The world is currently awash with fossil fuels, thanks partially to the commercial development of the tar sands in Canada and hydraulic fracturing (fracking) in the USA. Every day, each source produces the energy equivalent of one million barrels of oil, much to the chagrin of the former global warming alarmists who now promote climate change. US petroleum production is at a 42-year high, with global supply exceeding demand. This seems to discredit the peak oil theory posited in the 1950s that global oil production has peaked and will continue to decline.
These new energy extraction technologies are having a direct impact on reducing the manufacturing costs of tires and synthetic rubber, as well as fuel costs for all forms of transportation. The tar sands, for example, yield the heavy crude from which butadiene monomer is obtained for the polymerization of SBR, while fracking of oil and gas from energy-rich shale yields the light liquid crude preferred for the distillation of vehicle fuels. Although oil prices remain volatile and are subject to man-made supply disruptions, these new developments tend to undermine the drive for renewable sources of energy. Even with oil priced at US$100 per barrel, wind and solar power, as well as biomass energy sources, would not be economically competitive unless propped up with tax incentives and other rent-seeking subsidies.
The price of crude oil impacts the downstream markets from which the synthetic rubber industry obtains butadiene, styrene and isoprene monomers that form the backbone of most polymers. Consider styrene-butadiene rubber, or SBR, the world’s most readily available tire rubber used in all automotive tires – especially tread compounds. SBR is a co-polymer of butadiene (C4H6, a gas) and styrene (C8H8, a liquid) with weight fractions of about 75/25, respectively. Over the prior decades, many sources of butadiene have emerged starting from a variety of biomass or fossil fuel sources. Interestingly, the US government decision to undertake the large-scale development of SBR during WWII using petroleum rather than grain alcohol was based principally on expediency and cost, much to the disadvantage of the US farm lobby, which advocated ethanol from corn as a viable starting raw material. And so it remains today that the most economical technologies for obtaining butadiene monomer for synthetic rubber are
based on petroleum.
Similar arguments can be made for isoprene. The first attempts to prepare the synthetic equivalent of NR were made over a century ago using isoprene (C5H8) monomer as the starting material. Polyisoprene rubber (IR) was ultimately commercialized in the 1950s, but its poor building tack and green strength limit its use in tires. Notwithstanding, Goodyear and DuPont are now developing processes for converting renewable materials such as fermented sugar into biologically derived isoprene. A prototype bio-isoprene tire was exhibited at the 2012 Geneva Motor Show with much fanfare. Other bio-routes to isoprene are being studied using materials such as algae.
We live in an era when new sources of renewable energy and bio-based rubber are being patented by technophiles at an expanded rate, but novelty does not necessarily ensure commercial feasibility. I don’t want to pour cold water on industry’s efforts toward sustainability and the use of non-fossil fuel alternatives, but a US company would quickly go bankrupt operating a 40,000 per day tire plant with solar panels, windmills and Kazakh dandelions. America’s electric power is now generated from oil and gas (70%), nuclear (20%) and renewable (10%) sources. Similarly, it seems that Hevea brasiliensis, a perennial, will remain the tire industry’s favored source of NR for decades compared with its agronomy-based alternatives, which usually need to be replanted yearly. Developing alternatives, however, does provide a hedge in the unlikely event that Hevea succumbs to the South American leaf blight that permanently devastated the Brazilian rubber industry.
In the short term, the global glut in petroleum will tend to trigger more highway travel and tire sales in 2015. Longer term, the relatively low price of hydrocarbon energy sources and their by-products, if stabilized, will provide economic relief to millions of drivers with cheaper fuel, and to tire companies with reduced energy and feedstock costs. Remember that oil prices fell and remained low during the 1980s and 1990s, contributing to global well-being. A repeat of this would be welcome.
