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Topics
List:
How
is Biomass Energy used?
Comprehensive
Exploitation And Utilization of Energy Sources
In Chinese Rural Areas
The
Large-sized Industrial Biogas Technology
A
Wastewater Treatment System for Pig Farms
How
is Biomass Energy Used?
Various
energy forms such as electricity, light, heat,
motion and fuels can be produced from biomass
feedstock through a number of processes and conversion
techniques.
- Combustion;
the burning of biomass, such as the use of biogases
by the sugar industry in NSW to produce heat
and electricity using steam turbine generators.
- Gasification;
the efficient conversion of solid fuel to gaseous
fuel such as was used to produce "town
gas" from coal, before the advent of natural
gas. The gas made can produce heat and electricity
using gas engine generators.
- Pyrolisis;
the production of a carbon rich solid fuel and
a hydrocarbon rich gas by heating a biomass
feedstock in the absence of oxygen, such as
used to produce charcoal from wood.
- Digestion;
the production of gas by biological means (biogas)
such as used at pig farms or landfill sites
to produce methane which is then used to generate
heat and electricity, as well as recycle water
and produce fertilizers.
- Fermentation;
the production of alcohol by the action of yeast
on biomass such as used to produce alcohols
from sugars and starches
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Comprehensive
Exploitation And Utilization of Energy Sources
In Chinese Rural Areas
At
present, eight ministries and commissions of Chinese
government are making joint effort to carry out
the comprehensive energy exploitation programs
of one hundred counties.
The
major points of the comprehensive exploitation
of energy sources in Chinese rural areas are as
follows: in each unit area county, the county
government exercises unified leadership in scientifically
analyzing and evaluating various energy exploitation
projects in the whole county, making a unified
plan with the consideration of the conditions
of the local economic and social development,
and exploiting energy sources comprehensively,
according to the principle of planning in accordance
with local resources available and economic conditions,
multi-energy complementary supply, making comprehensive
use and striving for benefits and effects"
and "stressing both exploitation and economization."
In the process, great efforts are made to popularize
various advanced and applicable technical skills,
exploit and utilize local natural resources, properly
and efficiently use and economize energy sources,
gradually build up and perfect a multi-complementary
energy-providing system and a relevant management
and service system, and eventually ensure desirable
and comprehensive effects or benefits in all aspects'
energy sources, economy, ecology and society.
The
execution of the programs in the past few years
has shown that the comprehensive exploitation
of the rural energy sources in many counties has
greatly promoted the local economic development
and ecological improvement .
In
the future, China will continue the comprehensive
exploitation of the rural energy sources on a
larger scale and at a higher rate.
Here
is an introduction of the comprehensive exploitation
of the rural energy sources in two counties in
Sichuan Province .
The
comprehensive exploitation of rural energy project
organized by the Fucheng District of Mianyang
City and Mianzhu County has make a great Progress
. In Fucheng District, 34 thousands new types
of household biogas digesters have been built
up, which are used in 41.6% of the total households,
and 49 thousand fuel-saving stoves have been set
up. In Mianzhu county, 78 thousands household
biogas digesters were established, which account
for 78.7% of the total,137 thousands fuel-saving
stoves were built up, which account for 97.5%
of the total. In the county, the biogas digester
for disposing sewage were set up in 95%of government
organizations, factories and schools , and the
total volume of digesters is over 40 thousand
m3. By the comprehensive use with biogas, noticeable
economic and eco-environmental benefits are gained,
the construction of spiritual and material civilization
is promoted .
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The
Large-sized Industrial Biogas Technology
At
the biogas station of Huian Chemical Plant (Xi'an
City), the technology for exploiting biomass energy
on large scale is utilized to treat the wastewater
from butanol production with corn. The technical
parameters are: PH over 7.0, digestion temperature
55-60 degree, HRT 10 days, biogas production rate
by digester 1 ms/ms, COD remove rate 85-90%, CH4
content over 60%, heat value of biogas 5000-5500
kcal/m3. The technique is suitable for treating
low/high concentration industrial waste.
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A
Wastewater Treatment System for Pig Farms
The
solid-liquid separating pretreatment, high rate
anaerobic digestion and after treatment are adopted
in the system designed by Guangzhou institute
of Energy Conversion. The system is capable of
treating manure from 10,000-100,000 pigs. For
example, Wanfeng Pig Farm (the biggest in Asia)
turns out over 100,000 heads each year, with sludge
1,400 m3/d and COD concentration over 20,000 mg/L.
After treating the sludge. COD and BOD concentration
in effluent are 130.7 and 11.33 mg/L respectively,
the COD remove rate is 99.4%, thus it conforms
to the standard set by the local environmental
protection bureau for wastewater draining. Treated
water recycles and is used to washing Pig sties.
Average biogas production rate is 1,400 m3/d,
and the biogas is supplied to households and canteen
as energy. The digested residues is recovered
for comprehensive use.
The
system has produced substantial economic and ecologic
benefits, and usually the investment could be
recovered in 2-3 years.
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