Theoretical and experimental metals flow calculations during biomass combustion

Study of Temperature Fields and Heavy Metal Content in the Ash and Flue Gas Produced by the Combustion of Briquettes Coming from Paper and Cardboard Waste

“…Note that the Pb, Hg and Mn contents in the flue gas and collected ash were higher than that reported in the raw biomass by the literature [15,24]. In contrast, the Cd and As content were similar to those reported in the raw biomass by Kovacs et al [15].…”

“…Due to the high temperature of the combustion (750 • C to 950 • C), the heavy metal contained in the raw paper waste were predominantly transferred into the flue gas than into the ash as shown in the Table 3. According to Kovacs et al [15], high percent of the heavy metals may be content in the flue gas even at relatively low temperature of 250 • C. Indeed, the temperature increases the heavy metal content in flue gas at the expense of ash [21]. The low volatilization temperature of heavy metal, particularly Hg, Cd and Pb, explained their large content in the flue gas comparatively to the bottom ash as shown in the literature [21,23].…”

“…The ink is composed up to 30% of pigment which contents many types of heavy metals according to its formulation [12][13][14]. Thus, during the combustion process the heavy metals can be found in the bottom ash, the fly ash and the flue gas [15]. Heavy metals could cause air, water and soil pollution according to Kovacs et al [15].…”

“…Thus, during the combustion process the heavy metals can be found in the bottom ash, the fly ash and the flue gas [15]. Heavy metals could cause air, water and soil pollution according to Kovacs et al [15]. As a result, the combustion and valorization of residual ash are subject to multiple regulations, mainly on the content of heavy metals.…”

Biofuel Production Using Thermochemical Conversion of Heavy Metal-Contaminated Biomass (HMCB) Harvested from Phytoextraction Process

“…Some potential products extracted from HMCBs comprise sugar via enzymolysis, marketable chemicals and fuels, as well as the HMs recovery via thermochemical processes [21]. To do so, thermochemical conversion (pyrolysis [160][161][162], gasification [53,163,164], liquefaction [94,165,166], and combustion [128,[167][168][169]), and biochemical processes (anaerobic digestion [54,170], and fermentation [147,171]) have been investigated. In addition, some pretreatments, including dry and/or physical [172][173][174], wet and/or chemical [175][176][177], and physicochemical methods [148] have been examined prior to HMCBs conversion to biofuel or to other valuable products, such as char, activated carbons, etc.…”