A study about a new chain based on biogas whose aim is to prove that it is feasible to substitute 10% Italian petrol consumption with non-fossil fuel by exploiting only non-edible crops, livestock manure, residues and wastes.

1. Biofuels and
alternative fuels
Ideas to substitute 10% italian petrol
by mean of non-fossil fuels
Project by Riccardo Dalla Costa, Stefano Maronese,
Arianna Barison e Valentina Codemo

2.  Italian petrol demand in 2010: ~10’000 kt
 We suppose to substitute the same amount of input
energy: car engine has the same efficiency independently
the fuel used
 Assessing a LHV of 43.6 MJ/kg we have to supply about
43.5∙109 MJ of energy
 Most interesting alternative:
 Biomethane
 Biodiesel from microalgae
 Why?
 Exploitation of residual and organic waste and not
conflictual with food cultivation
 No need to change the vehicles: the existing engines
can run with these fuels. Reliable and well-established
technology; high autonomy; quick refueling
Objective: substitute 10%
Italian petrol consumption
1/21

3. How to achieve our goal?
A new chain based on biogas
Biogas
Residual biomass
CHP Energy
Stack
gases
Algae
Biodiesel
Upgrade
Biogas
CO2
Bio
methane
2/21
“Waste is something which
the owner no longer wants
at a given place and time
and which has no current
perceived value” (WHO)

4. The approach to the new chains
4
March – Mid April
• Focus on the issue, consumption and
available technologies
• Analyze Italian biogas potential
• Sketchy design of the new chains
Mid April – Mid May
• Assess parameters for each chains
• First check for general feasibility in
term of energy and extension
Mid May – Mid June
• Modify the chain according to the
result obtained
• Go for further analysis (economical and
environmental)
3/21

5. Expertise and job organization
4/21
Stefano Maronese
CHP design and
economic analysis
Valentina Codemo
Microalgae production
and emissions analysis
Riccardo Dalla Costa
Biogas potential analysis
and plant design
Arianna Barison
Upgrade analysis and
upgrade unit design

6. Evolution of the chain
 Growing algae to produce biodiesel is unfeasible: stack
gas flow is too small to feed a medium-sized open-pond
reactor
5/21

7. Italian biogas potential
 Main biomass:
 Livestock manure: 130 Mt/year
 Food-processing waste: 5 Mt/year
 Municipal sludge: 3.5 Mt/year
 Municipal organic waste: 10 Mt/year
 Crop residues: 8.5 Mt/year
 Estimated biogas production: 8·109 m3/year → estimated
methane production: 4.5·109 m3/year
 Current biogas production used to produce electricity:
1.2·109 m3/year → 500 MWe
 Biogas potential not yet exploited: 3.3·109 m3/year.
Assessing LHV = 31.5 MJ/m3 there are 104·109 MJ
available (greater than our target: 43.5·109 MJ)
 Acknowledgment:
6/21

8. Design of the chain:
Biogas Plant
 Biogas plant of 1 MWe (equivalent):
 Suitable dimension for a medium-sized Italian farm
 No need to transport biomass to larger plant
 Workforce and machinery (loader) already available
within the farm
 Simple management
 Plant alimentation
 130 t/d slurry and manure
 8.5 t/d residual crops (straw, corn stalks, etc.)
 4 t/d food-processing waste
 Plant design
 2 digesters 32x6 m
 1 storage tank 38x6
 1 CHP: 190 kWe and 230 kWt
 Retention Time
 60 days
7/21
Manure Crops residues Food Waste

9. Design of the chain:
Biogas Plant
 Economic cost
 Total investment (digester, machinery): 2.44 M€
 Operating cost (O&M, energy, transportation): 498 k€
 Energy cost
 Biogas production: 4.3 Mm³/year
 Methane content: 55 %
 Electric consumption: 453 Mwhe/year
 Thermal requirements: 2,460 MWht/year
 Biogas used for the process: 0.754 Mm³/year
 Net purchased electricity: 28 Mwhe
 Net electricity sold to the grid: 1,114 MWhe
 Biogas available to upgrade: 3.54 Mm³/year
 Acknowledgment: Industrial Data, UTS Biogas S.r.L.
8/21

10. Design of the upgrade chain
Rimozione componenti minori
Upgrade Chain
Rimozione componenti minori
Biomethane
Odorization
and
conditioning
Compression Methane grid
Post Treatment
9/21
 Injection into the gas grid according to the Italian regulation
(D. Lgs 28/2011)

11. Most widespread upgrading techniques:
 Pressure Swing Adsorption (PSA)
 Advantages: BM with >97% CH4, low energetic request, low
emissions, no heat demand
 Disadvantages: pretreatment needed, high investments cost
 Pressure Water Scrubbing (PWS)
 Advantages: BM with >98% CH4, high purity of BM, removing gas
and particulates, low energy request, no heat demand
 Disadvantages: pretreatment needed, high quantities of water
needed
 Acknowledgment: Technische Universität Wien, Althesys (Strategic consultants)
Design of the chain:
the upgrade unit
10/21

12.  Columns with adsorbent material (activated carbon or zeolites)
and in which are applied pressures which vary during the
process.
 At high pressures the CO2 is adsorbed by the material, which is
then regenerated thanks to a progressive decrease of the
applied pressure
 The plant consists of 4 ÷ 6 ÷ 9 columns that work in parallel.
Design of the chain:
PSA upgrade unit
Biomethane
OffgasCompressor
Raw Biogas
11/21

13.  Economic cost
 Total investment (upgrade plant, connection and post
treatment): 1.66 M€
 Operative annual cost (electricity, maintenance): 220 k€
 Energy cost
 Biogas upgradabile: 3.54 Mm³/year
 Upgrade efficiency: 97 %
 Methane content in biomethane: 97 %
 Electric consumption: 0.250 kWh/m³
 Net purchased electricity: 885.5 MWh
 Biomethane produced: 1.89 Mm³/year
 Acknowledgment:
Design of the chain:
PSA upgrade unit
12/21

14. Emissions analysis: the system
CO2
Manure and
residues
Digestate
Biogas
Electricity and
Biomethane
CH4, CO2, N2O,
NH3
CO2
CH4, CO2
CH4
CO2
CH4, CO2, N2O,
NH3
Biomass
Storage
Transport to
the plant
Anaerobic
Digestion
Transport to
the farms
Storage and
spread
Biogas
Valorization
System Boundary
Electricity
from the
grid
13/21

15. Emissions analysis:
Traditional Management
Manure and
residues
CH4, CO2, N2O,
NH3
CH4, CO2, N2O,
NH3
Biomass
Storage
Storage and
spread
System Boundary
14/21

16. Emissions analysis: balance sheet
63.263
4,083
85.000
-80,917
-90 -70 -50 -30 -10 10 30 50 70 90
Biogas plant
Traditional management
Balance
GWP for petrol
Results (difference)
Emissions credits CO2 Emissions
Biomass storage (17,793) Fuel Consumption (1,46)
AD loss (5,601) Plant operation (Electric consumption) (5,353)
Methane loss in combustion (3,19) Effluent storage and spread (26,626)
Methane loss in upgrading (13,854) Net electric output (-6,531)
gCO2eq/MJ
85.00
63.26
-80.92
15/21
Acknowledgment: TiS, GEMIS - Globales Emissions-Modell Integrierter Systeme®
4.08
67.35

17. Energy analysis: the system
16/21
Fuel
Electricity
from the
grid
Fuel
Manure and
residues
Biomass
Transport
Anerobic
Digestion
Effluent
Transport
Digestate
Biogas CHP
Thermal
Energy
Electric
Energy
Upgrade
Electricity
to the grid
Biomethane
System Boundary
Consumption
Consumption
Input Output

18. Energy analysis: Output/Input
17/21
 All inputs and outputs are referred to primary energy!
 Global energy inputs:
 Fuel for biomass and effluent transportation: 412 MWh
 Thermal energy for anaerobic digestion: 7.73 GWh
(η = 90% heat generator efficiency)
 Electricity for upgrade unit and biogas plant: 3.23 GWh
(η = 45% average efficiency of Italian plant)
 Global energy outputs:
 Biomethane: 18.38 GWh (LHV = 9.7 kWh/m3)
 Electricity to the grid: 2.96 GWh (η = 37.7% efficiency of
the CHP unit)
 Global O/I ratio: 3.34 (considering all the energy needed
and the energy obtained)
 Higher than traditional biofuels (rapeseed 1.44,
sunflower 1.33, sugar beet 1.37)
 Output/input ratio: 8.74 (considering the process designed
for being energy self- sufficient)

19. Economic analysis: parameters
18/21
 Economic parameters for a 1 MW equivalent plant:
 Biogas investment 2.44 M€
 Upgrade investment 1.66 M€
 Financial structure:
 80% loan (5.5% interest rate)
 20% equity (8% interest rate)
 Project life time: 20 years (obtain subsidies for
the electricity sold to the grid 0.23 €/kWh)
 Average operating cost:
 Biogas 498.35 k€/year
 Upgrade 220.42 k€/year
 Outputs:
 Revenue from electricity 257.75 k€
 Biomethane produced 1.89 Mm3
 How much money can be made out of this chain?

20. Economic analysis: scenarios
19
13
7
4
-
2
4
6
8
10
12
14
16
18
20
-10,000,000
-5,000,000
-
5,000,000
10,000,000
15,000,000
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
PB(years)
NPV(€)
Biomethane price (€/m3)
NPV PB
Average
methane price
0.35 €/m3
Levelized Biomethane
cost 0.57 €/m3
Average car
methane price
0.63 €/m3
19/21
 There is still a void in the Italian regulation although the EU
has already focused on biomethane with specific directives
(2009/28 and 2009/73) which state subsidies for biomethane
(grant switch will be needed)

21.  Biomethane-to-grid chain is an idea that adds
up to substitute 10% Italian petrol. Advantages:
 Turn wastes into resources:
 No use any kind of energetic crop but only residues and
organic wastes
 Minimum cost of methane transportation and
distribution:
 Exploitation of existing gas pipelines
 There is no need to change the car park and the fuel
supply chain
 Reduce Italian energy dependency:
 Improve import/export balance: economical resources
invested in the rural area
 Stimulate local economy (bank, farms, industry, FIAT is
market leader in methane engine)
Biomethane chain:
Conclusion I
20/21

22.  High output/input ratio:
 O/I= 3.34-8.74, more than average fuel crops
 Low carbon emission:
 Biomethane saves up to 95% of greenhouse emission
compared to petrol
 Flexible and programmable source
 In perspective biomethane is a reliable choice to
achieve the target:
 The Italian Energy Strategy (SEN) states that new fuel
stations must be provided with methane pump
 About 730 plans could provide enough biomethane to
substitute 10% Italian petrol
Biomethane chain:
Conclusion II
21/21

23. Thanks for your attention!