Fuel Alcohol: 1C, 2C, 4C?

Up to now, most of the alcohols fuels action has centered on the 2-carbon alcohol, Ethanol (EtOH). The Brazilians have made a 3 decade success of their EtOH experiment – turning the liability of a huge sugar cane processing waste stream into an economic asset largely unencumbered by petroleum imports. And over the past few years, of course, corn-based fuel EtOH has flourished in the US on the strength of Federal mandate and the Midwest farm lobby.

Ethanol enjoys a large experience advantage today, and – in Brazil – a true competitive advantage. In the US, the economics of corn based EtOH is not nearly so clear – not to mention the political liability of diverting farmland and farming resources from food crops to gas guzzlers. But Ethanol isn’t the only potential fuel alcohol – maybe it’s not even the best. Both the simplest alcohol, 1-carbon alcohol Methanol MeOH, and 4-carbon Butanol BuOH present (alike with EtOH) and array of advantages – and, to be fair, some significant drawbacks.

Methanol is already a huge item of commerce, produced and traded in the many tens-of-billions of pounds per year. In a large sense, you can view MeOH as a handy way to move huge amounts of inconvenient and unusable natural gas from the Middle East to industrial users in the US, Europe, and increasingly, in Asia. And since MeOH is easily derived from nearly any carbon source, it may have a bright future as an environmentally less offensive way to tap huge coal reserves in the US and China.

Similarly, there is a large (although a couple of Zero’s less large than MeOH) commercial marketplace today in Butanol (primarily as an ingredient in paints, flexible plastics, etc). Today, nearly all BuOH comes from petroluem sources, so conventional BuOH for fuels doesn’t make much environmental or energy independence sense. But recently, there have been substantial improvements in bio routes to BuOH that (in some cases, at least) start with ag waste, not food or feed grains.

Lots of sources compare the properties of these fuel alcohols with the gasoline they might replace. I think this version (from ButylFuels, LLC – http://www.butanol.com) is especially easy to use.

Source: ButylFuel, LLC

Source: ButylFuel, LLC

Both 1-carbon MeOH and 2-carbon EtOH suffer from low energy density (poor miles-per-gallon) and an inconvenient propensity to pick up corrosion causing moisture from the air. The more carbon-rich BuOH behaves much more like conventional gasoline in the fuel tank. Indeed, some claim that most US cars on the road today can run quite well on BuOH. And some industry heavyweights – DuPont and BP, for example – are pushing for Butanol as the next motor fuel.

So, bottom line, there is no single right answer to the 1 vs 2 vs 4 in the alcohol fuels question. (And, indeed, there are strong manufacturing arguments favoring a mixture of these and other alcohols.) Each has it’s place – except the truly wasteful diversion of food resources into fuel tanks – and each can make important contributions during our transformation from a fossil fuels economy to one fueled by renewable energy.


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2 Responses to “Fuel Alcohol: 1C, 2C, 4C?”

  1. Gerald Keep Says:

    First point — my understanding is that butanol is sufficiently more miscible with gasoline that it can be used with existing infrastructure and not require the extra mixing stations that ethanol currently uses.

    Second point — my consulting firm has been working with multiple entities on the issue of using the byproducts from fuel generation to make value-added compoutnds, many of them aromatic. Capturing this value can change a marginal economic proposition into a very positive one. I would be happy to have further discussions on this issue.

  2. Fuel Alcohol: 1C, 2C, 4C? « The Alternative Energy Page | PetroleumArea.Com Says:

    […] See the original post:  Fuel Alcohol: 1C, 2C, 4C? « The Alternative Energy Page […]

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