As towns and cities expand their infrastructure, the demand for better transportation grows. Whilst roadbuilding is certainly not on the list as one of the most sustainable sectors of construction – largely due to the negative impact the production of asphalt has on the environment – changes are being made in the industry to ensure it is working towards an environmentally conscious future.

Climate agreements and stringent regulations issued by governments and authorities worldwide are posing increased challenges for the asphalt industry concerning reducing greenhouse gases, such as CO2.

Many markets are phasing out coal as a fuel, while systems running on oil are subject to these regulations and restrictions says Benninghoven. In moves to work toward a more sustainable future, Benninghoven technologies have enhanced their Evo Jet multi-fuel burners, which can use renewable fuels such as biomass to liquid (BtL) and wood dust, in addition to both having a carbon neutral footprint.

Owners of asphalt mixing plants need to be conscious of driving down emissions to help secure the future of the plant site. Changing from oil or coal dust to gas is a major step says Germany-based Benninghoven – the use of natural gas or liquid gas already halves the CO2 emissions.

Benninghoven’s Evo Jet wood dust burner allows wood dust to be used in asphalt mixing plants. Engineers at Benninghoven are said to have identified the ideal particle size of the wood dust, which is produced from scrap wood and wood waste.

The fuels of the future, wood dust and biomass to liquid, are attractive when it comes to their availability, as fossil fuels are not only limited but are becoming increasingly more difficult to produce. Benninghoven says that this makes it even more important that plant owners use the right technologies to be prepared for the future by using alternative fuels.

Lowering emissions has driven machine development in recent years, and this has been a key focus for Benninghoven.

Among the company’s advances in the application of low-temperature asphalt, which although not new, has become the focus of road construction authorities today. The demand for balancing CO₂ levels, conserving resources, and reducing energy are driving innovation and asking companies across the sector to develop their capabilities.

It was formally requested in August 2021 by National Highways that everyone involved in the construction and maintenance of the strategic road network, particularly designers and main contractors, use low-temperature asphalt as their default surfacing material to help achieve net zero.

Low-temperature asphalt is a mixture that requires a production temperature between 110° and 130°. Hot asphalts, on the other hand, are produced at a temperature range between 140° and 180°, although 160° with hot bitumen as a binder is most common. The advantage is that the production and the processing of low-temperature blends can be conducted conventionally.

According to the German Asphalt Association, a temperature reduction of just 30 °C saves 0.9 litres of fuel oil (or equivalent fuel) per ton of finished asphalt; a daily production of 2,000 tons of mixture thus saves 1,800 litres of oil or up to three-quarters of the annual energy consumption for heating a house – the reduction in CO₂ emissions is 6,000kg per day.