The pencil problem

Many years ago the well know economist Milton Friedman made a short film about pencils that continues to resonate today. While the film can be interpreted as simply a defence for capitalism, which Friedman was famous for defending, it nevertheless does make a good point about the complexity of the world we live in. The manufacture of an item as simple as a pencil requires such a wide range of resources, skills, machines and knowledge that no one person could easily craft a pencil as refined as the product we can buy for not very much money in a local shop or online.

The steps to make a pencil are many, but at least the basics are outlined in this short video.

What is missing however, from both Friedman’s and the manufacturing video, is any reference to the energy (and hydrocarbon materials) required and where that energy (and hydrocarbons) might come from. There’s almost an underlying assumption that the energy is just there, available in abundance. But the complexity of the system to deliver the pencil relies entirely on a complex energy system that we are collectively now trying to change. Unfortunately a rhetoric has emerged that this change will be both simple and quick, yet neither are true. The energy system that delivered the pencil took over 150 years to evolve, and it continues to do so even without the more recent changes related to renewable energy. But the pencil that emerges has CO2 emissions related both directly and indirectly to its manufacture, largely because of the energy system used to power the manufacturing steps, which of course is why that energy system needs to change. However, that energy system is only there because we need pencils, and other manufactured goods and energy services.

Within the pencil the most visible material is wood, which is often cedar as noted in the above video. While this is entirely natural, sourcing it requires considerable amounts of energy to fell trees, transport the logs, cut and shape the wood, then move the final wood pieces to the pencil manufacturing plant. While some of this energy is electricity, there is considerable use of diesel for transport.

The pencil lead is noted as being a mixture of graphite and clay, baked at over 800°C in a furnace. The world’s largest graphite producers are China, Madagascar, Mozambique and Brazil, so there will almost always be considerable transport involved, probably by sea using marine fuel oil or marine diesel. As well as the energy used in the mining and refining process, baking the graphite with clay will likely require natural gas. But there is also synthetic graphite as an alternative. Synthetic graphite is produced through a complex process of baking petroleum coke at very high temperatures. Synthetic graphite can have a purity of over 99% carbon, and it is used in manufactured products where extremely pure material is required, which includes pencils.

Then there is the glue. Modern wood glues are largely synthetic, made from petroleum-derived plastics like polyvinyl acetate (PVA). Almost all vinyl acetate monomer is now produced via the vapor-phase reaction of ethylene and acetic acid over a noble-metal catalyst, usually palladium. The reaction is typically carried out at 175–200 ºC and 5–9 bar pressure. The ethylene might come from an ethane cracker, such as the Shell facility in Pennsylvania which uses the ethane in natural gas to produce ethylene for the further manufacture of chemicals and plastics (like polyethylene). But along the way considerable energy is required for the synthesis process, also coming from fuels such as natural gas, but some electricity as well which could be sourced renewably.

The ferrule at the end of the pencil is made of aluminium, which is also an energy intensive mining, refining, electrolysis based process with multiple transport steps. Much of this requires liquid fuels and natural gas, although the electrolysis step often uses renewable electricity in places of abundance, like Iceland. However, the electrolysis currently requires graphite in the anode and cathode, with the anode being consumed during the electrolysis process (producing CO2) and needing constant replacement.

Finally there is the pencil eraser, which may be made from natural rubber sourced from a country such as Malaysia and transported on ships using marine fuels. But much of the global rubber industry is now based on synthetic rubber, which derives from yet another complex chemical process. Synthetic rubber production begins with the refining of oil or other hydrocarbons. During the refining process, naphtha is produced. The naphtha is then used to produce monomers such as styrene and isoprene, which are necessary for the production of synthetic rubber. The most common synthetic rubber is styrene-butadiene rubber (SBR) derived from the copolymerization of styrene and 1,3-butadiene.

The paint used to decorate the pencil may also have various components in it derived from crude oil and the manufacturing process will require energy as well.

So far I have only discussed the pencil itself, but there is an enormous dependency on milling machines, cutting devices, refineries, pipes, ships, trucks, tanks, storage depots, roads, trains and various other pieces of infrastructure, many of which are made of steel and therefore require iron ore mining and coal fired smelting for production. And all the roads used for transport, including the final delivery of the pencil to a shop or to a home to fulfil an online order, are largely made of bitumen, derived from crude oil.

While the pencil itself is a relatively simple implement, as Milton Friedman points out it requires the cooperation of thousands of people to produce. But it also requires the operation of hundreds of different mining, chemical and energy production facilities, not to mention factories making machines, trucks, ships and other pieces of equipment. All of these run on energy and most will use coal, oil or natural gas to do so. Only a fraction have been fully converted to renewable power, although many more may use some renewable energy as part of the electricity the facility uses or the final delivery may be in an electric van. Some of the processes required to ultimately make a pencil may not yet have an alternative that doesn’t use oil or natural gas as a feedstock for the carbon in the final product.

The job ahead is to convert all of these, or rebuild them, to facilities that don’t use coal, oil products or natural gas for energy. In our recently released Sky 2050 scenario, the near 80 years between now and the end of the century sees a world largely achieve this, but at a pace of change that is unprecedented. In the Sky 2050 scenario, in the year 2100, fossil fuels make up less than 5% of primary energy demand, with a good portion of that going into products like pencils rather than being used for energy. But this is not the case at all in 2050, when fossil fuels are still about a third of primary energy and therefore emissions from their use must be managed through land use mechanisms and geological storage of CO2. This is what net zero is all about, since zero use of fossil energy is much more a 22nd century possibility than it is a 21st century reality.

Note: Shell Scenarios are not predictions or expectations of what will happen, or what will probably happen. They are not expressions of Shell’s strategy, and they are not Shell’s business plan; they are one of the many inputs used by Shell to stretch thinking whilst making decisions. Read more in the Definitions and Cautionary note. Scenarios are informed by data, constructed using models and contain insights from leading experts in the relevant fields. Ultimately, for all readers, scenarios are intended as an aid to making better decisions. They stretch minds, broaden horizons and explore assumptions.