In this paper, the characteristics of NO x reduction by reagent injection into the fuel-rich zone (RIFR) in coal combustion were investigated, under high temperatures and reducing atmosphere conditions. The stoichiometry and temperature have a major influence on the chemistry of NO and NH3 reagent (ammonia or urea). Therefore, experiments were conducted on a bench-scale test system with urea solution as the reagent to investigate the key factors influencing NO x reduction, including primary stoichiometric ratio (SR1), temperature in the reaction zone, and normalized stoichiometric ratio (NSR) of the injected reagent. The results indicated that the primary stoichiometric ratio SR1 was the key parameter affecting the reduction of NO x emissions. Better NO x reduction was achieved with a decrease in the SR1 for bare air staging. However, there was no benefit for NO x reduction by reagent injection in the very fuel-rich zone (SR1 ≤ 0.75), which depended on the distribution of N-intermediates and initial NO concentration. On the other hand, a negative NO x reduction was obtained by reagent injection when SR1 ≥ 0.95 because the added reagent was oxidized to form NO. The optimum SR1 for RIFR was found to be 0.85 in this study. A higher SR1 greatly improved the NO x reduction by RIFR only when SR1 was less than 1, and high temperatures (1473–1673 K) were required for the generation of more OH free-radicals in the fuel-rich zone, which promoted NO x reduction by NH3 in the absence of oxygen. Therefore, RIFR is different from the traditional selective non-catalytic reduction technology, which has a strong temperature dependency from 1100–1300 K. The NO x reduction efficiency was increased by 21.4% with RIFR compared to the bare air-staged method, under the optimum conditions of SR1 = 0.85, T = 1673 K, and NSR = 2. More urea solution led to greater NO x formation in the burnout zone but with no ammonia slip. This method can be applied as a new alternative technology to further reduce NO x in combination with the existing low NO x combustion technologies.

This papers deals with the study of the fayalite with high content of iron in the initial layer of coal ash, using the generalized gradient approximation and Perdew-Wang91 algorithm based on the Quantum chemistry. By calculating, we found that the gap between the highest occupied molecular orbital(HOMO) energy and the lowest unoccupied molecular orbital(LUMO) energy of the Fayalite is very small, so the structure is unstable. Thus show that the water-cooling wall slagging more active due to Fe atoms,prone to transformations of physical phenomena.

Entrainedflow Gasifier with Large Capacity and Slagging Tap is Usually Use for IGCC and Largescale Chemical Industrial Factory. while, there are 57% of Reserved Coal is Highfusion Temperature Coal, which Cannot Satisfy the Requirement of Thegasification for Slagging Tap. . Therefore, Two Typical Kinds of Chinese Coals Wereselected and Gasified in a Lab-Scale down-Flow Gasifier with Feeding Rate Ataround 1kg/h. the Results Show that along with the Increasing Temperature, Thecarbon Conversion and Cold Gas Efficiency will be Increased Quickly Whentemperature is below 1400°C, and then Increased Slowly when above 1400°C. the Optimum O/C Molarratio is around 1:1, the Cold Gas Efficiency and Carbon Conversion under Thisexperimental Condition (1300-1400°C) are Separately 31% and 80%. at the Optimumgasification Condition, Increasing the Residence Time will also Increase Thecoal Gas Concentration, Carbon Conversion and Cold Gas Efficiency. under Thisexperimental Condition, the Best Residence Time is at Least 1.5~2.0s.

The main reason resulting in the greenhouse effect is the fact that CO2 concentration of atmosphere is raised up. The largest part of CO2 emissions caused by human activities is derived from coal-fired power plant. Consequently, in order to reduce CO2 emissions on a large scale, we must focus on capturing CO2 which is produced by coal-fired power stations. In this paper, we introduce advanced biological CCS technology which makes use of the Chlorella sp. to fix CO2 from coal-fired power plant. The objective of the work is to discuss the effects of biological conditions (inoculums density, cultivation temperature and light intensity) on carbon sequestration efficiency, and to find a suitable cultivation environment for the growth of Chlorella sp.