Proponents of sludge incineration have an uphill fight because many environmentalists are against the process, no matters what. Other alternatives to land application are difficult to find for sludge from heavily urbanized areas. But that is another story.
In all events, those who would like to move toward considering sludge incineration do their prospects no good, in my view, by disguising incineration in other terms, calling it “waste to energy,” or “burning.”
This recent BBC News article, entitled “Could ‘poo power’ help heat the country?” is a case in point. The article is interesting in that it points how how a humongous sewage plant is able to save some money by anaerobically digesting sludge to produce methane, which it can burn to create heat and/or electricity; and by “burning” sludge.
The savings is not a huge amount of money in terms of what it costs to treat sewage, but it’s not bad. As they note
Human waste has long been seen as a by-product, but Thames Water claims it saved £15m last year, and generated 14% of its power, from either burning sludge or methane derived from its 13 million customers’ toilets.
The sludge is routed to
compressors where the water is squeezed out, leaving solid “poo cakes”.
These cakes, which still contain a large amount of water but burn easily, are fed into a gigantic hot furnace which produces steam that drives a large turbine, creating electricity.
Incineration. Let’s tell it like it is.