## Sasol 100% CTL Synthetic Jet Fuel Approved for Use Internationally in Commercial Aviation

##### 09 April 2008
 Sasol’s synthetic jet fuel is derived from four synthetic streams: Iso-paraffinic kerosene, Heavy naptha kerosene, Light distillate #1 and Naptha #2. Click to enlarge.

Sasol’s synthetic jet fuel, produced by its proprietary Coal to Liquids (CTL) process, has received approval for full, unblended use in international commercial aviation. Sasol’s fully synthetic jet fuel (FSJF) is the first such fuel to be approved.

For the past nine years, Sasol has supplied a semi-synthetic jet fuel—a mixture of CTL components with petroleum-derived kerosene—to international airlines operating from OR Tambo International Airport in Johannesburg. Based on the success of the alternative fuel blend and following a several-year period of testing and evaluation, international aviation fuel authorities including the UK Ministry of Defence (UK MoD), governing the Defence Standard DEFSTAN 91-91, approved Sasol’s fully synthetic jet fuel as Jet A-1 fuel for commercial use in all types of turbine aircraft.

ASTM International, originally known as the American Society for Testing and Materials, has also been working closely with the UK MoD and is expected to include Sasol CTL synthetic jet fuel in its ASTM D1655 specification following the publication of the UK’s DEFSTAN 91-91. Jet A-1 according to the DEFSTAN 91-91 specification is very similar to Jet A-1 defined by the ASTM D1655 except for a small number of areas where DEFSTAN 91-91 is more stringent.

Aviation industry stakeholders, including airframe, engine and ancillary equipment manufacturers; airlines and aviation authorities such as the International Air Transport Association (IATA); and relevant oil companies have all participated in the approval process.

The fuel is a drop-in replacement for petroleum jet fuel; it is fully fungible and aligned with the current aviation infrastructure through its compatibility with the existing engine requirements and can be used with conventional crude oil-derived jet fuelling systems.

Sasol produces its synthetic jet fuel from four primary synthetic streams from its high-temperature Fischer-Tropsch (HTFT) process:

• Iso-paraffinic kerosene, with a few percent n-paraffins and no aromatics;

• Heavy naptha kerosene, with about 10% aromatics;

• Light distillate #1, with about 24% aromatics; and

• Naptha #2, with about 39% aromatics.

The full synthetic jet fuel is ultra-low sulfur (< 5 ppm) and with 8-25% aromatics. Engine-out emissions of Sasol’s jet fuel are lower than those from jet fuel derived from crude oil due to its limited sulfur content.

The current approval covers jet fuel produced at Sasol’s Synfuels facility in Secunda, South Africa. Sasol jet fuel products that will also be submitted for sanction include Oryx GTL plant in Qatar, the joint venture GTL plant in Nigeria and the potential CTL ventures in the USA, China and India.

Research is also underway to find an effective process to produce synthetic fuel from biomass to further improve environmental sustainability.

Resources

"[...] to further improve sustainability"

CTL and GTL are not sustainable at all from an environmental point of view. F-T is also very wasteful, usually only 60-70% of the primary energy feedstock ends up as liquid fuel.

However, if that feedstock were genuinely sustainable, i.e. biomass produced such that it doesn't compete with food or feed and also doesn't leach soils or cause salts to accumulate, then that wouldn't matter.

One option would be to grow algae in race ponds fertilized by the cooled waste CO2 from the BTL plant. Since the focus would be on biomass volume, it wouldn't much matter if the ponds contained multiple species. There would be no need to optimize for starch or triglyceride content. However, there would be a need to dry the harvested algae before using them as BTL feedstock. The acreage required for such a system would be vast, but there are many places where that would not be a problem. Water would be, since shallow open ponds tend to suffer from a lot of evaporation.

One of the benefits of drip irrigation, with buried pipes is there is less salt accumulation due to evaporation. But it costs and lots of acreage with drip irrigation would be expensive. It would be best to grow the cellulose using natural rainfall.

Salt accumulation from surface irrigated land can build up until the land is rendered less productive for crops and in some cases is not able to produce at all for quite a while. Water resources are an important factor in biofuel production.

Now it seems Man plays God. Once upon a time only volcanoes could take carbon from deep underground and inject it directly into the high atmosphere. But CTL jet fuel has done just that. If there is no CO2 capture at the FT plant then this fuel should pay double carbon tax ie ex-process and ex-engine exhaust. Alternatively if the double emissions ate into a tough carbon cap then jet setters could be taking heating fuel from pensioners. If this is the only way to keep aircraft flying then we should prohibit other forms of coal use.

It is very impressive that they can now do all important fuels from coal (gasoline, diesel, and jet fuels). That is new to me. I thought this coal to liquid was only able to do dimethyl ether and other fuels that needed modified vehicle engines to run. Now presumable anything is doable. South-Africa has been under oil-embargo before and they mine the worlds cheapest coal at $10 to$20 per metric tons so it is not a surprise that the expertise to do such chemical marvels originate in this country. Of cause it must be associated with massive labor cost and capital investment in process facilities to do what they do and this has stopped the rest of the world from doing it as well when oil was cheap. However, with oil going from $20 to over$100 per barrel it may be profitable to synthesize fuels from coal or biomass. In terms of metric ton prices crude oil has gone from $125 per metric ton (6.25*20) to$625 per metric ton (6.25*100). Dry biomass can be made for about $50 -$60 per ton delivered and in the US coal is mined for $20 to$50 per ton. In the rest of the world coal is mined for up to $100 per ton. Biomass has one cost advantage to coal and that is that it can be produced locally so that the transportation cost may be lower than for coal. I am not certain but I think that I have seen prices at$10 to $25 per ton for long-distance shipping of coal. However, you could put a massive CTL plant on top of a coal mine in order to save transportation cost. Then only the end fuel products should be transported and it is less costly to transport liquids. However, from these numbers it is also clear that by far the most important cost to produce fuel from coal or biomass is not the cost of feedstock but the cost of refining the feedstock. This is where all the jobs and the investments are. Assume that feedstock cost$50 per ton delivered and that it breaks even cost wise with oil at $80 per barrel or$500 per ton of crude oil. In that case the labor and capital cost of converting feedstock to liquid fuel is 90% ((500-50)/500). The price of the feedstock is only 10%! In other words, whether we pay $25 for coal or$50 for biomass is not going to affect the price of the produced fuel by more than about 5%.

Hopefully the planet can agree to ban coal as a feedstock or just impose a worldwide \$50 tax per ton of CO2 emissions so that it will be more economic to use biomass as a feedstock rather than coal. The good thing from this news is that it shows that chemical engineers can do almost anything they are asked to do and now the cost seems to make sense as well. The bad thing is that more agriculture to grow food and biomass for fuel with destroy more nature and the species that live in that nature. Therefore, I personally hope that those lithium batteries (or ESTOR supercapasitators) are going to replace the ICE sooner rather than later. A few more nanotech breakthroughs in this area and all this rush to produce more liquid fuels will end. Conservation can’t save the planet because nobody but a few green extremists are willing to cut consumption. We need green technology so that consumption can go on without destroying the planet and ultimately ourselves.

Rafael,
you would not need to dry the algae.
CTL means Carbon (pure carbon, without hydrogen) to liquid fuels (hydrocarbons, which is around two hydrogen atoms for each carbon atom). The hydrogen for the conversion is deliverd by water, while the oxygen from the H2O is converted to CO2.
So if wet algae are deliverd to the reaction, the water content is used as a hydrogen source. In fact, they would probably need additional water to convert al the carbon.
So, the CO2 of the reaction can be converted to algae, which are converted to more fuel. That way, a zero-emission CTL-plant could be built (of course, burning the fuel will not be zero-emission).

(On the other hand it may not be wise to burn algae in the CTL-transformation. It would be much more efficient to produce biodiesel directly from the algae, and to use the algae-waste as animal-feed. ordinnary biomass (with low nutricional value) could then be used in the CTL-reactor)

Another thing we should remember is that while the CTL-conversion is about 60%, conversion of crude to liquid fuels is also far from 100%. Open-pit coal mining is very energy-efficient, compared to huge oil installations. Also, 100% of the coal is converted, while petroleum-refining does not convert 100%. Additionally, refining installations also produce a lot of CO2, and they even need huge amounts of (natural gas derived) hydrogen to transform low-quality crude to high-quality crude.
I wouldn't be surprised if the petroleum-to-liquid efficiency wouldn't even be 60%.

Moreover, a petroleum-spill is an ecological disaster, a coal-spill is just a truck with a flat tire.

"Moreover, a petroleum-spill is an ecological disaster, a coal-spill is just a truck with a flat tire."

I can tell you first-hand being from North Western PA where there are both strip mines for coal and oil wells, that oil is a much cleaner to extract. The strip mines have turned miles of streams into orange, acidic, cesspools with high metal levels. The old mine site are worthless for anything and the EPA is having to clean up up many of them. And the oil wells haven't really hurt much at all.

My point is, oil spills only happen every now and again. Sure, they are terrible, but coal mining is an everyday disaster that no one hears about.

Generally, this is good news. As we diversify our energy sources it will give us some breathing room to explore better options, and move away from the politically-charged market of oil.
While I understand many are excited about biological sources of energy, we must consider that at this point, there is no infrastructure for it now. It's not quite vaporware, but it can by no means offer a substantial dent in energy production now or in the near future. It is going to take some time.

Henrik:

I'm not so sure that the majority can't consume less energy (and food) while maintaining and even increasing comfort level.

We can all buy or modify existing homes to be more energy efficient. Governments can regulate insultion level, lighting, windows & doors efficiency etc.

Current inefficient HVACs can easily be upgraded (or changed) with very high efficiency heat pumps to reduce the energy used by up to 50%.

Light weight PHEVs and BEVs can use less energy, use much less liquid fuel and produce much less GHG and noise while maintaining or increasing comfort level.

Many of us may not agree but the majority (in many industrial countries) would be much better off with 1000 less calories each a day. Multiplied by one to thre billion, this would be a huge energy reduction while increasing comfort and health levels.

There are many more areas where energy is wasted and over-consumption is not only avoidable but harmful.

"Conservation can’t save the planet because nobody but a few green extremists are willing to cut consumption."

I do not know about saving the planet, but efficiency can do a lot. Amory Lovins of rmi.org has been showing businesses how to change behavior (conservation) and improve efficiency (technology) for quite a while. Companies have saved so much money that he is asked back to show them more ways to save more money.

If enough companies and individuals can do this, then maybe that will be part of saving the planet. In the book The End of Oil, the author talks about how during the 2000-2001 gaming of the natural gas and electricity markets by Enron and others, conservation made an immediate 10% reduction in usage that was sustainable. That pretty much solved the problem in the short run so the systemic problems could be worked through.

Unlike Dick Cheney, I believe conservation is more than a personal virtue. It has been and should be a major part of our national energy policy. It involves behavior and that is at the root of excess wasteful energy usage by all.

I do not mind conservation at all in fact I did a few things my selves such as getting rid of old fashioned light bulbs etc. When I was referring to green extremists I was more thinking of people who believe we should live in smaller houses, drive bicycles and grow our own food. This is something most of us will not and should not do when we can afford a better living. Also reducing CO2 emissions by ordinary conservation will not solve the problem of accelerating global warming only postpone it a little. In order to solve that problem we need 100% emission free technologies such as EVs running on wind power or hydropower. In that way all 6 billion people on the planet can drive a car without destroying the ecosystems of the planet. The synthetic fuel that this article mentions is bad for the planet either in terms of CO2 emissions from burning coal or with biomass as feedstock in terms of destroying natural habitat for other species that will have to die out to provide space for more agriculture.

Fortunately there are other ways to make transportation green without compromising performance or comfort. For instance, this year wind power will account for more than 10% of all new electricity added globally and the industry grow at 30% per year. If it can keep that industry growing at that rate it will be able to do more than 100% of all needs for new electricity generation globally by 2018 even if you assume that the needed global electric capacity needs to grow at 3.34% per year in order to sustain future economic growth. We should get really serious about EVs now because it will be easy to provide emission free electricity for these cars should they start to replace old ICE vehicles by large numbers. The only remaining technical problem is making the EVs. Project Better Place is a very useful assembling of ideas of how to do it quickly. Still it would be nice to see more highway capable EVs on the road to prove that the battery technology is indeed ready.

I think that we want to go after the big factors first and not so much individual habits. Rail freight is much more efficient than long haul trucking, but go out on the interstate highways and see how many long haul trucks are out there.

If we had a widespread system of rail networks, there would be no long haul trucking wasting billions of gallons of diesel fuel every year. The trucks would drive outside the city and put the trailers on trains, where the freight would be transported long distances efficiently. Some of this is done, but no where near enough.

Instead we depend on the invisible hand of the free market to have corporations truck freight long haul while we import 14 million barrels of oil per day. This is what I call a National Energy Policy. The government works with the private sector to find the best and most efficient ways of moving freight so that we do not have to import so much oil, have the dollar decline and create problems.

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