Combustion of sewage sludge as alternative fuel for cement industry

Abstract

The combustion of sewage sludge and coal was studied by thermogravimetric analysis. Both differential scanning calorimetric analysis and derivative thermogravimetric profi les showed differences between combustion of sewage sludge and coal, and non-isothermal kinetics analysis method was applied to evaluate the combustion process. Based on Coats-Redfern integral method, some reaction models were tested, the mechanism and kinetics of the combustion reaction were discussed. The results show that the combustion of sewage sludge is mainly in the low temperature stage, meanwhile the ignition temperature and Arrhenius activation energy are lower than that of coal. The combustion of sewage sludge has the advantage over coal in some aspects, thus sewage sludge can partly replace coal used as cement industry fuel.

Study on New Cement Slurry System for Heavy Crude Oil Thermal Recovery in Well Cementation

“…The figure that the temperature has a great impact on the pressure strength of aluminates cement. In order to find out the relationship of hydration product of aluminates cement and strength, in combination with data [3,4] , the following analyse have been performed: When the temperature is less than 15˚C, the major cement hydration products CAH 10 are hexagonal with dense structure ; At 15~30 ˚C accompanied with the generation of C 2 AH 8 , the strength is declined; When the temperature is more than 30˚C, with increased temperatures, metastable phase CAH 10 , C 2 AH 8 gradually form a stable phase C 3 AH 6 that belongs to a cubic crystal system which has poor adhesive effect. In the process of hydration, a transformation reaction occurs in this crystal, which makes it change from a hexagonal crystal system to a cubic system.…”

Co combustion of sewage sludge and Turkish lignite: the effect of blending on combustion characteristics

“…Thermo-analytical methods have been extensively used to determine combustion characteristics of sewage sludge and co-combustion of sewage sludge with other fuels [10,[12][13][14][15][16]. Thermogravimetric techniques enable us to study combustion characteristics such as Ti (ignition temperature), Tmax (the temperature where the maximum mass loss occurred), Tb (burnout temperature) and to conduct proximate analysis to determine the volatile matter, fix carbon and ash content.…”

Evaluation of Ecological Concrete Using Multi-Criteria Ecological Index and Performance Index Approach

“…The cement industry has been using waste materials over many years for the production of CEM II and CEM III cements, whose market share has been increasing recently from year to year [12,13,14]. Alternative fillers such as scrap tires or sludge ash from sewage treatment plants have been introduced [15,16,17]. The use of cements with additives often does not cause any deterioration of the properties of…”