Mercury measurement and control in a CO2-enriched flue gas

Zhuang, Ye; Pavlish, John H.; Lentz, Nicholas; Hamre, Lucinda L.

doi:10.1016/j.ijggc.2011.05.019

Cited by 13 publications

(17 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Overall, no clear bias in high CO 2 environments was noted. While other studies have suggested bias (Pavlish 2011) (Zhuang, et al 2011), difference in the amount of NaOH solution and the method of contact between the solution and gas stream may account for the apparent lack of bias found in this study.…”

Section: Resultscontrasting

confidence: 68%

“…The purpose of this task was to investigate the potential biases of Hg measurement techniques, dependent on the nature of the flue-gas composition: air vs. oxy. EERC has performed some experimentation showing that wet-chemical conditioning systems may bias mercury concentration measurements by scrubbing CO 2 from the flue gas stream (Pavlish 2011) (Zhuang, et al 2011). This bias has not been observed in the measurements performed by REI so far.…”

Section: Mercury Measurement Recalibrationmentioning

confidence: 99%

“…It is suspected that traditional mercury measurement methods may be adversely impacted by high CO 2 in flue gas, such as would exist under oxy-firing conditions. EERC has performed some experimentation showing that wet-chemical conditioning systems may bias mercury concentration measurements by scrubbing CO 2 from the flue gas stream (Pavlish 2011) (Zhuang, et al 2011). In addition, the variability in average molecular weight of the flue gas stream can cause some mercury analyzers to volumize the sampled gas incorrectly.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Adams

Davis

Senior

et al. 2013

View full text Add to dashboard Cite

This report summarizes Year 1 results of a research program designed to use multi-scale experimental studies and fundamental theoretical models to characterize and predict the impacts of retrofit of existing coal-fired utility boilers for oxy-combustion. Through the course of Year 1 activities, great progress was made toward understanding the issues associated with oxy-combustion retrofit of coal-fired boilers. All four Year 1 milestones and objectives have been, or will be, completed on schedule and within budget. Progress in the four milestone areas may be summarized as follows:• University of Utah has performed size segregated ash composition measurements in the Oxy-Fuel Combustor (OFC). These experiments indicate that oxy-combustion retrofit may impact ash aerosol mineral matter composition. Both flame temperature and flue gas composition have been observed to influence the concentration of calcium, magnesium and iron in the fine particulate. This could in turn impact boiler fouling and slagging.• Sandia National Labs has shown that char oxidation rate is dependent on particle size (for sizes between 60 and 100 microns) by performing fundamental simulations of reacting char particles. These predictions will be verified by making time-resolved optical measurements of char particle temperature, velocity and size in bench-scale experiments before the end of Year 1.• REI and Siemens have completed the design of an oxy-research burner that will be mounted on University of Utah's pilot-scale furnace, the L1500. This burner will accommodate a wide range of O 2 , FGR and mixing strategies under conditions relevant for utility boiler operation. Through CFD modeling of the different burner designs, it was determined that the key factor influencing flame stabilization location is particle heat-up rate. The new oxy-research burner and associated equipment is scheduled for delivery before the end of Year 1.• REI has completed a literature survey of slagging and fouling mechanisms in coal-fired power plants to understand key issues influencing these deposition regimes and infer their behavior under oxy-fired conditions. Based on the results of this survey, an algorithm for integrating slagging predictions into CFD models was outlined. This method accounts for ash formation, particle impaction and sticking, deposit growth and physical properties and impact of the deposit on system flow and heat transfer. A model for fouling in the back pass has also been identified which includes vaporization of sodium, deposition of sodium sulfate on fly ash particles and tube surfaces, and deposit growth rate on tubes.In Year 1, REI has also performed a review of the literature describing corrosion in order to understand the behavior of oxidation, sulfidation, chloridation, and carburization mechanisms in air-fired and oxycombustion systems. REI and Vattenfall have met and exchanged information concerning oxy-coal combustion mechanisms for CFD simulations currently used by Vattenfall. In preparation for Year 2 of this program, tw...

show abstract

Section: Resultscontrasting

confidence: 68%

Section: Mercury Measurement Recalibrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Adams

Davis

Senior

et al. 2013

View full text Add to dashboard Cite

show abstract

“…In addition to the advantage to avoid the CO 2 separation from flue gas, NO x emission can be reduced to less than one-third of that of combustion in air because not only of the reduction of thermal NO x (due to the air-nitrogen elimination) but also because of the reburning of recycled NO x with volatiles as well as reaction of recycled NO x with char [1,3,4]. On the other hand, the SO 2 concentration increases during oxycoal combustion with RFG [1,5] and gas purification by flue gas desulphurisation systems is mandatory because of the high risk of in-furnace corrosion and CO 2 transportation systems [6].…”

Section: Introductionmentioning

confidence: 99%

Mercury emissions from coal combustion in fluidized beds under oxy-fuel and air conditions: Influence of coal characteristics and O2 concentration

Izquierdo

Loscertales

Diego

et al. 2017

Fuel Processing Technology

View full text Add to dashboard Cite

In this work, the fate of mercury in a bubbling fluidized bed combustor working under oxy-combustion conditions has been studied and compared with air combustion. The influence of burning three different rank coals, with sulphur content ranging from 0.65 % to 5.17 %, on Hg partitioning has been studied. The presence of limestone as sorbent for SO 2 capture as well as the concentration of O 2 at the entrance of the combustor were also evaluated. Coal rank does not have a direct influence on coal partitioning. However, sulphur content of the coal is an important parameter to describe not only the high percentage of particle-bound mercury, up to 87 %, in presence of limestone but also the prevalence of Hg(0) as the main species in the gas phase when burning the lignite. The O 2 /CO 2 ratio has little effect on Hg partitioning in experiments carried out in presence of limestone at 925 ºC (the optimum temperature for sorbent sulphating under oxy-combustion conditions) and little differences are found with air combustion at 850 ºC (the optimum temperature for sorbent sulphating under air combustion conditions). Percentage of particle-bound mercury shows a maximum at 925 ºC independently of the coal studied, which it is related with the maximum sulphur retention for each coal at this temperature.

show abstract

“…The new oxy-combustion conditions may lead to certain changes with respect to conventional combustion conditions, which might involve modifications not only in the composition of the reactive gases (Normann et al, 2009;Liémans et al, 2011;Stanger and Wall, 2011;Ting et al, 2013), but also in the fate of the trace elements (Roy and Bhattacharya, 2014). Of the trace elements, mercury is the one of greatest concern because coal combustion is one of the major anthropogenic sources of mercury to the environment (Zhuang et al, 2011b;Roy et al, 2013).…”

Section: Introductionmentioning

confidence: 99%