Over the past several years, there has been a significant effort to bring corrosion monitoring into the realm of online, real-time management with plant process control technology. As part of this new direction in corrosion monitoring, corrosion data (e.g. information on corrosion rate, measured Stern Geary constant (or B value), and parameters for pitting and corrosion filming tendencies) are directed to the plant process control system. Availability of such online corrosion data in real-time by process and corrosion engineers along with key process variables facilitates optimal management of process/plant safety and reliability. This paper reviews this new corrosion monitoring approach and experience gained from two monitoring campaigns in a post combustion CO2 capture plant and identification of corrosion upsets and correlations with plant operating modes. It provides an indication of how real-time corrosion data can more specifically identify periods and causes of corrosion upsets that were previously "invisible" to process engineers facilitating quicker resolution and deployment of corrosion solutions with greater value than what was available with offline, reactive older corrosion monitoring approaches.@en

Degradation of amines is one of the most important issues to be addressed for absorption-desorption based post-combustion CO2 capture. Several laboratory studies have been performed to identify the degradation products and understand the mechanisms of degradation. However, there seems to be a gap in knowledge from translating the lab scale studies to observations from the pilot campaigns. Moreover, the observations from different pilot plant campaigns can be quite different. The objective of this study is to compare the solvent degradation behavior from different campaigns and highlight their causes in terms of solvent metal content and ammonia emissions. Results from the following different pilot plants are evaluated: (a) TNO's CO2 capture plant at Maasvlakte, the Netherlands, (b) EnBW's CO2 capture plant at Heilbronn, Germany and (c) ENEL's CO2 capture plant at Brindisi, Italy. The different rate of oxidative degradation are correlated to the different operating conditions and layout of the pilot plants. Along with these results, kinetic models based on laboratory studies are used to compare the pilot plant observations, highlighting the differences between lab-scale studies and pilot plant studies.@en

The amine-based post combustion carbon capture process is one of the most advanced and preferred technologies to reduce CO2 emissions from point sources like power plants. The emissions of amine from capture plants is one of the biggest challenges faced by this technology. These emissions typically occur by means of aerosol/mist formation. To develop effective countermeasures, it is crucial to understand the dynamic behavior of aerosols within the column, which is currently not well understood. This manuscript presents the results from a study aiming to understand the mechanism of aerosol growth and its behavior along the absorber column in terms of particles number concentration, particle size distribution, and amine emissions. For that, a series of experiments were performed in TNO’s bench scale CO2 capture plant using 30 wt% monoethnolamine (MEA) as solvent. For a SO3 and CO2 concentrations of 5.25 ppm and 12.5 vol.% in the flue gas, MEA emissions at the top exit of the column were recorded as 1051 mg/Nm3 (with vapour emissions of 381 mg/Nm3). In the absence of SO3 in the flue gas, inlet particle concentration was 2.71 × 107/cm3 and resulting MEA emissions reduced by 63.5%–383 mg/Nm3. From the bottom of the column until the point of maximum temperature, the MEA content in the vapour phase was consistent with the volatility of the solvent. After this point it drastically increases to 1051 mg/Nm3. Both the number of particles and the total particle mass has lowered from the bottom to the top of the column. For the benchmark test, inlet and outlet total particle concentration were found to be 6.24 × 107/cm3 and 2.3 × 107/cm3 respectively, while total particle mass is 2.22 mg/m3 at inlet and 1.32 mg/m3 at outlet. Particles with a dimeter below 0.006 μm contribute the most to total particle concentration both at the inlet (50%) and outlet (32%), while particles with diameter of 0.087 μm contributes the most to the total particle mass at inlet (47%) and outlet (55%). The measured total mass of particles was in the order of magnitude of 1 mg/m3. This is much lower than the expected aerosol mass emissions, in the order of magnitude of 1 g/Nm3 based on FTIR emissions. No particles larger than 0.147 μm were recorded, which might explain the low total mass recorded. The cause for this is still under investigation, but it suggests that the sampling procedure may induce systematic errors to the measurements. Nonetheless, the observations from this study have given further insight into the aerosol dynamics in the absorber column and corresponding emissions.@en

Aerosol based emissions have been reported from several Post-Combustion CO2 capture (PCCC)pilot plants. These are known to pose a significant challenge in large scale implementation of PCCC processes. The aerosol nuclei are in the form of H2SO4 droplets or Na2SO4 particles, typically less than 0.1 μm and 0.255 μm, respectively. A wet electrostatic precipitator (WESP)is considered to be a potential counter-measure for removing these ultrafine aerosol nuclei from the flue gas. However, it has been observed that at certain operating conditions of the WESP, additional particles are formed which can act as aerosol nuclei. This study was performed to find out the specific operating conditions in terms of feed SO2 concentration and applied WESP voltage, at which WESP results in generation of new particles. In the absence of SO2, no additional particles are formed for the entire range of applied WESP voltage. At the lowest SO2 concentration of 9 ppmv, additional particles were generated beyond 10 kV. The smallest size fractions contribute to more than 99% of the total number of particles, with 0.006 μm contributing to more than 80%. At the outlet of the absorber, although majority of the particles are of 0.006 μm (>60%)and 0.0158 μm (ca. 5%), larger particles of sizes 0.0945 to 0.945 μm, contributes to the remaining 35% of the total number. The shift in number distribution results in increase of aerosol mass from about 10−4 to 5 × 10-3 mg/m3 to 0.2 to 0.5 mg/m3, from the inlet to the outlet of the absorber, respectively. Aerosol based MEA emissions were observed for the lowest SO2 concentration of 9 ppmv and a voltage of 16 kV. Total MEA emissions were in the range of 600–1050 mg/Nm3. Based on these tests, industrial scale WESPs are likely to result in additional particles which can act as aerosol nuclei even at a SO2 concentration as low as 9 ppmv. Additional tests aimed at SO2 concentration lower than 9 ppmv in the feed gas, combinations of varying H2SO4 aerosol and SO2 in feed gas, and varying flue gas velocity needs immediate attention to define the operating limits for WESP.@en

Oxidative degradation is a serious concern for upscaling of amine-based carbon capture technology. Different kinetic models have been proposed based on laboratory experiments, however the kinetic parameters included are limited to those relevant for a lab-scale system and not a capture plant. Besides, most of the models fail to recognize the catalytic effect of metals. The objective of this work is to develop a representative kinetic model based on an apparent auto-catalytic reaction mechanism between solvent degradation, corrosion and ammonia emissions. Measurements from four different pilot plants: (i) EnBW's plant at Heilbronn, Germany (ii) TNO's plant at Maasvlakte, The Netherlands; (iii) CSIRO's plants at Loy Yang and Tarong, Australia and (iv) DONG Energy's plant at Esbjerg, Denmark are utilized to propose a degradation kinetic model for 30 wt % ethanolamine (MEA) as the capture solvent. The kinetic parameters of the model were regressed based on the pilot plant campaign at EnBW. The kinetic model was validated by comparing it with the measurements at the remaining pilot campaigns. The model predicted the trends of ammonia emissions and metal concentration within the same order of magnitude. This study provides a methodology to establish a quantitative approach for predicting the onset of unacceptable degradation levels which can be further used to devise counter-measure strategies such as reclaiming and metal removal.@en

We report on a detailed study of emissions from a pilot-plant for CO 2 capture at Maasvlakte (in the Netherlands). Three contributions to emissions were identified and analyzed: Gas phase emission, aerosols (also referred to as mist or fog) and droplets of entrained solvents. For the emission campaign at Maasvlakte aerosols were found to be the major contributor to overall emissions. Entrainment was found to be a very small contributor to overall emissions. A Brownian demister unit (BDU) was tested as an emission reducing technology. It was found to be very efficient in reducing aerosol emissions.@en

The company Carbon Clean Solutions (CCS) has developed a variety of energy efficient solvents and processes such as PCCMax, which aim to reduce the overall operating and capital cost of CO2 capture. Highly successful R&D in collaboration with TNO, considering aspects from fundamental properties such as VLE and current work has been focused on developing energy efficient chemical solvents and addressing solvent management aspects such as solvent degradation, corrosion and emissions. CCS demonstrated their solvent technology at TNO's 6 MTPD (metric tons per day) CO2 capture pilot plant connected to a coalfired power plant from E.ON, Maasvlakte near Rotterdam. The advanced novel solvent APBS was compared with conventional solvents in terms of CO2 absorption capacity, energy, cyclic capacity and absorption kinetics over 1000 operation hours. This APBS solvent was specifically developed to capture CO2 from flue gas emissions from coal based power plants. This solvent system is based on an innovative combination of solvent components used to overcome the particular weaknesses of the state of art CO2 capture solvents. Useful performance data and operational experience was obtained for the continued development of the CCS's PCCMax technology. A well designed test plan was successfully executed during this testing period to obtain detailed solvent performance and optimization data. Importantly process data was collected to validate thermodynamic and process models. Thus, validated CCS simulation modelscan beused for the further scale up of the technology. This article provides general description of results and operating experiences in the areas of solvent handling, solvent performance which includes long term stability testing, energy demand, solvent degradation, corrosion and emissions testing as compared to benchmark solvent monoethanolamine (MEA) and CESAR1 solvent previously tested on same EON, Maasvlakte CO2 capture facility for 90% CO2 capture from power plant flue gas. Mainly focused on measuring overall regeneration energy, detailed metal content analysis (to predict the corrosivity), detailed overall oxidative and thermal degradation and gas emission characterization including aerosols and nitrosamine emissions. Energy consumption of the solvent system per ton of CO2 captured with a standard flowsheet is around 2.5 GJ per tonne of CO2. However, due to the solvent matrix novel flowsheet options can be used to further reduce energy consumption. Moreover, the solvent is compared to MEA at least a factor of 10 more stable. Next to that, aerosol based emission of the APBS solvent as compared to MEA is negligible. Details of the measurement campaign will be further elaborated in our contribution.@en

Amine based solvent used for SO4 capture can be lost during the process due to: degradation, vaporization, mechanical losses and aerosol (mist) formation. Only recently, studies have appeared pointing out that aerosols can dominate the total amine emission at pilot plant scale behind coal fired power plants. Future full scale amine scrubber installations will be imposed emission limit values (ELV) for a number of components including NH3 and the amine itself. Most likely these ELV will be expressed as maximum concentrations tolerated in the SO4 poor flue gas leaving the stack so it is important to prevent or cure amine aerosol emission. The study presents a novel combination of two existing measurement techniques, that measure: (i) amine emissions from the top of the absorber using FTIR and (ii) PSD of the incoming flue gas using the ELPI+. The study is the first to show how combining these two measurement techniques allows to predict the presence or absence of mist formation. This hypothesis is based on information obtained during several measurement campaigns on different pilot plants.@en