It’s been awhile since I posted my most recent entry in my series on petroleum. If you want to start at the beginning, follow the links below.
My sense is that the concept of Peak Oil is beginning to creep into the popular consciousness. However, the focus is primarily on fuel shortages and fuel prices. While this is certainly a very important piece of the puzzle, what tends not to get much press is that the vast, vast majority of all products in modern society come from petroleum. So if the price for crude petroleum rises, not only do fuel prices rise, but the price of almost everything rises. Furthermore, if petroleum becomes scarce, all of the products made from petroleum become scarce as well.
Look around you. Almost everything you see which is not made of metal, wood, stone, glass, wool or cotton is made from petroleum. Even products made from these natural materials tend to be supplemented with petroleum products: paint on metal, varnish on wood, dye on cotton. Everything else is made primarily from petroleum: plastics, carpets, soaps, pharmaceuticals, clothing, glue, bowling balls, wind turbine blades, boats, shoes …. you get the point. To really try to drive the point home further, here is an additional list of common petroleum products.
Crude petroleum (meaning what comes directly out of the well) consists of hundreds and hundreds of organic compounds which had their origins as part of algae and bacteria which lived in ancient seas hundreds of millions of years ago. With time, temperature and pressure these dead microorganisms where converted into the thick, black mixture which supports modern society.
The cartoon at the top of the page gives you a simplified but accurate concept of how a petroleum refinery works. Petroleum is transported to refineries in large tanker ships where it is heated and then run through a series of distillation columns to separate the oil into different fractions based on the boiling points. As you can see from the cartoon, most of these fractions are used for fuels, but about 15% of the petroleum is separated out as a fraction called naphthas.
The naphthas are used as raw materials for a series of chemical plants where chemical reactions are carried out to convert the various molecules in the naphthas into useful compounds. The first chemical plants to which the naphthas are typically sent produce molecules with familiar names like propylene, styrene, butane, isopropyl alcohol, benzene, ethylene glycol, etc. Some of these basic chemicals can be used directly, but most are sold as raw materials to other chemical plants which make them into polymers (plastics), fragrances, glues, coatings, or raw material for other manufacturing. For example, I used to work for a company which bought some of these basic chemicals and made them into a class of polymers called unsaturated polyester resins. Unsaturated polyester resins are the key raw material for fiberglass. So our customers were people who made fiberglass for boats, shower stalls, car fenders, and the like.
Petroleum also shows up in some unexpected places. Let me try an experiment. Picture and aspirin tablet. When you pictured it did you think of it as petroleum product? You should have. The active ingredient in aspirin is acetylsalicylic acid. For thousands of years up until 1897, people extracted salicylic acid from the bark of willow trees to relieve aches and pains. In 1897 Felix Hoffman of Bayer figured out how to synthesize salicylic acid in the lab and further how to convert it to acetylsalicylic acid which preserved its pain relieving properties while making it less irritating to the stomach. Bayer Aspirin hit the market in 1899 and, to the great relief of willow trees, has been there ever since.
To make aspirin (acetylsalicylic acid) you react salicylic acid with acetic anhydride. Bear with me for a moment while I walk you through the path from petroleum to aspirin. To obtain the salicylic acid you start with the naphthas from the refinery, separate out benzene, react the benzene with propylene to make cumene, react cumene with oxygen to get phenol and react phenol with carbon dioxide to get salicylic acid. To get the acetic anhydride you start with methane (from natural gas, the lightest fraction of petroleum) react it with water to make methanol, react the methanol with carbon monoxide to make methyl acetate and react the methyl acetate with carbon monoxide to get the acetic anhydride. My apologies for the lengthy example, but it is instructive to know that almost every modern product is made through a similar series of chemical transformations all starting with petroleum.
With that background under our belts, let me get to the heart of the matter. Just as is the case for fuels, there is no viable substitute for petroleum as a raw material for these products. For 300 million years Mother Nature did the work of creating an incredibly useful mixture of organic compounds that we could extract, separate and transform into the useful chemical compound we have today. In a little over 100 years we have used up about half of this amazing gift.
Some useful chemicals can be made from plant extracts like starch or cellulose, but this will never be more than a very small fraction of what we produce from petroleum today. Recall that petroleum began as algae and bacteria which used energy from the sun to create the organic hydrocarbons which made up their cells. Currently the world is using up the equivalent of more than 1.5 million years of accumulated sunshine, as stored in the petroleum, each year.
Once the petroleum is gone we will need to reduce our consumption of hydrocarbons to be no more than what is produced by one year of sunshine via photosynthesis. We have already begun to encounter this limitation on the fuel side of the question as the biofuels industry is starting to compete for arable land with food production. Imagine trying to find space to grow soy beans or sugar beets intended to supply biopolymer production into this already crowded space. To understand the difficulty of this, perhaps we can revisit aspirin once again. Global consumption of aspirin is in excess of 100 billion tablets per year. Without petroleum as the raw material for aspirin, either the quiet lives that the willow trees have enjoyed since 1899 would be over or we would all have to live with our headaches.
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