Biofuels and

alternative fuelsIdeas to substitute 10% italian petrol

by mean of non-fossil fuels

Project by Riccardo Dalla Costa, Stefano Maronese,

Arianna Barison e Valentina Codemo

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

How to achieve our goal?

A new chain based on biogas

Biogas

Residual biomass

CHP Energy

Stackgases

Algae

Biodiesel

Upgrade Biogas

CO2

Biomethane

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)

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

Expertise and job organization

4/21

Stefano MaroneseCHP design and

economic analysis

Valentina CodemoMicroalgae production

and emissions analysis

Riccardo Dalla CostaBiogas potential analysis

and plant design

Arianna BarisonUpgrade analysis and

upgrade unit design

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

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

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

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

Design of the upgrade chain

Rimozione componenti minori

Upgrade Chain

Rimozione componenti minoriBiomethane

Odorizationand

conditioningCompression Methane grid

Post Treatment

9/21 Injection into the gas grid according to the Italian regulation

(D. Lgs 28/2011)

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

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

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

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

Emissions analysis:

Traditional Management

Manure and

residues

CH4, CO2, N2O,

NH3

CH4, CO2, N2O,

NH3

Biomass

Storage

Storage and

spread

System Boundary

14/21

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

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

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)

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?

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)

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

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

Thanks for your attention!