Rebecca Swann, product manager fuels & services, Certas Energy

The 2018 Department for Transport’s Road to Zero paper leans heavily towards electrification as the most viable and ‘proven’ solution for reducing levels of harmful emissions on our roads.

However, in the interest of being technologically neutral and ‘open to alternatives’, the paper sets out no clear directive. Particularly for HGVs, where e-mobility isn’t set up to meet commercial energy demands.

Although we are all on the journey to a low-emission future, the transport industry must be realistic with how quickly zero-emission haulage can be implemented – especially where existing infrastructure is lacking. It is here that liquid fuels must act as a stepping stone for transport businesses on the road to the zero-emission end-point.

So why should liquid fuels be part of the transition to cleaner air? What does the current liquid fuel mix look like? And how can they support hauliers in the journey to a zero-emission future?

Time for action 

There’s no question the road transport industry is under pressure to reduce emissions of air pollutants such as nitrogen oxides (NOₓ) and particulate matter (PM). According to the Clean Air Strategy, road transport is responsible for 34 per cent of NOₓ and 12 per cent of primary PM. The sector is also expected to remain the largest

contributor of carbon dioxide (CO2) emissions, consuming 32 per cent of total energy demand.

Much progress has been made in reducing emissions from HGVs, with recent figures showing NOₓ emissions to have halved in the past five years thanks to the introduction of Euro 6 engines. But business as usual is not an option. As the world looks to the UK to take the lead on emissions, the transport sector will have a big part to play in the clean energy transition.

So what’s holding back the switch to cleaner fuels? The successful, widespread adoption of any new technology primarily depends on three factors: cost, feasibility and policy. It is an uncomfortable truth that when it comes to HGVs, there is no single energy solution to the air quality problem.

While retrofitting vehicles with new technologies could have a significant impact, this would be unrealistic in the short term due to its cost-prohibitive nature. Furthermore, the high energy density requirement of HGVs limits alternative options. Vehicle weights are also a consideration – with the bulky, heavy-weight fuel cells required for some alternative energy sources likely to impact on HGV efficiency and payload capacity. Looking to electrification, the infrastructure simply isn’t there to support a full transition – for now.

With no clear short or mid-term directive from the government when it comes to alternative energy sources for HGVs, and different OEMs championing different solutions, it’s little wonder there’s a confused transitional landscape.

The reality is, the intense duty cycles of HGVs mean liquid fuels will still be required well into the future. But there’s good news: liquid fuel technologies do exist to reduce emissions of air pollutants from HGVs to improve local air quality immediately – without requiring investment in new machinery or retrofitting existing vehicles.

However, it must be acknowledged that low levels of uptake in the transport sector are first and foremost a commercial challenge. Without an incentive to switch or a recommendation of which fuel to switch to, the business case for investing in the majority of alternative fuels is a difficult one to build.

But as much as this is a challenge, it also represents a huge opportunity for wider uptake of alternative liquid fuels to have an immediate and tangible impact on air quality. These readily-available ‘fuels for now’ are key to kick-starting the journey to low emissions, offering a technically and commercially sound stop-gap while paving the way for longer term developments.

Making the case for alternative liquid fuels

There are already many liquid fuel technologies being tested and trialled. These include gas to liquid (GTL), power to liquid, biomass to liquid, hydrothermal liquefaction and hydro-treated biofuel products. However, many of these technologies and developments remain unproven.

In the case of GTL, part of the paraffinic family of fuels, the benefits have been proven. This particular formulation is based on gasification chemistry and can achieve similar performance levels to diesel while reducing emissions of NOₓ, PM and carbon monoxide. With noted benefits including high energy density, ease of use and safe handling – supported by security of supply and approvals from many OEMs – GTL delivers an exceptionally strong value proposition.

The growing portfolio of paraffinic fuels are particularly well-suited alternatives for HGVs. Contained within the EN15940 category, these have huge potential as commercially viable, environmentally beneficial solutions to better the present day situation. This suite of products could also prove to be more effective than other alternatives, with drop-in technologies such as GTL requiring no modifications to machinery or investments in equipment upgrades.

While there are various pros and cons associated with each of the different feedstocks for paraffinic fuels, from a transitional standpoint it needn’t be that one composition is used over another. It’s entirely possible – in certain uses – to explore a ‘blend’ of compositions and/or performance additives.

Furthermore, the infrastructure for liquid fuels is well-established; its supply chain can be commoditised and developed (with the potential to be low cost) and, as such, this energy category represents the most robust and reliable transformation path – at least in the short term.

Alt fuels in action

Already adopted throughout Europe, GTL is one of the few available paraffinic fuels in the UK. To date, its uptake has largely been by commercial users and local authorities seeking to lower emissions in built-up urban areas – where harmful air pollutants can have the greatest impact.

Most recently, Go Plant Fleet Services has started a trial that sees select vehicles in its London and Birmingham road sweeper fleets switch from diesel to Shell GTL Fuel – a cleaner-burning, drop-in alternative. The trial has been initiated to lower emissions for the benefit of the environment, the workforce and the local community. As an added advantage when operating in residential areas, Shell GTL Fuel is odourless and able to reduce noise levels in some engines.

“The search for alternative fuels and the requirements of emission standards being introduced in towns and cities across the country pose a major challenge to the industry,” says Phil Quelch, national fleet engineering director at Go Plant Fleet Services. “But we’re leading the way in the quest for a viable and long-term solution and have been looking into this area for quite some time.

“If the industry was to wait around for new technology to become available, that would take a lot of time. Shell GTL Fuel has an immediate effect on reducing emissions and improving local air quality without engine modification.”

One high-profile, long-term user of GTL fuel is food wholesaler, Brakes. The fuel powers cleaner deliveries from the 50 new DAF LF230 fridge trucks operating in Brakes’ London fleet. Independent testing at Millbrook confirmed the switch has delivered significant air quality improvements in the fleet’s Euro 6 engines – including a 47 per cent reduction in NOₓ emissions.

But for Brakes, the benefits of using an alternative liquid fuel have gone beyond just reducing emissions in the capital. Since making the switch to GTL fuel, none of the vehicles in Brakes’ Park Royal HGV fleet have required a single DPF regeneration cycle. As well as extending time between maintenance periods and enabling more deliveries with fewer vehicles, this has created another unexpected benefit: a fuel economy improvement of 0.4 mpg.

Looking ahead

As renewable energy sources remain unreliable as a failsafe alternative, there has to be a short to medium-term stopgap that satisfies security of supply and sustainability concerns, while driving towards all the strategies and government policy initiatives.

No one can predict the future as technologies develop and evolve – but it’s clear there is no utopian solution that completely satisfies all the criteria. In addition, we mustn’t overlook the importance of social acceptance and freedom of choice in ensuring the energy transition. A broad mix of energy sources will surely enable the most cost-effective and robust transformation path to a low-emission future.

The liquid fuels industry already has a strong track record in technological development, with many alternative fuels being readily available and offering an immediate solution to the air quality problem without the need for additional investment. From a commercial perspective, the fact the infrastructure and supply chain is strongly in place for these types of fuels is a key consideration.

It’s possible the quick wins offered by alternative liquid fuels are being overlooked because of an over-emphasis on the zero-emission end goal. Naturally, that is where we all want to be. But without embracing evolving enhancements in fuel technology, the truth is it will take us much longer to get there.