Technology for the Production of Energy Syngas from Wastewater Sludges

In this paper, scientifically substantiated recommendations on the technological processing and utilization of wastewater sludges for the production of energy resources are formulated. The analysis of earlier studies shows that sludges contain mineral, organic, and bacterial origin contaminants of different composition in the form of solutions, colloids, and floating and suspended compounds. It is demonstrated that the removal of sludges is one of the most urgent environmental problems associated with the propagation of bacteria, which have a negative effect on the environment, people, animals, and plants. The most attractive alternative to sludge utilization is the production of energy syngas from it. The objective of studies is to develop an innovative technology for the production of energy syngas from wastewater sludges. Some characteristics of initial materials and equipment used for investigations are given. A syngas production process flowchart based on a patented setup with two screw retorts from a catalytically active material is proposed to optimize the temperature regimes of outer sludge heating from 200 to 850°C. The setup provides the production of multicomponent energy syngas at atmospheric pressure without air access with a conversion of 90% and a calorific value of 3300–3600 kcal/m³ to be superior to the known technologies of gasification at the same temperatures and pressure. The developed technology for the production of energy syngas from wastewater sludges results in syngas of increased calorific value due to gas generator elements providing rational temperature regimes for the chemical destruction reactions of sludges with an increased humidity. The combination of fuel gas and steam generation processes results in a high degree of sludge gasification with the formation of syngas with an increased calorific value due to acceleration of chemical reactions.