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Figure 2. Block scheme of the steps of which a typical Waste to Chemical process is composed.
syngas composition must be adjusted to meet the
synthesis requirements.
5. Final synthesis. The syngas can be separated to
obtain hydrogen, and either methanol, through catalytic
synthesis, or ethanol, through biological fermentation,
can be produced.
The scheme described above is the conventional
configuration of the waste to chemical process, which
allows about half of the carbon in the waste to be
converted into new molecules, methanol or ethanol.
Here below the two process schemes for production of
methanol Figure 4 or ethanol Figure 5.
Further, it could be proposed the coproduction of
methanol or ethanol with hydrogen. The hybrid schemes
would allow to produce about 1500 KTY of hydrogen Figure 3. Sezione trasversale del reattore di gassificazione.
which is the right amount for the developing of
hydrogen valley to shape the utilization of low carbon
hydrogen in new sector such as sustainable mobility. share of renewable sources, an improved integrated
One possible upside of the scheme is the simultaneous waste to chemical scheme can also be implemented.
production of hydrogen together with methanol or Thus, green hydrogen produced through green power
ethanol. Such co-production allows low-carbon can be directly added to the syngas in order to fulfill the
hydrogen to be placed on the market at a lower price requirements, another way of conditioning, by which all
than green hydrogen from electrolysis, thus stimulating the carbon contained in waste is converted into final
the implementation of the required infrastructure for molecules and the yield of the process is doubled.
hydrogen use. The methanol and ethanol produced by this scheme
Nevertheless, in a long-term scenario, when the power can be applied as precursors for other chemical
grid will most likely be able to rely on a 100% (or nearly) syntheses and then plastics, thus closing the loop (of
Figure 4. Waste to methanol block scheme.
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