Performance analysis of RDF gasification in a two stage fluidized bed–plasma process

Abstract

The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.

Metodologia para processo integrado de comissionamento em unidades industriais

“…Nessa perspectiva, a sustentabilidade é um diferencial estratégico para as empresas na busca de maior eficiência e ganhos de desempenhos por meio da inovação (Assis et al, 2012). Com a busca por combustíveis limpos e pela redução do uso de combustíveis fósseis, a gaseificação tem recebido bastante destaque nas últimas décadas, segundo Materazzi et al (2016). Continuando com o pensamento de Materazzi et al (2016), a gaseificação é a conversão de um combustível só-lido em eletricidade ou em gases combustíveis (gás de sín-tese).…”

“…Com a busca por combustíveis limpos e pela redução do uso de combustíveis fósseis, a gaseificação tem recebido bastante destaque nas últimas décadas, segundo Materazzi et al (2016). Continuando com o pensamento de Materazzi et al (2016), a gaseificação é a conversão de um combustível só-lido em eletricidade ou em gases combustíveis (gás de sín-tese). Antes de apresentar o macroprocesso de gaseificação, serão apresentados dois exemplos utilizados pela indústria, que são: o processo da Texaco e o processo da E-Gas.…”

Micro cogeneration - rich-methane gasifier and micro gas turbine

“…The increase in the conversion rate was achieved by improving the construction of gasification chambers. Gasification in cyclone chambers [4], with fluidized grate in bladder and circulation bed [5], double layer gasification [6], gasification in plasma [7]-all these were implemented. The effect of process improvements has been achieved by reactive additives to fuels, that affect the increase in the content of flammable components in the generator gas, which translates into an increase in the calorific value of the syngas.…”

Combustion characteristics of ultrafine gasified semi‐char in circulating fluidized bed

“…Fluidized bed gasification technology is an efficient and clean coal use method . Some advantages of fluidized bed gasification (FBG) are that it can use bigger particle sizes, has a wider adaptability to a range of solid fuels, and operates at a lower temperature.…”

“…F luidized bed gasification technology is an efficient and clean coal use method. [1][2][3][4][5][6][7][8] Some advantages of fluidized bed gasification (FBG) are that it can use bigger particle sizes, has a wider adaptability to a range of solid fuels, and operates at a lower temperature. However, the low operating temperature also brings about the problem of a high loss of ignition, resulting in high amounts of unburned carbon in the semi-char, which is the solid residue from coal gasification.…”