Estimation of atmospheric carbon sequestration rate through carbonate rock dissolution in Karst Jonggrangan, Java Island, Indonesia (case study: the underground river of Anjani Cave)

PURPOSES: In this study, alkali-activated blast-furnace slag (AABFS) was investigated to determine its capacity to absorb carbon dioxide and to demonstrate the feasibility of its use as an alternative to ordinary Portland cement (OPC). In addition, this study was performed to evaluate the influence of the alkali-activator concentration on the absorption capacity and physicochemical characteristics. METHODS: To determine the characteristics of the AABFS as a function of the activator concentration, blast-furnace slag was activated by using calcium hydroxide at mass ratios ranging from 6 to 24%. The AABFS pastes were used to evaluate the carbon dioxide absorption capacity and rate, while the OPC paste was tested under the same conditions for comparison. The changes in the surface morphology and chemical composition before and after the carbon dioxide absorption were analyzed by using SEM and XRF. RESULTS: At an activator concentration of 24%, the AABFS absorbed approximately 42g of carbon dioxide per mass of paste. Meanwhile, the amount of carbon dioxide absorbed onto the OPC was minimal at the same activator concentration, indicating that the AABFS actively absorbed carbon dioxide as a result of the carbonation reaction on its surface. However, the carbon dioxide absorption capacity and rate decreased as the activator concentration increased, because a high concentration of the activator promoted a hydration reaction and formed a dense internal structure, which was confirmed by SEM analysis. The results of the XRF analyses showed that the CaO ratio increased after the carbon dioxide absorption. CONCLUSIONS : The experimental results confirmed that the AABFS was capable of absorbing large amounts of carbon dioxide, suggesting that it can be used as a dry absorbent for carbon capture and sequestration and as a feasible alternative to OPC. In the formation of AABFS, the activator concentration affected the hydration reaction and changed the surface and internal structure, resulting in changes to the carbon dioxide absorption capacity and rate. Accordingly, the activator ratio should be carefully selected to enhance not only the carbon capture capacity but also the physicochemical characteristics of the geopolymer.

Present work analyzes the behavior of several gas-liquid-liquid systems for carbon dioxide separation using chemical absorption. The type of amine center in a solvent with two liquid phases (organic and aqueous) shows a high importance in relation to the overall behavior. The experimental results for these solvents have been compared with a previous study using octylamine in the chemical solvent because it has shown suitable results for carbon dioxide loading, absorption rate and energy cost associated to solvent regeneration. Present study analyzes the carbon dioxide absorption mechanism in multiphasic reactors (specifically G-L-L) using different types of amines in order to understand the overall behavior that involves steps of mass transfer and chemical reaction.

Выполнены измерения чистого экосистемного обмена (NEE) на мочажинном участке грядовомочажинного комплекса олиготрофного болота «Мухрино» с разделением на составляющие компоненты: валовую первичную продукцию (GPP) и дыхание экосистемы (R eco ). Измерения проводились в течение самого тёплого (июль), переходного (сентябрь) и самого холодного (октябрь) месяцев летне-осеннего сезона методом автоматизированных камер с 30-минутным интервалом. Это позволило получить подробную информацию о суточном ходе и сезонной динамике показателей. Для исследованных месяцев по отдельности и полевого сезона в целом осуществлен корреляционный анализ связи между гидрометеорологическими параметрами и величиной потоков. Для дыхания экосистемы (R eco ) наиболее высокий уровень корреляции за сезон выявлен с температурой почвы (0.88), температурой воздуха (0.71) и уровнем болотных вод (-0.73); за июль наиболее сильная корреляция выявлена с температурой воздуха (0.70) и температурой почвы (0.68); за сентябрь -с температурой почвы (0.81) и уровнем болотных вод (-0.78); за октябрь -с фотосинтетически активной радиацией (-0.59). Валовая первичная продукция (GPP) сильнее всего коррелирует с фотосинтетически активной радиацией (PAR) -в июле коэффициент корреляции равен -0.95, в сентябре -0.86, в октябре -0.79, в целом за полевой сезон -0.89. Чистый экосистемный обмен (PAR), аналогично GPP, наиболее тесно связан с PAR. В июле коэффициент корреляции NEE и PAR составляет -0.91, в сентябре -0.74, в октябре -0.71, за весь полевой сезон -0.73. Стоит подчеркнуть, что для каждого рассматриваемого месяца влияние внешних факторов на потоки уменьшается с течением времени от июля к октябрю, достигая минимума корреляции в самом холодном месяце. Ключевые слова: Дыхание экосистемы (R eco ); валовая первичная продукция (GPP); чистый экосистемный обмен (NEE); фотосинтетически активная радиация (PAR); LI-8100A; уровень грунтовых вод (WTL); автоматические камеры; Мухрино; болотные экосистемы Западной Сибири; круговорот углерода. Global climate change is one of the most important and promising phenomena to study in actual time. One of the key causes of global climate change is increasing the greenhouse gas (GHG) concentrations in the atmosphere [IPCC, 2023]. The main greenhouse gases are methane, carbon dioxides and nitric oxide, which contribute to the greenhouse effect and global warming [Lashof, Ahuja, 1990] . Carbon dioxide (CO 2 ) is one of the most significant and widespread gases involved in the planet's global carbon cycle [Lashof, Ahuja. 1990] . At the same time, living organisms play a key role in creation of atmosphere composition. Autotrophic organisms use a carbon dioxide to build their body structures, including complex organic compounds. During ecosystem functioning, the part of the carbon dioxide is released into the atmosphere through organism respiration, while another part is released through the decomposition of dead organic matter. Carbon dioxide may also be produced through natural and anthropogenic processes. Peatland ecosystems play a significant role in the planet's carbon cycle, both locally and globally. Peatlands in their natural undisturbed state are a significant long-term carbon sink 1 . However, the process of carbon deposition is not constantin different years, peatlands may serve either as carbon sink or source 2 . The main factor stimulating the carbon sequestration by peatland ecosystems is climatic conditions [Harenda et al., 2018; Bond-Lamberty et al., 2018] . Peatlands are the second most significant carbon stock on Earth and the largest on land. Despite covering only 2.84% of the Earth's land surface, the amount of soil organic carbon stored in them accounts for about one-third of all soil organic carbon on Earth. Peatlands in the northern hemisphere play a particularly important role in carbon sequestration, with an estimated accumulated carbon quantity of ~473-621 Gt of carbon [Yu et al., 2010] . The largest area of peatlands in Russia is located in Western Siberia, estimated at ~42% of the total Russian area [Vomperskiy et al., 1994; Sheng et al., 2004]. The territory of Western Siberia is featured to a high share of peatlands in original undisturbed state, making them an ideal location to study the impact of global changes on peatland biogeochemical functioning worldwide. The carbon balance of peatlands is mainly determined by two processes: photosynthesis and respiration [Harenda et al., 2018] . The main factors influencing the CO 2 flux from peatlands are photosynthetically active radiation, atmospheric air temperature (T avg ), soil temperature (T soil ), and water table level (WTL) [Miao et al., 2013;

Absorption of carbon dioxide in O/W emulsion absorbent: Kinetics of absorption in N-methylcyclohexylamine and 2,6-dimethylpiperidine emulsion

Comparison of Carbon Dioxide Absorption Rates in Gynecologic Laparoscopy with a Valveless versus Standard Insufflation System: Randomized Controlled Trial

Chemical absorption into concentrated slurry: Absorptions of carbon dioxide and sulfur dioxide into aqueous concentrated slurries of calcium hydroxide

Absorption of carbon dioxide into carbonate solution (Na2CO3) with PAM (non-Newtonian fluid) has been performed in a countercurrent packed column (0.075m i.d. ×1.25 m height) packed with glass Raschig rings (1×1cm) to a depth of 1m. The influence of liquid flow rate, gas flow rate, liquid temperature, and polyacrylamind (PAM) concentration on the absorption rate, overall mass transfer coefficient and the reaction kinetics regime are studied at constant carbonate concentration and atmospheric pressure. The results show that the absorption rate and overall mass transfer coefficient increases with increasing liquid flow rate and temperature. The mass transfer coefficient decreases with increasing gas flow rate while the absorption rate of carbon dioxide is virtually independent of gas flow rate. This indicates that carbon dioxide absorption is liquid film controlled. Increasing PAM concentration results of reduction of absorption rate and overall mass transfer coefficient. The reaction kinetics between carbon dioxide and carbonate solution with PAM was obtained as a pseudo first order reaction (Hatta number, Ha >>1).

In this research, thermodynamic and absorption rate of carbon dioxide in monoethanolamine (MEA) solution was investigated. A correlation based on both liquid and a gas phase variable for carbon dioxide absorption rate was presented using the π-Buckingham theorem. The correlation was constructed based on dimensionless numbers, including carbon dioxide loading, carbon dioxide partial pressure, film parameter and the ratio of liquid phase film thickness and gas phase film thickness. The film parameter is used to apply the effect of chemical reactions on absorption rate. A thermodynamic model based on the extended-UNIQUAC equations for the activity coefficients coupled with the Virial equation of state for representing the non-ideality of the vapor phase was used to predict the CO2 solubility in the CO2-MEA-H2O system. The average absolute error of the results for the correlation was 6.4%, which indicates the accuracy of the proposed correlation.

It is widely accepted that increasing carbon dioxide (CO2) emissions to our atmosphere is the major contributor to global climate change, which pollutes environment. The chemical absorption using tertiary alkanolamines solution is one of most important method, which have been proposed and studied for the removal of carbon dioxide because the MDEA solvent has low cost, low corrosive tendencies, high stability, low viscosity, low tendency to foam, and low flammability, however it has low reaction rate. Therefore, we added glycine promoter to conventional solvents to increase the rate of the reaction because glycine is a primary amine compound which is reactive. Moreover, glycine has resistance to high temperatures; so, it will not easy to degrade making it not suitable for application in industry. The main purpose of this study was to provide reaction kinetics data of CO2 absorption into glycine promoted methyldiethanolamine (MDEA) by using laboratory scale wetted wall column equipment at the atmospheric pressure by varying temperature from 303.15 to 328.15 and glycine concentration from 1% to 3%, while the carbon dioxide absorption rate was measured by titration of liquid effluent. Based on the result of this study, we observed that by increasing temperature and concentration of glycine, the absorption rate of carbon dioxide in MDEA solution was increase. In addition, the reaction rate constant will be affected by the temperature and the concentration of promoter. The correlation of reaction rate constant (k glycine) was: k glycine = 5.3409E+13exp(-3251.9/T) with the activation energy for glycine promoter is 27.0363kJ/kmol, indicating it a very influencing, compared to diethanolamine (DEA).

Dry forests in semi-arid region plays important roles in humans’ life, whether it is socially, economically, or ecologically. Most of the time, it is very difficult to maintain the equilibrium of those roles, especially in developing-country where the economic role is more exploited than the other roles. This mismanagement of forests would lead to the situation where the forest will be in rapid retreat. On the other hand, maintaining as well as increasing the forests is the most essential solution for climate change, as forests play integral part on carbon sequestration therefore stabilizing the climate. In carbon sequestration, plants incorporate carbon from atmospheric carbon dioxide (CO2) through photosynthesis then storing it in biomass and soil. As each vegetation has different capacity to store carbon, this study tries to estimate the absorption rate of carbon dioxide (CO2) and the potential carbon storage of Borneo camphor (Dryobalanops aromatica) and Kesambi (Schleichera oleosa) in Oebatu Dano Ina forest (RTK.24) Pantai Baru sub-district, Rote Ndao district, Nusa Tenggara Timur province. The result shows carbon storage range of 6.51–42.998 ton/ha for both vegetation with average of 0,135–1,791 ton/ha for each tree, while the average of carbon dioxide (CO2) absorption rate is 0,498–6,575 ton/ha for each tree.

Carbon dioxide chemical absorption using methylpiperidines aqueous solutions

Laboratory differential simulation design method of pressure absorbers for carbonization of phenolate solution by carbon dioxide in coal-tar processing

A hydrogeochemical and isotopic study was conducted on the subterranean karst stream, namely the Guancun subterranean stream (GSS). The hydrogeochemical processes of the GSS were controlled through calcite dissolution and precipitation and were driven by the concentration of CO2, which controlled changes in the pH and of PCO2 in the water. The δ18O and δD values of the GSS were within the global meteoric water line and the local meteoric water line, thereby indicating that the water of the GSS comes from precipitation. Certain abnormal δ18O and δD values suggest the effect of evaporation on the GSS given its use in a particular irrigation system, wherein the GSS in transformed into a surface stream and flows for a relatively long time on the surface during the wet season. The δ13CDIC values of the GSS range from −13.5 to −11.3‰ in the dry season and from −13.9 to −9.5‰ in the wet season, thereby indicating that the GSS belongs to a semi-open system. The δ13CDIC values in the GSS were formed by the δ13CDIC values of the soil CO2 and carbonate dissolution at different proportions. According to the simplified mass balance formula, the contributions of carbonate dissolution to the dissolved inorganic carbon (DIC) of the GSS were calculated to be 50.2–58.3% and 48.7–64.7% in the dry and wet seasons, respectively, thereby indicating a less than 50% carbonate dissolution contribution during the formation of DIC in karst groundwater. Moreover, sulfuric acid and nitric acid were observed to participate in karst processes.

In this research, the reactive absorption of carbon dioxide in an aqueous solution of NH3, H2O, and NaOH has experimentally been investigated. The experiments were carried out in an absorption pilot plant in different operational conditions. The composition and temperature of both gas and liquid phases were obtained during the column height. The concentration of molecular and ionic species in the liquid phase was calculated using the principles of electrolyte and Pitzer model. In the experiments, the effect of sodium hydroxide concentration on carbon dioxide absorption was considered. The results revealed that the concentrations of ionic and molecular species in the liquid phase drastically influence the absorption rate of carbon dioxide. Also, the results showed that the absorption rate of carbon dioxide was increased by increasing ammonia and sodium hydroxide concentration.

NMR Studies in Carbon Dioxide – Amine Chemical Absorption