Bioconversion: Methane Sustainable society reduction of
dependency on fossil fuels lowering of the amount of pollution than
is generated
Wastewater Treatment a paradigm shift; disposing of waste using
waste Wastewater are potential commodities from which bioenergy and
biochemicals may be produced. bio-processing strategies
methanogenic anaerobic digestion biological hydrogen production
microbial fuel cells fermentation for production of valuable
products
Integrated bio-reactor and bio-gas generator
CO2
Fertilizer
N, P, H2OHydrogen Fertilizers Animal feeds Biopolymers Methane
Bio-fuels Bio-prods CarbonatesInnoventures Canada
Natural Health Prods Chemicals
Alternative Energy Sources Using
MicroorganismsBiomassBioconversion
Methane or ethyl alcohol
Figure 28.15
Main stages of anaerobic (methane) fermentation
Bioconversion of exhaust gases to methane
Conversion up to 60%Methanogenesis: methanobacteria, clostridia
(anaerobics) Bioreactor: immobilized cells, replacement 6-12 months
Requirments: Mass transfer, non-corrosive reactor, 40-55
Biological chemical production major limitation of bio-energy
tech. the relative low cost of the current non-renewable energy
source government subsidies, direct local need to save on energy
costs
It cannot entirely satisfy the energy demand of our society.
Therefore, biological chemical production may be more feasible
than bio-energy production. conversion to valuable products
Strategies to enhance bioconversion improvement of the amount of
product formed per reactor volume, per time period process
modification (culture immobilization), coupling two separate
bioreactors separation and purificationLab. for Water Environmental
System
the manufacturing cost more selective, more efficient, and
shorter separation routes 2007Winter School For MFCs 6
Biological methane production Reaction
Methanogenic anaerobic digestionhigh organic removal rates low
energy-input requirement energy production (i.e. methane) low
sludge production
Methane formation from glucose; C6H12O6 CH4 + CO2
UASB
Upflow Anaerobic Sludge Blanket efficiently retains the complex
microbial consortium without the need for immobilization on a
carrier material by formation of biological granules with good
settling characteristics. Approximately 60% of the thousands of
anaerobic full-scale treatment facilities worldwide are now based
on the UASB design concept.2007 Winter School For MFCs7
Lab. for Water Environmental System
Biological methane production AMBR Anaerobic Migrating Blanket
Reactor The organic removal rates are higher than those in
UASB.
ASBR Anaerobic Sequencing Batch Reactor operating in a four-step
cycle 1) wastewater is fed into the reactor with settled biomass.
2) wastewater and biomass are mixed intermittently. 3) biomass is
settled. 4) effluent is withdrawn from the reactor.
The methane has been used as a fuel source for on-site heating
used as a fuel source for electricity production. converted to
methanol for use in production of biodiesel.Lab. for Water
Environmental System
2007 Winter School For MFCs
8
Biological methane production
Lab. for Water Environmental System
2007 Winter School For MFCs
9
Biological methane production UASB
source: http://www.uasb.org/
Lab. for Water Environmental System
2007 Winter School For MFCs
Anaerobic sludge granules from a UASB reactor treating effluent
from a recycle paper mill (Roermond, The Netherlands). 10
Biological methane production
source: Angenent et al., Wat. Res. 35(7) pp.1739-1747, 2001Lab.
for Water Environmental System
2007 Winter School For MFCs
11
Biogas plants of German Agrogas AG company in Denmark