Across the world, the cement sector is one of the largest emitters of greenhouse gases, releasing around 2 Gt of carbon dioxide into the atmosphere every year, which works out at about 5 percent of the global total.
Cutting emissions in the cement industry is vital to meeting Australia's target of reducing carbon emissions by 30 percent from their 2005 level by 2030. So how can cement processors achieve this goal?
Use Alternative Energy Sources
The energy that cement plants use is a major determinant of their energy efficiency. Thankfully, cement has a couple of key advantages regarding the use of biomass fuels. The high temperatures created by cement kilns promote the combustion of fuel stocks, while cement clinker can function as a gas cleaning agent, removing impurities from the air.
Alternative fuels don't have to be produced using complex processes. They can actually be derived from everyday items like tyres and carpets, both of which are commonly burned in waste disposal facilities instead of being used to power industry.
Clear Out Material Blockages with Air Cannons
Caking is another particularly acute problem in the cement processing industry that can make production processes much less efficient. This generally applies to stages in the production process before the kiln itself, such as kiln inlets and riser ducts, where caking around the edges can rapidly clog up the system.
When companies experience blockages in their ducts and vessels, air cannons are often a good solution. These devices deliver bursts of high pressure air, cleaning out chutes and silos and avoiding the need to clear them manually. This drastically reduces carbon emissions caused by plants operating at low efficiency levels or that require the need for shutdowns to maintain processing vessels.
Use Decarbonated Raw Materials
Making processes more efficient and using alternative fuels will help, but even larger emissions reductions can be achieved by using low carbon feedstocks in the first place. Instead of using traditional limestone as the raw material for cement production, plants can use materials that have been decarbonated during other industrial processes instead.
This will make a huge difference. 60 percent of emissions generated during the cement production process are caused by processes that strip carbon from limestone. Now, manufacturers are finding ways to use materials like silica, aluminium oxide, calcium, iron or even sewage sludge as raw materials for cement production. All of these are waste products that have been decarbonated during other processes. Smart cement producers are reclaiming them and turning them into profit.
The cement sector shows that tackling climate change can have beneficial consequences for industry. By using technology like air cannons to maintain material flows, adopting low carbon energy sources and using reclaimed decarbonated feedstocks from other industrial processes, the cement industry will be able to reduce its emissions targets and become more economically efficient at the same time.