- 19 Apr 2023
- Chris Kjelgaard
- Engines - BizAv
Carbon-offsetting programs represent an important way for Business Aviation users to help reduce their greenhouse gas emissions. But can they also contribute directly to the development of Sustainable Aviation Fuel (SAF) production? Chris Kjelgaard finds out.
Today, carbon-offsetting programs represent one of the most important ways Business Aviation operators and users can practically reduce the amounts of carbon-containing greenhouse gasses their flying activities emit into the atmosphere. But can they fund development of a longer-term solution, namely Sustainable Aviation Fuel (SAF)?
Reducing greenhouse gasses is an important concern for the Business Aviation community both politically and in terms of the high profile in the eyes of the media and the general public.
While a vitally important activity in lubricating the global flow of commerce and industrial development, Business Aviation is widely seen as being the province of influential and wealthy individuals, involving small numbers of people flying in luxurious aircraft – those aircraft often being large jets flying very long distances.
Business Aviation operators and users therefore make an easy target for environmentalists seeking to demonize the aviation industry for its carbon footprint. As a result, it is important for Business Aviation users and operators to demonstrate to the world at large that they’re doing their utmost to minimize their contributions to greenhouse-gas emissions.
Indeed, the whole aviation industry recognizes this need as “flight shaming” campaigns become more widespread.
In facing this challenge, the aviation industry has officially developed a goal for all its operations globally to achieve ‘net zero’ status by 2050 regarding emissions of carbon into the atmosphere. In other words, as of that year, aviation is aiming not to release any net additional amounts of carbon emissions.
To do so the aviation community is relying on four basic pillars of improved efficiency.
Such programs don’t directly reduce the amount of carbon emissions that aviation operations create. What they do instead – if they are well-designed, well-managed and well-regulated – is effectively reduce the volume of carbon-based emissions generated by aviation operations by increasing the amounts of carbon captured from the atmosphere by other means, helping to partially compensate for aviation’s carbon emissions.
Often, but not exclusively, carbon-offset programs do this by investing in programs to plant huge amounts of trees, shrubs and plants worldwide, which grow by using the photosynthetic process, extracting carbon directly from the atmosphere in order to create the hydrocarbon-based materials from which plant cells are composed.
Growth of all photosynthesis-based vegetation is seen as providing a key contribution to reducing the amount of carbon-containing atmospheric greenhouse gases.
To date, however, some – perhaps many – carbon-offsetting programs, offered by all sorts of companies globally and operating in various industries, have not provided the carbon- reduction results their creators hoped. For instance, inadequate management and oversight has resulted in millions of young trees planted in those initiatives dying off within a few years of their seedlings being dug into the ground.
That said, many carbon-offsetting programs are proving successful, particularly those created and managed by large companies which have the multinational reach and substantial financial resources necessary for them to be able to monitor, oversee and manage their programs closely.
Those companies include many if not all the world’s largest oil and gas companies, including some of its largest refiners of jet fuel and avgas.
Many if not most of the most successful carbon-offsetting programs spread the risk of failing to obtain reductions in atmospheric carbon by investing in various individual carbon-reduction projects in different countries. Each of these individual projects is designed to obtain carbon reductions in different ways. By no means do all of them rely on vegetation-planting as its reduction mechanism.
Commercially – and soon governmentally – operated entities now exist to oversee, verify, certify, enumerate and provide financial accounting for the carbon reductions the individual projects and overall programs generate.
This allows companies to put revenue and cost accounting values on the carbon emissions reductions they collect by participating in high-quality carbon-offset programs.
But while such programs are to some extent an end to themselves in helping companies and high-profile individuals reduce their carbon footprints, sustainability experts think carbon-offsetting programs can directly foster the development of another avenue by which aviation can cut its emissions of carbon.
This avenue – seen by the entire industry as crucially important to its future ability to reduce carbon emissions – is the development and use of Sustainable Aviation Fuel (SAF), either in blended or pure (‘100% drop-in’) form, or even potentially in the future in ‘100 % non-drop-in’ form.
SAF can be refined from feedstock materials which do not include any primary fossil fuels such as crude oil or natural gas. Its ingredients can be blended with those of conventional jet fuel to produce a blend certified as being completely usable in turbine aero engines and completely able to replace 100% conventional jet fuel in terms of its chemical, physical, flow, ignition and energy-creation properties.
In fact, 50%-blended SAF is already fully certified internationally for commercial, and in many cases military aviation use – though Stephane Albert, Associate Director of Strategic Sustainability for Pratt & Whitney Canada, says 30% SAF blends are more widely available in commercial, private and Business Aviation.
A subcommittee of US materials standards organization ASTM International has been hard at work for the past two or more years in developing a standard for 100% drop-in SAF, certification of which is expected within the next year or so according to the subcommittee’s Chairman Gurhan Andac, Fuels Leader for GE Aerospace, after a balloting process has allowed all relevant aviation- and refining-industry participants to reach a consensus on the standard’s properties and characteristics.
The subcommittee’s intention is that the 100% drop-in SAF standard will be identical both chemically and operationally in all aspects with conventional jet fuel, Andac says. However, it will be made of a blend of chemical components, none of which will be derived from fossil fuel.
All of these – each a different paraffin, of one of two chemical categories – will potentially be refined from a variety of different feedstock materials, using a variety of different chemical refining pathways. (To date there are seven chemical pathways by which SAF component paraffins can be produced.)
Certifying a 100% drop-in SAF standard as a full replacement for conventional jet fuel is the aviation industry’s ultimate goal. Once the standard is achieved – and when production of 100% drop-in SAF becomes sufficient to replace conventional fuel entirely – then the aviation industry will no longer need to rely on any jet fuel refined as a fossil-fuel product.
At that point, SAF will offer aviation what today is widely expected to be an 80% reduction in lifecycle carbon emissions compared with conventional jet fuel. The remaining 20% takes into account the carbon which will be emitted in creating the electrical power to refine the SAF, to deliver and store it, and to pump it into aircraft fuel tanks.
The ASTM subcommittee is now working to develop and certify an additional standard, for 100% non-drop-in SAF, which Andac says it expects to certify about a year after the standard for 100% drop-in SAF is certified. It is certain that 100% non-drop-in SAF will not be the same chemically as 100% drop-in SAF, but its utility to the aviation industry as a new fuel not derived from fossil fuels is currently unclear.
It’s possible that 100% non-drop-in SAF could ultimately prove to be an even more efficient jet fuel than the 100% drop-in standard fuel in terms of its energy density and other properties, Andac suggests.
Having established the standard for 100% drop-in and non-drop-in SAF, how can today’s carbon-offsetting programs overcome some of the negative perception within the BizAv community to become a major contributor to SAF production? Continue reading in the AvBuyer May digital edition, or read online clicking the Page 2 button below.