People are flying more than ever before. According to Airports Council International (ACI), the number of passengers increased by 6.5% between 2015 and 2016. Consequently, the carbon footprint is immense, and so is the need for a greener alternative.
For those who have flown across Sweden, or travelled by train across the country, it is striking how much of the country’s 441,000 square kilometres are covered by forest. Actually, 55 per cent of the country is made up of forests, compared to 31 percent for the whole planet.
There is a lively discussion ongoing about the impact of modern forestry and its repercussions on species richness and biodiversity, but the fact is that almost all forests in Sweden are the result of forestry practices in one form or another. And if we accept that the forest is a resource, the question is, how can we utilise it most effectively?
What if we could produce jet fuel with renewable material from the forests? Renewable materials could definitely be part of the answer to bringing down CO₂ emissions from the growing volume of air traffic.
The financial association Fly Green Fund in Karlstad, Sweden, has been careful thought to this matter for years. The idea is to encourage the production of green aviation fuel and to give passengers and airlines the opportunity of using it.
Of course, the business aspect is paramount. Many agree that there is a huge need for airlines and passengers to opt for a greener alternative, but how much are we willing to pay for it? To begin with, we have the consumers or passengers, who might be willing to pay ten per cent more if they knew that 50 per cent of the fuel was renewable.
But are they willing to pay 50 per cent more? That question is of course also key to the airlines. They are also dependent on access to a reliable resource. It is not enough for someone to produce a few barrels of green jet fuel here and there. If there is going to be a serious breakthrough, a certified working process and continuous large-scale production are required. Which in turn call for major investment.
COWI, IVL Swedish Environmental Institute, the Fly Green Fund, Swedavia, Luleå University of Technology and Jämtlandsgas have set up a consortium with the vision of having a Swedish bio-refinery in place to provide airlines with aviation fuel derived from renewable raw materials. The project is 80 per cent financed by Sweden’s Innovation Agency Vinnova.
There are two principal focus areas; 1) the raw materials and 2) the technology.
In terms of the raw material, the source is wood chips and black liquor.
Wood chips are logging residue left over from harvesting operations. Currently, most are left at the felling site where they slowly decay. Black liquor is a by-product of pulp manufacture resulting from the sulphate process, and consists of the cooking chemicals that are recycled in the process as well as wood solids released from the wood and incinerated.
The technology path involves converting synthesis gas, which occurs when organic raw materials are gasified, into a synthetic hydrocarbon based propellant. In the past, there has been interest in refining the raw materials through fermentation, which is similar to the process of producing ethanol as a propellant.
January saw the launch of a project to ferment forest sugar into jet fuel funded by the Swedish Transport Administration and Fly Green Fund.
The next step was to initiate laboratory trials. At COWI, we were responsible for obtaining the necessary permits, while the goal remained the same - to arrive at a process that works thereby paving the way for large-scale and economically sustainable manufacturing.
A new initiative was to add green raw materials directly to traditional refineries, making traditional fossil-based aviation fuel greener than it is today.
In any event, the economics of this are the main constraint. In order to produce enough green aviation fuel to satisfy the airlines and to achieve sustained volumes over time, the industry needs major investments. At this point, no operator is prepared to invest the billions that would be required to construct a full-scale manufacturing plant, and technological advancement probably needs to be matched by exports.
I know thisis the subject of many political discussions, and over time I believe there is hope for change in a more sustainable direction.