The topic has become topical again with the sanctions against Russia. What are the advantages of using recycled rubber?
Synthetic rubber recently hit the headlines due to a clash between Italy and Poland concerning the restriction of imports from Russia as part of the tenth sanctions package. After lengthy discussions, the EU states gave the green light to the measure, which includes restrictions totalling EUR 11 billion. What does this mean?
Synthetic rubber: a widely used raw material.
Synthetic rubber was born as a response to the growing demand for natural rubber for a material that had equivalent properties but could be produced artificially. The first patents on synthetic rubber date back to 1910. Others followed in the 1930s, with materials resistant to wear and tear or to oils and solvents, but research accelerated, especially in the USA, after the Japanese attack on Pearl Harbor, which made supplies of natural rubber from the East difficult.
Today, synthetic rubbers are obtained from petroleum derivatives and consist of long hydrocarbon chains (polymers) to which chemical groups and atoms such as chlorine are bonded at regular intervals. In general, synthetic rubbers are suitable for applications at extreme temperatures, and where good resistance to heat ageing is required.
Synthetic rubber production in the world
Asia is the largest synthetic rubber production and consumption region worldwide, with 8.365 million tonnes produced and 8.5 million tonnes consumed, accounting for approximately 58% and 60% of global production and demand (2020 figures). In particular, China is the world's largest producer and consumer of synthetic rubber, with 8.117 million tonnes in 2021. Despite considerable domestic production, Chinese synthetic rubber is still unable to meet market demand, with a high dependence on imports.
In Europe, synthetic rubber production and demand were 3.6 and 3.2 million tonnes respectively, accounting for approximately 25.3% and 22.2% of the global total. In the Americas, production and consumption were broadly equivalent, at 2.4 million tonnes or 16.7% and 17% of the global total (Source: ReportLinker).
During the pandemic, production and consumption fell to 14.4 and 14.2 million tonnes, but the rebound will lead to 17.7 million tonnes of production and 17.6 million tonnes of consumption by 2027.
The growth in demand for rubber
Over the period 2023-2031, the International Rubber Study Group (IRSG) estimates that global demand for natural (NR) and synthetic (SR) rubber will grow at an average annual rate of 2.4%.
After rebounding in 2021 - boosted by the exceptional economic recovery in advanced countries and emerging markets such as China and India and linked to the decline during the pandemic crisis - to 29.88 million tonnes (+11% year-on-year), rubber demand in 2022 grew by only 1.8% due to the global economic slowdown.
For 2023, the forecast is for an increase of 2.8% compared to 2022 and an average of 2.4% per year over the period 2023-2031.
For natural rubber, market growth is estimated to slow to 1.9% in 2022 and recover to 2.8% in 2023 mainly due to a drop in demand in China, while synthetic rubber. It is expected to register a consumption growth of 1.7% in 2022 and a growth forecast of 2.8% in 2023, similar to natural rubber.
However, the expansion of natural rubber production will proceed at a slower pace than demand growth, leading to a general market contraction in the medium to long term due to a slower development of new plantations than rubber demand would need.
The advantages of devulcanised recycled rubber
Increased production of recycled rubber could fill this production gap, also improving sustainability. In particular, devulcanised rubber has several advantages over natural and synthetic rubber.
Roberto De Simone, sales manager of Rubber Conversion:
Thanks to our mechano-chemical process, which operates at low temperatures and is extremely efficient for every percentage point of addition of our devulcanised compounds derived from ELTs, emission savings of between 0.4 and 0.6 % are achieved. Thanks to our cooperation with leading tyre manufacturers and the validation of our formula, we have now achieved integration rates within car and truck treads of more than 10 per cent, which is significantly higher than with non-devulcanised reclaim products.
If we look at the Life Cycle Assessment (LCA), the production of a Rubber Conversion SRC compound generates an LCA value of 0.73 Kg CO2eq of which only about 35% is attributable to the actual devulcanisation process, compared to 2.5 Kg CO2eq of synthetic rubber and just above the 0.6 Kg CO2eq of natural rubber.
Recycled rubber, and devulcanised rubber in particular, is therefore confirmed as an ideal solution, in the medium term, to cope with increased demand and significantly reduce the impact on the environment.
'Today, our technology,' continues De Simone, 'is successfully applied to different types of feedstock, including the most common NR, SBR and NBR-based. Reagents to treat FKM, silicone rubbers and EPDM are also at an advanced stage of study'.