Technology

All Aboard The Cow Train

Natural gas from the manure of about 30 cows powers a train.

By Bill SchuttMay 28, 2006 12:00 AM
rd-cowtrain.jpg
Courtesy Kalle Rimling

Newsletter

Sign up for our email newsletter for the latest science news
 

The Svensk Biogas company of Linköping, Sweden, has built a locomotive that runs on cows and cow manure. The $1.25 million engine, which replaces an old Fiat diesel-powered locomotive along a local commuter line, is billed as the most environmentally friendly train in the world.

Engineers at Svensk Biogas produce the train's methane fuel much the same way that marshes and swamps generate the gas naturally, by fermentation. Workers collect heaps of manure and organic waste, mix it into a slurry, kill off unwanted strains of bacteria with steam, then introduce new bacteria to digest the sludge. As a by-product of digestion, the bacteria pump out methane, which the company pipes off and purifies.

Until recently, only cow manure and other farm waste fueled this process. This summer, however, Svensk found a way to use the whole heifer. Now the company chops up the cows and converts their guts, fat, and bones into an organic sludge, which then gets processed as before.

It takes about 30 cows to power the train along its 75-mile route from Linköping to Västervik, one of the countryside's most beautiful stretches of rail. Linköping is especially green-minded: The town's fleet of 65 biogas-fueled buses was the first in the world, and many of the taxis, garbage trucks, and personal cars there also run on cow-derived methane.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Magazine Examples
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2021 Kalmbach Media Co.