4. Conclusions
The results obtained in the present research study facilitate a
better understanding of the effects of organic solid waste composition
on the potential production of hydrogen that can be obtained
from a process of dark fermentation. The findings indicated that
the variability of waste composition of OFMSW produced a marked
effect on hydrogen potential production. OFMSW is made up of
carbohydrate rich materials, characterised by high hydrogen
potentials, and by protein and lipid-rich fractions, characterised
by low hydrogen potentials. Small variations in waste composition
may result in important changes on hydrogen yields. On the contrary,
methane potential productions are less influenced by
changes in waste composition.
It is fundamental therefore that definition of waste composition
is reported in scientific literature for the purpose of data comparison.
The effects of waste type used in experimental studies on
hydrogen yields may exceed the achievable potentials under the
process conditions evaluated, thus leading to incomparable data
or unrepeatable experimental tests.
The variability of OFMSW and its effects on hydrogen potentials
may similarly represent a problematic issue in the management of
pilot or full-scale plants for the production of hydrogen by dark
fermentation.