The industrial gas community can benefit the biofuels sector of the future, just as it is fundamental to our energy landscape of today. Rob Cockerill explains…

The use of vegetable oils for engine fuels may seem insignificant today. But such oils may become, in the course of time, as important as petroleum and the coal tar products of the present time.”

Those are reportedly the words of Rudolph Diesel back in 1912, regarded as the ‘father’ of the diesel engine and clearly a visionary ahead of his time.

Another vehicle visionary, Henry Ford, was quoted in 1934 as saying, “I am convinced that we shall be able to get out of the yearly crops most of the basic materials which we now get from forest and mine. We shall grow annually many, if not most, of the substances needed in manufacturing.”

“When that day comes… chemistry will reunite agriculture and industry.”

It’s perhaps testament to their foresight that both these pioneers were able to envisage a cleaner, greener future, long before biofuels would come to the fore quite so prominently.

In fact, Rudolph Diesel was so ahead of the game, that the first diesel engine was powered by peanut oil. It seems incredible to think that we may now be heading full circle and as our biofuels landscape develops, vehicle engines could once again be running on peanut oil derivatives – in essence at least.

Why biofuels?
Going full circle is where we’re heading right now, as the quest for sustainability and renewable energy sources grows ever stronger.

Traditional fossil fuel-dependent energy sources are slowly depleting, as we’re all too well aware. It makes sense then, to make the switch to biofuels or biomass – material derived from recently living organisms and an entirely renewable source of energy.

Biofuels are booming globally, albeit at a gradual pace. The industry is expanding in Europe, Asia, the Americas and Brazil in particular, where the country produces up to 40% of the ethanol fuel used globally and is widely seen as the first sustainable biofuel economy.

Some sources had even expected the global biofuels market to reach a value of around $61bn by this year, such is the blossoming nature of this business.

So what are biofuels?
Solid, liquid or gaseous fuels, biofuels actually cover a multitude of forms and by-products including agrofuels, woodgas, methanol and ethanol fuel, not to mention cellulosic ethanol and other climate-friendly biofuels.

Living or recently living biological materials, in addition to various plants and plant-derived materials, form the basis for biofuel manufacturing, while waste processes and landfill gas can also be utilised for the production of agrofuels.

Controversy
It’s often the feedstocks for biofuels that are the source of such controversy, including the much-discussed biofuels debate.

So-called ‘first generation biofuels’ are produced using sugar, starch, vegetable oil and animal fats, using conventional technology and basic feedstocks such as seeds or grains like wheat.

Wheat yields starch that’s fermented into bioethanol, while sunflower seeds can be pressed to yield vegetable oil and this is in turn, used in biodiesel. However, first generation biofuels comprise a basic flaw – their feedstocks could easily be used in the animal or human food chain.

While first generation biofuels are not always economically competitive, it’s the fact that these feedstocks could be used in the human or animal food chain (especially when the global population continues to rise) that attracts so much attention. Their use has been criticised for diverting potential food away from the food chain, leading to shortages and price increases.

And so, the pendulum swings towards ‘second generation biofuels’.

Research and reviews of recent years suggests that second generation biofuels do not always have a clear cut advantage over their first generation alternatives, yet it was because of the perceived benefits that the latter stage first emerged.

Second generation biofuels technologies have been developed because the manufacture of first generation fuels from biomass has certain limitations. As mentioned earlier, they are not always cost-competitive with existing fossil fuels. Furthermore, while their usefulness is not in question, there exists a threshold above which they cannot produce enough biofuel without affecting food supplies and biodiversity.

Second generation biofuels however, can alleviate some of these problems and provide a larger proportion of our fuel supply sustainability – with greater greenhouse gas savings too.

Biomass consisting of the residual non-food part of crops is utilised instead, including stems, leaves and husks that are left behind once the food used for food purposes has been extracted. Other crops that are not used for food purposes are used too, such as switch grass, jatropha and industry waste like wood chips and pulp from fruit pressing.

Gases and biofuels
Although not exhaustive, the list of links between the gases business and biofuels does seem to go on and on – such is the intrinsic link between the two.

Whether it’s the off-gases or by-product, or the gas-intensive processes used for biofuels production, gases are prevalent throughout.

Among the second generation biofuels under development is biohydrogen, essentially the same as hydrogen but produced from a biomass feedstock.

This is achieved by using gasification of the biomass and then reforming the methane produced or alternatively, using select organisms that produce hydrogen directly under certain conditions.

The future might also see the availability of bio-synthetic liquid fuels, produced perhaps through the gas-to-liquids (GTL) process like the Fischer-Tropsch technique for example. However, when biomass is the source of gas production it would be referred to as biomass-to-liquids (BTL).

Bio-demethylether (Bio-DME), biomethanol and mixed alcohols all use syngas for production, a gas mixture containing varying amounts of carbon monoxide and hydrogen and made from the gasification of biomass.

Although not really that economically viable at present, it’s not inconceivable to think that biohydrogen and other biofuels, using industrial gases at some juncture, might be fuelling our vehicles in the future.

Making the most of first generation biofuels too, gases could be key to optimising the operations of these production processes.

While pointing the way to a more sustainable future, biomass production does also produce varying quantities of sulphur dioxide (SO2), nitrogen oxides (NOx) and carbon dioxide (CO2). The raw gas from such operations might well have gone to waste were it not for the industrial gas community making the most of this by-product resource.

A very topical and recent example of this can be found in the UK’s northern England, at the Wilton wheat refinery run by Ensus.

Yara International ASA has invested €30m in a new world-scale liquid CO2 facility adjacent to the Ensus wheat plant, set to take the raw CO2 gas produced and upgrade this to high purity liquid CO2 for the growing UK food and beverages facility.

Yara’s plant has recently been completed and opened (September 2009), though the supply of raw gas from the wheat refinery only began very recently in fact.

The Ensus Group has built Europe’s largest wheat refinery at Wilton, Teesside and will use locally grown animal feed wheat to produce over 400 million litres of bioethanol, 350,000 tonnes of high protein animal feed, and 300,000 tonnes of CO2 each year.

From this supply of CO2 raw gas, Yara will upgrade this to high purity liquid CO2 with an annual capacity of 250,000 tonnes. Coupled with its existing plants in Billingham and the Thames terminal, both UK, the company will be able to supply a growing number of customers in the food and beverages industry. In addition, Yara can allow for shipment of product to terminals in Scandinavia and northern Europe, thanks to the teminal facility at Teesside.

In terms of biofuels and gases, the Ensus-Yara partnership is a shining example of the way in which the gases business is intrinsically linked to the biofuels industry and can maximise the efficiencies and output of such processes.

Another aspect of involvement for the gases industry is from an engineering perspective and the construction of biofuels plants themselves. Air Liquide’s 100% subsidiary Lurgi, for example, revealed in 2008 that it would be building a second generation biofuel plant in Germany as part of a joint venture agreement with the Karlsruhe Institute of Technology (KIT).

The pilot plant will demonstrate the viability of the three-stage bioliq® process (biomass to pyrolysis oil, which is then mixed with pyrolysis coke to create a biocrude slurry for gasification to syngas and conversion to chemicals/fuels) from which the bioliqSynCrude generated from straw in the first stage is processed to become synthesis gas.

For its part, Lurgi will cover the engineering, construction, supply, installation and commissioning.

Reflecting on Air Liquide’s role in the sustainable sector, Senior Vice-President Francois Darchis said in a statement back in 2008, “We are very proud that the bioliq® project by Lurgi in Germany is being continued. In a world where energy and environmental issues take on greater importance every day, Air Liquide intends to play an active role in creating viable alternative energy solutions. Energy and the Environment remain two of the group’s growth drivers.”

Biofuels and aviation
ASTM International, one of the largest voluntary standards development organisations in the world, has recently issued a new international standard that could be influential in the future production and use of aviation fuel derived from biomass.

Based in the US, ASTM (the American Society for Testing and Materials) announced the issuance of ASTM D7566, specification for Aviation Turbine Fuels Containing Synthesized Hydrocarbons, in September 2009.

Cited as the culmination of a collaborative effort to move towards more environmentally friendly fuels, the standard was developed out of concerns about the future cost and supply of conventionally derived aviation fuel – according to Mark Rumizen, aviation fuels specialist for the Federal Aviation Administration and Chair of the task group behind ASTM D7566.

This initial version of ASTM D7566 provides criteria for the production, distribution and use of aviation turbine engine fuel produced from coal, natural gas or biomass using the Fischer-Tropsch process.

However, the standard is structured to accommodate other future types of synthetic fuels produced from non-conventional feedstocks and processes as they are developed.

In the media
Such a topical industry is the biofuels sector, that global oil & gas group and household name ExxonMobil has embarked upon a programme of advertising on UK television screens.

The company is launching a significant new programme to research and develop next generation biofuels from photosynthetic algae.

The initiative forms part of ExxonMobil’s ongoing commitment to advance breakthrough energy technologies and address an evolving energy landscape ahead. It’s a cause the company clearly believes in and is attempting to gather public acceptance of, proof of which is seen in the advertising campaign currently broadcast on UK television screens.

ExxonMobil believes algae-based biofuels could be a ‘meaningful part of the solution’ to our future energy demands, which will require fuels from a multitude of resources, due to its potential as an economically viable, low emissions transport fuel. The algae-based biofuels programme is cited as a reflection of its long-term commitment to sustainability and after considerable study, ExxonMobil has concluded that biofuels from algae has a whole range of advantages.

Among these, it’s known that algae can be grown using water and land not required for food production, while select species of algae produce bio-oils naturally and growing algae consume CO2 – adding greenhouse gas mitigation almost as a by-product.

Algae also have the potential to produce a greater yield of biofuel per acre of production and in addition, the bio-oil produced by photosynthetic algae has a similar molecular structure to that of the refined products we use today. If successful, biofuels from algae could be used to make a range of fuels, including gasoline, diesel fuel and jet fuel that meet the same specifications as today’s products.