CNG buses coming to Johannesburg

© skyscrapercity.comCNG with added diesel may not be as good (environmentally-wise) as dedicated CNG, but still way better than diesel alone

The conversion initiative is a part of a "Going Green” program, under which methane as motor fuel for public transport is being promoted by the South African city. In the future dedicated CNG-powered vehicles will be purchased, but for now regular buses running on diesel fuel are having their engines adapted to add CNG to the mix. 30 8-year old vehicles have been converted for a start, with more to follow – the plan is to have all the existing Metrobus fleet switched to dual-fuel mode.

According to a press release, the buses now use up to 70% compressed natural gas or biogas and the rest is diesel, so tailpipe emissions have become remarkably cleaner. The alternative fuel system used is Ecomotive Solutions' D-Gid (diesel-gas dynamic injection), developed in Italy and fitted in Johannesburg by Ecomotive Solutions' local partner, Vehicle Gas Solutions. The system allows the use of any kind and form of methane – compressed or liquefied, fossil or renewable (biogas). If refueling with gaseous fuel is for any reason not possible, the buses' engines run on diesel alone just as they did before.