Success depends on cheap transport, good quality control
Aug 1, 2008 12:00 PM
Low-Cost transportation and consistent product quality are two of the biggest challenges facing the biofuels industry today. How the industry resolves those issues will determine how much of a role biofuels play in the US energy market in the future.
Biofuels issues were on the agenda at the ILTA's 28th annual International Operating Conference and Trade Show in Houston, Texas. Shirley Neff, Association of Oil Pipe Lines, addressed the outlook for pipeline distribution of ethanol and gasoline/ethanol blends. Paul Nazzaro, National Biodiesel Board, discussed the latest developments in biodiesel quality.
Neff said there is no question that pipeline movements of ethanol and gasoline/ethanol blends would be beneficial for the market. Railroads across the United States are reaching their capacity limits, and road congestion is nearing critical levels in many parts of the country.
“Nobody thought about infrastructure when the ethanol mandates were announced by the federal government,” she said. “We're now trying to fix all of that as the ethanol volumes increase. Exxon has announced E10 (10% ethanol and 90% gasoline) for nationwide distribution, and we expect other refiners to join them. Pipelines will have to play a major role in the transportation process in the future.”
Transport congestion is particularly severe in the middle section of the United States, where most of the ethanol is produced. Railroads currently handle about 60% of the ethanol shipments, with trucks hauling 30%, plus the final delivery to the point of sale. Barges are a minor player at 10%.
For a variety of reasons, pipelines are not part of the transportation mix at this time. However, several pipelines have run trials with batches of denatured ethanol. More tests are coming for existing multi-product pipelines, and some operators are talking about building dedicated ethanol pipelines.
Fuel quality is a major concern for pipeline operators. Many pipeline operators believe certain sections of the existing pipeline system may never be able to handle ethanol, but other sections probably can work with it.
Problems start with ethanol's affinity for water, which can be picked up as product flows through the pipeline network. In addition, ethanol has a scouring effect on the internal surface that can lead to fuel quality issues in multi-product pipelines.
Ethanol has been known to cause stress corrosion cracking (SCC) in pipelines and storage tanks. Pipeline operators are concerned that corrosion damage may be accelerated at weld joints or stress points where the metallurgy has been altered.
The causes and potential solutions for SCC are the focus of extensive on-going technical studies. Recent findings suggest that SCC potential in ethanol/gasoline blends decreases with higher gasoline concentration. No SCC has been observed with E10 blends. SCC potential also decreases in fuel grade ethanol with a lower oxygen concentration.
Neff emphasized that most, if not all, of the challenges can be overcome. “As with any economic issue, the players in this industry will figure out solutions to the problems,” she said. “They are going to find those solutions sooner, rather than later.”
Biodiesel has moved beyond being a niche product, but a number of issues continue to cloud the future for the renewable fuel. “The industry must successfully address those issues, but this is a great fuel,” Nazzaro said.
On the downside, biodiesel is more perishable than petroleum diesel. Once biodiesel begins to deteriorate, the process is irreversible. Quality problems that contribute to deterioration can go unnoticed for months before problems occur.
Nazzaro emphasized that producers must be relentless in removing even the smallest levels of non-biodiesel components. Glycerine, catalyst, alcohol, and fatty acids must be completely removed in the production process.
Once biodiesel enters the distribution process, additional steps must be taken to maintain fuel quality over time. To minimize degradation, fuel may need to be treated with a variety of additives that may include dispersants, metal deactivators, corrosion inhibitors, anti-oxidants, cold flow improvers, and microbicides.
“Studies suggest that B100 (100% biodiesel) will begin oxidation from the minute it is produced,” Nazzaro said. “These studies also suggest that B100 will go out of spec for oxidation at around four months after production. Free fatty acids and insoluble deposits will begin forming.
“It is recommended that B100 should not be stored for more than several months without being treated with stabilizers. However, B5 and B20 blends should remain stable for 12 months.”
Nazzaro cautioned that terminal operators should check storage tanks for water. Even blended fuels can be degraded by microbial growth when water is present in the tank. Microbicides offer the best means of combating that threat.
When biodiesel is in long-term storage, tank operators should replace filters in the product handling system on a quarterly and semi-annual schedule. Maintenance program also should include removing free water from the tank at regular intervals.
Finally, biodiesel inventories should be turned over as frequently as possible. Product should not be kept more than 12 months.
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