Biofuel components: current efforts and prospects

Hey mechanics,
I found this information at http://www.wissenschaft.de/wissen/hintergrund/243734:

'Alcohol for the Tank: Some of the first German gas stations already offer gasoline with blends containing bio-ethanol.'

Biomass-based fuels are poised for a bright future: Some gas station operators in this country have already begun adding bio-ethanol and bio-diesel to conventional fuels. Other major suppliers plan to do the same starting this winter. Up to approximately one-sixth of a tank's capacity can be derived from renewable raw materials without affecting the engine's performance.


'Gasoline in the tank, and the journey continues. What was previously only seen in cheap comedies is about to become standard in Germany: in the coming years, gasoline and diesel will increasingly be mixed with alcohol. The manufacturers refer to this as 'bio-ethanol,' as the alcohol is largely produced from grains, sugar beets, or potatoes.' Approximately nine volume percent of ethanol can be added to gasoline without damaging the engine.

'Some smaller gas station operators are already blending the alcohol,' says Markwart Kunz, a member of the board of Südzucker AG. Shell and BP plan to start doing so this winter. In addition to bio-ethanol, biodiesel is also experiencing a surge in popularity: 'During the course of February, we delivered diesel fuel with a bio-component to BP and Aral gas stations for the first time,' said a BP spokesperson in Bochum. Shell followed almost immediately. Until now, only a few gas stations have offered rapeseed oil-based fuel in its pure form. However, sales are now expected to triple, as the biofuel will soon be allowed to be added to commercially available diesel.

The reason for the changes in the fuel market is a new EU directive that exempts mixtures containing a certain percentage of biofuels from taxation. Furthermore, the directive requires a two percent share of biofuels in fuel tanks by the year 2005. The share is expected to rise to 5.75 percent by the year 2010.

'The intermediate target for 2005 cannot be achieved in Germany, and it is unclear how the requirements for 2010 can be met,' says Kunz. Only in recent months have manufacturers and gas station operators begun to respond to the legal requirements: Currently, three plants for the production of bio-ethanol are under construction in Germany. One of them is the Südzucker plant in Zeitz, which is scheduled to begin operations in the second quarter of next year. It will then produce 260,000 cubic meters of alcohol annually from biomass.

'Without the EU directive, no one would invest,' Kunz admits. This is because the production of bio-ethanol is not yet as economically viable as the production of petroleum-based fuels. Bio-ethanol is about one-third more expensive than gasoline. 'However, if the price of oil continues to rise, biofuels could become an economically viable alternative,' Kunz explained to ddp. 'Alcohol can, in fact, improve the octane rating of gasoline, resulting in a higher quality fuel,' explains Kunz. 'Gasoline can be partially upgraded to premium fuel using bio-ethanol.'

Because alcohol mixes easily with water and always contains a small amount of moisture, difficulties are anticipated. This moisture could damage the engine when it burns. The fuel must therefore be thoroughly dried beforehand and protected from moisture.

Some gas station operators therefore prefer a refined product made from bio-ethanol: ethyl tert-butyl ether (ETBE). This is produced from equal parts of ethanol and isobutene, which is a byproduct in oil refineries. ETBE can be added to gasoline at a volume percentage of up to 15 percent. 'From an ecological point of view, however, bio-ethanol is preferable to ETBE, as it requires one less processing step and therefore has a better carbon dioxide balance,' says Kunz.

However, the key factor for all biofuels is their economic viability. Südzucker uses highly cultivated yeasts to extract the maximum amount of alcohol from the grain. 'We are constantly improving these yeasts,' explains Kunz. Approximately 375 liters of bioethanol can be produced per ton of wheat.

The production process could be more profitable if bacteria were used instead of yeast in the conversion process. Südzucker, among others, is researching this. Furthermore, if materials like straw or even household waste could be fermented instead of grain, the price of bio-ethanol would decrease even further. In the USA and Brazil, development is further along thanks to subsidies amounting to hundreds of millions of dollars: The company 'Iogen' in Montreal produces ethanol from straw. Approximately 340 liters of alcohol are produced from each ton of straw. In the United States and Brazil, gasoline is blended with up to a quarter of biofuels, and every engine can run perfectly well with it.

Well then, let's see what the future holds...

Greetings.

Eike.

Recently, there was a report on TV about the successor to the Lupo, the FOX. The report was filmed in Brazil, where the Fox is already being manufactured for the South American market. The car had a type of BiFuel engine because they can run on pure alcohol there. There's a separate tap for alcoholic beverages.

Status of Diesel-Alcohol Blends in Brazil.

Engine: 4-cylinder, 115 hp Maxion-International.
Pump: VE4/11F2000R858 (HDI)
Fuel: MAD8 - optimized (89.4% Diesel + 8% AEAC (water-free alcohol) + 2.3% AEP102 (soy oil ester = alcohol-diesel emulsion) + 0.2% cetane improver + 0.1% lubricity improver).
Goal: 1000 hours of development log.

Performance degradation at 860 hours:
Cause: SV function affected due to a stuck SV valve.
Cause of wear: low lubricity and low vapor pressure properties.
Other functions are working properly.
Pump and nozzle inspection:
Claw and crossbar with signs of wear.
Pressure regulating valve with signs of corrosion.
black deposits inside the pump housing.
Minor cavitation marks on the needle guide (condition after 700 hours).





ADMIXTURE PROPERTIES
Emulsion consisting of diesel fuel, AEHC (hydrated ethyl alcohol, 6% alcohol), Dalco additive (emulsion forming), 0.24% cetane booster, and 0.004% anti-corrosive agent.
PERFORMANCE/EMISSIONS TESTS
Torque decrease: 4% at the rated power speed and 9% at the peak torque speed.
Emission improvements: 16% reduction in CO and 32% reduction in particulate matter.
Without improvements: HC and NOx.
Source: MCT (Ministry of Science and Technology) report.

DURABILITY TESTS

A fleet durability test was performed using 4 DC transit buses. The following results were reported:
Supply pump failure after 14,337 km, caused by a sticking valve (alcohol has affected the polyamide).
Nozzle Holder Assembly with a pressure drop of 15% (specification: 6%), and gas blow-back occurring within the nozzle. Cause: Wear and corrosion on the connection point of the spindle, needle, and nozzle seat.




ADMIXTURE PROPERTIES
Solution of Diesel + 11.2% AEAC (anhydrous ethanol, with <1% H2O) + 2.6% AEP102 (stabilizer, co-solvent additive).
PERFORMANCE/EMISSIONS TESTS
Torque losses: 4.5% at rated power and 11% at peak torque speed.
Emission improvements: 2.5% CO, 7% NOx, 22% soot, and 9% particulate matter.
Emission losses: an 11% increase in HC (hydrocarbons).
Source: MCT (Ministry of Science and Technology)

DURABILITY TESTS

The following tests were performed:
2 x Endurance tests with DC buses (100,000 km).
2 x Bench durability test with the OM366LA (DC) engine pump (1,000 hours).
The results of the field endurance and bench durability tests were similar, with the following relevant aspects:

There were no significant changes reported in the full load injection rate following durability tests.
Wear and cavitation marks in pressure valve seats.
Comes with signs of wear and tear.
Nozzle-holder assembly with pressure drop (approximately 20%, specification <14%), caused by wear on the pressure pin.
Nozzle needle seats with cavitation damage.




ADMIXTURE PROPERTIES
Solution of Diesel + 3% AEAC (anhydrous ethanol, with <1% H2O).
PERFORMANCE/EXHAUST EMISSIONS
Power decrease from 2% up to 22% at the rated power speed, and from 2% up to 26% at the peak torque speed.
There were no confirmed technical evidences regarding emission benefits reported in the performance and emission tests. (see pages 17 to 27)
Source: CENPES/PETROBRAS, MAXION, MWM/IPT and MBB/IPT (see pages 04 to 07)
Performance tests conducted by VOLVO using UIS resulted in failure due to vapor lock in the fuel feeding system.

ENDURANCE TESTS

RBBR and its customers conducted bench durability, dynamometer, and vehicle endurance tests. Most of the tests were performed using the VE pump, which is more susceptible to the effects of fuel properties.

Both pumps failed after 376 hours and 456 hours of operation due to wear on the slotted washers.
The diesel pump was due for replacement after 1500 operating hours.

@ Gremlin

Where did you get this information that you are publishing it?