How nature works?
The Emergy methodology approach.
Some ideas about how to produce
Biofuels in Eco-units taking into
account nature and society.
Enrique Ortega, FEA/Unicamp.
Campinas, SP, August 6th, 2006
Exergy
Complementary
exergies and
materials
Available
energy
potential
Recycling
(internal flow)
Feedback
Interaction
process
System
Exergies of
different
quality
Work that flows out
of the system
Production
Net exergy produced
adding exergies
Dispersed energy (heat)
In nature, the potential energy interact with other available
exergies and raw materials to produce resources with higher
energy intensity, that constitute the work of the system!
The potential energy is used to produce this transformation and
a great part of it is degraded to produce the work. The degraded
energy is usually referred as “heat”.
Complementary
energies
Complementary
energies
Better
quality
energies
Available
potential
energy
Interaction
Better
quality
energies
Interaction
The external exergy captured by the
system is transformed into a new
resource that has potential energy
of a different kind; this product will
participate of a sequence of steps
of intake and conversion of exergy
until all the useful potential is used.
Raw materials
from nature
Exergy of a
external diffuse
continuous
source
Recycled
materials
Materials
recycling
Materials
with better
exergy
Interaction
Potential energy
transferred to
other systems
Dispersed
materials
Dispersed Energy
It is external exergy that is transformed within the system
that impulses the materials cycle in ecosystems, in human
beings, in human economy and in biosphere.
Materials
Recycling
Diffuse
Exergy
Decomposers
The diffuse solar exergy is transformed into vegetal biomass
and then used by a net of consumers. At each new stage of
the chain the quantity of exergy transferred diminishes.
Wastes might have materials with available energy that
decomposers can use to grow and as result nutrients (humus)
can be returned to initial steps of energy chain.
Main system functions: external source, photosynthesis, stocks
of materials, consumers, decomposers, flows.
The self-organization develops a hierarchical structure.
In this diagram the symbol’s sizes are proportional to mass.
Minerals
Natural carrying capacity
Fossil
energies
Predatory use
of renewable
resources
Non sustainable carrying capacity
The chain can grow when receiving additional exergy (renewable
resources used faster than their recovering time, fossil fuels and
minerals that are extracted with these additional resources).
Non renewable
resources
Natural
Ecosystems
Renewable
resources
Agricultural
ecosystems
Urban
systems
There is a interdependence among the systems components.
Form left to right exergy flows to provide support to upper
levels of trophic chain; high quality exergy and basic nutrients
flows in a countercurrent. The feedback flows changes its
quantity and quality when non renewable resources are used.
Fossil fuels
Water in atmosphere
Petroleum, gas, coal
Ocean
Renewable
energy
resources
New
resources
Water and
environmental
services
Minerals and sediments
Volcanoes
Infra-structure
organization
Biomass
biodiversity
Minerals after
microbial
solubilization
Industrial
products
obtained
from oil
Raw
materials
from rural
areas
Natural
landscape
and farms
Anthropic
interaction
with
Biosphere
Environmental services
Direct solar radiation
Urban systems
External
emergy: 15,8
Total emergy:
50,1
Gravitation
force of Moon
and Sun
3,84
8,06
Hydrocarbons: 26,1
Nuclear: 2,9
Wood and soil: 2,8
Minerals: 2,5
Earth
internal
heat
Materials
Minerals
and other
stocks
Minerals
Atmosphere
3,93
Solar
Emergy
Intense
heat
Non renewable
resources
Terrestrial
crust
Ocean
34,3
Civilization
Gases,
Sediments,
Wastes
Flows expressed in E24 sej/year
Emergy flows in the nature-society system (Brown & Ulgiati, 2004)
Earth
deep
heat
Basic raw
minerals Material
stocks
Product
flow
Product
flow
Gravitation
force from
Sun and
Moon
P1
P3
P2
Interactions
Solar
radiation
Efficiency =
Product
flow
Product exergy
_____________________________________
Total emergy used
Transformity =
Emergy
_______________________________________
Product exergy
Transformity =
1
________________________
Efficiency
Y = cost of exergy used,
in terms of solar emergy
P
P
P1
Y
2
3
Y
Tr = ----EPi
Emergy used
Transformity = ----------------Product
exergy
Biosphere emergy (Y) can be assumed constant. As the
product mass (Pi) and its energy content (Ep) decreases along
the chain, the transformity (Tr) grows along the network.
The transformity reveals the hierarchical position of each
resource in the different networks of the Universe. As more
scarce or concentrated it is the resource becomes more
valuable due to its interaction power.
Transformity of rain water
Tr = Emergy/Exergy = Y / E
Y = Earth total emergy flow = 15,83 E24 sej/year
Rain water total flow = 1,04 E17 kg/year
Gibbs Free Energy of rain water = 5 E3 J/kg
E = Rain water exergy =
5,19 E20 J/year
Tr = Y/E = 15,83 E24 sej/year / 5,19 E20 J/year
Tr = 3,1 E4 sej/J
And so on …
Transformity = Exergy incorporated / Exergy of resource
Biological species genetic information
(DNA, biodiversity)
sej / J
1015
Global geologic systems
1014
10
13
Information and
society knowledge
1012
1011
Digital data and knowledge
1010
109
108
107
106
105
104
Metalic products
Humans
Aquatic animals
Terrestrial animals
Agriculture
products
green plants
Water
Rain
103
102
101
10
0
Wind
Sun
Simple organic matter
Eletronic products
Chemical products
Fertilizers
Sedimentar minerals
Evaporites
Petrochemicals
Minerals
Fossil fuels
Transformity in present human society
biodiversity
Earth’s
deep
heat
petroleum
energy
tide
energy
solar
energy
green
plants
animals
human
beings
social
activities
geologic
processes
complex
biological
processes
biodiversity
industrial
products
services
soil
rain
persons
local
materials
direct solar
energy
stocks
Interactions
in a farm
Farm
products
Goods and services
soil
industrial products
rain
corn
fuel
fuel
solo
transport
raw materials
petroleum
Industrial
products
goods and
services
biodiversity
soil
rain
local
mineral
resources
people
biomass
sun
corn
losses
J3
J2
J4
Tr4
Tr3
Tr2
e2
J5
e3
External energy resources
in order of intensity and renewability
Tr5
e4
e5
Internal
stocks
Q
Solar direct J1
energy
e1
Agricultural
ecosystem
Products
EP
Transformity of resource produced
Emergy used
Tr =
Energy produced
ei
Ji Tri
=
=
Ep
Ep
Energy
source
flow
flow
energy / area / time
J2
transformity
Procedure for emergy calculation:
Tr 2
e2
emergy / energy
emergy / area / time
Interaction process
1.
Show the flow J2 in its usual units;
2.
Convert the usual units to International Systems units (SI);
3.
Multiply by corresponding transformity (Tr);
4.
Express the flow in solar emergy terms (seJ or seJ/area/time).
Aggregation and comparison of flows on the same basis
N
R2
M
Internal
stocks
Q
S
$
$ sales
R1
interactions
Ep
Products
energy
Resumed
diagram
Indicators
Efficiency:
Tr = Y/Ep
Net emergy:
EYR = Y/F
R3
Local hydric
resources (free
or at low cost)
R2
Chemical
elements from
rocks and
atmosphere
N = Non-renewable energy
from nature
F = Feedback from human economy
(maybe non-renewable)
N
Organic matter
from soil lost by
erosion
F=M+S
Industrial raw materials,
goods, external work,
public services. Water
from reservoirs and
channels.
Payments
R1
Accumulated
solar energy:
regional
biodiversity
Q
Internal
stocks of
emergy
interactions
Investment:
EIR = F/I
Renewability:
%R = 100(R/Y)
R0
Direct solar
energy: radiation,
wind, rain
Agricultural
ecosystem
Renewable energy from nature:
R = R 0 + R1 + R 2 + R3
Total contribution from nature:
I=R+N
$
Money
$
Investment.
Loans.
Profit. Main
and interests
$ sales
Product
Ep = Energy of
product(s)
Degraded and dispersed energy
Incorporated emergy:
Y=I+F
Label of energy
performance
for certification
purposes
F = inputs from human economy
M
S
I = Total contribution from nature
N
F
I
R
Process
Y=I+F
Y emergy used
Ep exergy in product
Emergy used: Y
Transformity: Tr = Y/Ep
Emergy Yield Ratio: EYR = Y/R
Emergy Investment Ratio: EIR = F/I
Renewability: %R = 100(R/Y)
Environmental services and biomass fuel production
Ecosystem processing of emissions, effluents and solid wastes.
Control of local and global temperature,
atmosphere quality maintenance,
Bio-diversity genetic vigor preservation.
and biomass
Polinization, top soil production and
preservation, flooding control, percolated
Natural
clean water, top water biological filtration.
ecosystems
Rural
products
Spare time leisure,
medicinal herbs,
ecologic culture
Agroecosystems
Food, wood, and
textile fibers
Biofuels Energy
knowledge,
democratic
Minerals
control
and oil Industrial
products
Polluted
water
People at
the cities
Emissions, effluents and solid wastes.
Model 1: individual small land areas
Very reduced area for natural
ecosystems and practically no
environmental services
Individual farms or parcels:
low intensity subsystems with
production destined to selfconsumption (subsistence) or
regional market (with low
productivity)
Natural ecosystems
reduced to a minimum.
Fertilizers,
Pesticides,
Herbicides,
Machinery,
Fossil fuel.
Model 2: plantation
Agri-business:
Monoculture plantation
concentrates land
ownership, decreases
manpower in rural area
and produces several
kinds of erosion: top
soil, native vegetation,
genetic reserves,
human culture.
Commodities
Hidden subsidy
Additional services:
negative externalities.
Model 3: Eco-unit
Integrated system:
Native forest,
Agro-forestry,
Individual parcels,
Animal husbandry,
Biomass energy;
Industry;
Recycling,
Waste treatment.
Native
vegetation
Agroforestry
People
Individual
parcel
Food, meat
Grain, grass,
shrubs
Cattle
Biomass energy
Local industry
Energy
crops
Waste recovery
Water, top soil,
biodiversity,
local climate
Native
vegetation
Eco-unit: micro-distillery
Native forest products
Agro-forestry products
Agroforestry
Self-consumption
People
Individual parcels products
Individual
parcel
Recycling: vinasse,
ash, manure
Grass, grains,
shrubs.
Energy
crops
Food (meat)
Cattle
Micro-distillery,
local and
regional agroindustry
Energy
Waste use
Regional
biodiversity
and water
resources
Lean
calves
Soil
minerals
Atmospheric
nitrogen
Eco-unit:
Fazenda Jardim,
Mateus Leme,
MG, Brazil
Urea
Water, soil,
biodiversity,
local climate
Family
consumption
People
Individual
parcel
Efficiency:
Tr = Y/Ep
Net emergy:
EYR = Y/F
Investment:
EIR = F/I
Renewability:
%R = 100(R/Y)
Vinasse
Grasses,
grains, shrubs
Public
services
External
manpower
Environmental
products and
services
Native
vegetation
Sun,
wind,
rain.
Indices:
Pesticide
for ants
Other
materials
& energy
Vegetable
garden products
Young bulls
(meat)
Cattle
Ash, fiber
Wood poles
(posts)
Eucalypt
Sugar
cane
Micro-distillery, local
agro-industry and
regional industry
Ethanol (94%)
Manure
Pictures
and
results
Indices:
Transformity:
Tr = Y/Ep = 260 000 seJ/J
Net emergy:
EYR = Y/F = 3.1
Investment:
EIR = F/I = 0.47
Renewability:
%R = 100(R/Y) = 66%
Fazenda Jardim, Mateus Leme, MG, Brazil