For environmental purposes, I would like to know which are the main gas compounds generated during the activation process of lignocellulosic materials in general, specially when you use Nitrogen as activating agent.
This depends on which kind activation (chemical = 1-step, or physical = 2-steps) you use. And even with physical activation, the results will be different whether you use steam or CO2 (e.g. C + H2O --> CO + H2, or C + CO2 -> 2 CO). Chemical activation is both an oxidation and a dehydration, and other gases can be produced, but mainly CO, CO2, H2 and water vapour. See a list of possible reactions (not exhaustive) in the attachment.
Alain
Dear Cindy:
Depending of the conditions, the resulting gas from a thermal activation are syn-gas (CO+H2) and CO2 when the case is fuidized bed and CO, CO2 and HC (hydrocanbons) when the case is pyrolylis.
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Hi cindy,
Pyro-gasification can be realized using ligno-cellulosic materials in different atmospheres (first stape nitrogen N2 and then a mixture of steam and or CO2 in different molar compositions in order to converse the obtained char by pyrolysis). Obtained gaseous emissions are a mixture of volatiles CxHy (mainly methane) and the cyngas (CO+H2). The type of process concerning the heating rate (x°C/s) (fast, moderate or slow) is crucial for obtained comosition repartition between tar, char and gas.
I have a related question, forgive the intrusion, but it appears there may be someone here who knows the answer to a question I posted elsewhere.
https://www.researchgate.net/post/If_I_placed_granular_activated_charcoal_GAC_in_a_container_and_purged_it_with_CO2_gas_would_the_CO2_displace_oxygen_that_was_adsorbed_on_the_GAC
Nice day for everyone
dear Douglas, I think that there is a misleading because when you are realizing a char gasification under CO2 attack there is no oxygen adsorbed by the char. Oxygen will penetrate inner the char particle during the gasification mechanism to produce CO which is the major component of the syngas
all reactions that should be taken into consideration are the following:
1) CO2 +CH4 = 2 H2 + 2 CO with delta(H) = +246 KJ/mol
2) CO2 + H2 = H2O + CO with delta (H) = +41.2 KJ/mol
3) C(char or fixed carbon) + CO2 = 2CO with delta (H) = -179.5 KJ/mol
Hence the main result of these three reations is especially the CO and the H2 yields.
I hope responding to your query.
Best regards
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