Environmental Engineering Reference
In-Depth Information
Municipal solid waste
(MSW, 1000 kg)
Metals
(
30 kg
)
Refuse derived
fuel (
420 kg
)
Organic fraction
of MSW
(OFMSW,
400 kg
)
Paper/plastic
(
150 kg
)
Washing
Sand (
39 kg
)
Biodegradable
OFMSW (
261 kg
)
Coarse inerts
(
100 kg
)
AD
Biogas
(
137 m
3
)
Digestate
(
162 kg
)
Process water
(
162 kg
)
FIGURE 14.11
Typical mass balance for a MSW treatment plant including anaerobic
digestion (AD) of the biodegradable organic fraction. This example is based on the Vagron
plant for treatment of 230,000 tonnes MSW per year, located in Groningen.
Depending on the quality and potential local application of the digestate, it will
require several postprocessing steps. Usually, these processing steps involve
phase separation resulting in a nutrient-rich liquid fraction and a solid fraction
that after drying is suitable for combustion in a power plant. Nutrient removal
or recovery strategies are available for treatment of the liquid fraction of the
digestate.
Utilization of the biogas for electricity and heat production requires the construc-
tion of a CHP plant.
In the following paragraphs, some integration aspects of the anaerobic digestion proc-
ess will be discussed.
14.4.3.1 Biogas Upgrading and Utilization
Biogas is composed of methane
(CH
4
) and carbon dioxide (CO
2
) with smaller amounts of hydrogen sulfide (H
2
S),
ammonia (NH
3
), and dinitrogen gas (N
2
). Usually, biogas is saturated with water
vapor. In principle, biogas can be used for all applications designed for natural
gas. Not all gas applications require the same gas standards.
For utilization of biogas in a CHP, hydrogen sulfide needs to be removed in order
to avoid corrosion of the boiler due to sulfuric acid (H
2
SO
4
) production by oxidation
Search WWH ::
Custom Search