Advanced engine technologies

Dr. Amer Amer is Chief Technologist for Aramco’s global transport R&D program.

As countries and industries increasingly adopt net-zero ambitions, the need to reduce CO₂ emissions becomes more evident. We must adapt our existing infrastructure and explore new technologies to aid in solving this complex problem: a world with growing energy and mobility needs, but with fewer CO₂ emissions.

This is no easy feat. We understand where we need to be and we have some of the solutions to get there, but not all. 

We need advanced renewable fuels and they have to be produced sustainably. And we also need advanced and highly-efficient combustion engines if we are to succeed.    

Aramco is rising to the challenge.

Gasoline compression ignition

Compression ignition engines are among the most energy efficient internal combustion engines on the road today. 

The issue, however, is that the diesel fuel that is used to power the engine produces soot and NOx emissions. This requires complex and costly after-treatment systems to reduce emissions of these pollutants into the environment.

This is common for many conventional diesel engines that use conventional diesel fuel.

An innovation that we are actively pursuing is the unconventional use of a gasoline fuel in a modern compression ignition engine. Gasoline Compression Ignition (GCI) can increase the efficiency of gasoline engines by harnessing the efficiency of the diesel compression ignition architecture. If coupled with modern after-treatment systems, it has the potential to reduce engine emissions substantially. 

Our early prototypes demonstrate that GCI could reduce fuel consumption and CO₂ emissions by up to 25% compared to conventional gasoline vehicles.

To realize this potential, we have partnered with global automakers and leading technology developers to accelerate fleet deployment opportunities, particularly in sectors and markets that are unlikely to be fully electrified soon.

We recently demonstrated with a leading engine manufacturer that a heavy-duty truck in China could potentially achieve lower pollutant emissions by optimizing the fuel, engine, and after-treatment systems. This collaboration resulted in NOx emissions that are 90% below the current US regulatory standard, when tested under the combined heavy-duty Federal Test Procedure (FTP) cycle. 

Opposed piston engines

 Another technology we have been working on is the opposed piston engine.

These engines provide a promising alternative architecture to conventional gasoline vehicles, potentially offering enhanced fuel efficiency, lower CO₂ emissions and lower pollutant emissions than conventional gasoline vehicles.

Here’s how it works: 

The engine uses two pistons per cylinder, working in opposite reciprocating motion, eliminating the need for the cylinder head and valve-train components – reducing weight, cost and energy loss in the engine due to heat loss and friction.

This unique prototype reduces heat losses and overall friction, making the engine more efficient. 

When operated in a two-stroke architecture, the opposed piston design can potentially deliver better fuel economy and lower CO₂ emissions, while achieving significantly lower NOx emissions, than conventional gasoline vehicles.

Together with our partners, we are making great strides towards realizing the potential of opposed piston engines for commercial transport. 

Turbulent jet ignition 

We are also working on an advanced combustion strategy for gasoline engines using Turbulent Jet Ignition (TJI). This technology greatly enhances the ignition and combustion processes, promising better efficiency and lower emissions.

It works by mixing a small quantity of air and fuel in a separate pre-chamber, which is then ignited, generating high turbulence and high temperature jets into the main combustion chamber. With such a strong ignition source, many times higher than a conventional spark-plug, the engines can yield improved efficiency and lower emissions, while unleashing greater performances.      

So far, this technology has been successfully tested and we are currently working with leading automakers to explore opportunities for its application.

Dilute boost engines

Dilute Boost is the next frontier for spark-ignited engine technology.

Dilute Boost is a careful combination of several technologies that, when optimized as a system, greatly improve engine efficiency.

By adopting a whole-vehicle approach, Dilute Boost maximizes engine performance while mitigating adverse impacts. The integration of advanced Dilute Boost technologies enables up to 15% efficiency improvement compared to conventional gasoline vehicles. 

We have signed joint development agreements with several automakers, covering major global markets, to implement the Dilute Boost solution on production engines. This will be an exciting and promising space to watch.