Transcript Helping to Curbing Global Warming

EM technology, Biodigesters and Biogas
Methane
20 times more GWP than
carbon dioxide
 Anthropogenic sources
 Agriculture
 Domestic animals
 From 1750 to 2000, methane increased in atmosphere
from 700 ppb to 1800 ppb
Biodigesters:
what and where
 A biodigester is a biogas generator where anaerobic
decomposition of organic waste occurs
 Work best in warm climates- optimum ~35 degrees C
 Biogas is a mixture of gasses resulting from material
breakdown
 Heating power of 4500 to 6500 kcal per cu m
 1 cu m of biogas is equivalent to
o .6 liters of gasoline and .5 liters
of kerosine
Stages of EM digestion
 Stage 1: hydrolysis
 Bacteria break down organic molecules
 Stage 2: acidification
 Monomers are acidified
 Stage 3: methanization
 Methane is produced when bacteria break down acids
 Optimum: 35 degrees C, 6-7 pH
 Satisfactory gas production can take place at 25
degrees C, but below about 10 production effectively
stops
Annual methane emissions from
agriculture
calculations
 How much energy we could get from cow and pig
manure?
 19.5 billion tons of cow manure produced worldwide
each year
 30.5 quadrillion Btu per year potential methane from
cow manure
 5.9 million tons of pig manure produced worldwide each
year
 1.37 quadrillion Btu per year potential methane from pig
manure
Where biodigesters are most
important
 India’s population is increasing rapidly
 China’s people are seeking higher levels of wealth –
pigs are increasingly wanted
 Both countries
have already
implemented
millions of
biodigesters
Sustainability
 Energy yield from methane would have a minimal impact,
but other factors make biodigesters worthwhile
investments
 Relative costs
 Replacement for coal?
 Health issues
 Biogas is similar to natural gas
 But- renewable and less prone to costly extraction and
leakage problems
 Biogas would provide affordable heat and electricity and
reduce emissions related to dirty fuels by replacing them
 Germany predicts they can produce enough biogas by 2020
to replace all of Russian natural gas imports
Conclusions
 Ambiguous long-term and global effects
 Yield from worldwide manure amounts would be 6%
of projected worldwide energy use in 2010
 For more information, consult our web page at
http://web.me.com/climate_acahnp
 Thanks to the members of the Earth Institute of Costa
Rica for their help