Benefits of natural gas to Tanzania's economy

Saturday, 09 October 2010 09:46

The CNG filling station at Ubungo in Dar es Salaam. Currently there are over 31 vehicles converted to be natural gas compatible. Photo/Emmanuel Herman

By McEdriss Elroy

Natural gas has long been considered an alternative fuel for the transportation sector. In fact, natural gas has been used to fuel vehicles since the 1930's! In Tanzania, it’s been recently introduced and according to Mr Bernard Sepetu, a project manager of Triangle Tanzania Ltd, a company involved in converting petrol powered motor vehicles into hybrid (natural gas compatible) vehicles, there are over 31 vehicles so far converted and the number is still growing as awareness levels intensify.

According to experts at the Tanzania Petroleum Development Cooperation (TPDC), the technology has improved in recent years to allow for a proliferation of natural gas vehicles, particularly for fuel intensive vehicle fleets, such as taxicabs and public buses.

Most natural gas vehicles operate using compressed natural gas (CNG). This compressed gas is stored in similar fashion to a car's gasoline tank, attached to the rear, top, or undercarriage of the vehicle in a tube shaped storage tank. A CNG tank can be filled in a similar manner, and in a similar amount of time, to a gasoline tank.

Mr Sepetu explained that compressed natural gas fuels a combustion engine similar to engines fueled by other sources.

He also noted that in bid to develop and promote CNG technology, they are developing a wide range of application possibilities so as to enable CNG to become the country’s primary fuel.

In addition to using CNG, some natural gas vehicles are fueled by Liquefied Natural Gas (LNG). Natural gas powered vehicles that exist today are bi-fuel vehicles, meaning they can use gasoline or natural gas, allowing for more flexibility in fuel choice. Many of these vehicles, which were originally gasoline, only, have been converted to allow the vehicle to run on either fuel. This conversion is costly, and typically results in less efficient use of natural gas.

Environmental benefits of CNG powered vehicles

One of the primary reasons for pursuing alternative fueled vehicle technology is to decrease environmentally harmful emissions. CNG powered vehicles are much cleaner burning than traditionally fueled vehicles due to the chemical composition of natural gas.

While natural gas is primarily methane and gasoline, diesel fuel contains numerous other harmful compounds that are released into the environment through vehicle exhaust.

While natural gas may emit small amounts of ethane, propane, and butane when used as a vehicular fuel, it does not emit many of the other, more harmful substances emitted by the combustion of gasoline or diesel.

These compounds include volatile organic compounds, sulfur dioxide, and nitrogen oxides (which combine in the atmosphere to produce ground level ozone), benzene, arsenic, nickel, and over 40 other substances classified as toxic by the National Environmental Management Council (NEMC).

Dedicated CNG powered vehicles also produce, on average, 70 per cent less carbon monoxide, 87 per cent less non-methane organic gas, than traditional gasoline powered vehicles.

“Much has been said about non-polluting energy sources, but none has found an application workable on a wide scale. Meanwhile, pollution has gone on unabated and it has now reached unbearable levels. CNG brings with it a chain of benefits: easy availability, environmental conservation due to its being emission-free, low cost, safety as well as its wide range of application in the national economy,” said Mr Onesmo Nathan, the marketing manager of Triangle Tanzania Ltd.