Ikelic - Alliance Digital Repository

NATURAL GAS
The BNL process employs a homogeneous Ni
catalyst and alkoxide in an organic solvent, while
methanol synthesis via MF employs a mixture of
copper-based oxide and alkoxide as a catalyst.
Both processes are operated at around 373 K,
where high equilibrium conversion of carbon
monoxide to methanol is expected. The
processes have been reported to show excellent
activity even at such low temperatures.
S. Ohyama of the Central Research Institute of
Electric Power Industry in Tokyo, Japan has ex
amined the catalytic activities of these two
processes and assessed their possibilities as in
dustrial processes in terms of Space Time Yield
(STY). He discussed his findings at the Sym
posium on Alternative Routes for the Production
of Fuels, held as part of the 208th American
Chemical Society National Meeting held in
Washington, D.C. in August.
BNL Methanol Process
Methanol was formed quite selectively
over the
BNL catalysts at 353-433 K and 1 .1-5.0 MPa of ini
tial pressure. The STY with the BNL catalysts
varied with Ni concentration in the catalyst sys
tem and reached 0.89 kilograms per liter per hour
at the optimum concentration. At 433 K, the BNL
catalysts yielded almost 90 percent for CO con
version and over 99 percent for selectivity to
methanol. Because the catalyst is highly active
even at temperatures much lower than the operat
ing
temperature of the conventional methanol
process (503-543 K), it should be possible to
eliminate recycling facilities for unconverted gas,
which would reduce the production cost of
methanol.
Methanol Synthesis via MF
Methanol was formed rapidly
using
at around 373 K
a mixture of copper-based oxide and
alkoxide. Using catalyst N203SD and potassium
methoxkJe, CO conversion was 87-94 percent,
to methanol was 87-98 percent.
selectivity
Higher temperatures and higher initial pressures
enhanced methanol productivity, while lower tem-
5-6
peratures and higher pressures Increased methyl
formate formation.
STY Evaluation of Low-Temperature Methanol
Synthesis
The STY of low-temperature methanol synthesis
and that of the conventional methanol production
process are compared in Figure 1. In the conven
tional process, copper-zinc-based oxide
catalysts or (CuO/ZnO/AI203 CuO/ZnO/Cr203)
are employed under the conditions of tempera
ture of 505-573 K, pressure of 5-20 MPA, and
space velocity
of 10,000-40,000 h*\ In the ICI
process, a typical methanol process, the STY of
0.66 kilograms per liter per hour is obtained un
der the conditions of 500-523 K and 5-10 MPa.
The BNL process showed a STY of
0.89 kilograms per liter per hour at 433 K and
5 MPa. Thus, the BNL process has the possibility
of producing methanol more efficiently than the
FIGURE 1
SPACE TIME YIELD OF METHANOL
SYNTHESIS TECHNOLOGIES
Conventional
methanol process
(ICI process)
BVL km-temperature
methanol process
Lo -temperahire
methanoi process ria
methyl formate
SOURCE: OHYAMA
CuCVZnOAl2Oj
500-523 K, 5-10 MPa
- SV 10.000 40.000
0.66
-
Ni(CH3CCX))2 KaH -
trn-vay\ alcohol
433K.5MP1
0.13 -
Batrt Reaction
CuCyCr20yMnOB40 ? CH,OK
423 K. 5 MPa
Baicb lUaoioo
0.0 0.1 0.2 0.3 04 05 06 07 0 09
Space Urne yield (kf-MeOH r1
r1)
0J9
THE SYNTHETIC FUELS REPORT, JANUARY 1995