Looking to the past for the fuel of the future
IN NOVEMBER 1942, Belgium’s public bus system ground to a halt, crippled by a wartime shortage of diesel.
The standstill caused chaos. Engineers at the country’s public transport company got to work and by April 1943 the service was up and running again. They had adapted about 100 buses to run on an alternative fuel – liquid ammonia, pumped into tanks on the buses’ roofs.
The experiment was short-lived, but it proved the point that ammonia – plus a small amount of coal gas to help combustion – could be used as a transport fuel.
Seventy years later, ammonia may be ready to ride to the rescue again. As a fuel it has a number of attractive attributes. It doesn’t release carbon when burned, is relatively easy to store and transport, and could take advantage of an existing infrastructure of storage tanks, transport ships and pipelines.
These attributes give ammonia an edge over hydrogen, long touted as the fuel of the future in a hypothetical “hydrogen economy”. It also has certain advantages over electricity, which has storage problems of its own.
Ammonia isn’t a panacea. Conventional production consumes a lot of energy, the infrastructure is still dwarfed by that for petroleum, and engines would need to be modified to run on pure ammonia (like Belgium’s buses, most experimental vehicles need some conventional fuel mixed in with the ammonia).
But interest is growing in new production processes that use renewable energy (see “Grab ammonia out of thin air for fuel of the future“). If successful they could form the seeds of a low-carbon “ammonia economy” – which would actually be a hydrogen economy of sorts, with ammonia acting as the storage medium for hydrogen.
The road to a low-carbon future won’t be straightforward, and it seems certain that we will need a range of energy sources to arrive there in good time.
Ammonia ought to be part of the mix.
This article appeared in print under the headline “Fill her up… with ammonia”