Utilize of plastic waste and reduction of CO₂ emissions in cement production

Abstract

Various types of industrial waste are used in the cement industry. In particular, the alternative energy resources used in cement burning include automobile shredder residues and other plastic waste that are difficult to materially or chemically recycle. In general, such plastic waste is incinerated without energy recovery and/or disposed of in landfills, but it is effectively used as an energy source in cement production.

This study aimed to determine the effect of using plastic waste in cement production on the reduction of CO₂ emissions applying the life cycle assessment method. CO₂ emissions were compared between the following two systems: (1) the recovery system to use plastic waste substituted for coal and (2) the conventional system to use coal and dispose of plastic waste by simple incineration in landfills. The system boundary was defined to cover the disposal of plastic waste, pretreatment of plastic waste, transport of raw materials and residues, and the production of required energy in addition to cement production.

Results indicated that using 23 kg of plastic waste per ton of cement resulted in a reduction in coal use by 29 kg. This led to a reduction of 75 kg in CO₂ emissions per ton of cement produced.