Team-BHP > Technical Stuff
Register New Topics New Posts Top Thanked Team-BHP FAQ


Reply
  Search this Thread
12,023 views
Old 6th August 2007, 15:19   #1
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,221
Thanked: 212 Times
Ethanol 5%, 10% blending

While going through the paper in ToI/HT Delhi, I saw an ad for Honda City touting it as `technology for tomorrow' because it was E10. What that means is that it can take petrol blended with ethanol to the extent of 10%, or 10% ethanol in a litre of petrol.

The accepted fact is that Honda City is E10 compatible. But what the customers should also know that all other cars that have been launched over the last decade or so are also compatible. That would perhaps not include Amby or Fiat. In fact Brazil uses more than 20% and been using it for 30 years. So much for Honda's nonsense about 10% ethanol engines as `technology for tomorrow'.

As you would know, 5% ethanol blending programme (EBP) has now started in UP, Delhi, Uttaranchal, Karnataka, Goa, Maharashtra (partially), and AP (partially). The EBP programme has not yet been implemented in other states due to high state taxes, excise duties, and levies, which makes the ethanol supply for blending commercially unviable. Over the medium term, the Government plans to increase the ethanol blend ratio from 5% to 10%.

What is the impact of ethanol on fuel efficiency.
According to International Energy Agency (IEA), OECD, Oil & Gas Journal, EIA and all other reputed organisations, ethanol has a higher octane number of 120, much higher than that of petrol, which is between 87 and 98. Thus, ethanol blending increases the octane number without having to add a carcinogenic substance like benzene or a health-risk posing chemical like methyl tertiary butyl ether (MTBE). However, the energy content of ethanol is only 26.75 megajoules (MJ)/kg compared with 43.5 MJ/kg for petrol. Thus, the fuel economy of a vehicle running on ethanol-blended petrol would be lower than that of a pure petrol-powered vehicle. In reality, however, the difference is around 30% since ethanol-blended petrol engines can run more efficiently (at a higher compression ratio) because of the higher octane rating. For 5% ethanol blending, the fuel economy disadvantage is estimated at 2-3%. However, fuel economy can be re-optimised for ethanol blends through minor vehicle modifications, such as adjusting engine timing and increasing compression ratio. Some newer vehicles automatically detect the higher octane provided by higher ethanol blends, and adjust timing automatically. A number of studies have tested (or reviewed tests of) the fuel economy impacts of low-level ethanol blends, and have found a wide range of impacts, from slightly worse to substantially better energy efficiency than the same vehicles on pure petrol. However, ethanol is less polluting. For each unit of sugar-based ethanol produced in Brazil for instance, only about 12% of a unit of fossil energy is required. As a result, carbon dioxide emissions calculated on a `well-to-wheels’ basis are also very low, at about 10% of those of conventional gasoline.

Is engine modification required or will ethanol damage the car
Ethanol can be used as an automotive fuel by either replacing gasoline outright in dedicated internal combustion engines; or as an octane booster, when mixed (blended) with petrol/gasoline. Ethanol is easily blended up to at least 10% with modern conventional gasoline vehicles, and to much higher levels in vehicles that have been modified to accommodate it. Biodiesel can be blended with petroleum diesel fuel in any ratio up to 100% for operation in conventional diesel engines (small amounts of ethanol can also be blended with diesel under certain conditions). When ethanol is used as a blend in lower proportions, no automotive engine modifications are required. Nearly all recent-model conventional gasoline vehicles produced for international sale are fully compatible with 10% ethanol blends (E10). These vehicles require no modifications or engine adjustments to run on E10, and operating on it will not violate most vehicle manufacturers’ warranties. In blend levels above E10, some engine modifications may be necessary, though the exact level at which modifications are needed varies with local conditions such as climate, altitude and driver performance criteria. In Brazil, cars with electronic fuel injection, including imported cars built for the Brazilian market with minor modifications (such as tuning and the use of ethanol-resistant elastomers), have operated satisfactorily on a 20-25% ethanol blend since 1994, with very few reported complaints about drivability or corrosion. In Brazil, after the government inaugurated the national ethanol programme in 1975, ethanol use has now expanded to account for about 40% of passenger car fuel use, and 15% of total motor-vehicle fuels use. Brazil requires that every gallon of gasoline sold should contain an admixture of 23% ethanol (raised from 20% in November 2006). Thus, for about 30 years and on older generation cars, more than 10% ethanol has been used.

The technology for tomorrow with respect to ethanol is flexible fuel vehicles (FFVs) that use E85. E85 is an alternative fuel that is 85% ethanol and 15%. Vehicles are not modified to run on E85; they are specially manufactured as FFVs. At present, ethanol-gasoline blends above 85% can pose problems for gasoline engines, but pure or `hydrous ethanol (mixture of 96% ethanol and 4% water by volume) can be used in specially designed engines. This type of engine has been in use in Brazil for many years. They are not significantly more expensive to produce than FFVs.
vasudeva is offline  
Old 6th August 2007, 15:52   #2
BHPian
 
risga's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 233
Thanked: 59 Times

Don't know if true, but this is what I have heard..............

I have heard that in Brazil, most vehicles are designed to take pure ethanol/ petrol or any combination. At the pumps, both fuels are available in pure form.

Customers decide what to fill (or what blend) depending upon the relative prices of the 2 fuels taking into account the other paraments such as FE, thermal efficiency, etc.
risga is offline  
Old 6th August 2007, 16:03   #3
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,221
Thanked: 212 Times

Yes they can, but for higher ethanol they need to buy a FFV. The first ethanol-use mandate in Brazil required a 4.5% mixture of ethanol to gas in 1977. Current legislation requires an ethanol content of between 20 and 25%, with the executive branch having the flexibility to adjust within that band. This can be used in cars with no engine modifications. Conventional cars account for 90% of Brazils' car population, and they do not have the flexibility that you noted. For FFVs, which now account for 10% of car fleet, tax incentives play an especially important role in supporting ethanol consumption and using ethanol or gasoline. In Brazil, ethanol is a better buy if priced at 70% or less of the price of gasoline (due to better mileage obtained when using gasoline). Therefore, in theory, all FFV car owners will opt for gasoline if the price of ethanol rises above 70% of the gasoline price, and all FFVs owners will buy ethanol at a lower price. With FFVs cars approaching 10% of Brazil's car population and sugarcane production growing more slowly, it is likely that ethanol demand will be rationed for years to come via seasonal and/or regional price changes.

Last edited by Rehaan : 7th August 2007 at 11:55. Reason: [html] formatting removed.
vasudeva is offline  
Old 6th August 2007, 16:08   #4
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,221
Thanked: 212 Times

Gasoline without ethanol can no longer be marketed in Brazil. In Brazil, FFVs were introduced in 2003-04, and now make up around 75% of new cars sold, but around 10% of the present car population. FF vehicle prices are no higher than those for conventional gasoline cars. All refuelling stations in Brazil sell near-pure hydrous ethanol (E95) and anhydrous gasohol (E10), and about a quarter also sell a 20% anhydrous ethanol blend (E20). In total, almost two-thirds of the ethanol currently consumed in Brazil is anhydrous.
vasudeva is offline  
Old 14th August 2007, 20:20   #5
BHPian
 
Firebird's Avatar
 
Join Date: Jul 2005
Location: Mumbai / EC1M 3NH
Posts: 470
Thanked: 65 Times

If the engine doesn't need any modification then could it be just a marketing promo to boost sales.

I dont remember seeing this statement in any other adds of Toyota or Scoda cars.

It is highly impossible that Honda carryout any technological change in the engine and keep the price same.
Firebird is offline  
Old 17th August 2007, 12:07   #6
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,221
Thanked: 212 Times

Efforts to introduce ethanol into the market for road-transport fuels for spark ignition engines have focused on low-percentage blends, such as ethanol E10, a 10% ethanol and 90% gasoline blend (known as gasohol in Brazil and the US). Such blends, which are already marketed in many countries, do not require engine modifications at all (and thus Honda's `tech. breakthrough' is just a marketing gimmick) and can be supplied in the same way as gasoline through existing retail outlets. Higher-percentage blends, with more than 30% ethanol, or pure ethanol can be used only with some modifications to the vehicle engine. Ethanol has a high octane value, which makes it an attractive gasoline-blending component. It has generally good performance characteristics, though its energy content by volume is only two-thirds that of gasoline. The higher volatility of ethanol can create problems, especially in the summer months. The fuel economy of a vehicle with an engine modified to run on pure ethanol, measured by kilometres per litre, can approach that of a gasoline-only version of the same vehicle, despite ethanol’s lower energy content. In several countries, flex-fuel vehicles, which allow consumers to switch freely between high-proportion
ethanol blends and gasoline, have recently become available. This insulates the consumer from any sudden jump in the price of ethanol relative to gasoline that might result from a supply shortage or a drop in gasoline prices.
vasudeva is offline  
Old 17th August 2007, 12:35   #7
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,221
Thanked: 212 Times

Cellulosic materials, including grasses, trees, and various waste products from crops, wood processing facilities and municipal solid waste, can also be converted to ethanol. But the process is more complex relative to processing sugars and grains. Techniques are being developed, however, to more effectively convert cellulosic crops and crop wastes to ethanol. Cellulose can also be gasified to produce a variety of gases, such as hydrogen, which can be used directly in some vehicles or can be used to produce synthesis gas which is further converted to various types of liquid fuels, such as dimethyl ether (DME) and even synthetic gasoline and diesel.

Cellulosic feedstocks could be used to produce ethanol with very low greenhouse gases (GHG), since they can be converted to ethanol using lignin (i.e. the non-cellulose part of the plant) and excess cellulose instead of fossil fuels as the main process fuel. This new approach would nearly eliminate the need for fossil energy inputs into the conversion process. But advanced conversion technologies not yet developed are needed to efficiently convert cellulose to alcohol and other fuels such as synthetic diesel, natural gas or even hydrogen in a cost-effective manner.

If large-scale plants using advanced conversion processes were constructed today, ethanol from cellulosic feedstocks would cost more per litre than ethanol from corn/sugarcane, but would provide green house gas (GHG) reductions at a lower cost per tonne (around $200). Over the next decade the costs of producing cellulosic ethanol may drop considerably, bringing cost per tonne down to $100 or even $50. Ethanol produced today in Brazil, with an incremental cost of $0.03 to $0.13 per gasoline-equivalent litre already provides reductions at a cost of $20 to $60 per tonne.
vasudeva is offline  
Old 31st August 2007, 02:26   #8
BHPian
 
Tech's Avatar
 
Join Date: Apr 2006
Location: India
Posts: 216
Thanked: 20 Times

Govt is going in for 10% ethanol soon. It's already out in the news.
Tech is offline  
Old 31st August 2007, 17:35   #9
BANNED
 
Join Date: Jan 2006
Location: Cochin
Posts: 2,195
Thanked: 268 Times

Quote:
Originally Posted by Tech View Post
Govt is going in for 10% ethanol soon. It's already out in the news.
I think it's from November only !
mithun is offline  
Old 31st August 2007, 20:23   #10
Senior - BHPian
 
Join Date: May 2005
Location: Location
Posts: 5,766
Thanked: 9,053 Times

Quote:
Originally Posted by Tech View Post
Govt is going in for 10% ethanol soon. It's already out in the news.
So what will happen to the vehicles that were not designed to run on ethanol blends? Especially older vehicles that use carburetors/older generation FI systems and designed to run on 87octane fuel.

Does it cause corrosion of rubber parts and gumming up if the fuel injectors & carburetors?
Sankar is offline  
Old 3rd September 2007, 08:26   #11
BHPian
 
Join Date: Jul 2006
Location: pune
Posts: 241
Thanked: 2 Times
low on milage!

u can expect upto 10 % drop in fuel efficiency when e10 is used in the car.. because of low energy density of the ethanol , .
ion brazil the alcohol fuel is priced lower so it morethan compensates the extra consumption.
ethanol <or for that matter all alcohols> are hydroscopic they absorb moisture from air . it can create additional problems.
petrol tends to lubricate the carb and injectors, so the carb slides slide type or barrel type slides dont stick . alcohol doesent lubricate so the slides may stick .. may be at wode open throttle!!
alcohol fuels absorb water. so either a stainless steel or triple marine geade anodozed aluminimum fuel rail and special injestors are issential.
alcohol burns slowly, so its necessory to advance the ignition advance graph accordingly.. it can be up to 15-25% more advance than for petrol through the rev range.(four stroke performance tunning-by a graham bell - chapter - fuel and fuel boosters)

Last edited by TURBOSAM : 3rd September 2007 at 08:28.
TURBOSAM is offline  
Old 12th October 2007, 22:20   #12
Senior - BHPian
 
gemithomas's Avatar
 
Join Date: Jan 2007
Location: Trivandrum
Posts: 2,366
Thanked: 143 Times

Todays hindu mentions that Indian oil Corporation would bring out an ethonol mixed fuel brand. Now can all vehicles use this or is it going ot be exclusively for Honda City-ians!!!
gemithomas is offline  
Old 12th October 2007, 23:01   #13
BHPian
 
blue2ki's Avatar
 
Join Date: Sep 2007
Location: city of ghosts
Posts: 185
Thanked: Once

what's the brighter side? all the pros please
blue2ki is offline  
Old 26th October 2007, 15:55   #14
Team-BHP Support
 
Rtech's Avatar
 
Join Date: Apr 2004
Location: Bombay
Posts: 5,770
Thanked: 359 Times

We get closer. What does this mean for those of us with older, non E10 compliant vehicles?

E10 by 2008 October
Rtech is offline  
Old 26th October 2007, 16:29   #15
BHPian
 
dkamath's Avatar
 
Join Date: May 2006
Location: Bangalore
Posts: 577
Thanked: 155 Times

nice writeup and appreciate your sharing knowledge on such topics, vasudeva. thanks and keep writing more!

by the way, i remember reading an article related to mahindra scorpio (and possibly the ingenio) that their engines are being made ethanol-compatible by modifying/developing a new engine cylinder gasket. not sure though (think i'll google it sometime again, and confirm)

some of you guys living in Chennai would have spotted the mercedes c-class with stickers around it claiming to be running on biofuel. i happened to spot it on mount road during my last trip there
dkamath is offline  
Reply

Most Viewed


Copyright ©2000 - 2024, Team-BHP.com
Proudly powered by E2E Networks