Biogas: Producing Ultra-Efficient Fuel From Sewage

We could be generating huge amounts of power from sewage. The process is fairly simple — just ferment sewage to produce a fuel called biogas. Biogas is almost entirely methane, and so is natural gas, so the two are essential interchangeable. The potential to produce biogas is almost entirely overlooked by most countries — except Sweden.

In Sweden, 25% of all energy use is derived from biomass. In Linköping, Sweden’s fifth biggest city, all the buses and garbage trucks run on biogas. The also have a biogas powered train line and some private taxis run on biogas.

Last year, the Swedish government converted more than 700,000 liters of ‘confiscated alcohol’ into biofuel, which otherwise are poured down the drain by the customs officials, as a standard procedure. “Amanda,” thought to be the world’s first biogas train, started chugging along the southeast coast of Sweden in 2005.

You can find biogas being sold at gas stations around Sweden. Cars using biogas created a stir when they began to be rolled out on a large scale at the start of the decade. The tailpipe emissions are virtually odorless, the fuel is cheaper than gasoline and diesel, and the idea of recovering energy from toilet waste appealed to green-minded Swedes.

In Stockholm, 25% of city buses run on biogas or ethanol.

A comprehensive book about of biogas is the Complete Biogas Handbook. It’s technical but full of information on this fuel. See also the book, Reusing the Resource, which is all about treating sewage as resource, not a waste product.

For more on biogas in Sweden, see this article in The Guardian

15 thoughts on “Biogas: Producing Ultra-Efficient Fuel From Sewage”

  1. This is very useful to use biogas for automobiles insted of other conventional fuels beacuse of its cheaper price so i reall congratulate Uruguay South America.

  2. I have graduated from Haramaya Universirty in the Department of Conservation enginering. I am working in Mizan Agriculture College as instrucror in Natural resource department, on the course of soil water conservation and Alternative Energy. I have read about the Biogas tecnology in your website. Even I do have a research which might be your institution help me. My research title cocern evaluation of the potential of veteever grass on production of Biogas. The main reason why i am doing this research to motivate farmers on plantation of vetever grass on their soil water conservation structure activities. I could send my proposal if necessary for your institution. What is your advise as well as your technical or training support on this burninig essue?. I am looking forward your posetive response.

    Your best

    Amberber Wasihun

  3. I was so impressed by your article on biogas.I am from kenya where we have a problem of raw sewage effluent being diverted into the rivers.
    i would wont to know how the sewage can be used to produce Biogas and if you have agents in nairobi kenya who you can refer me to.
    thank you

  4. i travelled through Asia to Australasia at the beginning of the 1990’s and pitched up in Christchurch, New Zealand in 1992 where someone told me that the city council burned the rubbish and ran the city buses off the gaseous by-product.

    At the time this seemed amazingly forward thinking and if true way ahead of the UK, both then and now.. Can anyone tell me if this was in fact the case or just a tall story?

  5. Interesting. I have not looked into biogas lately, but I think that there are (were) issues with scaleup, with anaerobic fermentation. I wonder what kind of subsidies does the Swedish government provide this industry…

    I have a suggestion for the title of the article:
    “Biogas: Producing Ultra-Efficient Fuel From Sewage” does not reflect what the article is about. IMO, fuels by themselves cannot be termed as efficient, it is the conversion processes that are efficient or otherwise. For example, efficiency of burning natural gas in a fuel in SOFC (solid oxide fuel cell) is higher than that in a conventional gas turbine. Here, the natural gas by itself is not “ultra-efficient”, it is just clean burning (low SOx emissions, low particulates).

  6. Many large landfills and sewage treatment plants in the US (large being a relative term) capture and combust their biogas in engines. Reciprocating engines are the most efficient use of a gas power supply (turbines would be more efficient), but due to some impurities in biogas, it requires recips and sometimes a bunch of maintenance. In Washington State, the largest landfill powers electric generators and both Seattle’s large sewage treatment plants have similar units.

    I love the idea of getting the fuel distributed to mobile sources of air pollution. Now that more of the bus and taxi fleets are running natural gas-fired units, it would be realtively easy to convert to biogas!

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