Tar sands can improve our roads

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Building roads with Alberta bitumen is good for drivers, government budgets and the environment

The future looks bleak for Canada’s oil sands. But given the world’s continued need for smooth and safe roads, there is hope for the industry. Asphalt binder made from oil sands bitumen is the perfect glue to hold the 40 million kilometers of roads in the world together, and it can be done in a sustainable, economical and environmental way.

With the global transition to electric vehicles in progress, and Canada’s 2021 commitment to reduce greenhouse gas emissions 40-45% below 2005 levels by 2030 To meet its obligations under the Paris Agreement, Canada will use less fossil fuels, especially imports and upgraded products, including those from the Alberta oil sands.

About 10% of Canada’s current emissions come from the extraction and upgrading of raw bitumen from the oil sands, about 70 million tons per year. Worldwide, approximately 70 to 80% of greenhouse gas emissions come from the combustion of fuels for electricity, heating and transport, and from industry.

Our research group has studied the life cycle performance of asphalt roads over the past 30 years, providing remarkable insights into the relative advantages of Alberta straight binding, produced with minimal refining and without upgrading. Production of asphalt binder from raw Alberta bitumen can realistically reduce greenhouse gas emissions from oil sands combustion and life cycle by 40-60%.

How Asphalt Works

Alberta bitumen has a low wax content, which makes it highly desirable for the production of asphalt binders. The low wax content means pavement can be recycled and recycled again—support a true circular economy.

Pavement life is declining due to heavy traffic, extreme temperatures and the incorrect use of salvaged materials to rehabilitate and rebuild old roads. The use of so-called green technologies, recycled and inexpensive motor oil, for example,offers short-term satisfaction at the expense of long-term performance.

Government transport agencies have no incentive to use stronger binders. Yet pavement cracking can be reduced up to 30-50% by building roads that maximize the use of pure, pure Alberta binder.

This enables municipal, provincial and state infrastructure owners around the world to reduce construction and rehabilitation budgets, reduce travel delays and associated costs and improve security.

Two components of the binder influence the service life of roads: asphaltenes and waxes. The asphaltenes are large molecules that give the binder its cohesive strength (the adhesive’s ability to hold together) and adhesive strength (the strength between the adhesive and another material), but prevent it from sinking in cold temperatures. Paraffin waxes are often a natural component of asphaltoccurring in varying amounts depending on the source of the crude used to make the binder.

The binder is a mixture of solid asphaltenes and waxes in an oily material. When the wax content is high, asphaltenes tend to separate from oils and pack more tightly. A high wax binder is more rigid at low temperatures, which reduces adhesion and promotes cracking. An optimal binder has a minimum of wax and has a more or less uniform composition.

More sustainable roads

Construction specifications for asphalt often fail to identify poorly performing binders. More than a few substandard binders are currently used in road construction in Canada. Oil sands crudes have the lowest wax content of any source and can produce superior binders.

Alberta binders of various grades work well on their own, without additives, as long as they are used with good pavement designs. However, adding PET (polyethylene terephthalate) fibers from recycled plastic bottles can significantly strengthen the asphalt.

For example, a 12-year-old asphalt test section in northern Ontario, built with a premium binder sourced from Alberta and modified with 0.3% recycled PET fibers, shows virtually no no deterioration today. It should have an ultimate lifespan of around 38 years; a significant improvement over historical performance cycles of 15 to 25 years.

Producing asphalt binder from Alberta’s oil sands will not only reduce industry greenhouse gas emissions by 40-60%, but can also extend pavement life by 30-50 %.

Today, about 2-5% of crude oil is turned into asphaltand the rest is turned into combustible fuels. As government regulations shift towards reducing greenhouse gas emissions, companies that extract and/or produce crude oil will see their demand drop and be pressured to create products that do not need be refined or that will not be burned. Light and medium crudes cannot meet demand for bituminous binders in a 2050 net zero scenariomaking bitumen a strong contender for use as an asphalt binder.

The world has nearly 40 million kilometers of roads, 65% of which are paved. Paved roads are safer than unpaved roads and are more economical for a higher volume of traffic.

The volume of unpaved roads around the world presents a tremendous economic opportunity. Carbon pricing and credits will accelerate the transition from bitumen. Produce high performance asphalt binders from Alberta raw bitumens, especially those mined by in situ process that require a smaller area – can position the oil sands industry to remain viable.

Alberta has enough bitumen to supply the global road construction industry for more than 100 years if oil sands companies divert about 50% of every barrel to produce asphalt binder.

Simon Adrien Maria Hesp is a professor of chemistry at Queen’s University. Haibo Ding is an assistant professor at the School of Civil Engineering at Southwest Jiaotong University in China. Jen Kovinich, Aiden Kuhn and Alison Wong, undergraduate research assistants at Queen’s, co-authored this article, which first appeared in The conversation.

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