Note: Descriptions are shown in the official language in which they were submitted.
~C~t7C~7~
The present invention relates to a single-stage,
catalytic process Eor preparing butanediol-(1.4) from maleic
anhydride, maleic acid or mixtures of both compounds.
Butanediol-(1.4) is used, for example, as initial pro-
duct for preparing polyester fibers; in this process butanediol-
(1.4) is reacted, for example, with terephthalic acid at elevated
temperature in the presence of catalysts to yield polybutylene
terephthalate.
Processes for preparing butanediol-(1.4) are already
known. Besides a number of formerprocesses with syntheses based,
for example, on acetyleneformaldehyde or 1.4-dihalogenobutane
processes for preparing butanediol-(l.~) by using as starting
material ~-butyrolactone haverecently been described.
Economic and technically utilizable processes for
directly preparing butanediol-(1.4) from maleic anhydride r
or maleic acid have not been known, hitherto. It is true that
maleic anhydride may be converted into butanediol-(1.43 in a -
yield of at most 64 %, but ~aney cobalt used as catalyst in
said process is not ~uitable for technical continuous operation,
as it is dissolve`d and deactivated in an irreversible manner by
maleic anhydride and maleic acid partly formed intermediary
already after a short period. The reaction moreover requires -
extremely high pressures of about 800 bars and temperatures of
about 275C, at which the diol formed is again dehydrated with
considerable formation of tetrahydrofurane.
When using nickel molybdate or nickel chromate catalysts
described in former processes butanediol-(1.4) is obtained from
maleic anhydride only in a yield of about 50 % besides
. ~ ~
,
.
~7~t~
conside~able qua~tlties of tetrahydrofllrarle. T~ s process
also requlres very high pressure of about 800 bars which
may only be obtained with difficulty technicallyO Sa~d
catalysts are also unstable when used in long-time operatio~
and are dissolved and deactivated by acidsSlike ~ecopper
chromi~tm oxides known for ester hydrogenations. The same
applies to pure nickel catalysts.
When using catalysts which are clascrlbed as being stabler
towards acids and contàin for example rhenium, rhenium-
molybdenu~cobalt or nickel~molybdenum-rheniu~l or nickel-
rhenium~ maleic anhydride or maleic acid can only b~ co~1~erted
into butanediol-(1.4) up to at most 9 to 14 ~oO In this proce~s
there are formed asMain products in a yield of partly more
than 90 % succinic acid, tetrahydrofurane and ~ butyrolactone.
In this case as well a dissolution, especially of the nick~l
or cobalt portiorls of the catalysts~ takes place. In other
disclosed cases butanediol-(1.4)is not at ~lformed from malelc
acid anhydride or maleic acid when using rhenium catalysts,
but only succinic acid. The same applies to platinum and
20- rhodium catalysts. Whon ~1sing palladium catalysts, for example
palladium/carbon catalysts, maleic anhydride may only be
hydrogenated to the stage of ~-butyrolactone or the reaction
i~ Qtopped at the stage of succinic acid.
A catalytic process for preparing butanediol-(1.4) has
now been found9 in which maleic anhydride or maleic acid or
mixtures thereof may be directly converted into butanedi~l-
(1.4) in a one-step reaction with excellent yields and con~
versions and a very high ser~ice life of -che catalysts.
29 This i~ very surprising as acceptable yields snay only
.~ ~J
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71~
be obtained accordi~g to the state of the ar~ wi~h unstable
catalyst~ ab~olu~ely unsuit~le for technlcal long-tirne
operation.
When using stabler catalyst~ ~ery low yields of
butan0diol-(l.4!. if any~ are obtained or only succinic
acid.
The present invention proYides a process for preparing
butanediol-(1.4) from maleic anhydri~le; maleic acid or
mixtures thereof, which comprises hydrogenating maleic anhy-
dride, maleic acid or mixture~ th0reDf in one step in thepresence of catalysts comprising simultaneously eleme~ts of
subgroup VII or compound~ thereof and elements of subgroup
VIII or compounds thereof or mixtures of these clements and
- compound 5 .
The novel pr~cess is espocially distinguishcd by the fact
that by~products ~uch as tetrah~Ydrofurane, ~-butyrolactone
and succlnic aci`~ are not obtained practically and that the
formation of n-butanol disclo~ed in literature concernlng
hydrogenations of maleic anhydride and maleic acid to yield
tetra~ydrofurane and ~-butyrolactone i.5 lnSignifiCaIlt.
The noYel proce~s for preparing butanediol-~1.4) is
con~equently a tochnically simple and very economical method,
in which pro,blems involved with waste products~which may be
observed in the former processes for preparing butanediol- :
(1.4) from dihalogenobutanes do not occur.
The catalysts used in the noYel process contain elements
or compounds of elements of subgroup YII as well a~ of sub-
group VIII of the Periodical Table, with the inc~usi.on of
29 mixtures of el.ements o~ one group with cornp~lds of eleme.ts
: J
,...'
- ' : . ::
, ~
.~7~
of the other group~ ~speoially sultable elements are manganesc~
rhenium~ rutheniutn, rhorlium, palladium, osmium, iridium,
and platinium. Rhenium~ palladlum and platinum are used
preferably~
An especially surprising advantage in the novel proces~
resides in the ~act that a selectivity of butanediol-(1.4
may be obtalned by a simple combination of elements of sub-
group VII or compounds thereof with elements of subgroup VIII
or compounds thereof, which cannot be obtained when using
alone elements o~ one group or compound~ thereof, especially
with rhenium or palladium, ~.
Moreover, it was not to be expected that practically
quantitative conversions o~ maleic anhydride and/or maloic
acld co~ld thus be ~tained without a notable less of activit~
of th~ catalysts accord~ng to the invention. The combination
according to the invention of the elcmeItts of subgroup ~II
with elements o~ subgroup VIII, especially rhenium and
palladlum9 and/or their compounds has therefore ~urprlslngly
a considerable ~tabilizing effert and lncreases significantly ~:
the service life o~ the catal~sts as compared to those
described in the former literature. This ~s of decisive
importance for technical lo~g~tlme operation and as a result
th~ no~el process is superior to the prior art proces~es~
In the process according to the invention the catalysts
are generally used in a pulverulent form. They may also be
used, however, in a tabletted ~orm or mixed wi~h inert ma~
terials optionally s~rv~ng as a support.
Suitable carr~r~ are, for example. silicon dioxide,
29 titanlum dioxlde, ~ilicon dioxide aluminium oxide~ carbon
- 5 -
.
: . ' '' , :
07~
thorium~oxide, zlrconium oxide, silicon carbide~ spinels and
aluminiu~ oxid2.
I~ supported catalysts or those mixsd with inert materials
are use~, the quantity of the catalytically actiYe ~ub~tances
i5 generally in the ranFe from 0~1 to 50 ~ by wei~ht of the
total quanti-ty of the catalyst~ The quantity of the inert
materials (carrier) is consequently in th~ range from 99.9
to 50 ~ of the total mass o~ the catalyst J
The ratio of the elements of subgroup VII and those o~
subgroup VIII is in the range from 99:1 to 1:99, pre~erably
from 10:1 to 1:10.
The catalysts may be present ~n the form of elemants as
well as compounds or as mixture~ o~ both, optiona:Lly together
with carriers, Consequently they may be prepared by uqln~
direc~y sui.table compolmds being optinally supported or by
reducing these compounds to a more or less consid0rable
extent, optinally up to the stage o~ the ele~ents.
Suitable compounds to be used are, for example: oxide~
hydrated oxides, carbonates, nitrates, borides, carboxylates
20- (such as acetates, propionates, butyrates), chelates of
1.3-diketo compounds (for examp~e enolates such as acetyl
acctonates, benzoyl acetollates, acetoacetic acid ester com-
pounds). Especially suitable are carbo~ylates, acetylaceto-
nates, oxides and hydrous oxides. For technical and
econom~cal reasons the use of rhenium9 ~or example, in the
~orm of potassium perrhenate or rhenium heptoxide and of
palladium in the form of palladium(II) acetate or acetyl-
acetonate is especially ad~antageou~, a~ these compo~nds are
29 commercially availabe.
- 6 -
7C~7~L
For preparing, for example, palladium-rhenium catalysts
a solution of a palladium carboxylate or of a compound reacting
with carboxylic acids to yield palladium carboxylate such as
hydrous palladium oxide, palladium nitrate, palladium hydroxy-
carbonate or a salt of a 1.3-diketo-compound such as acetoacetic
acid ester or acetylacetone in an anhydrous or water containing
carboxylic acid together with perrhenic acid or its salts is
applied on the carrier, by impregnating, immersing or suspending
the carrier material or by spraying. Instead of palladium
carboxylate there may also be chosen a compound reacting with
carboxylic acid to yield a palladium carboxylate, for example
the hydrous oxide, the nitrate or the hydroxycarbonate of
palladium. The carboxylic acid is then eliminated by drying
at higher temperatures in vacuo or under atmospheric pressure.
The catalyst may now be directly used, but is treated preferably
in the gaseous or liquid phase at a temperature from 15 to 200C
with reducing agents.
Suitable carboxylic acids are all liquid aliphatic
carboxylic acids having from 2 to 10 carbon atoms which may be
vaporized in vacuo without being decomposed. Acetic acid,
propionic acid or butyric acid, are preferably used, especially
preferred is acetic acid.
The solutions of both compounds used for preparing
the catalysts, for example of a palladium salt and a rhenium
compound may be applied separately on the carrier material,
but the palladium and rhenium compounds are preferably dissolved
in one carboxylic acid. It is also possible to apply firstly
one of the aforesaid palladium compounds on the
7~L
carrier m~ter:;a.]. antI to apply th~r~a~ter th~ 501ution of
a rhenllml compound in a carboxylic acld. The carriers may be
pulveruleIlt or ~hape(I 9 for example as granules 9 p~llets,
tablets, compressed extruded materials, saddles, rings or
tubes having a honeycomb structurn.
The reductio~ o~ the catalysts tnay be performed in the
liquid phase, for example with hydrazine hydrate, but i9
carried out advantageously at ele~ated te~nperatures, ~or
example in the range from 100 to 200C in the gaseous phase
with reducing vapors or gases such as hydrogen, methanol~
formaldeh~de, ethylene, propylene, butene ~in a diluted or
undiluted form. Stronglr diluting at the beglnni.ng with inert
gases such as ni.trogen, carbon dioxlde or noble gase~ and
~ncreasin~ the coneentration of the reducing agent in ~he
measure as the reduction progresses has pro~ed especially
advantageous so tha-t the reduction may be terminated for
example in pure hydrogen, The reduction may be per~ormed
in ~ separate devlce as well as in the apparatus used for
converting malelc anhydride and/or ~aleic acid into butane-
2~ diol-t 1.4).
The catalysts may be pyrophoric~ In this case they must be
tre~$ed adequatly. Reducing the catalyst and reacting maleic
acid and/or the anhydride in one apparatus is especially
advantageous in thl.s case.
An important factor for performing the single-~ctep
direct pl'OCeSS of the invention on an industrial scale is
that succinic acid is not formed practically, an acid which
would readily precipitate owing to its extremely low solubility
29 and cause obstructlon of the apparatus or requIre a further
~,
:
step 3
T~`or carrying out the process o~ the in~ention in an
optimum mann~r the hydrogenolysis of maleic anhydride and/or
maleic acid is generally per~ormed und~r an elevated pressure
and at elevated temperature.
The reaction temperatures are therefore generally in
tha range ~rom 50 to 300C~ preferably from 150 to 250C.
The reactio~ pressure is generally in the range from
50 to 500 bars~ preferably from lO0 to 350 bars.
Hydrogen used for th~ hydrogenolysis of maleic anhydr.i.de
or maleic acid is generally in a considerable stoichiometrical
exce~s. Unreacted hydrogen may be recycled to the reaction
as circulating gas. The reaction may be carried out con-
tinuously or discontinuously. Hydrogen is generally us~d in
1~ a technically pure form. Admixtures of inert gases such as
nitrogen7 however, do not disturbe the course of the reaction.
The re~ction time in the process of the inv~ntion i3
general~y in the range from 5 minutes to 8 hours 9 f`or exampls
about 3 to 6 hours, when working discontinuously in an
autoclave.
Pulverulent catalysts may be ~iltered off at the end Or
the reaction or by separated by centrifugation and be reusecl
without a notable loss of activity.
When working continuously, for example in the trickling
phase, tabletted catalysts or those applied on carriers are
generally usedr
When performing the reactivn in practice, the solvents
known for hydrogenations may be used 9 for example dioxane,
29 tetrahydropyrane ~ oth~cyclic or strai.ght chain ethers, for
,
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' ' ' : ~' ~: ,
7~)7~
ex;llnpl~ tetra}lydrol`-tra~le or diethyl ether, Polyalkylene gly~ol
dialkyl ether~,~ f`or exalnple tetramethyl~neglycol dibtltyl
eth~r, tctra~D~tllylene~lycol dipenty:L ether~ tetra~thylen.e-
glycol dimothyl etherl tetraethylaneglycol diethyl ether
and diethyleneglycol dibuty:L ethar or m.i~tures of these or
other solvents may also ba used. Solvcnt3 ha~ing a boiling
point nbove 245~ have pro~ed especially advantageous. The
content of maleic acid and/or anhydrlde in the initial
soluti.on in this case is generally in the range ~rom 5 to
1060 %~ Using maleic anhydride as a 20 to 40 ~0 solution in 1,4-
dioxane has proved advantageous~ Water ls also suitable as
solvent for maleic acid. The quanti$y o~ catalyst used for
hydrogenating is generally in the range ~ro~ 0.5 to 2g
Or the quantlty of maleic anhydride or maleic acid.
15Malelc ~nhydride as well as maleic aicd and any mixture~
of both substancos may be used a5 charge products.
The reaction m.ixtures arc gen~rally worked up by fractio_
nated distillation.
The following method has pro~ed e~peclally advantageous
~or preparing butanedlol-(1.4) discontinuously: A solution o~
maleic anhydride in 1.4 dioxane is gi.ven into a high pressure
aukoclave together with the catalyst, hydrogen i5 introduced
under pressure and the reaction mixture i5 heated. At the
erld o~ ~he r~action the reaction mixture is cooled~ the
catalyst is separated and the mixture is distilled.by fractio-
nation.
The rollowing examples illustrate the invantion:
E X A M P 1, E 1~
2~ 27 g of palladium acetate and 4 g o~ rhenium heptoxlde
,
- 10 -
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w0r~ clis80].~red ir~ 120C) ml o~ acetic acid at 80C~ 100 g of ~ :
kiese~guhr ~r~a~ded~ khe mlxture was evaporated to drynes~
in VAOUO while stlrring and roduced in a hydrogen atmosphere
at 200C,
0,5 mol of` maleic anhydride (49g) were dissolv~d in 1Q0 ml
of dioxaneO The solution was poured into a 1 liter autocla~e
pro~ided with a shaking dlvics together with 5 g o~ the
pulverulent kleselguhr catalyst containing 10.6 ~ o~ palladium
and 2.3 /0 o-~ rhenium~ Hydrogen was introduced until a pressurs
of 215 ba~s was r~ached and the mixture obtained was rapidly
heated to 225 to 230C. After about 6 hours tho reaction was
interrupted and the reaction mixture was rapidly clried. After
separation o~ the catalyst 151.5 g o~ a water-clear9 colorless
reactio~ solution was obtained cont~ning 27~9 /~ of 1.4~bu~ne~
1$ diol (42,2 g) correspondin~ to 93,8 ~o o~ the theory. Besides
butanediol~ and the solvent dioxane 9 water could be de-
tected as well as rather small quantities of ~-butyrolactone~
tetrahydrofurane~ n-butanol by gaschromatography and traces
of succinic acid by titrimetry.
E X A M P L E 2:
49 g of maleic anhydride were dissolved in 100 ml o~
dioxane. The solution was reacted together with 5.9 g of the
slightly wet catalyst, which had already been used ln Example
1 and bee~ filtered off, in the manner descrlbed in Example 1.
There wcre obtained 149,8 g of a wate. clear colorless
solution containing 28.2 % of ~ .4-butanediol (42.3 g~. Tllis
corresponded to 93.9 ~ of the theory, The reaction mixture
contained still small quantities o~ a polyestsr bsides the
29 substances cited ::Ln Example ~,
1 1
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E X A ~I Y L ~ ~:
The calculated quantity o~ platin~lm acetate and rhaniu~
heptoxide in acetic acid solution was ad~nixed wlth kie~elguh:r~
dricd and reduced as describ~d in Example 1.
A ~olution of 58 g of maleic acid (0p5 mol) in 200 ml
o~ water was given lnto a 1 liter steel autoclave together
wit;h 6 g of the kieselguhr catalyst containing 10 ~0 Or platinum
and 2.8 ~0 o~ rheniump Hydrogen was introduced unti.l a pressure
of 195 bars wa~ obtained and the reaction mixture was rapidly
heated to 230C.
A~ter a reaction time of about 3 arld a half hours another
Z5 bars o~ hydrogen were introduced. After a total r~action
time of 5 hours the reaction wa~ stopped, as no further
hydro~en absorption could be observ0d. The catalyst was
separated by a centrifuge and 2~5 g o~ a reaction solution
were obtained.
The water-clear, colorless solution contained 16 ~o or
40.8 g of butanediol ~ ) corresponding to 90.0 % of the
theory.
20. The reaction mixture contair.~ed b~sid0s butanediol-(1.4)
and watar 0.53 % o~ ~-butyrolactorle~ 0. 6 % of n-butanol as
well as small portions o~ tetrahydrofurane, succinic acid
and butyric acid.
~ L r 4:
For preparing the dèsired qua~tity of the catalyst)
palladium acetate, rhodium acetate and rhenium heptoxide
were dissolved in the calculated quantities ln ac.etic ac-ld 9
alumosilicate powder~as added and dried a~d reduced as des-
29 cribed in E~ample 1p Then 0.5 ~.ol of maleic arlhydride (ll~ g)
_ 12 ~
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were dis~olved in 100 g Or tetrahydropyrane (about 114 ml)~
5.2 g o~ the kieselguhr~aluminium oxide catalyst were added
contalning 8.3 ~ of palladium, 4 2 '~o of rhodium and 2.7 %
o~` rhenium and the m~xture was placed into a 0.5 liter
autoOElave provided wltll a magnetic type lifting stirrer.
After having introduced hydrogen until a pressure of 189 bars ?
was obtained the mixture was rapidly heated to 220C and
allowed to react for a total of 4 and a half hours. There-
after it was rapidly cooted, the catcllyst was separated and
the reaction mixture was analyzed by gaschromatography.
i47 g Of a solution were obtained containing 26 9 /v
of butanediol-(1.4) (39.6 g), which corresponded to about
88 % of the theory.
E X A M P T E 5:
For preparing the catalyst 100 g of` active carboll (810
m /g according to ~ET, pore volume of 0.9 mllg) wer~ impreg-
nated with a solution of 20 g of Na2PdC14 in 86 ml of water,
dried while stirring, impregnated with a solution o~ 4 g of
NaOH in 88 ml of H20 and ~llowed to stand for 2 hours~ There~
after the mixture was washed until it was free from chloride~
dried to a w0ight of 150 g, impregnated with a solutlon of
6 g of Re207 in 50 ml of water, dried while stirring and
reducsd in hydrogen at 200C.
0.25 mol of maleic anhydride (24 g) and 0.25 mol o~
maleic acid ~29 g) were dissolved in 100 ml of slightly
heated dioxane. 5 g of the catalyst based on act~ve carbon
powder were added which contained 4.1 ~ of rhenium and
8.2 ~ of palladium oxide and the mixture was given into a
29 0~5 liter high pressura autoclave pro~ided with a shalc~ng
~j .
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dovico~
After having tntroduced hydrogen until a pressure of
170 bars was obtained~ -the mixture was heated to 232C and
allowed to react for 3 hours~ Anothar 40 bar~ of hydroge~a wero
inkroduced and the reaction mixture was rapidly cooled after
1.5 hours. The catalyst was sep~rated.
149.3 g of reaction solution were olbtain~d containing
39.8 g of butanedlol-(1.43
E X A M P L E 6:
The kieselguhr catalyst used in Exampla 1 was compressed
to tablets having a diameter of 6 !~m and a thickness of 2 mm
on a pelleting machine. 1 liter of this catalyst was gi~en
into a stainless steel high pressure reactor havin2 a length
of about 2 ~n~;l`he apparatu~ was ~lushed w$th nltrogen and
15 ~aydrogen was Lowly added until a pressure o~ 260 bars was
attained. While add~ng hydrogen at the lower end o~ the
reactor a 32 ~ solution o~ maleic anhydride in dioxane was
added at the upper end and allo~red to trid~e o~er the
catalyst. As soon as a liquid left the reactor at thc lower
end, the reaction mixture ~as slowly ~leated to tho working
te~perature of 225 C while continuing the a~dition of
hydrogen at a rate of about 8 to 10 Nm3/h (N meaning that
the ~ol~ame is calculated under normal conditlons of tempera~
ture and pressure i.e. of 0C and 760 mm~Ig) and dioxane-
maleic anhydride at a rate o~ about 1520 g/h. Two hours afterhaving attaine~a the working temp~rature of 225C the leavialg
reaction mixture was araalyzed at ho~arly intervals. Per hour
there were obtained about 1560 g o~ reaction mixture con-
29 taining on th~ a~erage from 25 to 26 % of butan~diol~ 4),
~, :
.,
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~76! 7~
which corresponded to abou-t 85 to 90 % of the theoretical yield
of butanediol~ ). A decrease of the output could not be
observed even after 300 working hours.
E X A M P L E 7:
20 g of palladium acetate, 10 g of iridium acetate~
4 g of rhenium heptoxide were dissolved in 600 ml of glacial
acetic acid, 100 g of kieselguhr were introduced by stirring; the
mixture was dried in the rotation evaporator at 60C in a water
jet vacuum. The dried catalyst was reduced in an aqueous solution
of sodium boron hydride having a temperature of ~0C, washed and
dried. It contained 8.2 % of palladium, 4 % of iridium and 2.3 %
of rhenium as borides, the percentages being calculated on the
elements.
5 g of this catalyst were given into an autoclave with
0.5 mol of maleic anhydride and 100 ml of dioxane and treated
as indicated in Example 1.
148.1 g of a water-clear colorless reaction solution
were obtained containing 39.~ g of butanediol-(1.4).
E X A M P L E 8:
19.5 g of palladium acetate, 7.7 g of ruthenium acetate
and 3.3 g of rhenium heptoxide were dissovled in 900 ml of
acetic acid, 1~0 g of zirconium oxide were introduced by stirring,
the mixture was dried in the rotation evaporator in vacuo and
and reduced in hydrogen at 200C.
0.5 mol of maleic acid (58 g) were dissolved in 100 ml
of warm dioxane. 7.5 g of a zirconium oxide catalyst containing
8.1 % of palladium, 205 ~ of ruthenium and 2.2 % of rhenium
were added and the mixture was placed into a 0.5 liter autoclave
provided with a magnetic type lifting stirrer.
- 15 -
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Hydrogen was introduced until a pressure of 178 bars was
obtained, the mixture was rapidly heated to 215C and allowed
to react or 3 and a half hours. It was cooled, expanded and
the reaction solution was analyzed. After having filtered o~f
the catalyst 138 g of a solution containing2g.8 ~ or 34.S g of
butanediol-~1.4) was obtained, which corresponded to about 78 %
of the theory.
C O M P A R A T I V E E X A M P L E 1:
27 g of palladium acetate were dissolved in 1200 g of
glacial acetic acid at 80C, 100 g of kieselguhr were added and
dried and reduced as described in Example 1.
0.5 mol of maleic acid (149 g) were dissolved in 100 ml
of dioxane. The solution was reacted with 5 g of the kieselguhr
catalyst containing 10% of palladium as indicated in Example 1.
148.3 g of a slightly yellow solution were obtained,
containing only 3.5 % (5.2 g) of butanediol-(1.4). The main
product of the reaction was ~ butyrolactone being present in
the reaction solution in an amount of 23.1 ~.
C O M P A R A T I V E E X A M P L E 2:
3.2 g of rhenium heptoxide were dissolved in 400 ml of
glacial acetic acid, 100 g of kieselguhr were introduced by
stirring, dried and reduced as in Example 1.
The example was carried out in the same way as in
Comparative Example 1, but by using instead of the catalyst used
therein 5 g of a SiO2 catalyst containing 2~3 % of rhenium.
147.2 y of a reaction solution were obtained containing only
traces (<0.2 %) of butanediol-(1.4), 10.2~ of ~-butyrolactone but
more considerable quantities of succinic acid, p;artly precipitat-
ing .
- 16 -
