Municipal solid waste (MSW) management has become a major issue worldwide. Issues related to landfilling include: occupation of large areas, generation of green­house gases by digestion of the waste, generation of hazardous and refuse materials, etc. New recovery strategies to generate energy, such as incineration, have also given rise to many problems. In Europe, particularly in Germany, rotary kiln incinerators have been extensively studied and issues related to the high temperature have been reported: leaching of metals, emission of carcinogen compounds, emission of par­ticulate matter, etc. Pyrolysis has been identified as a promising avenue for MSW management: its lower operating temperature and absence of oxygen decrease the pollutant emissions as well as the cost of post-treating flue gases.

11.2.1.6 Municipal Biosolids

Waste water treatment is a critical process for our society: waste water contains dissolved organics and inorganics as well as suspended solids and microorganisms that must be eliminated before the water can be released into the environment or purified further to be drinkable. The recovered waste forms sewage sludge, which is difficult to recycle. When dried, contaminants such as heavy metals limit its po­tential applications. Currently, it is common practice to incinerate sewage sludge with the similar disadvantages to MSW incineration (see Sect. 11.2.1.9). However, incineration could be replaced by more efficient technologies, such as pyrolysis.