Gasifier, Solid Oxide Fuel Cell Integrated Systems for Energy Production From Wet Biomass

Abstract

Nowadays, there is worldwide interest in diversifying energy supply. In this regard, biomass is the best possible renewable organic substitute for fossil fuels. In particular, the energy content of very wet biomass, recovered with appropriate technology, could potentially be used for power generation. In addition to power generation, this technology would represent a sanitary option to improve the quality of public health and the environment. Supercritical water gasification (SCWG) is a technology applied for the conversion of wet biomass into gas. It uses the specific physical properties of water at supercritical conditions to decompose the organic matter. However, near 100% conversion, close to thermodynamic equilibrium, of real biomass into gas is not yet demonstrated. The conversion is higher at dry biomass concentrations below 10 wt.%, but at these conditions, the system is not energetically sustainable. The conversion depends on the SCWG operating conditions and the properties of the catalyst. Because of present-day technical limitations, the conversion efficiency in SCWG is low when fed with real biomass. The net electrical efficiency of a combined system SCWG-solid oxide fuel cell (SOFC), fed with fecal sludge at 15 wt.% dry biomass, reaches between 50 and 70% (thermodynamically calculated values), whereas utilizing an SCWG designed with present-day engineering gives 29-40%. The SOFC fuel utilization influences the system efficiency significantly, as the processed heat available for the heat integration depends on fuel utilization. The extreme operating conditions of an SCWG-based system cause technical limitations toward reaching complete conversion during gasification. An efficient and stable catalyst is not yet available at competitive costs for low-temperature SCWG of real biomass. Intensive research in different gasification-SOFC system configurations that include the integration of complementary processes, such as the electrochemical oxidation of higher hydrocarbons or the electrochemical reduction of CO 2 and H 2 O, will increase the potential of the gasification-SOFC system for commercialization in medium scale in the future and become a technology that provides economic, environmental, and health benefits.

Tar Formation in Gasification Systems: A Holistic Review of Remediation Approaches and Removal Methods

“…The feedstock includes coal, biomass, waste materials such as municipal solid waste (MSW), sewage sludge, and other waste. − It should be noted that due to the anticipated 70% rapid increase in the global waste generation between the year 2016 and 2050, gasification of waste materials is becoming a key technology interest . Apart from thermal applications, the product gas known as “syngas” from gasification can be utilized in various applications, such as fuelling an internal combustion (IC) engine, , gas turbine, and integrated gasification combined cycle − for power generation; as a feed for Fischer–Tropsch/Alcohol synthesis reactors, synthetic natural gas, and hydrogen; and in advanced technologies like solid oxide fuel cells. ,− Several reactor configurations are available for gasification, including fixed bed, fluidized bed, entrained bed, and others, each with specific preferences for process conditions. By selecting the appropriate reactor configuration, the required syngas composition and conversion rates can be achieved to meet the specific needs of a particular application.…”

Simulation Integrated Low Rank Coal Gasification SOFC Fuel Cell using Cycle Tempo: Energetic Analysis

“…Similarly, Taufiq et al, [14] conducted a simulation of a power generation system that combined a coal gasification system, steam turbine system, gas turbine system, and fuel cell system, and the simulation results indicated an efficiency of 46.35 to 60.32%. Recalde et al, [15] performed a combined power plant simulation with a supercritical water gasification system and a SOFC using Aspen Plus. The simulation results showed that the resulting efficiency was around 50 to 70%.…”

Effects of Temperature and Additives on NOx Emission From Combustion of Fast-Growing Grass

“…Developing clean and efficient renewable energy sources are urgently required. Biomass fuels are considered the best renewable organic alternative to fossil fuels because of their extremely low sulfur content and renewable characteristics (Recalde et al, 2019;Wang et al, 2021). Lvxin fast-growing grass (hereafter referred to as the "fast-growing grass") is a fast-growing plant developed by Prof. Lei Xuejun (Lei, 2015) by hybridizing seven different varieties Lvxin grass.…”