The Sunday Mail
Harmony Agere
The discovery of coal-bed methane gas (CBM) reserves in Matabeleland North was made at a moment when the energy sector is enduring a difficult spell plagued with electricity shortages, limited access to clean energy as well as high cost of power, thereby lifting hopes for an improved and efficient energy delivery system in the country.
With vast deposits of CBM believed to be lying underneath the Hwange-Lupane basin, the energy troubles look set to become a thing of the past.
The anticipation is that the gas reserves – which are said to be the largest in the Sadc – will improve electricity generation and gas supplies in homes and industries.
Studies show that there is not much difference between the uses of CBM and conventional natural gas.
In fact, the World Coal Association (WCA) suggest that CBM can easily replace conventional natural gas given it has got the right methane concentration levels.
“Concentration levels of methane recovered via these techniques (draining gas from coal seams) can often exceed 95 percent, making the gas suitable for use as a direct replacement for conventional natural gas in pipeline networks,” reads a WCW report.
Therefore, this qualifies CBM to substitute most of conventional natural gas uses such as power generation and the manufacturing of Liquefied Petroleum Gas (LPG) for domestic use.
Engineering expert and public policy analyst who is also based at the World Bank, Mr Norman Mukwakwami, said CBM has got multiple uses and could help reduce the import bill of energy-based products.
“CBM has the potential to change Zimbabwe’s Balance of Payments by reducing the imports of fertilisers and petroleum products, which together account for 32,2 percent of total imports,” he said.
“CBM can be converted into diesel, petrol or ethanol. Recovered CBM can also be stored in gas canisters for local distribution as a domestic fuel and is also storable in compressed liquid form for utilisation as vehicle fuel.”
According to Mukwakwami, these products can be achieved after being converted or compressed using a model called the Fischer Tropsch Synthesis model.
Research shows that this model has been successfully implemented by South Africa Synthetic Oil Limited (SASOL) as it has produced many by-products.
Experts say with the assistance of other countries that are into similar projects, the idea of establishing such an organisation in the country is not far-fetched.
Mr Mukwakwami said CBM can also be used as an industrial raw material in the production of fertilisers and stock feeds as well as providing basis of the pharmaceutical and plastics industries.
For power generation, WCW says CBM has enough quality to be used in gas turbines and gas engine systems.
“The high quality of the gas recovered from un-mined coal seams also renders it suitable for replacing or supplementing conventional natural gas in power generation systems, such as gas turbines and gas engine systems.”
With Zesa producing barely 1,2 MW per day against a national demand of about 2,2 MW, the importance of increasing power generation can never be over emphasised.
Research also shows that the gas can also be pumped directly to homes and businesses for use in cooking, heating and lighting.
However, although energy experts acknowledge the efficiency of CBM and its potential to replace conventional natural gas, some do not believe it can work as a direct replacement for electricity.
They say it can be an alternate when it comes to heating and lighting but lacks the convenience that comes with electricity.
“In a home you can use gas for almost everything that electricity does, except for appliances like television and radio sets. So it is easy to be tempted to believe that gas, wholesomely, can replace electricity,” said energy expert, Engineer Chengetai Karedzera.
“In my view electricity comes with a certain convenience that gas does not have. If you want to reach the same convenience with gas it means you will have to construct a vast pipe network in the whole country for both domestic and industry.
“Now just imagine the money and the time the process can take, not even mentioning that we could be dealing with a finite resource here. What will we do with the infrastructure when all the gas is gone?”
Engineer Karedzera said gas and electricity can only complement each other emphasising that domestic use of gas is better confined to delivering it in canisters for now. “For industry we can pipe gas to them but for domestic use, it should be delivered in canisters. It makes economic sense that way.”
The Zimbabwe Energy Regulatory Authority (Zera) is on record for encouraging the use of gas in the country.
Over the past four years the country recorded 100 percent increase in the use of liquid petroleum gas (LPG) due to the availability of the energy source and increase in power shortages.
“This can be seen from the emergence of small-scale retailers who man street corners and car parks in all country cities, suburbs and locations,” reads a Zera statement.
Zera says the use of gas in the country can reduce pressure on electricity demand. Canada, Russia and China have the largest gas resource base in the world with Europe being the largest gas market in the world.
