prof. r. shanthini feb 11, 2012 module 07 renewable energy (re) technologies & impacts...
TRANSCRIPT
Prof. R. Shanthini Feb 11, 2012
Module 07
Renewable Energy (RE) Technologies & Impacts
(continued)
- Use of RE sources in electricity generation, in transport, and in other energy consumption modes
- Ecological impacts of RE sources, and mitigation measures
Prof. R. Shanthini Feb 11, 2012
- Hydroelectric
- Solar Photovoltaics (Solar PVs)
- Solar Thermal (Solar T),
also known as Concentrated Solar Power (CSP)
- Wind
- Geothermal
- Marine (Wave and Tidal)
- Biofuels (Biomass, Bioethanol and Biodiesel)
RE technology options:
Prof. R. Shanthini Feb 11, 2012
Biodiesel
Biodiesel can be used in compression ignition engines with little or no modifications.
Biodiesel is derived from renewable lipid sources, such as vegetable oil or animal fat.
Biodiesel is a mixture of mono-alkyl esters of long chain fatty acids.
Prof. R. Shanthini Feb 11, 2012
Biodiesel production (traditional method)
Biodiesel is made by chemically combining
any natural oil or animal fat (major component of which is triglyceride)
with an alcohol (methanol / ethanol / iso-propanol)
in the presence of a cataylst (NaOH or KOH)
triglycerids methanolmethyl Ester
(biodiesel)
glycerol(glycerin)+ +KOH
This process is known as transestrification.
Prof. R. Shanthini Feb 11, 2012
Biodiesel production (traditional method)
Triglyceride
Methanol
Biodiesel: mixture of
methyl esters
Glycerol
KOH
Transestrification is a reaction of an ester with an alcohol to form a different ester.
Prof. R. Shanthini Feb 11, 2012
Triglyceride Glycerol
Prof. R. Shanthini Feb 11, 2012
Triglyceride to Free fatty acids
Prof. R. Shanthini Feb 11, 2012
Free fatty acid (FFA) to biodiesel
Free Fatty Acid Methyl ester Water
H2SO4
This process is known as estrification (which is a reaction of an acid with an alcohol to form an ester).
Methanol
Free Fatty Acid Soap Water
NaOH
This process is known as saponification, in which soap is produced.
Base
Na
Prof. R. Shanthini Feb 11, 2012
Biodiesel feedstock
Vegetable oils: - Rape seed/Canola (> 80%) - Soybean (USA, Brazil) - Cotton seed (Greece) - Palm (Malaysia) - Peanut - Sunflower (Italy, FranceSouth) - Linseed & Olive (Spain) - Safflower - Coconut - Jatropha (Nicaragua) - Guang-Pi (China)
Animal fats: - Beef tallow (Ireland) - Lard - Poultry fats
Waste oils: - Used frying oils (Austria)
Other feed stocks: - Algae
Prof. R. Shanthini Feb 11, 2012
Biodiesel production process
(5 to 25% FFA)
Prof. R. Shanthini Feb 11, 2012
Biodiesel blends used in diesel engines
B2 – 2% biodiesel and 98% petro diesel
B5 – 5% biodiesel and 95% petro diesel
B20 – 20% biodiesel and 80% petro diesel
http://www.mechanicalengineeringblog.com/tag/biodiesel-chemistry
Prof. R. Shanthini Feb 11, 2012
Biodiesel from algae
Claimed output of 10,000 gallons of biodiesel per hectare per year.
Prof. R. Shanthini Feb 11, 2012
Biodiesel from algae
10,000 gallons of biodiesel per hectare per year
= 37854 litres per 2.47 acres per year
= 15325 litres per acre per year
= 15325 / 160 litres per perch per year
= 96 litres per perch per year
= 96 /12 litres per perch per month
= about 8 litres per perch per month
Claimed output of 10,000 gallons of biodiesel per hectare per year.
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Algae harvesting from habitat
Culture maintenance/storage
Growth in open pond
Harvesting
Separation of cell components
Carbohydrate and protein contents
Conversion to biodiesel
Transportation and distribution
customer
Combustion in vehicles
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Manufacture / construction of
open pond
Manufacture / maintenance of
equipment
Acquiring resources of manufacture
Partial treatment of wastewater
Crude oil drilling
Crude oil refining
Hexane purification
Algae harvesting from habitat
Culture maintenance/storage
Growth in open pond
Harvesting
Separation of cell components
Carbohydrate and protein contents
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Sodium methoxide
Catalyst production
Salt mining HCl production
Conversion to biodiesel
Methanol production
Natural gas and methane
refining
Natural gas and methane
extraction
Metal mining
Salt mining NaOH production
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
Manufacture / maintenance of
equipment
Transportation and distribution
customer
Combustion in vehicles
Acquiring resources of manufacture
Crude oil drilling
Crude oil refining
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Hexane purification
Algae harvesting from habitat
Culture maintenance/storage
Growth in open pond
Harvesting
Separation of cell components
Carbohydrate and protein contents
When harvested, there is 0.05% algae in wastewater.
It has to be brought to 91% algae in wastewater (required by the hexane extraction step).
This is achieved by a dewatering process (filtration or centrifugation) followed by drying in a natural gas fired dryer.
Algae dewatering is the most significant energy sink in the entire process.
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
Algal lipid content
(%, w/w)
Total energy input
(MJ / 1000 MJ algae biodiesel)
40 2,500
30 3,292
20 4,878
15 6,470
10 9,665
5 19,347
Prof. R. Shanthini Feb 11, 2012
Algae biodiesel life cycle
K Sander & GS Murthy from Int J Life Cycle Assess (2010) 15:704–714
In most algae species, there is typically a larger percentage of carbohydrates than lipids in an algae cell.
With lipid removed to produce biodiesel, the remaining carbohydrates makes an excellent feedstock for bioethanol.
Every 24 kg of algal biodiesel produced (one functional unit,1,000 MJ algae biodiesel), 28.1 kg carbohydrates and cellulose coproduct are also produced.
With less than 2% lignin, bioethanol processing becomes more favourable.
Prof. R. Shanthini Feb 11, 2012
Prof. R. Shanthini Feb 11, 2012
Life-cycle assessment (LCA)
Is it better to use LED lights or CFL lights or incandescent lights?
Is electric car better than petrol/diesel car?
Is hydroelectricity better than fossil fuel electricity?
Is electricity from coal power is better than electricity from nuclear power?
How do we answer these questions?
We could do LCA analysis.
Prof. R. Shanthini Feb 11, 2012
LCA is a tool to assess the potential environmental impacts of product systems or services at all stages in their life cycle – from extraction of resources, through the production and use of the product to reuse, recycling or final disposal.
Life-cycle assessment (LCA)
Prof. R. Shanthini Feb 11, 2012
Life-cycle assessment (LCA)
- LCA determines the environmental and societal impacts (damages, in particular) of products, processes or services through its entire lifecycle.
- Environmental and societal impacts means the impacts of use of resources as well as the impacts of wastes generated on the environment and society.
- LCA considers all stages of a process, such as raw material (resource) extraction, processing and transport, manufacturing, packaging, distribution, use, and disposal/recycling.
Prof. R. Shanthini Feb 11, 2012
LCA is a technique to assess the potential environmental impacts associated with a product or service throughout its life cycle, by:
- Defining suitable goal and scope for the LCA study - Inventory analysis
- Impact assessment
- Interpreting the results
Life-cycle assessment (LCA)
Prof. R. Shanthini Feb 11, 2012
Inventory analysis provides information regarding consumption of material and energy resources (at the beginning of the cycle) and releases to the environment (during and at the end of the cycle).
Impact analysis provides information about the kind and degree of environmental impacts resulting from a complete life cycle of a product or activity. Improvement analysis
provides measures that can be taken to reduce impacts on the environment or resources.
Source: S. Manahan, Industrial Ecology, 1999
Life-cycle assessment (LCA)
Prof. R. Shanthini Feb 11, 2012
Life-cycle analysis must consider
- selection of materials, if there is a choice, that would minimise waste
- recyclable components
- alternate pathways for the manufacturing process or for various parts of it
- reusable and recyclable materials
Source: S. Manahan, Industrial Ecology, 1999
Life-cycle assessment (LCA)
Prof. R. Shanthini Feb 11, 2012
Life-cycle assessment (LCA)LCA looks at products or processes from start to finish.
Cradle
Gate
Prof. R. Shanthini Feb 11, 2012
Life-cycle assessment (LCA)LCA looks at products or processes from start to finish.
Coffee producerGate
Grave
Prof. R. Shanthini Feb 11, 2012 http://www.sustainability-ed.org.uk/pages/look4-1.htm
Cradle
Gate
Grave
Prof. R. Shanthini Feb 11, 2012
Life-cycle assessment (LCA)
supply transport
manufacturing
packagingUse
disposal
Cradle to Gate(4 stages)
Cradle to Grave(6 stages)
Prof. R. Shanthini Feb 11, 2012
Components of life-cycle assessment:
Prof. R. Shanthini Feb 11, 2012
Phases in a life-cycle assessment:
ISO 14040 framework
Goal and Scope Definition(Determining boundaries for
study)
Goal and Scope Definition(Determining boundaries for
study)
Inventory Analysis (Data on inputs and outputs
quantities for all relevant processes)
Inventory Analysis (Data on inputs and outputs
quantities for all relevant processes)
Impact Assessment (Contribution to impact
categories, such as energy consumption, through
normalization and weighing)
Impact Assessment (Contribution to impact
categories, such as energy consumption, through
normalization and weighing)
Interpretation(Major contributions,
sensitivity analysis: what can be learned from study?)
Interpretation(Major contributions,
sensitivity analysis: what can be learned from study?)
Prof. R. Shanthini Feb 11, 2012
Phases in a life-cycle assessment:
ISO 14040 framework
Prof. R. Shanthini Feb 11, 2012 - Tellus Institute
Goal definition and Scoping:
• Level of specificity in the study
– Is the product being analyzed specific to a company or a plant? (Two different plants producing the same type of product could have different emission levels, for example)
– Or, will we focus on industrial averages (e.g., impacts of using recycled aluminum in a design)?
Prof. R. Shanthini Feb 11, 2012 - Tellus Institute
Goal definition and Scoping:
• Level of accuracy in data collection / analysis
– Should be high if used in driving public policy
– If used in internal decision making for a firm, a reasonable estimate is generally enough
Prof. R. Shanthini Feb 11, 2012 - Tellus Institute
Goal definition and Scoping:
• How to display the results. Example: comparing two products
– Comparison should be made in terms of equivalent use
– Example: bar soap vs. liquid soap; the basis should be an equal number of hand washings
Prof. R. Shanthini Feb 11, 2012
An example life-cycle assessment:
Osram LCA for the following products: 1,000 hour lifetime for incandescent; 10,000 hour for CFL, and 25,000 hour for LED.
Source: www.osram-os.com
Prof. R. Shanthini Feb 11, 2012
The 1.7 kg microchip: Environmental implications of the IT revolution
Source: http://www.enviroliteracy.org/subcategory.php/334.html
by Eric D. Williams, Robert U. Ayres, and Miriam Heller, The 1.7 Kilogram Microchip: Energy and Material Use in the Production of Semiconductor Devices. Environmental Science & Technology (a peer-reviewed journal of the American Chemical Society), 2002, 36 (24), pp 5504–5510
One 32 MB DRAM chip (weight = 2 gram)
1600 g of fossil fuels
71 g of chemicals
32,000 g of water
700 g of elemental gases (mainly nitrogen)
An example life-cycle assessment:
Prof. R. Shanthini Feb 11, 2012 Primary Energy Consumption
An example life-cycle assessment:
Prof. R. Shanthini Feb 11, 2012 Primary Energy Consumption
An example life-cycle assessment:
Prof. R. Shanthini Feb 11, 2012 Primary Energy Consumption
Most of the energy use occurs in purchased parts
(manufacturing and raw material extraction.)
Remanufacturing is best!
An example life-cycle assessment:
Prof. R. Shanthini Feb 11, 2012
Limitations of LCA: some examples
• Weights given to different impacts
– What is more important? Use of water resources or CO2 emissions?
• Drawing the boundaries
– Cradle to Gate or Cradle to Grave?
– Do we consider supporting activities for the system?
• Example: a warehouse stores the product. Direct energy consumption for the warehouse should be part of the system, but emissions associated with garbage pickup for the facility probability shouldn’t be.
Life Cycle Assessment (LCA) 43
Prof. R. Shanthini Feb 11, 2012
Limitations of LCA: some examples
• Social and economic impacts
– Environmental impacts are relatively easy to measure, but socio-economic impacts are difficult to quantify
• Renewable vs. non-renewable resources
• Remanufacturing, recycling, and reuse
– Consideration of recycling makes significant impact, even though that depends on recycling rates
Life Cycle Assessment (LCA) 44
Prof. R. Shanthini Feb 11, 2012
Further Resources
• The web has an incredible amount of information on LCA
• For starters, please check the document “LCA_guide_EPA.pdf” on Angel, which has a more detailed guide to LCA (by the EPA), and it includes a list of software vendors
• See http://www.life-cycle.org/
Life Cycle Assessment (LCA) 45
Prof. R. Shanthini Feb 11, 2012
Life cycle assessment of biodiesel production from free fatty acid-rich wastes
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Biodiesel production systems considered:
- Acid-catalyzed esterification followed by alkali-catalyzed transesterification of waste vegetable oils (used cooking oil)
- Esterification and transesterification of beef tallow
- Esterification and transesterification of poultry fat
- Acid-catalyzed in-situ transesterification of sewage sludges
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Impact potentials evaluated:
- Global warming (GWP) in kg CO2 eq.
- Acidification (AP) in kg SO2 eq.
- Eutrophication (EP) in kg PO43- eq.
- Ozone layer depletion (ODP) in mg CFC-11 eq.
- Photochemical oxidant formation (POFP) in kg C2H4 eq.
- Cumulative non-renewable energy demand (CED) in GJ eq.
Life cycle assessment of biodiesel production from free fatty acid-rich wastes
Prof. R. Shanthini Feb 11, 2012
Biodiesel production system
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
FFA-rich waste
Transportation
Transportation
rendering
Esterification
Trans-esterification
Transportation
Electricity production
Thermal energy
production
Water suppy
Chemicals production
Wastes
Waste management
Biodiesel Glycerol
Other inputs
Other outputs
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
FFA-rich waste
Trans-esterification
Transportation
Electricity production
Thermal energy
production
Water suppy
Chemicals production
Wastes
Waste management
Biodiesel Glycerol
Other inputs
Other outputs
Biodiesel production system (for sewage sludges)
Prof. R. Shanthini Feb 11, 2012
Inventory of input data for the production of 1 t Biodiesel
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
waste rendered rendered dried Materials vegetable beef poultry sewage
oils tallow fat sludgeLipid feedstock 1205 1015 1013 10,000 kg
Methanol 112.67 113.32 99.00 670.18 kg
Sulphuric acid 0.15 - -76.35 kg
Calcium oxide 0.10 - - - kg
Water 56.08 71.32 32.00 0.88 kg
Sodium hydroxide 9.80 4.00 5.00 - kg
Sodium methoxide - 11.00 12.00 - kg
Phosphoric acid 7.95 - - - kg
Hydrogen chloride - 6.00 7.00 - kg
Hexane - - - 76.28 kg
Prof. R. Shanthini Feb 11, 2012
Inventory of input data for the production of 1 t Biodiesel
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
waste rendered rendered dried Energy vegetable beef poultry sewage
oils tallow fat sludgeThermal (rendering) 1628.93 - - - MJ
Electrical (rendering) 133.12 - - - kWh
Thermal (esterification) 222.30 175.94 90.04 - MJ
Electrical(esterification) 31.43 28.93 10.08 - kWh
Thermal (transesterification) 1650.84 1733.48 1886.96 2542.95 MJ
Electrical(transesterification) 20.34 30.36 28.98 28.47 kWh
Prof. R. Shanthini Feb 11, 2012
Inventory of input data for the production of 1 t Biodiesel
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
waste rendered rendered dried Transport vegetable beef poultry sewage(by lorry) oils tallow fat sludge
To rendering plant 187.76 - - - t km
To biodiesel plant 291.31 293.44 292.76 - t km
Prof. R. Shanthini Feb 11, 2012
Inventory of output data for the production of 1 t Biodiesel
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
waste rendered rendered dried Materials vegetable beef poultry sewage
oils tallow fat sludge
Biodiesel 1.00 1.00 1.00 1.00 t
Glycerol 102.21 115.64 109.00 129.05 kg
Salts to landfill 16 9 10 - kg
Hazardous liquid waste 30.46 24.00 26.00 - kg
Organic waste to landfill 85.40 - - - kg
Sludge - - - 2 t
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Global Warming Potential (kg CO2 eq per GJ of energy supply)
0
20
40
60
80
100
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Environmental profile of different transportation diesel fuels
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Acidification Potential(kg SO2 eq per GJ of energy supply)
0
0.1
0.2
0.3
0.4
0.5
0.6
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Environmental profile of different transportation diesel fuels
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Eutrophication Potential(kg PO4 ions eq per GJ of energy supply)
00.05
0.10.15
0.20.25
0.30.35
0.4
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Environmental profile of different transportation diesel fuels
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Ozone layer Depletion Potential(kg CFC-11 eq per GJ of energy supply)
0
2
4
6
8
10
12
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Environmental profile of different transportation diesel fuels
Prof. R. Shanthini Feb 11, 2012
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Photochemical Oxidant Formation Potential(kg C2H4 eq per GJ of energy supply)
0
0.01
0.02
0.03
0.04
0.05
0.06
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Environmental profile of different transportation diesel fuels
Prof. R. Shanthini Feb 11, 2012
Environmental profile of different transportation diesel fuels
J. Dufour and D. Iribarren in Renewable Energy 38 (2012) 155-162
Cumulative Non-renewable Energy Demand(GJ eq per GJ of energy supply)
00.20.40.60.8
11.21.4
Was
te v
eget
able
oils
Beef t
allo
w
Poultry
fats
Sewag
e sl
udges
Soybea
n
Rapes
eed
Low-sulp
hur die
sel
Prof. R. Shanthini Feb 11, 2012
Prof. R. Shanthini Feb 11, 2012
Prof. R. Shanthini Feb 11, 2012
Prof. R. Shanthini Feb 11, 2012