Biodiesel: is life too short?

16th January, 2008

Biofuels are having a hard enough time in the press at the moment, without offspec product fuelling the fire, so companies must ensure its properties remain unchanged throughout the supply chain. One particularly vulnerable link is when it reaches the terminal, where it can be kept for up to several weeks before being needed. Most countries have now mandated that a certain amount of biodiesel be blended into petroleum diesel, in order to reach environmental targets.

It is best to store pure biodiesel (B100) blended as it is easier to handle. Blending can occur at almost any point in the delivery stream, for example in the delivery pipeline, coming into the storage tank, while leaving the storage tank or as the product is being loaded.

Both before and after being blended, biodiesel must be kept in optimum conditions. Biodiesel is generally considered to be easier to store than its counterpart, bioethanol, which has a very high affinity to water, but several challenges still remain. Leading terminal operator Odfjell is adept at handling the product. Odfjell has eight terminals and nine associated terminals worldwide, one of which is located in the world’s largest oil and chemical port, Rotterdam. The Rotterdam terminal is just about to finish constructing three new tanks, each 28,000 cm in size, and each of which will be equipped with blending facilities to have the potential to store biodiesel.

Theo Kruithof, marketing executive for the Odfjell Terminal in Rotterdam, does not view storing the product as anything out of the ordinary. ‘Biodiesel in Europe can be kept at ambient temperatures and in standard carbon steel tanks,’ he explains.

This ease of storage is mainly because the terminal has such a high throughput rate, and the product is only stored for a few weeks.

However, storage is not always so straightforward, and varying feedstocks and climatic conditions can have a significant effect.

The heat is on

There is not one set of rules to be followed for biodiesel storage, as the product differs widely, depending on the quality, the feedstock from which it is produced, and the climate it is produced and stored in. The primary feedstock for biodiesel in the US is soybean oil, in Europe it is rapeseed oil and in Asia, a variety of feedstocks are used, depending on the region.

‘When it comes to storing biodiesel, there are two main varieties,’ explains Luis Sala, MD of Spanish independent terminal Tepsa. ‘That which is made from palm oil, and biodiesel from the majority of other feedstocks.’

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