ALTHOUGH many manufacturing and industrial companies have stated objectives to reduce use of fossil fuels, there are not yet any silver bullets in the green fuel space, says Dennis Williams, commercial director at steam and boiler operations and maintenance service provider, Associated Energy Services (AES).
Supply and logistics constraints, high costs and technological limitations are just some of the challenges encountered by AES, as they assist an increasing number of clients to investigate the use of more environmentally sustainable, lower carbon fuel alternatives – thereby obviating the requirement to pay carbon taxes both locally and abroad.
“When a global business decides to reduce its carbon footprint – or even go carbon neutral – this decision seems to be applied across all marketplaces, irrespective of the local economic pressures and technical challenges.”
One AES client is already running out of time to meet the ambitious decarbonisation target of its global parent company.
“We have reviewed all options – from electricity to solid fuels, liquid fuels, different gases, biomasses and agricultural residues – and shown the capex, opex and supply dynamics on multiple occasions. We have also considered the amount of space needed – and what each fuel choice will incur from an emissions and carbon tax perspective. In addition, we have looked at how much the steam will cost, the ash which could be generated and how to deal with that.”
Williams’s key message is that carbon taxes are here to stay – and that companies and consumers will not be able to absorb the costs of using fossil fuels indefinitely. Companies must be educated about different options that suit their specific needs.
Gas: just hot air?
For Williams, gas is best regarded as an interim step on the decarbonisation journey.
“Not only is supply an issue in terms of gas – but it remains a fossil fuel with a carbon footprint. Companies will still pay substantial carbon tax and find themselves only part of the way to a zero carbon target. There is naturally also a cost associated with making this interim switch – so it is a less than ideal option in most cases.”
Apart from the predicted local shortages of locally available natural gas, converting and transporting this fuel as liquefied natural gas (LNG) is not environmentally friendly and is expensive – with recent price indications at US $18 to 20 per gigajoule, which is probably four times the cost of coal.
Biomass: Why waste?
Williams says bagasse, derived from sugar cane residues, was probably the earliest biomass fuel used in South Africa.
“The business models for this have changed substantially over the years. Years ago, bagasse was regarded as a problem. This view has been turned on its head – to the point where local sugar mills maximise its use as energy feedstock in their boilers for steam and power generation.”
In the timber industry, the focus is on maximising the useful yield from timber. Each log is scanned to determine the sizes, widths and thicknesses which can be cut; as well as the potential wastage. White wood chips are often sold for board manufacture, typically leaving mainly contaminated wood chips, saw fines and bark. These can be used for energy.
