New concept promises to mitigate need for diesel after-treatment

The as-yet unnamed concept from Penumbra Power pre-treats air going into the cylinders to reduce the emission of nitrous oxides (NO_x) and other greenhouse gases.

Developed by 25 year old entrepreneur and former JCB engineer Adam Meekings, technical details are relatively scarce on the project, which has yet to be patented. What we do know is that the technology uses heat and carbon dioxide (CO₂) from the exhaust to alter the chemical composition of the air and fuel entering the engine.

“The product has the potential for CO₂ capture – similar to the systems used in power stations”

Meekings told The Engineer said that the system has the potential to completely replace conventional after-treatment, including catalytic converters and particulate filters.

“The original aim was to eliminate the use of liquid additives like Adblue, while achieving similar levels of emissions reduction,” he said. “Removing the after treatment system also means you no longer need precious metal catalysts and it could allow the engines to run leaner without a NO_x penalty, increasing fuel efficiency.”

“We’re aiming for a solution that’s cost-neutral [to produce] compared to existing after-treatment. Typical HGV applications require around four to eight litres of Adblue for every 100 litres of fuel, which obviously has cost implications for purchase and storage. The same idea could potentially be applied to passenger cars, as well as larger diesel applications like ships and power generation.”

The concept draws on techniques used in the gas processing and medical industries. It leaves the base engine unchanged, but the turbocharger may need to be modified; intriguingly, according to Meekings, it may even allow the turbo to be removed completely.

Penumbra Powers’s concept is described as a closed loop system and it uses CO₂ from the exhaust to enhance its operation.

“The product has the potential for CO₂ capture – similar to the systems used in power stations,” said Meekings. “We think this could be applied to heavy truck applications, even getting to the point where no CO₂ is emitted at all. Instead it could be contained on board in a tank and then used for enhanced oil recovery or stored in a depleted gas well. This is particularly relevant to trucks where the weight of the batteries that would be required effectively prevents the use of electric powertrains for zero emissions zones.”

Earlier this year Penumbra Power was awarded funding from Shell’s LiveWIRE scheme, which will be put towards the cost of building a working prototype. It’s also provided opportunities for mentoring and networking, Meekings explained.

It’s estimated that it will take three to five years to develop the system. “We need to secure more funding to develop the technology,” commented Meekings. “We’re looking at getting some private investment and grant investment to move forwards. Our target is to manufacture the product independently, but we may also look at taking part in a joint venture or selling the intellectual property.”