High Amounts Of CO2 Research Articles

Optimization of the Efficiency in a Syngas Powered Si Engine Through Numerical Studies Related to the Geometry of the Combustion Chamber

The combustion process occurring in an alternative Spark Ignition (SI) engine powered with bio-syngas from biomass gasification was previously studied by authors through the development of two different numerical models: a 0-1D model developed in the GT-Suite® environment, aimed at gaining a first look upon the main features of the heat release by the syngas and engine performances; a 3D Computational Fluid Dynamics (CFD) model developed within the AVL FireTM software reproducing the engine combustion cycle within a Reynolds Averaged Navier Stokes (RANS) schematization and employing a detailed chemical reaction mechanism to highlight the interaction between the fluid dynamics and the kinetics of the specific biofuel oxidation chain. The numerical results were validated with respect to experimental measurements in a baseline condition, where the presence of a relatively high amount of CO in the exhaust gases was noticed as related to an engine low combustion efficiency, mainly due to the peripheral spark plug position that determines the persistence of residual gases on the opposite side of the combustion chamber wall.The proposed work presents a numerical analysis made through the developed models on the effects of proper changes in the spark plug position. A multi-objective optimization problem is conducted also by varying the Start of Spark (SOS) and the mixture air-to-fuel ratio with the aim of reducing the engine environmental impact without affecting its performances. A centrally mounted spark, along with a correct calibration of the SOS and mixture ratio, allows a reduction of more than 90% of CO emission with respect to the baseline condition without penalizing the engine brake power and efficiency.

Techno-economic evaluation of membrane and enzymatic-absorption processes for CO2 capture from flue-gas

A large part of the global energy is supplied through fossil-fuel power plants which release a high amount of CO2 into the atmosphere. As long as this energy pattern prevails in the world, concerns about climate change due to sudden rise in the content of green-house gasses (GHGs) might be alleviated only through retrofitting the power plants to CO2 capture units. Gas separation methods such as amine-based absorption could be suggested to hit this target but they could result in a costly and highly intensive process. This study analyzes the integration of a 600 MWe power plant with two promising methods, including membrane technology and enzymatic-absorption process. A techno-economic analysis is then carried out to demonstrate the technical viability and economic efficiency of these two methods compared to traditional separation processes. It is found that the electricity losses are estimated at 95 and 89 MW respectively, to capture 90% of the CO2 which is as low as 15% of the output power. This study also presents cost optimization results including capital and operation expenditures for each method. In comparison, enzyme-based absorption is more economically attractive and results in a lower CO2 capture cost. Overall, this study allows to recognize bottlenecks in each process and then proposes initiatives to improve the capture efficiency.

Dolomite-supported Cu2O as heterogeneous photocatalysts for solar fuels production

The photocatalytic conversion of CO2 is a sustainable process to produce solar fuels. Also, this process would help to reduce the CO2 concentration to mitigate the global temperature and could partly fulfill energy demands. To achieve this, Cu2O photocatalyst represents an excellent option to convert the CO2 molecule into solar fuels. However, its capacity to adsorb CO2 is limited. Thus, it is necessary to support the photocatalyst in materials that provided strong basic active sites to adsorb CO2 spontaneously. In this case, dolomite is an earth-abundant material that contains alternating planes of Ca2+ and Mg2+ with the potential to be used as photocatalyst-support. Herein, for the first time, Cu2O was supported on an activated-dolomite via a microwave-hydrothermal method. The resulting materials were characterized by XRD, SEM, HRTEM, PL, FTIR, DRS, N2 physisorption, and Raman spectroscopy. Cu2O supported on activated-dolomite (Cu/DA) was evaluated in the photocatalytic CO2 conversion to solar fuels (CH3OH and HCOH) under LED-visible light, and its capacity to adsorb CO2 was evidenced by gas chromatography. The dolomite-activated sample (DA) exhibited high surface area (125 m2 g−1), low spherical and homogeneous particle size (200 nm), and small pore diameter (<2 nm), which contribute to a high amount of CO2 adsorbed (180 mgCO2 g−1). This result was also related to the presence of the crystalline phases presented (Mg(OH)2 and SiO2) in the DA sample. Regarding solar fuels generation, pure-Cu2O resulted in the highest HCOH production (419 μmol g−1 h−1) with a low amount of CH3OH generated (11 μmol g−1 h−1). After supported Cu2O in DA, CH3OH generation (38 μmol g−1 h−1) was favored up to 3.4 times. The selectivity for CH3OH generation was correlated to a more efficient charge transfer and the formation of unidentate carbonate species on Cu/DA sample, which was demonstrated by PL and FTIR analysis, respectively.

Experimental Validation of a Multidimensional Model for an Indirect Temperature Swing Adsorption Unit

AbstractConventional temperature swing adsorption (TSA) is mainly applied for the removal of trace contaminants. Indirectly heated and cooled adsorbers were developed to make bulk separation economically feasible. A quasi‐continuous TSA process to remove CO2 from an N2/CO2 mixture with a pilot plant is established. The experimentally determined data are taken to validate and to adjust a 2D simulation model. For the validation, the CO2 desorption, the N2 recovery rate as well as the axial temperature profile are compared. The successful model validation can be seen in the good agreement between simulation and experimental results. Moreover, this process is able to separate high amounts of CO2 and to produce a nearly CO2‐free product stream.

Au core stabilizes CO adsorption onto Pd leading to CO2 production

Au core and Pd shell supported on carbon structure Au@Pd/C can cleave the C–C bond of ethanol molecules leading to the production of a relatively high amount of CO2 when compared with Pd/C electrocatalyst as the attenuated total reflectance - Fourier transform infrared (ATR-FTIR) experiment shows. Density functional theory (DFT) calculations showed that this could be explained by the oxidation of CO species adsorbed into Pd sites that has a modified electronic structure compared with Pd/C. In terms of DFT analysis, the highest thermodynamical stability of CO in Pd shell with Au core atoms, when compared with Pd/C is because of the increase of virtual orbital states near Fermi level that can be occupied by valence electrons of CO molecule. The d-band center shift is experimentally verified using the valence band X-ray photoelectron spectroscopy and theoretically predicted by the Generalized Koopmans’ Theorem. Besides that, Au@Pd/C electrocatalyst has a better electrochemical activity when compared with Pd/C.

Review of CO2 injection techniques for enhanced shale gas recovery: Prospect and challenges

CO2 injection is a promising technique that not only enhances shale gas recovery but also achieves geological storage of CO2. This paper reviewed the performance of CO2 injection techniques based on simulations and field test studies. We observed that CO2 injection can be practical and successful in a hydraulically fractured shale. The techniques can lead up to 26% more methane production after primary recovery, and sequester more than 60% of the injected CO2 for continuous CO2 injection, while for huff-n-puff higher amount of CO2 is reproduced. Reservoir pressure gradient, competitive adsorption, flow dynamics, and shale properties were found as essential factors controlling CH4 recovery and CO2 storage. Despite the flow dynamics of gases being important for predicting gas production and storage, most simulations described it based on models suitable for well connected fractures and homogenous shale. Moreover, these models are incapable of analyzing fluid flow in stimulated fractures. Future studies on CO2 injection should address the issue of higher CO2 reproduction during the huff-n-puff, the effects of moisture content, induced effects on shale matrix properties by CO2 injection, the kinetics of CO2–CH4 competitive adsorption, flow dynamics of multicomponent gas, and consider the complex pore system of a heterogeneous shale.

Enrichment of Anaerobic Syngas-Converting Communities and Isolation of a Novel Carboxydotrophic Acetobacterium wieringae Strain JM.

Syngas is a substrate for the anaerobic bioproduction of fuels and valuable chemicals. In this study, anaerobic sludge was used for microbial enrichments with synthetic syngas and acetate as main substrates. The objectives of this study were to identify microbial networks (in enrichment cultures) for the conversion of syngas to added-value products, and to isolate robust, non-fastidious carboxydotrophs. Enrichment cultures produced methane and propionate, this last one an unusual product from syngas fermentation. A bacterium closely related to Acetobacterium wieringae was identified as most prevalent (87% relative abundance) in the enrichments. Methanospirillum sp. and propionate-producing bacteria clustering within the genera Anaerotignum and Pelobacter were also found. Further on, strain JM, was isolated and was found to be 99% identical (16S rRNA gene) to A. wieringae DSM 1911T. Digital DNA-DNA hybridization (dDDH) value between the genomes of strain JM and A. wieringae was 77.1%, indicating that strain JM is a new strain of A. wieringae. Strain JM can grow on carbon monoxide (100% CO, total pressure 170 kPa) without yeast extract or formate, producing mainly acetate. Remarkably, conversion of CO by strain JM showed shorter lag phase than in cultures of A. wieringae DSM 1911T, and about four times higher amount of CO was consumed in 7 days. Genome analysis suggests that strain JM uses the Wood-Ljungdahl pathway for the conversion of one carbon compounds (CO, formate, CO2/H2). Genes encoding bifurcational enzyme complexes with similarity to the bifurcational formate dehydrogenase (Fdh) of Clostridium autoethanogenum are present, and possibly relate to the higher tolerance to CO of strain JM compared to other Acetobacterium species. A. wieringae DSM 1911T grew on CO in medium containing 1 mM formate.

Transient multiphase flow modeling and validation in a real production system with high CO2 content using the drift-flux model

This study presents a transient multiphase flow simulator based on the non-isothermal Drift-Flux model that aims to reproduce oil and gas production systems. The mathematical model consists of three mass conservation equations, one equation for the momentum mixture and one equation to reproduce the energy conservation of the gas-liquid-liquid mixture, assuming mass transfer between the produced liquid and gas phases and neglecting the slip between the liquid phases. The solver utilizes the finite volume method with a semi-implicit approach making use of the upwind first order scheme with staggered grid. Liquid holdup and liquid amount between the liquid phases are evaluated explicitly whereas the coupling between velocities and pressure fields is implicit by building a global matrix. The temperature field is obtained in an uncoupled way after the volumetric fraction, mass flow rates and pressure calculus. For the sake of validation of the solver, the simulated profiles of pressure, temperature and liquid holdup along the production line are compared with those given by the reference benchmark for multiphase flow simulation in the Oil & Gas industry, OLGA® (OiL and GAs simulator), and real field data in the steady-state regime of an offshore oil producer well with high CO2 content. The influence of input parameters on the simulation results is investigated. A sensitivity analysis is performed on the fluid modeling, considering the Black-Oil model making use of two different Rs correlations and the compositional approach. The influence of drift parameters on the numerical solutions is also verified. Liquid holdup, pressure and temperature trends are analyzed upstream and downstream of the master valve as well as in the well bottom and on the separator regions. Finally, important production procedures such as well shutdown and start-up are analyzed. The main motivation is to verify the solver capability to reproduce the multiphase flow behavior during the oil and gas production, especially for a fluid with high GOR and high amount of CO2.

Sugar Beet Agronomic Performance Evolution in NW Spain in Future Scenarios of Climate Change

Changes in environmental conditions resulting from Climate Change are expected to have a major impact on crops. In order to foresee adaptation measures and to minimize yield decline, it is necessary to estimate the effect of those changes on the evapotranspiration and on the associated irrigation needs of crops. In the study presented herein, future conditions extracted from RCP4.5 scenario of IPCC, particularized for Castilla-y-León (Spain), were used as inputs for FAO crop simulation model (AquaCrop) to estimate sugar beet agronomic performance in the medium-term (2050 and 2070). A regional analysis of future trends in terms of yield, biomass and CO2 sequestration was carried out. An annual ET0 increase of up to 200 mm was estimated in 2050 and 2070 scenarios, with ETc increases of up to 40 mm/month. At current irrigation levels, temperature rise would be accompanied by a 9% decrease in yield and a ca. 6% decrease in assimilated CO2 in the 2050 and 2070 scenarios. However, it is also shown that the implementation of adequate adaptation measures, in combination with a more efficient irrigation management, may result in up to 17% higher yields and in the storage of between 9% and 13% higher amounts of CO2.

Present Status on Distribution, Biodiversity and Management of Indian Mangroves

Globally, mangroves are one of the most productive and threatened ecosystems situated within the intertidal zones of tropics and subtropics. Mangrove ecosystem of India is unique with the highest record of biodiversity, gifted with the mangrove genetic bliss at Bhitarkanika, and wildlife threatened species in the Sundarbans. They act as a guardians of juvenile stock and important source of livelihood for coastal communities andprotect from storm surges and tsunami. Mangroves are also a great source for carbon sinks and sequester the high amount of CO2. Mangrove ecosystems are vulnerable to various anthropogenic actions such as industry, agriculture, solid waste dumping, aquaculture ponds, construction of buildings and infrastructures. In recent years, the conservation of mangrove reserves and habitats has assumed great significance in developing countries. This article deals with the present status of mangroves biodiversity, conservation and management strategies for restoration of these fragile ecosystems.

Bioenergetic potential of Ponkan peel waste (Citrus reticulata) pyrolysis by kinetic modelling and product characterization

The purpose of this study is to investigate the kinetic and products of the pyrolysis of Ponkan peel waste (Citrus reticulata) to determine its bioenergy potential. Pyrolysis runs were performed under an inert environment at 5, 10 and 15 °C min−1 in a macro-TGA coupled to a GC-FID/TCD for analysis of non-condensable gases (CO, CO2, CH4 and H2), while the condensable gases were collected by a cold trap and analyzed in a GC/MS. The kinetic study was performed by a multi-step mechanism using the Vyazovkin method, compensation effect and master plot. Pyrolysis occurred mainly between temperatures of 130–400 °C, where the release of a high amount of CO2 and CO was observed, while CH4 and H2 were detected at temperatures >400 °C. The condensable fraction is represented mainly by furan, acids, ketones and phenol compounds, which account for 84.68% of the condensable gases. The kinetic parameters (Ea, A and f(α)) fit the reaction model for geometrical contraction and n-order, which satisfactorily described the pyrolysis of Ponkan peel waste.

Insight into graphite oxidation in a NiO-based hybrid direct carbon fuel cell

A direct carbon fuel cell is an electricity generation device using solid carbon as a fuel directly with no reforming process. In this study, three-carbon fuels, graphitic carbon (GC), carbon black (CB), and biomass carbon (BC) are tested as the fuel to investigate the influence of carbon fuel properties on the cell performance in HDCFC with a traditional nickel oxide as the anode. Either an electrolyte-supported cell with a thin nickel oxide anode or an anode-supported cell with a thick nickel oxide anode is used to evaluate the electrochemical reactivity of carbon samples. These three-carbon fuels are characterised on the crystal structure, particle size, composition, and surface property. It is found that GC shows excellent cell performance on thin nickel oxide anode. However, it displays relatively slow electrochemical reactivity on the thick anode due to its great extent of carbon oxidation. BC shows good initial cell performance but fast degradation of the cell performance, as much more hydrogen is released at the beginning of the cell test. The anode reactions of HDCFCs are explored by the in-situ gas analysis in open circuits and under current load conditions. It is observed that GC produces the highest amount of CO among these three fuels, suggesting that carbon oxidation is the dominant electrochemical process in HDCFCs after a certain time when most of the hydrogen is released from the pyrolysis process.

Apple storage in ultra-low oxygen cold store

Apple storage under lower concentration of oxygen (1.0-1.3% in some cases lower than 1%) in controlled atmosphere cold stores is described as apple storage in ultra-low oxygen cold store. Ultra-low oxygen store room is an airtight gas cold room and its atmosphere is composed of lower rate of oxygen and higher amount of CO2. It has been Investigated and recorded that ultra-low oxygen cold store extends storage life of apple varieties (Royal Gala, Red Delicious, Idared, Jonagold and Golden delicious) from 3 to 6 months under common cold stores to 7-11 months with preserving its nutritional, sensorial and biological parameters and characteristics after harvest. For storage of apples in Afghanistan, mostly simple and cold storerooms are applied but inadequately and with local methods and facilities, due to application of ultra-low oxygen cold storage both can benefitfarmers, customers and economic growth of the country.&#x0D; Int. J. Agril. Res. Innov. &amp; Tech. 9 (1): 18-22, June, 2019

Shock Tube and Kinetic Study on the Effects of CO2 on Dimethyl Ether Autoignition at High Pressures

First-stage and overall ignition delay times of dimethyl ether (DME) were measured in a high-pressure shock tube for various mixtures containing high amounts of CO2. The data are available for DME/air mixtures diluted with 40% CO2 as well as for the mixture of DME and oxidizer containing 20.5% O2 and 79.5% CO2. As a reference, data were also collected for mixtures containing the corresponding amounts of N2. Measurements were conducted for pressures of 15, 35, and 50 bar and a range of temperatures (744–1316 K). For the DME/air mixture diluted with CO2, the equivalence ratio was varied in the range of 0.5–2.0. The results demonstrate that CO2 dilution has a strong effect on ignition delay times in the NTC (negative temperature coefficient) region. The kinetic study that was conducted showed that this phenomenon can be attributed to a thermal effect resulting from the high heat capacity of CO2. In low and high temperature ranges, the effect of CO2 is less pronounced. Additionally, a chemical effect was identified. At high temperatures this effect can be attributed mostly to the influence of CO2 on third-body reactions and leads to slight acceleration of ignition. Various chemical-kinetic models available were evaluated with respect to their accuracy in prediction of ignition delay times for mixtures containing DME and large amounts of CO2.

CO2 capture from coalbed methane using membranes: a review

Coalbed methane is an abundant form of natural gas extracted from coal beds. Coalbed methane is viewed as a cleaner energy source versus petroleum and coal combustion because methane extraction, transport and use are more efficient and less polluting. However, coalbed methane contains high amounts of CO2 that induce solidification during liquefaction. Therefore, CO2 has to be reduced below 2% to meet the pipeline transportation standards. In addition, CO2 capture would reduce the amount of gas emissions to the atmosphere, thus mitigating global warming. Here, we review membrane absorption, which is an advanced method for CO2 capture from coalbed methane, by controlling the gas and liquid phases separately during the operation process. We compare CO2 removal methods for various coalbed methane sources. Parameters influencing CO2 removal by membrane absorption are discussed to conclude that CO2 capture efficiency is improved by increasing the flow rate, temperature, and absorbent concentration, reducing the gas flow rate, and selecting a mixed absorbent. We also explain the principles, processes and applications of CO2 membrane absorption.

EMISIÓN DE N2O, CO2 Y NH3 A PARTIR DE ESTIÉRCOL DE BOVINOS CON DIFERENTE PORCENTAJE DE PROTEÍNA CRUDA EN LA DIETA

The emission of nitrous oxide (N 2 O), carbon dioxide (CO 2 ) and ammonia (NH 3 ) in tropical dairy cattle (CLT) excreta, fed with different percentages of crude protein (CP), was quantified using static cameras. Sampling was performed at different times of day (7:00, 10:00, 13:00, 16:00, and 19:00 local time -LT-). The statistical model employed was a covariance analysis in a randomized complete block design with repeated measures. The variables were analyzed using the Glimmix procedure of the Statistical Analysis System (SAS) v. 9.2 with a covariance structure of compound symmetry. The best model that explains the flow of N 2 O-N and the emission of CO 2 and NH 3 is that which included the minimum ambient temperature and the pH as covariates, respectively. Treatment with 12 % of CP obtained the highest N 2 O-N flow and the lowest CO 2 emission. Treatment with 14 % CP had the lowest N 2 O emission and treatments with 14 and 16 % CP reflected higher amounts of CO 2 emissions. The hours of the day when there were greater emissions of NH 3 were 10:00 and 13:00 LT, which in turn were the hours where less amount of CO 2 and N 2 O was emitted. As the percentage of CP in the different treatments increases, there is also an increase in the weight gain of the animal, being the treatment with 16 % CP, commercial food, the diet that produced the highest increase in kilograms in animals.

Differences in quantity and composition of leaf particulate matter and morphological structures in three evergreen trees and their association in Harbin, China

Urban trees have been assumed to effectively clean air particulate matter (PM), while the inter-species differences are not yet well defined, especially the PM chemical composition. In this study, PM from leaf surface and wax layer of 3 evergreen tree species (Juniper: Juniperus rigida; Black pine: Pinus tabuliformis var. mukdeais; Spruce: Picea koraiensis) were used for finding differences in PM adsorption and its compositional traits (characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrum and Inductively coupled plasma-optical emission spectrometry). Possible improvement in PM removal was also evaluated by a detail whole city tree census and different scenarios of species adjustment data. We found that: 1) the amount of PM on juniper leaves was 5.73 g m−2, 2–2.5-fold higher than black pine and spruce (p < 0.05). Of them, 38.73%, 38.22%, and 23.11% were in the wax layer. 2) Compared with the explicit interspecies differences in PM quantity, more complex interspecies difference showed different patterns for different compositional traits. In general, leaf surface PM had higher O, Si, Al, Fe, N, Pb, Cu, Ni, Cr, and Cd, while the wax PM had higher C and Na contents (p < 0.05). 3) Association ordination found that the smaller leaf size, lower leaf water content, higher leaf area per unit mass, higher wax content, and larger stomatal openness aligned with the more PM adsorption by leaf, together with the higher amounts of CO stretching, O, Si, Al, N, heavy metals of Pb, Cu, Ni, Cr, and Cd in PM. 4) Compared with the other 2 species, increase of juniper percentage in urban forests is more effective for maximizing PM removal from air, accompanying more heavy metal removal but less crystalized minerals in PM. Our findings highlight that proper species configuration in urban afforestation could maximize the air PM removal capacity.

Surface Property-Activity Relations of Co/Sn Oxide Nanocatalysts Evaluated Using a Model Reaction: Surface Characterization Study

Herein we report on the synthesis, characterization and catalytic evaluation of cobalt (Co) and tin (Sn) oxide catalysts synthesized via the sol–gel approach. Preliminary characterization using nitrogen sorption measurements show the materials as mesoporous with relatively high surface area. The catalyst with the least amount of Co had the highest surface area (146 m2/g) compared to the catalysts with the highest amount of Co. Furthermore, temperature-programmed reduction (H2-TPR) was used to study the redox properties of the catalysts. The H2-TPR analysis revealed that the catalysts are only reduced at relatively high temperatures (> 300 °C). While the temperature-programmed desorption using ammonia (NH3-TPD) and carbon dioxide (CO2-TPD) results suggest that the total amount of acidic and basic sites is the function of different amounts of metal content in the catalytic materials. The catalyst with the least amount of Co appeared to have the highest number of acidic sites compared to other catalysts. Evaluation of the catalytic activity was studied using oxidation of morin as model reaction. The catalyst with the least amount of Co, (Co0.3Sn0.7Ox) appeared to be the most active catalyst.

The Carbon Dioxide Clathrate Disposal in a Pit near Japan

Abstract The research purpose is to present the possibility to deposit the carbon dioxide clathrate at the ocean bottom near Japan. As it is well known, a big amount of CO2 is produced nowadays, with a very damaging influence on the climate. These effects can already be seen all around the world. A possible solution to get rid of the CO2 surpluses is to liquefy it, transform it into carbon dioxide clathrate and send it through pipes at very low levels into the oceans or seas, where its density is bigger than the salted ocean water density. Theoretical ideas are presented at the beginning. An analytical method is used to calculate the carbon dioxide clathrate pressure at the exit of the pipe and also the pressure at a certain depth into the ocean. Because the carbon dioxide clathrate density and the sea water density are variable at different depths, an integral calculus must be done. The authors also calculated the flow rate through the pipes and the time needed to deposit the clathrate at the bottom of the ocean. The volume of the pit is also determined. A particular calculus is made in the case of the Ryukyu pit near Japan. It has steep slopes and the depth reaches around 8000 meters. The location was chosen because, in the case of Japan, high amounts of CO2 are produced. Hurricanes cross this country. Therefore, we suppose that large interest can appear for such a solution to change the climate even locally. Depending on the previous parameters, one can analyze the opportunity for the practical deposition of the carbon dioxide clathrate in the respective pit with a further economical calculus. The calculus which uses the prices in Japan can estimate the cost to liquefy the CO2 and to send it to the bottom of the ocean as well as compare it with other methods to reduce the CO2 quantity in the atmosphere.

Estructura, composición florística y almacenamiento de carbono en bosques nativos del páramo de Anaime, Tolima, Colombia

Los páramos tienen alta importancia ambiental por su alto endemismo, su regulación hídrica y su almacenamiento de carbono. En este trabajo se caracterizó la estructura y composición poblacional de la vegetación arbórea, se estimó el almacenamiento de carbono en biomasa aérea y el potencial de reducción de emisiones por deforestación, y se priorizó los tipos de bosques nativos en los esfuerzos de conservación en la Reserva Natural Semillas de Agua (RNSA) en el páramo de Anaime, Tolima, Colombia. En cada tipo de bosque (achaparrado, maduro y subpáramo), se establecieron nueve parcelas de muestreo de 10 x 15 m, en donde se midieron todos los individuos con un diámetro del tronco a la altura del pecho (dap) ≥ 10 cm. La biomasa aérea se estimó a través de un modelo alométrico multi-especie generado localmente. Las especies importantes, en términos de índice de valor de importancia y de almacenamiento de carbono, fueron Weinmannia auriculata y Miconia sp. El mayor almacenamiento de carbono se alcanzó en los bosques del subpáramo, seguido de los maduros y achaparrados (242 vs 147 vs 25 Mg/ha, respectivamente). Los bosques en la RNSA almacenan 3,2 Tg CO2e en biomasa aérea, de los cuales se podrían perder 0,2-0,5 Tg CO2e en 20 años con una deforestación anual de 0,78 y 0,28%, respectivamente. Estas reducciones de gases de efecto invernadero podrían ser comercializadas en un potencial proyecto REDD+, que ayuden a conservar estas áreas de bosque. Los bosques achaparrados y del subpáramo deberían ser priorizados en los esfuerzos de conservación debido a su diversidad, endemismo y a su gran cantidad de carbono en el caso de los bosques maduros.