Bilingual Tech Mapping for Pulp Paper Guideline - Asosiasi Pulp ...

a-2. Phase Two Digestion
Two-phase anaerobic digestion system is a process
where acid formation steps (hydrolysis and fermentation of
volatile acid) are physically separate from the step
formation of biogas (methane gas). This is different from
one stage anaerobic digestion, where acidogenesis and
methanogenesis occurs together (Shuizhou, et al, 2005).
Two-stage digestion system which separates the
formation of volatile fatty acid (VFA) from the process of
methanogenesis can enhance overall digestion
performance (Elliott, et al. 2007). It is shown from the
performance of two-phase anaerobic digestion process
which can reach not only the production of hydrogen but
also a higher methane production obtained by increasing
the hydrolysis process performance at an early stage.
Methane gas production reached about 21% higher than
that obtained in the digestion process one stage (Liu, et al.
2008). Thus the process of anaerobic digestion of twophase
becomes very important to increase the production
of biogas to produce methane (Medhat, et al. 2004).
Flowchart 2-stage anaerobic digestion can be seen in
Figure 5.9.
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