Biomedical Engineering Reference
In-Depth Information
Heat
recovery
Steam
system
Steam
Natural
gas
Feed gas
purification
Steam
reforming
Reformed
gas
Heat
recovery
Feed gas
Natural gas
Refined
methanol
Distillation
Crude methanol
Methanol synthesis
Syngas
Compression
FIGURE 1.1 Conventional methanol production.
hydrocarbons producing a synthesis gas of carbon dioxide and hydro-
gen; (3) methanol synthesis by passing the synthesis gas over a
catalyst bed at high temperatures and pressures to produce crude
liquid methanol; and (4) distillation typically accomplished in a two-
step process to remove water and some ethanol created in the process.
The finished methanol must meet rigorous purity standards generally
in the order of 99.85% (ASTM D-1152/97).
The production of methanol from natural gas, coal, or biomass shares
a number of basic processing steps (Zuberbuhler, 2005). The feedstock
must be gasified by heating in the presence of little or no oxygen to
produce a synthesis gas made up of carbon monoxide, hydrogen, carbon
dioxide, and water (along with various other gases). This “syngas” is
then catalytically processed into liquid methanol while much of the
“equipment” for gasification involves mature technologies using rec-
ognized feedstocks. While majority of methanol is produced through
the steam reformation of natural gas, China has focused on converting
its vast coal resources to methanol via gasification. For “biomethanol,”
the immature part of the equation is the first step, the gasification of
biomass (a feedstock with different characteristics). Once the syngas is
