Heat equivalents of noxious substances: a pollution indicator for environmental accounting

Abstract

The energy requirements of pollution control in coal and nuclear power plants and the resulting heat emissions are computed in first-order waste heat analysis. Pollution control reduces injection of noxious substances into the biosphere to values below limits determined by risk assessment and social consensus. The heat emissions associated with pollution control are still a relatively benign environmental burden. They can be considered as a thermodynamic indicator of the (least troublesome) pollution potential of a given energy carrier and its appropriate energy conversion process. In this sense, environmental accounting with respect to a reference state can be done with the help of the heat equivalents of noxious substances (HEONS). They are defined as the waste heat generated by pollution control in a production process of given utility output divided by the primary energy input into a non-pollution-controlled production process of the same utility output. In the discussed scenarios the HEONS are about 0.7% for 80% NO x reduction, 1–4.4% for 60–95% desulfuration, 38% for 66% cryogenic CO 2 removal and deep ocean storage, and 0.08%–3%; for the disposal of radioactive nuclear fuel rods in interstellar space via electromagnetic launchers. The relative primary energy required for the indicated processes of pollution control is equal to the HEONS with the exception of the nuclear fuel rods where 0.02–0.9% have to be added for the energy lost in space. Similar to the oxygen equivalents of organic waste water pollutants in the German sewage levy law, the heat or energy equivalents of noxious substances may serve as one criterion for charging taxes and levies to energy carriers.