Flue gas analysis for biomass and coal co-firing in fluidized bed: process simulation and validation

Abstract

Coal-conversion technologies, although used ubiquitously, are often discredited due to high pollutant emissions, thereby emphasizing a dire need to optimize the combustion process. The co-firing of coal/biomass in a fluidized bed reactor has been an efficient way to optimize the pollutants emission. Herein, a new model has been designed in Aspen Plus® to simultaneously include detailed reaction kinetics, volatile compositions, tar combustion, and hydrodynamics of the reactor. Validation of the process model was done with variations in the fuel including high-sulfur Spanish lignite, high-ash Ekibastuz coal, wood pellets, and locally collected municipal solid waste (MSW) and the temperature ranging from 1073 to 1223 K. The composition of the exhaust gases, namely, CO/CO2/NO/SO2 were determined from the model to be within 2% of the experimental observations. Co-combustion of local MSW with Ekibastuz coal had flue gas composition ranging from 1000 to 5000 ppm of CO, 16.2%–17.2% of CO2, 200–550 ppm of NO, and 130–210 ppm of SO2. A sensitivity analysis on co-firing of local biomass and Ekibastuz coal demonstrated the optimal operating temperature for fluidized bed reactor at 1148 K with the recommended biomass-to-coal ratio is 1/4, leading to minimum emissions of CO, NO, and SO2.

A Prototype Reactor Promoting the Hg(0) Capture in the Simulated Flue Gas from Small-Scale Boilers by Using Copper Oxide- and Copper Sulfide-Coated Teflon Pipes

“…The concentration of CO ranged from 1000 to 5000 ppm, CO 2 ranged from 16.2-17.2%, NO ranged from 200-550 ppm, and SO 2 ranged from 130-210 ppm (after desulphurization). As the biomass blending increased, the concentration of SO 2 and NOx decreased from almost 200 ppm to 100 ppm and from 350 ppm to 150 ppm, respectively [40]. The simulated gas had a flow rate of 108 L/h, which was generated by two mercury analyzer pumps (2 × 24 L/h) and two exhaust fans (2 × 30 L/h).…”

Multiscale analysis of fine slag from pulverized coal gasification in entrained-flow bed

“…Accordingly, it is urgent to realize the efficient and clean utilization of coal (Yang 2022;Chai 2021). Coal gasification technology is one of the main methods in this regard (Wang 2021a, b;Cao 2021;Ding et al 2022;Smolinski et al 2022;Zhakupov et al 2022). However, gasification generates a large amount of solid waste, known as fine slag (FS), which is usually disposed in landfills and causes environmental pollution.…”

Blending Effects of Nitrogenous Bio-Fuel on Soot and NOx Formation during Gasoline Combustion

“…At present, fossil energy still occupies a dominant position in the world energy consumption. Soot and NO x and CO 2 emissions from fossil fuel combustion are the main reasons for the greenhouse effect, climate change, and harm to living beings. − Bio-fuels from biomass pyrolysis or other conversion techniques are clean and low-carbon fuels, which have great potential to partly replace fossil fuels to reduce CO 2 and pollutant emissions. − However, due to the presence of nitrogen species in biomass resources, a trace amount of nitrogen compounds (such as pyridine, etc.) exists in bio-fuels, which affects the soot and NO x formation during the cofiring of bio-fuels with fossil fuels.…”