Energy consumption

In the United States, producing the roughly 80 million tons of cement used in 1992 required about 0.5 quadrillion KJ. This is roughly 0.6% of total U.S. energy use, a remarkable amount given the fact that in dollar value, cement represents only about 0.06% of the gross national product. Thus, cement production is approximately ten times as energy intensive as our economy in general. In some Third World countries, cement production accounts for as much as two-thirds of total energy use, according to the Worldwatch Institute.

Over the last 20 years the energy intensity of cement production has been reduced by approximately 20%. The concrete industry has made even greater gains in energy efficiency, reducing the energy required per unit volume of completed construction by at least 50% during the same time. Other factors that have contributed to these reductions include:

• improved performance of cement
• increased use of admixtures
• improved concrete production quality control
• improved design that allow smaller members to bear loads

This energy efficiency has resulted in reduced atmospheric emissions including carbon dioxides (CO₂), nitrous oxides (NO), sulfur oxides (SO) and particulate. Nevertheless, the manufacture of concrete produces approximately 8% of all carbon dioxide emissions created world wide.

In 1994, the U.S. cement industry consumed 366PJ of final energy (about 2% of total U.S. manufacturing energy use) and emitted 19 MtC of carbon dioxide5 (about 4% of total U.S. manufacturing carbon emissions).

Finish Grinding 

In the table below, we have estimated the type of energy savings if Insitec were used to optimize the milling process eg by reducing overgrinding. We have also estimated the amount of carbon emissions which could be saved each year, which, for world production, amounts to over 3/4 million tonnes of carbon per year. To give an idea in the real world, the carbon saving has been estimated in terms of the annual emissions from cars, and the electricity consumption of residential households.

The table below assumes an average electricity saving of 5% per annum (indicative only, savings may be lower or higher).

Please note that the above table details Malvern Instruments' own estimates.