µ-Reactor Technical Note
( RXA-001E )
Conversion of ethanol to ethylene using
Tandem µ-Reactor GC/MS system – Part 1
[Background] The Tandem µ-Reactor GC/MS system designed for the rapid screening and evaluation of catalysts is
described in Technical Note (RXT-001E). This technical note illustrates how the Tandem µ-Reactor GC/MS system can be
used to characterize the catalytic conversion of ethanol to ethylene.
[Experimental] The system configuration is shown in Fig. 1. A zeolite catalyst (H-ZSM-5, 3 x 10 mm) was packed in a
quartz insert tube which was placed in the 2nd reactor. A deactivated tube connected the GC injector to the MS. Carrier gas
(10 mL/min) was bubbled through ethanol. The saturated carrier gas continuously flowed through the 1st reactor. Additional
helium (50 mL/min) was added as the vapors flowed from the 1st to the 2nd reactor. The temperature of the 1st reactor was
held at 100ºC in order to prevent condensation in the reactor. The 2nd reactor temperature was programmed from 100ºC to
450ºC at 20 ºC/min) – see Fig. 2. The reaction products were monitored, real time.
[Results] As the temperature of the catalyst increases, the conversion of ethanol to ethylene is observed. Fig. 3 clearly
shows that the concentration of ethylene and water increases as the catalyst temperature increases beyond 200⁰C.
Equilibrium conversion is reached when the catalyst temperature is greater than 320⁰C. Reaction intermediates like diethyl
ether (formed during the dehydration of ethanol) are observed at temperatures between 180 and 320⁰C. This simple example
illustrates how this system can quickly and easily be used to characterize the catalytic conversion of species A to products B.
Using a mass spectrometer as a detector greatly simplifies the process of identifying conversion products.
Catalyst: H-ZSM-5 (20% coating on Al2O3, 20/30 mesh)
1st Reactor: 100ºC; 2nd Reactor: 100-450ºC (20 ºC/min)
He
1st Reactor
(10 ml/min)
2nd Reactor
EtOH
He
4x106
Vent
TIC
(50 ml/min)
Oven: 100ºC
Deactivated tube
(2.5 m, 0.15 mm i.d.)
GC
1 ml/min
MS
0
2x105
4
6
8
10
12
14
16 min18
8
10
12
14
16 min18
Water
(m/z 18)
Vent-free GC/MS adapter
1st Reactor: 100ºC
2
2nd Reactor: 100-450ºC (20 ºC/min)
Fig. 1 Tandem µ-Reactor GC/MS system
5x105
Ethylene
(m/z 28)
2x105
2nd Reactor temperature
Ethanol
(m/z 45)
2x105
Diethyl ether
(m/z 74)
0
Time
Fig. 2 Linear temperature mode
2
100
4
6
200
300
400ºC
Fig. 3 On line analysis of catalytic reaction of ethanol vapor
Ref.: R. Freeman et al., J. Anal. Appl. Pyrolysis, 111 (2015) 41-46
Keywords : Screening, evaluation, conversion of ethanol to ethylene
Products used : Tandem μ-Reactor, μ-Reactor, Selective Sampler, MicroJet Cryo-Trap, Vent-free GC/MS adapter, UA-1
Applications : Catalyst screening and evaluation
Related technical notes : RXT-001E, RXA-002E
Please forward your inquiries via our web page or send us a
fax message.
R&D and manufactured by :
Frontier Laboratories Ltd.
Phone: (81)24-935-5100 Fax: (81)24-935-5102
http://www.frontier-lab.com/
®: A registered trademark of Frontier Laboratories Ltd.