Patented Aug. 3, W48
2,446,273
UNITED STATES PATIENT‘ OFFICE _,
2,446,273
PURIFICATION OF SLUDGE ACID AND
ACTIVATION OF CLAYS
Wright W. Gary, Los Angeles, Calif., assignor to
Filtrol Corporation, Los Angeles, Calif;, a cor
poration of Delaware '
No‘ Drawing. Application November 9, 1943,
Serial No. 509,632
2 Claims.
(Cl. 252—-301)
1
2
Sulfuric acid is employed in petroleum tech
nology in various Ways, and the end product of its
utilization is usually a sludge composed of un
of hydrocarbons, by acid treatment of a sub
bentonite clay of the montmorillonite group.
‘
Such sludges are produced when acid is em
ployed as a treating agent for light hydrocarbons
In the process of my invention sludge acids,
produced by action of water on the sludge, may
be puri?ed by treatment with clay, and the puri
?ed acid employed in producing acid treated clay.
In employing the carbonaceous sludge acid in
my process the resulting acid treated clay con
tains the carbonaceous impurities of the. acid.
These impurities are removed by calcining the
clay in an oxidizing atmosphere such asis em
ployed in the regeneration stage of a catalytic
such as gasolne and kerosene and also when em
cracking operation,
ployed in the puri?cation of lubricating oils and
in the production of so-called medicinal white
In the process of my invention active clays of
high adsorption and catalytic properties may be
obtainedby diluting the acid sludge and then,
reacted sulfuric acid, petroleum sulfonates, in
cluding the sulfonic and sul?nic acids of the hy
drocarbons present in the petroleum to be treated,
and also sulfuric esters of complex character to
gether with dissolved hydrocarbons usually of ole
?nic character.
sludge.
Such material is termed acid
oils. A new source of acid sludges arises from the
use of sulfuric acid as a polymerizing agent and
as an alkylating agent.
with or without separation of the acid oils and
tars, contacting the diluted sludge with sub-bene
In the alkylation process the acid of about 98%
tonite clay at a relatively high temperature
strength is contacted with iso-paraf?ns, such as 20 around 200° or 215° F. for the period, of time
iso-butene, and with unsaturated hydrocarbons,
necessary to cause the desired extraction of alu
such as butenes. As a result of this operation the
mina, and then washing and ?ltering the clay.
The clay thus produced will be contaminatedwith
iso-para?in alkylates the unsaturated hydrocar
bon. The acid becomes fouled, it is believed by
a considerable amount of organic matter com
workers in this art, due to the dehydrogenating 26 posed of tars resulting from the extensive poly
e?ect of the sulfuric acid on ole?ns. The result,
merization of the hydrocarbons and sulfuric acid
it is believed, is the formation of highly unsatu
reaction products present in the sludge. I may
rated hydrocarbons soluble in the sulfuric acid.
then pellet the clay by any appropriate procedure
The concentration of the acid thus'decreases dur
such as extrusion through'dies in an extrusion
ing use, due to dilution by these organic com 30 press. The tar products present in the clay assist
pounds in the acid. The acid is usually discarded
the pelleting operation by acting as a supple
when it reaches a concentration of 85% to 90%,
mentary binder. I may then subject the pellets
more or less.
'
to combustion with air at a temperature of about
In the polymerization process the ole?nic hy
1000" F. to 1100° F. in a Herreshofl’ or Wedge fur
drocarbons, such as butene and isobutene, are 35 nace or in a regeneration unit such as used in
mixed with sulfuric acid at relatively low tem
regenerating catalysts employed in catalytic
perature and the acid hydrocarbon complex
cracking. The combustion of the organic matter
heated to an elevated temperature. The hydro
is controlled by controlling the concentration of
carbons become polymerized. The acid becomes
oxygen, diluting the air with fuel gas if neces
spent after a number of cycles of re-use.
.
40 sary. The combustion of the tars and coke in
creases the porosity of the clay pellet.
,
It is well known that unsaturated and other
organic bodies may be separated from such acid‘
_ The following examples illustrate my process
and are intended not as a limitation but as an ex
sludges on dilution with water. The oily fractions
empli?cation of my invention. While the ex
so separated are termed acid oils. The diluted
acid is still contaminated by polymerized bodies, ; amples given relate to the use of alkylation sludge
acid, the process illustrated may be applied to the
carbon, and other organic impurities. The dilu
acid sludges obtained in the acid treatment of
tion with water separates dissolved organic bodies
gasoline, kerosene, or lubricating oil cuts or re
whose solubility in dilute sulfuric acid is low.
sulting from use ina polymerization operation as
Oils are separated out by hydrolysis of the sul
‘described above.
, furic, sulfonic, and sul?nic esters. The elevated '
The spent alkylation acid discarded from a sul
temperatures obtained on dilution accelerates the
furic acid alkylation unit will usually contain
dehydrating, carbonizing, and polymerizing effect
about 85% to 90% of HzSO4 and from 10 to 15%,
of the acid on the organic matter of the sludge
more or less, of water and dissolved organic mat
acid.
'
ter. This acid may also contain free carbon.
The utilization and puri?cation of such acids
This acid is mixed with water in an amount suffi
present a substantial problem. I have discovered
cient to give a separated acid of about 60%
that I may employ such acids in the acid treat
acidity. The temperature rises from about 260°
ment of clay, particularly in the production of
catalysts to be employed in catalytic conversion 60
F. to 270° F.
-
Acid oil separates from the diluted acid and the
2,446,278
4
3
phases are separated. The diluted acid will carry
about 1% to 2% of carbon and carbonaceous ma
terial. The acid-water phase is best termed
"sludge acid.”
I may employ these sludge acids for the treat
ment of sub-bentonite claysof the montmoril
lonite class such as have been in the past ‘acti
vated by acid treatment. ~Anexample ‘of "such
clay is anhydrous clay of the following anal
ysis:
mayxthus constitute themake-up-whichis add
ed to make up for losses of catalyticpellets in
such an operation.
The pellets may, of course, be separately
treated either in a moving bed type of appa
ratus or a Herreshoff or Wedge furnace. In such
operation the pellets are treated and contacted
.at. a temperature ofiabout 700° to 1000° F. with
an oxygen containing gas, such as air or air
10 fuel gas mixture. The pellets of any such pro
cedure are puri?ed by the burning of the car
Per cent
Silica (S102) ___________________________ __ 67.3
Titanium oxide (TiOz) __________________ __ 0.3
Aluminum oxide (A1203) _______________ __ 19.5
Ferric oxide (F9203) ____________________ __
1.8
Manganese oxide (MnO) ________________ __ 0.8
Magnesium oxide (MgO) ________________ __ 6.9
Calcium oxide (CaO) ___________________ __ 3.2
- bonaceous material.
Instead of employing the sludge acid as pro
duced by the treatment action previously de
15 scribed, I may further purify the acid before
using the acid.
Such acids may -.be thus _- pro
duced in‘vpurity substantially equal to the purity
of commercial sulfuric vacid.
.
I have found that if acid sludge produced. in
99.8 20 the acid treatment of petroleum fractions, .01‘
produced in the sulfuricacid polymerization of
I‘ may employ the acid in dilutionof 'fromlO to
unsaturated gases, or in the alkylation of iso
60%,'preferably about 10 to 20%, an'd'mix the
para-l?ns by unsaturated gases, .isdiluted and
acid in such dilution with clay. The amountv of
the. liberated acid-oil separated from the..dilut
‘acid used, calculated as anhydrous H2304 ‘free,
ed acid, the residual sludge acid may bepro
may vary from 20 to ‘250% of the‘ clay used, cal
duced in adequate purity by contacting the ,di
culated as volatile/free. As an example,'I may
luted acid with a native, untreated sub-bentonite
employ from 30% to 50%. The clay vand the
clay or‘with an adsorbent clay such as previ
acid is reacted at about 210 to 215° F. The du
ously acid treated clay. The acid thus produced
ration‘ of‘treatment‘ is such as toextract a pol‘
is ofsuchpurityasto be useful in theproduce
tion of the clay by reaction with the acid to re 80 .tion of. the acid treated montmorillonite clays.
duce the Clay to about 10 to 20% of R203, (that
.An acid sludge produced in polymerization or
is, the sum of A1203 and FezO3),'mainly A1203
alkylation and employed in the following ex
withfrom'about l-to 2% F6203, for example 17%
ample was a viscous liquidhaving a strong odor
R203 ofwhich 15.5% is A1203 and 1.5% is Fezoz.
and an acid content of-.-84.3, the remaining .15.’?
“The'clay‘is then separated from the acid and
was composed of. some water and organic mat
washed substantially‘ free of acid‘ and dried and
ter. The sludge was heated to a high tempera
ground. Such clay will ‘be an active'decoloriz
ture to carbonize and coagulate the organic
ing and catalytic clay.
matter. Considerable separation of organic mat
The clay will be contaminated with carbona
ter was obtained. The sludge was forti?edwith
ceous material and polymerized tar, and other
fuming acid to further carbonize the organic
organic material present in the sludge.
matter and the carbonized matter was. settled
Such clay vmay be further puri?ed by heating
and the. puri?ed acid decanted. Substantial septo a temperature of about l000° to-1100°>F.‘and
aration of _the organic matter was thus ob~
exposing the hot clay to oxygen vcontaining'gas.
tained. ‘The sludge was boiled to. coagulate the
For example, the clay'may be fed-into the re
organic .matter, thus producing a viscous mass
generator of a ?uid type catalyst unit _where ‘it
of organic matter. The viscous mass was leached
is mixed with the clay undergoing regeneration
for the removal of dilute acid. The acid thus
and the carbonaceous material is burned out.
produced was adjusted to aconcentration 7. of
I may specially treat the clay in a Herreshoif
about 15% and employed for the acid treatment
or Wedge furnace such as has been used'for the
of clay as previously described.
regeneration of'spent contact clay employed in
_ The ‘acid may be produced in greater purity
the puri?cation of lubricating oil. The hot clay
is contacted with oxygen containing gas'and the
carbonaceous impurities are‘burned out.
Another procedure is to pellet the clay. ‘The
dry clay, usually about‘20' to 30% 'moisture,'is
mixed‘with water su?icientto give a pelleting
for the purposes of my process by contacting said
acid with clay. The diluted,_recovered acid ob
tained by the. above describedprocedures was
diluted to a concentration of about? 30% 'to 40%
H2SO4. The diluted acid of about 40% strength
was treated with clay such as .native, sub
mix" of say 40' to 45%, and extruded from to‘form
bentonite, montmorillonite clays such as used in
cylindrical pelletsyfor example, ‘115' of an inch
the‘ production of acid treated, decolorizing and
in "diameter and 1/6 ‘of an inch long. ’The pel 00 catalytic clay. ‘This contacting was carried out
"lets are dried carefully to reduce‘the moisture
at ordinary room temperatures and the acid and
content to about 15 ‘to 20%.1 The-pellets are
‘clay separated ‘substantially immediately, that is,
hard.
The carbonaceous material acts as a
binder. The carbonaceous material‘in the pel
no reaction time vwas provided above that neces
sary to produce the ‘contacting and separating
lets may be burned out by calciningv the pellets ($5 operation. ‘The clay was‘ thus subjected to minor
at a temperature of about l00D°'F. in an oxidiz
and ‘inconsiderable rea'ction’with the acid. For
ing atmosphere, The removal of‘this material
example, the acid of 40% strength was percolated
adds to the porosity and the activity of the'cat
through arcolumn of raw sub-bentonite clay such
alyst material.
‘
This may be accomplished by adding the pel 70 as employing a ratio of 14 pounds of clay per ‘100
pounds of ?ltrate ‘produced. The ?ltrate pro
lets-to the stream of spent catalyst moving? from
a moving bed catalystreaction chamber to a
moving‘bedcatalyst regenerating unit. ‘These
pellets are mixed and exposed to combustion re
generationin the regenerator of' the unit. They
duced had an acid strength of about 38%. Thus
substantially no consumption of acid by clay was
experienced. Instead of‘ employing the percolat»
ing -contacting method I maysemploy the. contact
2,448,278
5
?ltration method in which the clay is mixed with
the diluted acid and then separated by ?ltration.
The above ?ltrate was employed in the activa
tion of the sub-bentonite clay, for example, clay
whose analysis is given above. The acid concen
tration in the mixture of clay and acid was 8%,
calculated upon the total water content of the
clay-acid mixture. The amount of acid employed
proved if the acid ?ltrate, before it is employed
for activation of clay, is aerated by bubbling air
through the ?ltrate. When this blown acid solu
tion is employed in activation as described above,
the results obtained are substantially similar to
that of the unblown ?ltrate, giving clays having
substantially the same efficiency,
The color of
the clay, however, is improved, being almost
was 35% of H2804 (calculated as anhydrous),
white.
based upon the clay (calculated as volatile free). 10
While I have described a particular embodi
The resultant clay will be of a ‘composition simi~
ment of my invention for the purpose of illustra
lar to that given above for treated clay, to wit,
tion, it should be understood that various modi
?cations and adaptations thereof may be made
10 to 20% R203, for example, 17% R203, composed
within the spirit of the invention as set forth in
of about 15% A1203 and l to 2% F6203. The acid
consumption of such extraction will be from 50 15 the appended ‘claims.
I claim as my invention:
to,75% of the acid consumed by reaction with
1. A process for producing acid activated clay
the clay. The clay produced by activation was
and puri?ed sludge acid, which comprises con
white in color, showing no contamination by or
tasting a sub-bentonite clay with puri?ed sludge
ganic matter and had a catalytic and oil decoloriz
ing activity comparable to that produced em 20 acid to extract a material proportion of the alu
mina of said clay and to consume a substantial
ploying commercial grade sulfuric acid.
proportion of the acid in said activation and to
The concentration, reaction time, and amount
produce an acid activated clay, separating said
of acid here given are illustrative only. I may
acid activated clay from the sludge acid, diluting
employ the acid in any concentration and amount
and for any time where it is necessary to obtain 25 with water an acid sludge produced by the treat
ment of hydrocarbons with sulfuric acid, separat
the degree of extraction desired.
ing a sludge acid from said diluted acid sludge,
Instead of employing percolation through or
‘which sludge acid is contaminated by carbona
contacting with raw clay, I may purify the diluted
ceous impurities, contacting said sludge acid with
sludge acid, contaminated by carbonaceous im
purities, by contacting the acid treated clay, 30 the above named acid activated clay for a time
insufficient to cause any material consumption of
either by percolation or by contact ?ltration. I
said sludge acid, and separating the sludge acid
may use for such pretreatment and acid puri?ca
substantially free of carbonaceous impurities
tion an acid activated clay produced by contacting
from the acid activated clay ‘containing said im
the puri?ed sludge acid with native clay as de
scribed above. I may employ an acid activated 35 purities and employing said sludge acid to extract
additional sub-bentonite.
clay, commercially produced by activation, with
diluted commercial sulfuric acid. Thus the sludge
acid may be mixed with acid treated clay having
a high decolorizing activity such as described
above in an amount of 3.7 grams of clay (contain
ing 20% volatile matter) per 100 grams of
?ltrate produced. After the mixture was made,
it was immediately ?ltered without allowing any
2. A process for producing acid activated clay
and puri?ed sludge acid, which comprises con
tacting a sub-bentonite clay with puri?ed sludge
40 acid to extract a material proportion of the alu
substantial reaction time. The ?ltrate produced
had an acid strength of 35.3% H2SO4, substan
tially free of carbonaceous impurities. The yield
of acid was 96.8% of the charge showing that
substantially none of the acid was consumed by
reaction with the clay. The resultant clay will
be contaminated with the carbonaceous impuri- '
ties of the sludge acid.
The resultant acid was employed in activating
clay in the manner described under previous ex
amples wherein from 25% to 75% of the acid is
mina of said clay and to consume a substantial
proportion of the acid in said activation and to
produce an acid activated clay, separating said
acid activated clay from the sludge acid, diluting
with water an acid sludge produced by the treat
ment of hydrocarbons with sulfuric acid, s'epa
rating a sludge acid from said diluted acid sludge,
which sludge acid is contaminated by carbona~
ceous impurities, contacting said sludge acidmth
the above named acid activated clay for a time
insu?icient to cause any material consumption of
said sludge acid, separating the sludge acid sub
stantially free of carbonaceous impurities from
the acid activated clay containing said impuri
consumed in the activation of the clay, producing an‘ Cl ties, and heating said clay in an oxidizing atmos—
phere to lburn off said carbonaceous impurities
clays having activity comparable to that pro
and employing said puri?ed sludge acid to extract
duced in ordinary commercial treatment employ
additional sub-bentonite clay.
ing diluted commercial sulfuric acid. The clay
'
WRIGHT W. GARY.
produced had only a slight brownish tint, show
ing substantially no contamination by organic 60
REFERENCES CITED
matter. This clay may be used for the above
puri?cation to produce a countercurrent acid
The following references are of record in the
process of puri?cation and clay activation.
?le of this patent:
The clay employed in the puri?cation stage
UNITED STATES PATENTS
will contain the carbonaceous impurities removed 65
from the sludge acid. This clay may be treated
Number
Name
Date
as described above either in its granular form or
in its pellet form to burn oif the impurities as
described above.
The resultant acid activated clay is One of high 70
catalytic and adsorbent activity.
The color of the clay produced by treating with
reclaimed acid, as described above, may be im
1,953,144
1,960,348
2,018,987
2,044,341
Wilson ___________ __ Apr. 3,
Pongratz _________ ._ May 29,
Wirzmuller ______ __ Oct. 29,
Wollner ________ __ June 16,
1934
1934
1935
1936
2,066,685
Hechenbleikner ______ Jan. 5, 1937
2,139,026
2,222,400
Matheson ________ __ Dec. 6, 1938
Butz _____________ __ Nov. 19, 1940