Gasification of Densified Biomass (DB) and Municipal Solid Wastes (MSW) Using HTA/SG Technology

Abstract

The necessity of economical and rational use of natural energy sources caused a rapid development of research on the possibilities of using non-conventional energy resources. Taking the above into account, a new technological process of thermochemical conversion of biomass and communal waste, commonly known as High Temperature Air/Steam Gasification (HTA/SG) and Multi-Staged Enthalpy Extraction Technology (HTAG-MEET), was developed. In relation to traditional techniques of gasification or combustion of hydrocarbon fuels, the presented concept is characterized by higher thermal efficiency of the process, low emission of harmful compounds of carbon, sulfur, nitrogen, dioxins, furans and heavy metals. The use of a high-temperature gasification factor causes an increased thermochemical decomposition of solid fuels, biomass and municipal waste into gaseous fuel (syngas), also with increased hydrogen content and Lower Calorific Value (LCV). In this study, the possibility of using a batch type reactor (countercurrent gasifier) was analyzed for gasification of biomass and municipal waste in terms of energy recovery and environmental protection. The proposed research topic was aimed at examining the possibility of using the thermal utilization of biomass and municipal waste through their high-temperature decomposition in the presence of air, a mixture of air and steam. The main goals of the research were achieved during the implementation of several parallel stages of the schedule, which included, primarily: (a) study of the possibility of using thermal utilization of biomass and municipal waste through their high-temperature gasification in the presence of air or a mixture of air and steam and, secondary (b) analytical and numerical modeling of high-temperature gasification of biomass and municipal waste with the use of ANSYS CFD Fluent 6.3 software. Selected results of the experimental and numerical studies are properly presented. The higher temperature gasification concept shows the capability of this technology for maximizing the gaseous product yield in an up-draft fixed bed gasifier. It was also observed that at a high temperature, steam addition contributed to the thermal conversion of biofuels to gas with higher production of hydrogen.