ISSN 1070-4272, Russian Journal of Applied Chemistry, 2017, Vol. 90, No. 2, pp. 169−178. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © S.P. Banzaraktsaeva, E.V. Ovchinnikova, L.A. Isupova, V.A. Chumachenko,
2017, published in Zhurnal Prikladnoi Khimii, 2017, Vol. 90,
No. 2, pp. 146−155.
PROCESSES USING VARIOUS
Catalytic Dehydration of Ethanol into Ethylene
in a Tubular Reactor of the Pilot Installation
on Alumina Catalysts with Varied Grain Size
S. P. Banzaraktsaeva*, E. V. Ovchinnikova, L. A. Isupova, and V. A. Chumachenko
Boreskov Institute of Catalysis, Siberian Branch,
Russian Academy of Sciences, pr. Akademika Lavrentʼeva, 5 Novosibirsk, 630090 Russia
Received November 23, 2016
Abstract—Synthesis of ethylene on trefoil and cylindrical experimental acid-modiﬁ ed aluminum oxide samples
was studied under an ethanol (94%) gas load of 920–2200 h
and heat-carrier temperature of 400–440°C. In the
conditions of a 98% ethanol conversion, the higher activity of the trefoil made it possible to reduce the height
of the bed and its hydraulic resistance and, accordingly, raise the speciﬁ c catalyst throughput for ethylene.
Compared with industrial aluminum oxide, the throughput of 1 g of the catalyst for ethylene on experimental
samples is higher by 2.5–6.5 kg yr
, and the speciﬁ c expenditure of ethanol is lower by 0.22–0.23 kg kg
endothermic process in a tubular reactor is characterized by a high parametric sensitivity of the average integral
temperature along the catalyst bed, with the average temperature being higher on the less active catalyst. Thus,
the higher average temperature can compensate for the lower activity of the catalyst without additional increase
in the contact duration and(or) heat-carrier temperature.
Ethylene manufactured by pyrolysis of hydrocarbon
raw materials is among the basic chemical products and
underlies numerous technological chains in syntheses
of organic products and polymers [1, 2]. Because of
the wider practical application of polymer-composite
materials with prescribed properties, small-tonnage
ethylene production plants not bound to sources of
petrochemical raw materials became needed. The
process of obtaining “green” ethylene from renewable
biological resources via catalytic dehydration of ethanol is
regarded as a promising source for small plants producing
polyethylene and polymeric composites.
In the catalytic dehydration of ethanol, ethylene is
mostly formed by the parallel-consecutive pathway via
intermediate formation of diethyl ether (DEE) [3–5].
Acetaldehyde and butylenes are the main by-products
formed in small amounts. According to the overall heat ef-
fect of the occurring reactions, the process is endothermic,
which is associated with the intense heat intake at a high
input concentration of ethanol. Processes requiring that
heat should be delivered on being taken up in the course
of a catalytic reaction can be effectively implemented in
adiabatic reactors with several catalyst beds and interme-
diate introduction of a heat carrier or in tubular reactors
in which the catalyst is situated within tubes and the
heat-carrying agent is circulated in the intertubular space.
Tubular reactors are more complex in design, but are more
reliable in controlling the process. In a tubular reactor,
the minimum temperature (so-called “cold point,” T
is attained in approximately the ﬁ rst third (downstream)
of the catalyst bed. The extent to which T
is lower than
the heat-carrier temperature T
depends on the catalyst
activity and intensity of the heat-and-mass exchange.
The catalytic process parameters (conversion of raw
materials, yield of products) can be controlled at a ﬁ xed
tube diameter by varying the following technological
parameters: input concentration of reagents, ﬂ ow rate,
heat-carrier temperature, and inlet gas temperature; a
signiﬁ cant inﬂ uence is also exerted by the size and shape
of catalyst particles.