CO2 Concentration In Flue Gas Research Articles

Application of Advanced Technologies for CO2 Capture From Industrial Sources

The great majority of the research on CO2 capture worldwide is today devoted to the integration of new technologies in power plants, which are responsible for about 80% of the worldwide CO2 emission from large stationary sources. The remaining 20% are emitted from industrial sources, mainly cement production plants (∼7% of the total emission), refineries (∼6%) and iron and steel industry (∼5%). Despite their lower overall contribution, the CO2 concentration in flue gas and the average emission per source can be higher than in power plants. Therefore, application of CO2 capture processes on these sources can be more effective and can lead to competitive cost of the CO2 avoided with respect to power plants. Furthermore, industrial CO2 capture could be an important early-opportunity application, or a facilitate demonstration of capture technology at a relative small scale or in a side stream.This paper results from a collaborative activity carried out within the Joint Programme on Carbon Capture and Storage of the European Energy Research Alliance (EERA CCS-JP) and aims at investigating the potentiality of new CO2 technologies in the application on the major industrial emitters.

Thermodynamic analysis of combined cycle gas turbine power plant with post-combustion CO2 capture and exhaust gas recirculation

Natural gas is expected to make up a significant proportion of the future global energy mix. Therefore, reducing greenhouse gas emissions from gas-fired processes is very essential for most countries, before emission reduction targets can be met. This article aims to carry out thermodynamic analysis of combined cycle gas turbine power plant with post-combustion CO2 capture through modelling and simulation. The combined cycle gas turbine power plant and the CO2 capture plant were simulated in Aspen Plus®. The combined cycle gas turbine power plant model was validated with simulation data from GateCycle® and the CO2 capture plant model was validated with experimental data from the pilot plant at the University of Texas at Austin. The CO2 capture plant was scaled up from pilot plant to commercial scale to process flue gas from a 250 MWe combined cycle gas turbine power plant. The integrated model for combined cycle gas turbine and CO2 capture plant was further used for performance study. Exhaust gas recirculation has been proposed to increase CO2 concentration in flue gas and reduce the flue gas flow rate. Its effect on combined cycle gas turbine power plant performance and capture plant sizing has been investigated. The analysis indicated that exhaust gas recirculation can reduce penalty on thermal efficiency without any major modification to the original power plant.

Performance of a Wet Flue Gas Desulfurization Pilot Plant under Oxy-Fuel Conditions

Oxy-fuel firing is a promising technology that should enable the capture and storage of anthropogenic CO2 emissions from large stationary sources such as power plants and heavy industry. However, this new technology has a high energy demand for air separation and CO2 compression and storage. Unresolved issues, such as determination of the optimal recycle location of flue gas, the flue gas cleaning steps required (SO2, NOx, and particles), and the impact of an oxy-fuel flue gas on the cleaning steps, also persist. The aim of this work was to study the performance of the wet flue gas desulfurization (FGD) process under operating conditions corresponding to oxy-fuel firing. The most important output parameters were the overall degree of desulfurization and the residual limestone concentration in the gypsum slurry. Pilot-scale experiments quantified that the introduction of a flue gas with 90 vol % CO2, at a holding tank pH 5.4, reduced the limestone dissolution rate significantly and thereby increased the residual, particulate limestone concentration in the gypsum slurry from 3.2 to 5.0 g/L slurry relative to a base-case (air-firing) experiment with a flue gas CO2 concentration around 7 vol %. In the same experiment, due to the higher residual limestone concentration, the degree of desulfurization increased from 91 to 94%. The addition of 10 mM adipic acid to the slurry was not sufficient to return the increased concentration of residual limestone to the base-case level, but an additional increase in desulfurization degree, from 94 to 97%, was obtained. Using a holding tank pH 5.0 (no adipic acid) returned both parameters to the levels observed in the base-case experiment.

Effects of the Temperature Bulge in CO2 Absorption from Flue Gas by Aqueous Monoethanolamine

Pilot plant data for CO2 absorption by aqueous monoethanolamine (MEA) were simulated with the RateSep model and a dynamic model implemented in gPROMS. RateSep is the second generation rate-based model in AspenPlus. Because of the phenomena of combined absorption and water vaporization and condensation, a temperature bulge will appear in the absorber. The present study addresses the effects of column parameters including L/G, heat of absorption, height of packing, and flue gas CO2 concentration. The temperature bulge is quantified by its magnitude and location and how these parameters affect the absorber performance. When the bulge is located in the top or bottom of the column, the magnitude is close to the limiting values of the temperature in the liquid and gas, respectively, leaving the column. The magnitude is maximized when the bulge is located approximately in the middle of the column. The absorber performance seems to be independent of the bulge location when it is located in the top or in the botto...

Characteristics of Flue Gases and Ash in Oxygen-Blown Pulverized Coal Combustion

A new coal combustion technology for a large-scale power plant is required to be applicable to various kinds of coal. An oxygen-blown pulverized coal combustion experiment was investigated with a bench scale apparatus to understand such characteristics as the combustion efficiency, NOx concentration, conversion from fuel-N, the unburned fraction and composition of mineral matter in the collected ash. The experiment was conducted in a down-fired, cylindrical and vertical furnace. The primary oxygen is injected into the ejector to carry coal particles to the burner, and the swirled secondary one is fed through an annulus. The CO2 concentration in flue gas was much higher than that of air–coal combustion, and the value was eight out of ten. The results made a feasible condition for CO2 separation and sequestration. The NOx emission was ranged in concentrations from 1650 to 1800 ppm in the complete combustion region. The NOx concentration was much higher, however the NOx conversion ratio was about the same level as the case of air combustion. The decrease of low-boiling component such as Na, Mg, K and Ca was identified because the flame temperature of the oxygen-blown coal combustion was achieved about 3000 K. We suggested the vaporized calcium components in the fly ash have a potential of the furnace desulfurization and the effect of SOx attack to the heat exchanger was inhibited.