Environmental Engineering Reference
In-Depth Information
Heat and mass transfer limitations and their verification via criteria for gasification
Selection criteria for different reactor types
Gas cleaning requirements and selection options for contaminant removal
SHORT-ANSWER QUESTIONS
10.1 What are advantages and disadvantages of the use of air as the oxidizing agent
as compared to steam for biomass gasification for combined heat and power
production?
10.2 Mention a number of different bio-based ways to produce synthesis gas.
10.3
CO 2 can be used as gasifying agent; which advantages and complications do
you see for this use?
10.4
In Figure 10.1, indicate which by-products are formed (only the main
products are shown in this figure). Can these be used, and if so, how?
10.5 Why are fixed/moving beds not suitable for large-scale synthesis gas gener-
ation based on biomass gasification?
10.6 Why does a model based on chemical equilibrium calculations predict
higher CH 4 formation at higher pressure and typical fluidized bed gasifier
temperatures of about 850 C?
10.7 Why does the
carbon boundary
correspond to obtaining the highest cold gas
efficiency in gasification?
10.8 When a biochar particle is converted in Regime I, its conversion rate depends
on its particle size. Right or wrong?
10.9
A high value of the Thiele modulus during a biochar particle conversion
process corresponds to a Regime I conversion. Right or wrong?
10.10 How can you check experimentally whether gasification carried out in a fixed
bed gasifier takes place in Regime III?
10.11 What does it mean when a particle
'
s gasification process is limited by
intraphase heat transfer?
10.12 Why would the cross-draft gasifier only be suitable for the gasification of
charcoal?
10.13 Recap the pros and cons of the use of circulating fluidized bed gasifiers versus
entrained flow gasifiers.
10.14 What are the main differences between bubbling and circulating fluidized bed
gasifiers?
 
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