Commercial biogas plants: Review on operational parameters and guide for performance optimization

Fig. 3. Technical and management requirements for performance optimization of commercial biogas plants.
D. Wu et al.

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Fuel 303 (2021) 121282
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4.2. Technical requirements 
In the short term, creating management innovation to maintain 
relatively constant operational parameters and ensuring that no major 
variations occur are the key considerations for operators aiming to sta-
bilize the AD process and enhance biogas production. However, when 
operational parameters cannot be manipulated to improve performance, 
various auxiliary approaches can also be applied, such as the addition of 
nanoparticle additives, trace element supplementation and effluent 
recirculation (
Table 1
). These approaches can potentially induce new 
metabolic pathways (such as Direct interspecies electron transfer 
(DIET)) to shorten the recommended safety threshold value of HRT or 
enhance the robustness of AD to process disturbances such as ammonia 
inhibition and over-acidification 
[25,97]
. However, economic, techno-
logical and ecological concerns such as high capital investment, 
microorganism wash-out, competition among the members of the 
complex and highly dynamic microbial population, and possible soil and 
water pollution, greatly complicate the translation of lab-scale 
achievements into commercial-scale applications 
[19,26]
. Additional 
technical breakthroughs and appropriate environmental safety assess-
ments are necessary before such approaches can be used in industrial 
applications. 
5. Conclusions 
From the perspective of commercial operation of biogas plants, this 
paper presented a comprehensive review focusing on the relationships 
between commonly used operational parameters and AD process sta-
bility and operational efficiency. Technical and management sugges-
tions are also proposed to guide process optimization. The main results 
are as follows: 
•
Process stability of AD is a major priority for efforts aimed at opti-
mizing the overall performance of commercial biogas plants. Both 
process stability and process optimization largely depend on the 
manipulation of operational parameters.
•
Proper system configuration can maximize the utilization of process 
capacity and minimize internal energy consumption. 
•
Inadequate or faulty operating procedures resulting in large de-
viations in operational parameters are the primary cause of frequent 
process instability events and indirectly lead to suboptimal operation 
of commercial biogas plants.
•
Improved process monitoring and regular training can contribute to 
the achievement of management innovation for commercial biogas 
plants.
•
Various auxiliary approaches, such as the addition of nanoparticles 
and trace element supplementation, require additional technical 
improvements before industrial application.