that sold commer
the ?lter press is returned to themixture until it cially, any solution which yields hydrogen perox
runs crystal clear, after which it will be passed ide under ‘the conditions of’ treatment. Thus, I Y
'15 to a storage reservoir. The ?ltered glycerol is may use a metal peroxide, or a solution contain
suitable for use in the production of regenerated ing an alkali metal peroxide such as sodium per 15
cellulose peilicles which are to be used for wrap-' oxide, or an alkaline earth metal peroxide with
ping focdstuifs and the like. Ten cc. of the ?l
an acid such as sulfuric or hydrochloric. Simi
tered glycerol added to 10 cc. water and v10 cc. of
larly, I may use a solution of .a metal persalt such
20 0.5% E804 and heated to 75° C. and then cooled
will give o?' only the slightest trace of odor.
Thevegetable charcoal that I prefer to use is
a material made from residual organic material
incidental to cellulose manufacture, such as the
25 waste products‘ of paper. mills, and which has been '
activated in such a manner that due to its source
as an alkali metal percarbonate, an alkali metal
perborate or an alkali metal persulfate in an en
vironment providing an excess of acid. In brief,
any solution which yields hydrogen peroxide un
der the maintained conditions speci?ed in the process, or is equivalent to hydrogen peroxide un
der these conditions comes within the scope of
my invention. Also, ozone may. be added to the
solution or generated directly therein by means
of an ozonizing apparatus or gaseous oxygen may
and-method of activation, its water extract is dis
tinctly acid when tested with litmus paper. 'I
> have found that the product known to the trade
E30 as Nuchar-W, which is distributed by the Indus
25
' be passed in under pressure. lflthe presence of
trial Chemical Sales Company, Inc., 230 Park ‘small amounts of certain impurities in the result-' 30
Avenue, New York City, is particularly well suited ing glycerol‘would not, be injurious, or if it is
to this process. In its powdered formit is char
desired to remove these impurities by means of
acterized as having not more than a small amount further treatment small additions of aqueous so
35 of water extractable material and an acid con
lutions of chlorine or hypochlorous acid may be
dition upon the surface as indicated by the rela-.
made; in this case, the impurity remaining in the
35 .
tively lower pH of an extract of the carbon made ' glycerol will be hydrochloric acid. Other oxidiz- I
with neutral water.
However, any carbon‘ ob
ing'agents that might be substituted include the
‘‘
alkali chromates, the'dicheomates or'permanga- ,
40 surface condition will be suitable. Activated nates.
charcoal which is neutral or somewhat alkaline '
While glycerol obtained as aby-product in the
tained from a vegetable source and having an acid
may also be used if the charcoal-glycerol mix- .
soap industry has been chiefly considered, this
method of puri?cation may be appliedfor the re
ture is slightly acid. Such a mixture should have
a pH value less than '7 during the entire puri?
45
moval of odors from glycerols from other sources,
such‘ as fermentation processes and syntheses.
The glycerol to be puri?ed may be treated in ac 45
cation procedure. Activated charcoal of other
1 origin than vegetable, such as bone char, as well
as other adsorption agents having a strong ad- ‘
cordance with the present invention in relatively
sorption for odors, although somewhat inferior
to vegetable charcoal, may be used for the pur
pose of this invention if properly activated so that
the water extract of the adsorption agent is dis
tinctly acid. While it is preferred to suspend the
adsorptive material in the glycerol as 'a ?ne pow
der during the period of treatment, it is also pos
'55
sible to maintain beds of granular or powdered
material and circulate the glycerol therethrough.
high concentrations or diluted with ,water. ’ Glyc-.
erol containing as high as 50% water may be
treated advantageously as well as 95% glycerol.
.
I have found that crude glyecrol subjected to U
distillation, even several‘successive distillations,
does not give an odorless product when applied
to regenerated cellulose ?lm, nor does the accel-.
erated test that I use of ‘acidifying and heating
the glycerol so puri?ed "indicate a. satisfactory
It is necessary that the charcoal remain in‘ con product. The use of chars'for thelrremoval'l‘of
tact with the glycerol for a period of at least _6 color from glycerol is well known in the art:
60
hours and preferably for a period of fromv 12 to 24, however, in-such known decolorization methods
hours in order to obtain the required results. It it was only necessary to treat the glycerol for
is also preferred ‘that’ the treatment with the relatively short periods. (generally 10 to 30 min
charcoal be carried out at a temperature of'less
than50° C. It appears that in the treatment of
glycerol with charcoal as generally '- practiced
65 heretofore, it was considered that after a period
utes). Prior‘ to‘ this invention-it was unknown
that odorous’impurities i‘n-a liquid system, such
of 10 to 60 minutes,'it was useless to continue the
as glycerol, can be removed by the char, when
they are not removable by distillation, the com-.
mon‘ method of puri?cation of glycerol. Sur
.treatment' with the. charcoal; that the" charcoal
prisingly,_the treatment with char in accordance
had functioned to its optimum capacity. The fact I with the present invention removes not only. the
that if the treatment of glycerol ‘with activated ~ odorous substances-from glycerol, giving thereby "
charcoal ‘is continued for from 8 to 24 hours it an odor free product, but‘ removes as well sub
will removeodorous constituents as well as odor
stantiaily ‘all potential odor-forming materials
developing impurities comes as a‘great’ surprise. which may subsequently develop an odor either
Itjis still more surprising to ?nd thatrelatively v in regenerated cellulose ?im,'or in the accelerated
poor grades of glycerol which‘were never com ‘ test that is describedl'abovez It ishighly unob
75 templated for use where odor wasclziectionabile‘r vious that certain impurities will be removed from
9,120,227
-
a grade‘ of glycerol that may be crystal clear and
quite free from any objectionable ‘odor, which
maintaining glycerol in contact with an acti-l'
vated carbon with continuous agitation forjsuch
use of hydrogen peroxide. in connection .with
acid will be substantially free from. odor, the
are, in themselves, not odorous, but which may a period of time that a 50% aqueous solution of ,
develop an odor when subjected to the conditions ?ltered glycerol so contacted when heated to 75°",
C. with one-half its equivalent amount of 0.5%
obtaining in the preparation and use of regener
solution of sulfuric acid will be substantially free
ated cellulose ?lm.
While a satisfactory product may be obtained from odor, the glycerol-carbon mass having a
by the above-described use of vegetable char alone _' pH value of less than 7, and separating the ‘glyc
.
for the puri?cation of distilled glycerol, it is erol from the carbon.
3., The removal of odorous and odor-forming
10 preferred to use in conjunction with the char
constituents from glycerol which comprises
a simultaneous treatment with hydrogen perox
ide or the like. There are several advantages maintaining glycerol in contact with an activated
to be gained by a combination of the two reagents. carbon at a temperature of less than 50° C. for
First, it has been found that the addition of a such a period of time that a 50% aqueous solu
tion of ?ltered glycerol so contacted when heated
small amount of hydrogen peroxide will mate
rially reduce the amount of char necessary to to ‘75° C. with one-half its equivalent amount of
0.5% solution of sulfuric acid will be substantially
‘accomplish the puri?cation. Second, it will like
wise decrease the time of treatment. Third, the free from odor, the glycerol-carbon mass having
use of hydrogen peroxide results in a product of a pH valueof less than '7, and separating the
'
slightly higher purity than that obtainable in its glycerol from the carbon.~
4.-The removal of odorous and odor-forming
absence. Tests have shown that‘the treatment
of glycerol with hydrogen ‘peroxide without the constituents fromv glycerol which comprises
use of char results in a product which is in no maintaining glycerol in contact with an acti
wise improved and which, in many instances, is vated carbon for such a period of time that 'a
25 more odorous when used in regenerated cellulose 50% aqueous solution of ?ltered glycerol so con
film than glycerol which has not received such tacted' when heated to ‘75° C. with one-half its
treatment. It is surprising, therefore, that the equivalent amount of 0.5% solution of sulfuric
char would give an improved product and a more
satisfactory process of treatment.
30
glycerol-carbon mass having a pH value of less
than '7, and separating the glycerol from'th'e
It should be observed that the actions of - the
carbon.
I
5. The removal of odorous and odor-forming
hydrogen peroxide and of the char are not in
constituents from glycerol which comprises
dependent and ‘for this reason the preferred puri
?cation treatment consists of the simultaneous, maintaining glycerol in contact .with an acti
35 application of both hydrogen peroxide and char. vated carbon for aperiod of at least 6 hours, the
It might be supposed. that a relatively ‘high glycerol-carbon mass having a pH value of less
temperature of operation would be desirable due than _'7, and separating the glycerol from the
'
to the viscosity of the glycerol. There are certain carbon.
'6. Theremoval of odorous and odor-forming
objections to the use of‘ a high temperature and it
constituents from glycerol which comprises
has been found that a suitable‘ product is more
'. readily obtained at low temperatures. At high
maintaining glycerol in contact with an activated
without performing its function and the char
does not function as e?iciently in adsorbing the
45 odorous products. Therefore, the preferred tem
perature of treatment is below 50° C. ‘To obtain
the glycerol-carbon mass having a'pH value of
less than 7, and separating the glycerol from the
temperatures the hydrogen peroxide is destroyed vegetable carbon for a period of at least 6 hours,
carbon.
constituents from glycerol which comprises
the best results, it is necessary that the treatment
maintaining glycerol in contact with an activated
carbon for a period of at least 6 hours with con
tinuous agitation, the glycerol-carbon mass hav
ing a pH value‘ of 'less than 7, and separating
be exendedv over a period of hours, preferably
between 12 and 24 hours.
50
It is desirable [that the filtration as well as
the treatment be carried out in the temperature
range'specified for the treatment because, to heat
‘the mixture before the separation of the char,
would serve to liberate, in part at, least, the im-'
the glycerol from‘ the carbon.
maintaining glycerol in contact with an activated
carbon for a period of at least 6 hours at a tem
perature of less than 50° C.,'the glycerol-carbon
mass having a pH value of less than 7, and
separating the glycerol from the carbon.
9. The removal of odorous andvodor-forming
spirit of, the invention. It is therefore to be un
60 derstood that the invention is not to be limited
except as set forth in the appended claims.
constituents from glycerol which comprises mix
ing .with glycerol ?nely divided, activatedvege
table carbon the water extract of which is dis
1. The removal-of odorous and odor-forming
which
tinctly acid, maintaining'said carbon in contact
comprises v
with said glycerol for a period of at least 6 hours,
maintaining ‘glycerol ‘in contact with an activated
vegetable carbon: for such a periodgof time that
and separating the glycerol from the carbon.
a 50%..aqueous solution of ?ltered glycerol, so
contacted when heated to 75° C. with one-half
10. The removal of odorous and odor-forming
constituents from ‘glycerol which comprises mix
ing with glycerol ?nely divided,» activated vege
its equivalentfamountlof 0.5% solution of sul
table carbon the water extract of which is dis
70 furic acid ‘will be-‘substantially free from odor,
tinctly acid, maintaining said carbon in contact
the glycerol-‘carbon 'mass having a pH value of
less than PI,‘ and separating the glycerol from the
-2. The removal of odorous and odor-forming
with said glycerol for a period of'at least 6 hours
with continuous agitation, and separating the
glycerol from the carbon.
constituents from glycerol‘ which*comprises
11. The removal of odorous and odor-forming
carbon.
75
'
8. The removal of odorous and odor-forming
constituents from glycerol which comprises
55 purities adsorbed upon the surface of the char. ‘
' It is obvious that many changes and modi?ca
1 tions can be made in the above-described pro
- cedures without-departing from the nature and
constituents ‘from vglycerol
, -
"I. The removal of odorous and odor-forming
.
_
_
2,120,227
5
constituents from glycerol which comprises mix- '
14. The removal of odorous and odor-forming
ing with glycerol ?nely divided, activated vege
constituents from glycerol which comprises
table carbon the water extract of which is dis
maintaining glycerol in contact with an activated
tinctly acid, maintaining said carbon in‘ con
carbon and hydrogen peroxide for a period .0!
tact with said glycerol for a period of at least at least 6 hours, the glycerol-carbon-hydrogen
6 hours at a temperature of less than 50° ,C., peroxide mass having a pH value 'of less than
and separating the glycerol from the carbon.
7, and separating the glycerol from the carbon.
12. The removal of odorous and odor-forming
15. The'removal of odorous and odor-forming .
constituents from glycerol which comprises constituents from - glycerol which comprises
10 maintaining glycerol in contact with an activated maintaining glycerol in contact with an activated
carbon and an oxidizing agent which will re
carbon and hydrogen peroxide for a period of at
lease nascent oxygen during the process for a least 6 ‘hours at a temperature of less than 50°
period of at least 6 hours, the glycerol-carbon _ C., the glycerol-carbon~hydrogen peroxide mass
oxidizing agent mass having a pH value of less having a pH value of less than 7, and separating
15 than 7, and separating the glycerol from the the glycerol from-the carbon.
'
15
carbon.
'
16. The removal of odorous and odor-forming
13.» The removal of odorous and odor-forming constituents from glycerol which comprises mix
constituents from glycerol which comprises ing .with ‘glycerol ?nely divided, activated vege
maintaining glycerol in contact with an activated table carbon, the water extract of which is dis
20 carbon and an oxidizing agent which will pro
tinctly acid and hydrogen peroxide, maintaining 20
duce hydrogen peroxide in the process for a ' said carbon and hydrogen peroxide in contact
period of at least 6 hours at a temperature of with said glycerol for a period of at least 6 hours,
less than 50° C., the glycerol-carbon-oxidizing and separating the glycerol from said carbon.
agent mass having a pH value of less than 7,
25" and separating the glycerol from the carbon.
,
GIIIBERT W. BRANT.
26
Документ
Категория
Без категории
Просмотров
0
Размер файла
756 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа