Zim sets deadline for migration to 50 ppm diesel

Published: 27 September 2017

The Ministry of Energy and Power Development says Zimbabwe will be phasing out regular high sulphur diesel used in the country in favour of 50 ppm as part of efforts to promote a cleaner environment.

Minister of Energy Dr Samuel Undenge said the adoption of 50 ppm diesel is in line with the National Energy Policy which promotes the use of low sulphur and cleaner fuels as a measure to curb vehicle emissions. Currently, 50 ppm diesel is selling alongside 500 ppm diesel at a number of service stations.

Dr Undenge said the government is also finalising on the modalities of moving from unleaded petrol 93 to unleaded petrol 95.

Fuel importers will be given a grace period of four months will be allowed to flush out residual stocks of 500ppm diesel from the distribution infrastructure.

With effect from November 1, 2017, all fuel importers will be required to import 50 ppm diesel into the country.

"It is expected that with effect from March 1, 2018, all diesel sold at the retail sites shall be 50 ppm diesel and selling of any other fuel grade would become an offence as from March 1, 2018.

"The National Oil Infrastructure Company has been requested to prepare the pipeline and depots for the pumping and storage of 50 ppm diesel."

He said the free on board prices of 50 ppm diesel and 500ppm diesel do not differ significantly in favour of one or against the other from time to time.

Sulphur in fuel is the main contributing factor to harmful gas emissions. The environmentally friendly choice is therefore to use diesel containing 50 parts or particles per million (ppm) – i.e. 0,005% sulphur – instead of diesel containing 500 ppm or 0,05% sulphur.

Diesel with a lower sulphur content has other significant benefits which include performance and the longer lifespan of lubricants, resulting in extended service intervals and a prolonged engine lifetime.

Engine performance improves, because 50 ppm diesel has cleaner and more effective combustion properties than 500 ppm diesel.

Diesel of 50 ppm causes less wear and tear and therefore prolongs engine life. Sulphur oxidises during combustion and forms sulphur dioxide, while nitrogen from the air is also oxidised, forming nitrogen oxide. Both of these oxides react further and form acids which are detrimental to engine components and also adversely affect lubrication. The more sulphur fuel contains, the higher the chances are of engine wear and tear.

Service intervals are extended since engine oil has to be replaced less often. Lubricants containing additives help combat wear and tear caused by sulphuric acid, but these additives are exhausted more quickly when 500 ppm diesel is used.

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