Bio-fuels Performance, Emissions and Policy

Issues

Part-i

Ethanol

Alcohol Fuels

Low level blend.– Upto 5% can be used as oxygenate (as per IS 2796:

2000 - specifications for motor gasoline).– Upto 10% vol. Alcohol blend for gasoline vehicles.

High level blend.– Containing 10-85% vol alcohol blend for gasoline

vehicle.– Up to 15% alcohol for diesel blend.

• Generally recommended 5 to 7.5% for optimum emission performance.

Ethanol As Automotive Fuel : Advantages

Can be used as an oxygenateHigher CR can be used because of high

knock resistance of the fuelHigher volumetric efficiency, leading to

increased power Higher flame velocityWider flammability limits

Ethanol As Automotive Fuel : Limitations

Highly corrosive in nature - it affects badly metallic and non-metallic parts

Higher latent heat of vaporization causes cold and hot startability problems

Higher Aldehyde emissions Requires large fuel tank capacity due to lower

calorific value Higher evaporative emission due to higher RVP

Engine Modifications Required for Higher Blends (E15-E95)

Development of metal components for anti-corrosion properties

Oil seals/rubber components should be made of compatible elastomers (e.g. Viton)

Large fuel passages (jet/injector sizes) for equivalent energy

Retarded ignition timingHigher compression ratios

Ethanol in Diesel Vehicles

Flash pointFlammabilityMaterial compatibility and durability Storage and handlingDrivability

E Diesel Specifications and Emissions

Diesel ULSD E Diesel Viscosity, 40°C Cst 2.7 2.3Flash Point, °C 59 < 23Sulphur content, ppm 47 < 47CFPP, °C -20 -20Cloud Point, °C -3 -2Cetane Number 54 52

1.5% reduction in Nox, 9% increase in HC, 19% reduction in CO, 17% reduction in PM

For Best Emission Performance 7.5% ethanol is recommendedSource : Akzo Nobel Surface Chemistry AB, Sweden

Certification Issues Fuel System

Driving range - tank size, fuel economy Fuel indication - % alcohol read out Performance - compression ratio Exhaust emission measurement (Aldehydes) Durability of catalytic converter SHED emissions - permeability, canister volume Reliability - material upgrade, fuel quality Cold and hot startability

Certification Issues -Vehicle Fuel System

Tank inflammability Flame luminosity Anti-siphonFueling receptacle for misfueling protection Labeling and procedures for fuel handling

Certification Issues Material Compatibility

Corrosion of steel is accelerated by the presence of alcohol's in the fuel because of increased water content.

Both methanol and ethanol in gasoline can cause elastomers to swell and lose tensile strength leading to failures of critical.

Components such as fuel pumps, accelerator pumps and hoses.

Certification Issues Safety

– Electrical conductivity• Higher for alcohol than gasoline

• Less danger for ignition caused by static change sparking

– Invisible flame• Suitable additives may be added

– Rules for handling the fuel and instructions for fire fighting

– Crash safety of vehicles• Special rear end collision tests may be required to determine

potential safety hazard

Material Compatibility

Quality of ethanol has a strong influence on its corrosive effects.– General corrosion - caused by ionic impurities mainly

chloride ion and acetic acid in ethanol even in trace quantities.

– Dry corrosion - due to ethanol molecule and its polarity , the metals (mg, Pb, and al) are susceptible.

– Wet corrosion - caused by azeotropic water which oxidizes most metals. As ETOH has strong affinity for water it will absorb moisture when stored. Specially true for tractor/harvester engines.

Material Compatibility

Corrosion inhibitors added in additive packages (e.G: VCI-705 concentrate, PEC Puranol) have shown promising results.

Synthetic ethanol from coal and natural gas are significantly more corrosive in nature.

Elastomeric compounds such as seals and o-rings in FIP which tend to swell and stiffen loosing their properties.

Resin bonded or resin sealed components are also susceptible to swelling.

Engine Durability- Diesel Engines

Studies have shown no abnormal wear with 10-15 % ethanol diesel blends.

Some engines may be sensitive to lowering of Cetane no & increased ignition delay causing piston erosion.

Small injection timing retardation or addition of ignition improvers such as Triethylene glycol Dinitrate (TEGDN), Octyl nitrate have proven to offset the above problem.

Engine Durability- Diesel Engines

Studies have shown a decrease in injector coking over 460 hrs of testing with 15% ethanol blend whereas significant amounts of coking was found when ordinary diesel with only 20 hrs testing was used.

Blend Stability

Solubility of ethanol in diesel is dependent on temperature and water content. Lower limit of phase separation is 10°C.

Aromatic content affects stability as ethanol's polar nature induces a dipole in benzene ring allowing strong interaction.

Blend Stability

Emulsifiers: acts to suspend small droplets of ethanol in diesel. Requires heating, stirring steps to generate final blend.

• Types: detergent, ionic, detergent less.

Co-solvent: acts as a bridging agent through molecular compatibility and bonding to produce homogeneous blend.

• Ethyl acetate is a good co-solvent that ensures complete miscibility down to 0ºC at 1:2 ratio.

Blend Stability

Additive packages:– Pure energy corporation use 2-5% dosage with

15% ethanol.– AAE technologies use 1 to 1.25% for 7.7% to

10% blends.– Betz-Dearborn use around 2% for 15% ethanol

blend.Blends require less additive in summer

conditions compared to winter.

Blend Viscosity and Lubricity

The diesel engine fuel injection systems rely on fuel lubricity for their lubrication.

A study showed that blend of dry ethanol to diesel would lead to a considerable reduction in kinematic viscosity.

The reduction in viscosity would lead to fuel pump and injector leakage thereby reducing fuel delivery and hence reduction in power output.

Part II

Bio-diesel

What is Bio-Diesel

Biodiesel (Methyl Esters) is a diesel replacement fuel made from Vegetable Oils such as Soya beans, Mustard Seed, Sunflower, Corn, Palm or Rapeseed. It can also be made from recycled restaurant oils.

It is renewable, biodegradable, non-hazardous and dissolves in water faster than sugar making it safer for air, water and soil.

What is Bio-Diesel

It is 11% oxygen by weight. Soy biodiesel contains less than 1ppm sulfur.

Biodiesel requires no engine modification.

A chemical process called transesterification is used to transform the raw vegetable oil into biodiesel and glycerin using Methanol and lye (KOH or NaOH).

What is Bio-Diesel?

Biodiesel Lowers toxic emissions and Particulate Matter drastically.Biodiesel is safe to store, and has a high flash pointBiodiesel has greater Cetane (50-56) Better Lubricity than diesel fuelIn Fact, 1% biodiesel increases lubricity by up to 30%.Biodiesel is the first and only alternative fuel to have complete evaluation of emissions results and potential health effects submitted to the US EPA under the Clean Air Act 211 (b)*

* Source: Graham Noyes, World Energy, USA

Indian Perspective : Jatropha Curcas

Cultivation:

It grows readily from cuttings and seeds.

Cuttings strike root so easily that the plant can be used as an energy-producing living fence post

The remaining oil cake can be used as fertilizer for rejuvenating the soil.

Properties of Bio-Diesel

4.653Viscosity at 40 deg. C sq.mm/s

871830Density at 40deg. C kg/cu.m

12.5414.5Stoichiometric A/F ratio

5248Cetane no

0.0010.05Sulfur content % wt

11-Oxygen content % wt

7786.5Carbon Content C % wt

1213.4Hydrogen content H % wt

3654043000Net Heating Value LHV, kJ/kg

19:36:216:30:0C/H/O

Bio-DieselDieselProperties

Bio-Diesel : Diesel-Rapeseed Methyl Ester Blend

Characteristics of RME blends.A linear increase in density of dieselA small increase in viscosityChange in distillation rangeAn increase in foaming tendencyA light degradation of cold start characteristics

CFPP improvers, anti foaming agents are needed

Introduction of Rapeseed Methyl Ester- The French national Program

Tests were conducted on 18 lorries, 15 buses, 18 highway trucks, 19 private cars with around 5 million cumulative mileage accumulation.The elastomers tested for change in wt, swelling, permeability and mechanical properties, indicated no abnormal behaviour.RME >5% increased carbon content in fuel indicating micro-biological contaminationLead coating of fuel tanks was fouled, indicating chemical reaction with lead.

* Source: French Institute of Petroleum

….Introduction of Rapeseed Methyl Ester - The French National Program

Performance and emissions:Increase in FC was observed which is consistent with the lower heating value of RME No change in CO and HCPM remained same, IOF decreased while VOF increasedA slight increase in NOx was observedNo changes in unregulated emissions such as Aldehydes was observed.

Drivability: an increase in noise and smoke levels during cold start were observed. Tanks tended to overflow while refilling due to foaming tendencies. Can be corrected by anti-foaming additives.

Emission Benefits obtained with Bio-diesel

Regulated *B100 B20Total Unburned Hydro Carbons -93% -30%Carbon Monoxide -50% -20%Particulate Matter -30% -22%Nox +13% +2%

Non-regulatedSulfates -100% -20%PAH (Polycyclic Aromatic Hydrocarbons) -80% -13%nPah (nitrated PAH) -90% -50%Ozone Potential of speciated HC -50% -10%Mutagenicity -80% - 90% -20%

*B:Biodiesel ** source: Graham Noyes, world energy, USA

CO2 Emission Benefits

Biodiesel

Use in Automobiles

Photosynthesis

Biodiesel Production

Well-to-Wheel Analysis of Emissions with various FuelsFuel GHC PM NOx VOC CO

Gasoline +35 -70 -55 +170 +415

CNG +20 -80 -45 -30 +190

LPG +20 -80 -60 0 +210

Ethanol 85% 0 -75 -55 +130 +210

Diesel 0 0 0 0 0

Biodiesel 20% -15 -20 0 -10 -15

Hybrid -30 -20 -20 -20 -20

Electric -45 -80 -95 -100 -100

Biodiesel 100% -70 -55 +5 -55 -45

Well-to-wheel Analysis of Green House Gas of Various Fuels

Part III

Issues and Concluding Remarks for Bio-fuels

Summary

Ethanol as low level blend, high level blend and E100 can be used as an automotive fuel for better emission performance

Material compatibility is a concern for high level blends

Special rear end collision tests may be required for ensuring safety

Summary

The drivability, cold and hot startability problems of the vehicle can be addressed by proper engine calibration

Infrastructure for distribution of fuel will be required

The acetaldehyde emissions are to be measured and can be controlled by catalytic converters

Summary

10% ethanol blend in gasoline can be tried out which may not require any major modifications in the vehicle.

Evaluation Programme is necessary for vehicle performance, emission, safety, material compatibility.

5 to 7% ethanol blend in diesel could be a promising solution for the reducing in-use vehicle emissions especially for PM reduction.

Summary

Study in respect of performance, emission and safety is need to be launched for all types of vehicles.

Use of ethanol blend in gasoline and in diesel will help overall economy with the great benefit to rural areas.

Standards / procedures for testing and evaluation / certification are to be framed.

Summary

ARAI has already submitted a Joint Project proposal with Vasantdada Sugar Institute to MOPNG for evaluating different alcohol blends in Diesel and Gasoline

Indian make Vehicles ranging from Utility, LCV and HCV will be evaluated with 5% and 10% ethanol blends to assess the technology for– Performance– Emission– Durability

Summary

Field studies of using bio-diesel on Indian make vehicles are limited

Hence there is a need to conduct a comprehensive study on Indian make HCV and LCV diesel vehicles of different models and vintages to assess the emission benefits and overcome technical hick-ups

Thank YouThank You

Let us work together for cleaner ambience with use of Bio-Fuel as Auto

Fuel