Breakthrough Cement Production Technique Is CO2 Free
Source: http://www.gwu.edu
#cement #health #technology
As global warming begins to more strongly influence policy and economic decisions, attention is turning to the construction industry and its massive, 3 trillion kilogram annually cement addiction. The cement industry is the second largest emitter of greenhouse gases, surpassed only by fossil fuel energy sources. 5 to 6 percent of all carbon emissions come from cement production, which can release up to 9 kilogram of CO2 for every 10 kilogram of cement produced.
A team, at George Washington University in Ashburn, Virginia, has devised the first technique, called Solar Thermal Electrochemical Production (STEP), to completely eliminate CO2 emissions from the process, and it would even be cheaper than current methods of production.
The STEP of cement would harness the energy for two specific areas of production. When limestone is converted into lime, it undergoes a chemical change - at present, decarbonation. The limestone is separated into lime and CO2, with the greenhouse gases as an unfortunate byproduct. Carbon emissions are further increased by the burning of fossil fuels to heat up the limestone to start the decarbonation process.
The STEP method eliminates the needs for fossil fuels - the solar thermal heat melts the limestone, which then undergoes an electrolysis process. The electrolysis produces a different chemical output, lime-intact but free of greenhouse gas byproducts. At higher temperatures STEP creates a carbon monoxide (CO) byproduct which researchers believe could be sold to other industrial applications. If this were to be done, the cost of STEP-created cement would stand at around minus US$ 298 per ton, as opposed to the current cost of standard, environmentally destructive production of US$ 70 per ton.
With some cement manufacturers already looking into ways to reduce their industry's footprint, STEP could transform an industry responsible for a huge quantity of greenhouse gas emissions each year - if the process can be adapted to large scale commercial use. The scientists are also looking at how the STEP methods could be applied to a diverse range of industrial applications, such as purifying iron and aluminum; producing glass, paper, sugar, and agriculture; cleaning smoke stacks; softening water; and removing phosphates from sewage.
A team, at George Washington University in Ashburn, Virginia, has devised the first technique, called Solar Thermal Electrochemical Production (STEP), to completely eliminate CO2 emissions from the process, and it would even be cheaper than current methods of production.
The STEP of cement would harness the energy for two specific areas of production. When limestone is converted into lime, it undergoes a chemical change - at present, decarbonation. The limestone is separated into lime and CO2, with the greenhouse gases as an unfortunate byproduct. Carbon emissions are further increased by the burning of fossil fuels to heat up the limestone to start the decarbonation process.
The STEP method eliminates the needs for fossil fuels - the solar thermal heat melts the limestone, which then undergoes an electrolysis process. The electrolysis produces a different chemical output, lime-intact but free of greenhouse gas byproducts. At higher temperatures STEP creates a carbon monoxide (CO) byproduct which researchers believe could be sold to other industrial applications. If this were to be done, the cost of STEP-created cement would stand at around minus US$ 298 per ton, as opposed to the current cost of standard, environmentally destructive production of US$ 70 per ton.
With some cement manufacturers already looking into ways to reduce their industry's footprint, STEP could transform an industry responsible for a huge quantity of greenhouse gas emissions each year - if the process can be adapted to large scale commercial use. The scientists are also looking at how the STEP methods could be applied to a diverse range of industrial applications, such as purifying iron and aluminum; producing glass, paper, sugar, and agriculture; cleaning smoke stacks; softening water; and removing phosphates from sewage.
