International audience The problem of wastewater treatment plant sewage sludge is becoming crucial. Indeed the quantity of sewage sludge will increase with the population and the economic developments, the rise of the number of treatment plants and their better performance. Sewage sludge treatment is at the moment realized in limited ways. Whatever the future of those ways and without creating polemics, they will not be able, to absorb this increasing volume. It consequently becomes necessary to diversify the methods of treatment to answer the problems arising from the management of this waste. Within this framework, the new thermochemical ways of treatment by valorization seems more interesting. Indeed, they present in addition to the advantage of the possibility of processing, the capacity to easily produce "storable" and valuable compounds. Thus will treat, in this article, the interest to develop the processes of gasification of waste water sewage sludge.