1220
A. Krzyz˙anowska, E. Milchert/Chemical Papers 67 (9) 1218–1224 (2013)
3 mass % of CaCO3) (product of Chempur, Piekary
Sla˛skie, Poland).
stabilisation of the temperatures, the vacuum in the
installation was adjusted. Then, after heating the pre-
reactor (5), which is used as a performing mixer of III
and VI, the reaction–stripping column (6) and distil-
lation reboiler (12) under the reaction–stripping col-
umn were started. After stabilisation of the flow of
water from reservoir (15) by metering pump (1), the
heating steam generator (14) and steam superheater
(13) were turned on. The steam from the superheater
flowed through a bubbler into the distillation reboiler.
The temperature of the steam-flow was measured
using thermocouple (16). The temperature of these
elements was adjusted by changing the intensity of
the current flowing through the electric heaters in-
stalled on them. The adjustment was carried out using
autotransformers. After setting the steam-flow using
the metering pumps at a stabilised rate, the aque-
ous solutions of VI and III were introduced. At the
same time, the temperatures of pre-reactor (5) and
reaction–stripping column (6) were stabilised. On con-
tinuous supply of substrates and steam, after every
15 min the temperature was controlled in pre-reactor
(5), reaction–stripping column (6), distillation reboiler
(12), reservoir of waste water (11), steam generator
(14), and steam superheater (13); the pressure was
also controlled in the reaction system. In the course
of distillation, the reboiler temperature and pH were
measured. The concentrations of chloride ions and
chlorine in the organic compounds were determined
hourly by the potentiometric method. At the end of
the reaction, the metering pumps supplying III and
VI were turned off. For about 10 min after the reac-
tants’ supply was stopped, the steam supply contin-
ued; then the current setting on the heating elements
was zeroed. The pressure in the reaction system was
adjusted to atmospheric pressure. Consumption of III,
solution of VI, and steam was determined by mass
decrement. Similarly, the amount of distillate from
the reaction–stripping column (separated into aque-
ous and organic layers) and the amount of waste water
after combining with the solution that remained in the
distillation reboiler were determined. To make a mass
balance of organic compounds, quantitative analysis
of the distillate and waste water was carried out. Us-
ing gas chromatography, concentrations of compounds
III–V, glycerol (VII ), 3-chloropropane-1,2-diol (VIII ),
2-chloropropane-1,3-diol (IX ), diglycidyl ether (X ),
and glycidol (XI ) were determined. On the basis of
the analysis, the conversion of III and the selectivity
of the transformation to V related to III consumed
were calculated.
´
Organic compounds in the epichlorohydrin layer of
the distillate were determined quantitatively by gas
chromatography (GC) using octane as the internal
standard. The SRI 8610C (SRI Instrument Corpo-
ration, USA) apparatus was equipped with a flame
ionisation detector (FID) and a capillary column DB-
WAX (30 m × 0.25 mm × 1.0 µm). The following con-
ditions were used for the analyses: injector tempera-
ture: 200◦C, detector temperature: 240◦C, carrier gas:
He, flow-rate: 4 mL min−1, air-flow: 250 mL min−1
,
hydrogen-flow: 25 mL min−1. The oven temperature
was maintained at 55◦C for 2 min, then it was in-
creased to 160◦C at a rate of 15◦C min−1, held for
3 min, then increased by 25◦C min−1 to 240◦C and
maintained at 240◦C for 6 min.
Organic compounds in the water layer and in
the waste water were determined on a Trace GC
Ultra Thermo (Thermo Scientific, USA) appara-
tus. The chromatograph used was equipped with a
FID and a capillary column RTX Resteak 1701 (30
m × 0.53 mm × 1.0 µm). The following condi-
tions were used for the analyses: injector tempera-
ture: 280◦C, detector temperature: 300◦C, carrier gas:
He, flow-rate: 5 mL min−1, air-flow: 200 mL min−1
,
hydrogen-flow: 35 mL min−1. The oven temperature
was maintained at 40◦C for 4 min, then it was in-
creased to 155◦C at a rate of 10◦C min−1, and main-
tained at 155◦C for 1 min.
The concentrations of chlorine in organic and in-
organic compounds were determined by argentomet-
ric methods. A titrator TitroLine Easy module 3
(Schott, Germany) equipped with a combined silver
electrode with a platinum diaphragm 62Pt was used
for the determination. The water content in the or-
ganic layer of the distillate was determined by the
modified coulometric method on KF831 apparatus
(Metrohm, Switzerland).
Apparatus and experimental procedure
The installation scheme for the dehydrochlorina-
tion of III with an aqueous solution of VI is shown in
Fig. 3. The main apparatus comprises the reaction–
stripping column (6, height of 760 mm, inside diame-
ter of 36 mm), connected with pre-reactor (5, height
of 253 mm, inside diameter of 36 mm), filled with
Raschig rings (6 mm × 8 mm).
An aqueous solution of III was introduced into
reservoir (3), while VI was introduced into reservoir
(4). Reservoir (15) was filled with water. The pressure
was set in the reaction–stripping column (6), using a
vacuum pump (10). The temperature in the cold trap
(9) was kept in the range from –5◦C to –10◦C. Af-
ter stabilisation of the water-flow in the water cooler
(7), the cooling in cryostat (18) was turned on. The
cold trap was cooled to approximately –15◦C. After
Results and discussion
Influence of pre-reactor temperature
The influence of pre-reactor temperature on III
conversion and V selectivity for various methods of