Integration of direct combustion with gasification for reduction of NOx emissions

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

“…The influence of the aforementioned reaction on the NO conversion was intentionally omitted to emphasize the role of iron as an additive that supports the reburning process. The experiments were performed this way because the influence of temperature, reburning fuel type, reburning fuel heat input and other process parameters on the efficiency of NO reduction has already been intensively investigated [30][31][32][33], whereas relatively few studies on the influence of iron on the reburning efficiency have been published [9,14,23,24]. The efficiency of NO x reduction in the presence of iron as a function of the excess air numbers was calculated according to Eq.…”

“…Recently, the gas from biomass gasification has been recognized as a highly effective reburning agent. It is also worth noting that the high concentration of CO included in this fuel [30,31]. For example, the integration of a coalfired boiler with a biomass gasifier has been used in a thermal power plant in Zeltweg, Styria-Austria [34].…”

“…However, these results are interesting because they clearly show that iron or iron oxides can be used in a wide range of combustion conditions. Lissianski et al [9,23,30], who used a pilotscale combustion chamber, and Su et al [24], who used a laboratory-scale facility, both focused on the use of iron or iron oxide in pulverized coal combustion chambers. Fennel et al [12,17], who used the TGA method, Hayhurst and Lawrence [19], who used a laboratory-scale FB reactor, and Hayhurst and Ninomiya [15], who used a laboratoryscale FB reactor, suggested the use of iron as a de-NO x agent in fluidized-bed combustors.…”

The effect of biomass pyrolysis gas reburning on N2O emission in a coal-fired fluidized bed boiler

“…The radial H produced in the process of fuel gas reburning has significant serious influence on N 2 O reduction [15]. The combustible material of biomass pyrolysis gas mainly contains H 2 , CH 4 and CO, which are helpful to reduce nitrogen oxide emissions [5,16,17]. Because of low alkali metal and chlorine content, the gasified gas for co-firing can avoid most of the problems associated with direct co-firing, such as boiler fouling, corrosion and the utilization of co-firing ash.…”

生物质热解气流化床再燃过程中N<sub>2</sub>O排放特性研究

“…气体燃料在再燃过程中产生的 H 基对 N 2 O 的脱除有重要影响 [15] . 生物质热解气中 可燃组分主要包括 CO, CH 4 和 H 2 , 喷入煤粉炉与煤 粉再燃, 可有效降低氮氧化物的排放 [5,16,17] , 同时由 [16,13] . 除此之外, N 2 O 排放还受流 量等因素影响 [24] .…”