Managing the molecule: an update on 2005
An overall look at the opportunities for gas-to-liquids projects in Europe as tighter gasoline and diesel specifications loom
Simon C Clarke, Foster Wheeler Energy
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A few years ago, this author wrote a paper, Managing the Molecule, which reviewed likely future product specifications and how the refiner was likely to fare in the future. A scenario was presented whereby the refiner is faced with the realisation that existing technology is likely to struggle some time hence and that a more radical solution might be required. The paper then reviewed Fischer-Tropsch technology from the standpoint of product quality, and postulated a scenario where this might solve the refiner’s problems.
Now, more than three years later, Europe is facing some of the most stringent specifications for transport fuels the world has seen in a large market (ignoring local specialised requirements for city fuels). There has already been one round of specification tightening – in 2000 – which the refiners have spoken about with doom and gloom as the industry faces further tightening in 2005.
But where are the refinery-based Fischer-Tropsch projects promoted in that paper? The industry is still waiting for the first of the large-scale Fischer-Tropsch gas-to-liquids (GTL) projects to get off the ground. Here at present is the exact scenario postulated in the paper to act as a launch pad for refinery-based Fisher-Tropsch projects, but nothing has happened. Why?
Within the EU there has been a fairly trackable series of tightening specifications over time, which is precisely the model needed for some form of analysis. That is why this article focuses on EU specifications.
It will be useful to review the trends in EU specifications for 2000 and 2005, as currently debated (Table 1).
Looking back to 1997, when the EU refining industry was facing the 2000 specifications with the knowledge that the 2005 specs would follow, wild claims were made about the impact on the European refining industry: mass closures, unemployment, not enough time to implement, large scale hydrogen plant requirements and a bill equivalent to around US$33 billion.
With the first round of specifications enforced, and refiners planning for 2005, no refiner has decided that Fischer-Tropsch products are the solution to the problem – not even imported from a GTL plant located somewhere distant, let alone a refinery-based Fischer-Tropsch project.
So how has the refiner managed to meet these clean fuels specifications when faced with such adversity? There are two main pieces to this puzzle, the first involving the changes that were made for 2000 specifications, and what the refiners appear to be doing for 2005. For 2005 specifications, some recent unique experience from the UK is of interest, where 50ppm sulphur diesel has been introduced with apparent virtually zero investment in the UK refineries.
First, looking generally, the following strategies have been successfully used by the refiners thus far to delay investment needs: crude selection, hydrogen management, end point management (cutbacks), intermediate swaps, clever blending and moderate revamps.
Each of these in turn will be investigated from the perspective of what has happened for 2000 and what is being planned for 2005.
Many refiners for 2000 specifications in Europe have altered their normal crude slate, with a shift towards lower sulphur crudes. The quantities of North Sea crude run in European refineries has dramatically increased since the mid 1990s, and with it there has been a corresponding drop in exports of North Sea crude and imports of higher sulphur feedstocks from the Middle East.
This shift to the lower sulphur crudes has also shifted the product balance in the EU, with quantities of fuel oil production also decreased, which has contributed towards stabilising prices (rather than the catastrophic drops predicted a few years ago). Crude selection has worked to a degree for 2000 specifications, but the very low levels of sulphur planned for 2005 means that this route is probably no longer an option, as very few crudes in the world can make 50ppm sulphur gasoline without some form of hydrotreatment.
Crude selection for 2000 specifications allowed many refiners to use their existing equipment, with only minor revamps. This is not the case for 2005.
Large-scale investment in hydrogen production facilities did not materialise for 2000 specification adoption. What refiners discovered was that their incremental hydrogen requirements for 2000 could be met by existing refinery sources, and what was needed was a concerted hydrogen management philosophy to maximise use of their existing resources.
This approach involved a complete hydrogen balance of the refinery, and addition of membrane and pressure swing adsorption (PSA) facilities to recover hydrogen from fuel and waste gas streams. In this way, provision of new hydrogen plant facilities was largely avoided, again reducing the required investments to comply with 2000 specifications.
The situation that is emerging for 2005 is somewhat different, as most refiners have retrieved virtually every hydrogen molecule that is easy to get. In addition, the incremental hydrogen requirements for molecular rearrangement is significantly higher than that for straight sulphur removal.
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