3.13.2012

Jet fuels derived from waste resources: a new alternative!

This is an interview with my colleague and good friend Jeff Cooper, ISWA's president. I know Jeff for many years and I always like his scientific approach to resources and waste management as well as his broad understanding of the different waste management aspects.

His involvement in a project where waste resources are going to be trasnformed to jet fuel really triggered me  and I thought that interviewing him about that project would make us certainly wiser. So here comes his interview, I hope you will enjoy it as I did.


 Jeff, I think you are the only one I know involved in airplane biofuel production utilizing waste resources. It sounds exciting and I would like you to give us an idea about it. Let us know about the project you already work on.

Antonis, you are right, in that there very few people from the waste sector dealing with the issue of the development of jet fuel from residual waste sources, ie after the most immediately recyclable items in the municipal, and the C&I waste streams have been extracted.

In 2009 after two years of preliminary discussions the USA-based company Solena Group/Solena Fuels offered to join forces with British Airways (BA) in order to evaluate the possibility of developing a plant to produce liquid bio-jet fuels for BA from a range of feedstock sources ( www.solenagroup.com ).

The plant to be developed in Tilbury, Essex is a 500-560,000 tpa biomass processing facility – ideally using high carbon materials - in order to convert them into liquid bio-jet fuel. This would allow BA to substitute a small proportion of its fossil fuels used for its aircraft with a renewable and more sustainable energy source.

The plant proposed would use a combination of new technology, a plasma arc gasification unit and an old established chemical processing system, the Fischer-Tropsch process.  The syngas (synthetic gas), or Bio-SynGas in this case, generated by the plasma arc would be converted to a liquid fuel.  A further advantage of this bio-jet fuel is that it has better combustion properties and lower pollution potential than its fossil fuel alternative when it is used in jet engines.

The plasma arc system has been proposed for several years as a potential alternative energy recovery option for waste processing.  Until recently with lack of support and limited success its development and use has not been regarded as viable.  As with other alternative systems, such as several microwave, sterilisation and autoclave-based plants developed in the UK and overseas, there has been huge scepticism, especially regarding the energy balance of the whole process. 

The main question for the plasma arc process was, could the total input of energy to reach the high temperatures required by a plasma arc, around 4,000-5,000oC, be generated internally by processing waste, let alone generate a surplus of energy?  If a surplus were to be generated could it be used as heat, electricity or, in the case of the Solena/BA project, manufacture a liquid bio-jet fuel? 

The advantage of plasma technology over more conventional gasification technologies is that 20-50% more of the carbon-based waste materials are broken down to ensure gasification of even the most intransigent carbon components. The gasification process releases a range of gaseous products but mainly carbon monoxide and hydrogen.

The Fischer-Tropsch process on the other hand is a long-standing technology originally developed by two German scientists in the 1920s.  Subsequently this process was used by the Germans during WWII to convert some of their coal resources to liquid fuels. The technology was further developed by SASOL, the South African energy company, which ensured that South Africa could utilise its vast soft coal resources for conversion to liquid fuels to withstand international oil embargoes in the 1970s and 1980s.   Even now the SASOL plant is in full production and produces jet fuel that is used by aircraft at Johannesburg airport.

In 2009 Solena started construction of their first commercial scale bio-fuel plant for liquid bio-fuel at Gilroy, California.  This plant is similar in size but the technology is different to the plant being proposed for the UK.  No plasma technology is involved and the fuel generated will be utilised by road vehicles.

The advantage of the Solena plasma arc process is that it uses a metallic catalyst in order to spread the heat impact of the plasma arcs used in the gasification units to a greater processing area and thus convert more of the carbon based wastes to gases.  Solena claims that only 5% of the energy content of the waste is required to gasify the waste in its latest processing system, thus leaving the energy surplus for a wide range of processes.  The types of feedstock which can be processed can include a wide range of wastes left after initial recycling of municipal, commercial and industrial waste streams, such as contaminated paper and plastics, multi-layered and other plastics which cannot be recycled, tyre chips, food waste, crop and forestry residues. 

The proposed Solena plasma arc system provides several productive outputs from the process: heat, electricity as well as the syngas, which can then be utilised to produce a liquid bio-fuel source.  The 500,000 tpa plant can provide sufficient energy to process waste into renewable liquid bio-fuel energy resources but also yields 20MW of electrical power, in addition to that required to operate the plant, plus surplus heat energy that could be used for industrial process heat or perhaps district heating. 

At full production the process should yield 1170 barrels a day of BioJetFuel and 630 blls day of bio-naphtha, which can also be used as a constituent of liquid fuel or as a chemical source.   Even the small amounts of final residue from the process can be readily utilised as a construction product because the high temperature used in the plasma arc system yields an inert glass-like solid material, which also has the advantage of locking in within the vitrified matrix any non-organic contaminants in the waste. 

For BA this project provides a substantial opportunity to reduce its carbon footprint.  Fuel usage generates 99% of its carbon footprint, a total of 17,583.853 tonnes CO2eq in 2008 from all BA’s operations, and therefore its main environmental impact. Unless BA were to address the future sources of its fuel consumption then anything else would be largely irrelevant. 

What is the concept behind it? I mean why British Airways is interested to invest in such a project and from the other side, why such a project is important for the waste management industry?

For BA (British Airways) – now part of the International Airlines Group (AIG) they needed to show positive support for to the IATA commitment to have 50% of renewable fuel sources for the airline sector by 2050.  At Board level therefore BA has therefore guaranteed to ensure that they will purchase the fuel for a lengthy period into the future for a minimum price.  This is something that the US military have not done despite President Obama’s commitment to the same target for their fuels but within a shorter timescale of 2015, “we’ve always worked on annual contracts and will continue to do so”.

For the waste management industry worldwide this project demonstrates that there is a further option within the portfolio of products that we can be producing in the future – we already have various EfW options but this is a product stream which has little other alternative except in specialist short/medium haul applications.    

Speaking about the technologies, I wonder if we are speaking for proven and commercial technologies? I would also like to know what types of waste are suitable and if such a technological approach could provide solutions in a city scale?

 The plasma arc system has been proposed for several years as a potential alternative energy recovery option for waste processing.  Until recently, with lack of support and limited success its development and use has not been regarded as viable.  As with other alternative systems, such as several microwave, sterilisation and autoclave-based plants developed in the UK and overseas, there has been huge scepticism, especially regarding the energy balance of the whole process. 

The main question for the plasma arc process was, could the total input of energy to reach the high temperatures required by a plasma arc, around 4,000-5,000oC, be generated internally by processing waste, let alone generate a surplus of energy?  If a surplus were to be generated could it be used as heat, electricity or, in the case of the Solena/BA project, manufacture a liquid bio-jet fuel? 

The advantage of plasma technology over more conventional gasification technologies is that 20-50% more of the carbon-based waste materials are broken down to ensure gasification of even the most intransigent carbon components. The gasification process releases a range of gaseous products but mainly carbon monoxide and hydrogen.

The Fischer-Tropsch process on the other hand is a long-standing technology originally developed by two German scientists in the 1920s.  Subsequently this process was used by the Germans during WWII to convert some of their coal resources to liquid fuels. The technology was further developed by SASOL, the South African energy company, which ensured that South Africa could utilise its vast soft coal resources for conversion to liquid fuels to withstand international oil embargoes in the 1970s and 1980s.   Even now the SASOL plant is in full production and produces jet fuel that is used by aircraft at Johannesburg airport.

According your knowledge, when it will be the date when such a solution will become really available? And give us an idea for its costs, related to other options.

This is a difficult question but we envisage the GreenSky project, as the British project is now called, being fully operational in 2015. 
As for the costs again it is difficult because each country will have its own constraints and incentives.  In the UK we have a landfill tax that is currently £56 per tonne but from April this year will be £64 per tonne so the provision of even well processed residual waste should cost the plant nothing – a gate fee would be negotiated against a quality specification from the suppliers as they will be saving huge amounts of money through diverting waste from landfill.  Nevertheless, if there are suitably large quantities of residual waste available the opportunity to establish a bio-jet fuel facility becomes increasingly attractive.    

 Last but not least, I would like to have your personal opinion regarding the future of waste to energy technologies. Can we hope to pyrolysis and gasification or their commercial application is too far? Biofuel production is an alternative or a supplementary solution? And how about H2 production from waste?

My personal opinion I’ve expressed in answer to Q1&2 but I’ve been looking at the whole range of new technologies over the past few years of my 30-year career in waste management.  I am a resource scientist by training and the shift to increasing resource cost extraction of both renewable and non-renewable resources occurred about 12-14 years ago compared to a reducing trend before that, as I’d always proposed when dealing with the issues of resource economics in the 1970s as an academic.  Before that time technological and other developments could provide resources at increasingly lower resource (and possibly environmental) cost.  Now we need more resources into order to extract resources and therefore we are in a spiral of decline which makes the financial crisis look like a party.  However, the two are inextricably linked – but perhaps that is outside the scope of this feature.

As for H2 production and use, this would be possible and indeed is often suggested for a variety of applications, particularly: for storage of the energy, use in fuel cells and within the road transport sector.  I would support these opportunities being exploited but we are looking for a specific liquid fuel substitute for the current kerosene jet fuel used for the past 60 years. However we provide it in the future, the conventional mechanism of distillation from fossil oil extracted from under the earth will decline in the future.    

2 comments:

StephaniePumphrey said...

So generally this way of generating energy is the most environmental friendly way. Still it may sound peculiar to speak of first generating the product and using it to make energy.

Manufacturer Of Tyre Pyrolysis Plants

StephaniePumphrey said...

This work has also been key in identifying the required development necessary for commercial level operation with the majority of the required technologies already developed from the use of heavy fuels in gas turbines.

Pyrolysis Fuel System