Fly Ash Formation and Characteristics from (co-)Combustion of an Herbaceous Biomass and a Greek Lignite (Low-Rank Coal) in a Pulverized Fuel Pilot-Scale Test Facility

Abstract

The lignite boilers are designed for lower quality fuels, and often the ash is not utilized. This work assessed the impact of combustion of an herbaceous biomass with a low-quality Greek lignite on the quality of the resulting fly ash. Test results were compared with those of fly ash samples from an industrial facility using the same fuel qualities. Inductively coupled plasma-optical (ICP) emission spectroscopy, X-ray powder diffraction (XRD), and scanning electron microscope (SEM) analyses were performed on the collected samples. Despite the significantly higher contents of K, Na and S in the biomass, at a 50% co-firing thermal share, the major and minor oxides in the fly ash were comparable to the lignite fly ash quality. This is attributed to the high ash content of the lignite, the low ash content of the biomass, and the much higher heating value of the biomass. There were improvements in fly ash performance characteristics with the herbaceous biomass in the fuel blend. The initial setting time and volume stability evaluations were improved with the biomass in the fuel blend. The work supports efforts of good practices in ash management, social responsibility, a circular economy, power plant renewable energy operations, and co-firing herbaceous biomass fuels in lignite power plants.

Emission Behaviors of Inorganic Ultrafine Particles during Zhundong Coal Oxy-Fuel Combustion with Characterized Oxygen Input Fractions Comparable to Air Combustion

“…However, the emission of PM during Zhundong coal combustion, also as an important ash-related problem, has rarely been reported until now. The distinctive coal was reported to emit much more PM 10 (particulate matter with an aerodynamic diameter of ≤10 µm) than other lignite and bituminous coals during combustion [12], which could cause both the operating problem of initial deposition and the environmental problem of haze [17].…”

Advances in Biomass Co-Combustion with Fossil Fuels in the European Context: A Review

“…Hein and Bemtgen (1998) [17] summed up results from several full scale co-combustion trials, stating that at low biomass share, properties of the ash and fly ash formed resemble those from sole fossil fuel combustion, and though the slagging, fouling, and corrosion tendencies increased, they are at a tolerable level. More recently, results of low quality high ash lignite and herbaceous biomass co-combustion in a 500 kW combustor were presented by Fuller et al (2018) [28], confirming only minor changes in the fly ash composition even at 50% co-combustion biomass share. Kopzyński et al (2017) [127] found that ash from torrefied biomass samples co-combusted with coal exhibits higher initial softening temperatures than that from raw biomass co-combustion.…”

“…Biomass and waste co-combustion has been intensely researched in the last decade. Pilot and full scale systems studies conducted several decades ago [17][18][19] continue to be published [20,21], but they are more recently accompanied by laboratory experiments employing drop tube furnaces [22][23][24], thermogravimetric analyses (TGA) [25][26][27], and other laboratory equipment [28,29]. Experience with co-combustion systems operation are reported in the USA [30,31], Europe [32], as well as other parts of the world [33], generally claiming reduction in CO 2 and other greenhouse gases emissions [34] with only minor changes in co-fired power plants and utility boilers thermal efficiencies [35].…”

BioEnergy and BioChemicals Production from Biomass and Residual Resources

“…The twenty-one published papers cover a variety of biomass or waste residuals that have been converted into different types of energy, biofuels or biochemicals including heat [1,11,16], methane [2,4,[7][8][9]17,[19][20][21], electricity [2,11,16], short chain fatty acids [2,19], ethanol [3,12,19], syngas [5,19], nutrient pellets [6], hydroxymethylfurfura [15], and hydrogen [2,10,14,18,19]. The key information including biomass or residuals, products, and technology for the production and type of research are summarized in Table 1.…”

“…The first contribution by Fuller et al [1] assessed the impact of co-combustion of an herbaceous biomass with low-quality Greek lignite on the quality of the fly ash. The authors compared the results with those of fly ash samples from an industrial facility using the same fuel qualities.…”