Maximum Amount Of CO2 Research Articles

Različite kontrole mehaničkog načina uništavanja korova u vinogradu zbog redukcije ekološkog otiska

The purpose of the study was to investigate the alternative methods of weed control in the vineyard under 'Sauvignon' vines to reduce ecological footprint in vineyard production. Weed control was performed at the experimental site with the mechanical weed control under vines with a grass cutter, a rotating star hoe (roll hoe) and a vine trunk cleaner, while at the same time additional mulching was carried out in the belts between the rows. The ecological footprint of each production operation was estimated by including environmental impacts related to fossil-C (kg CO2/hm2 ), air, water, soil, nonrenewable, renewable, and area resources. While carrying out the mechanical control, we analysed the weed coverage, grape yield and yield loss. Grape yield was highest for weedfree control plots, followed by plots where ploughshare was used. Yield loss was lowest when using ploughshare. In addition to the weed-free plot, weed coverage was lowest when glyphosate was used. The maximum amount of CO2 is released while using rotating star hoe. At the grass cutter and vine trunk cleaner less CO2 was released. The same is with global warming potential (GWP).

Techno-Economic Evaluation of Novel Hybrid Biomass and Electricity-Based Ethanol Fuel Production

In order to limit climate change, fast greenhouse gas reductions are required already before 2030. Ethanol commonly produced by fermentation of sugars derived either from starch-based raw material such as corn, or lignocellulosic biomass is an established fuel decarbonizing the transport sector. We present a novel selective and flexible process concept for the production of ethanol with electricity and lignocellulosic biomass as main inputs. The process consists of several consecutive steps. First synthesis gas from gasification of biomass is purified by filtration and reforming and fed to methanol synthesis. The produced methanol is fed to acetic acid synthesis, together with a carbon monoxide-rich stream separated from the synthesis gas by membranes. Finally, acetic acid is hydrogenated to yield ethanol. With the exception of acetic acid hydrogenation, the overall process consists of technically mature subprocesses. Each process step was modelled in Aspen Plus to generate the mass and energy balances for the overall process. Additionally, the CO2 emissions and economic feasibility were assessed. Three separate cases were investigated. In the first two cases, the syngas carbon (CO and CO2) was split between methanol and acetic acid synthesis. The cases included either allothermal (case A) or electrically heated reforming (case B). In case C, maximum amount of CO was sent to acetic acid synthesis to maximize the acetic acid output, requiring a small additional carbon dioxide input to methanol synthesis. In all cases, additional hydrogen to methanol synthesis was provided by water electrolysis. Each case was designed at biomass input of 27.9 MW and the electrolyzer electricity requirement between 36 and 43.5 MW, depending on the case. The overall energy efficiency was calculated at 53–57%, and carbon efficiencies were above 90%. The lowest levelized cost of ethanol was 0.65 €/l, at biomass cost of 20 €/MWh and electricity cost of 45 €/MWh and production scale of approximately 42 kt ethanol per year. The levelized cost is competitive with the current biological route for lignocellulosic ethanol production. The ethanol price is very sensitive to the electricity cost, varying from 0.56 to 0.74 €/l at ±30% variation in electricity cost.

Assessment of phytoremedial potential of invasive weeds Acalypha indica and Amaranthus viridis

In the present study intercropping of two plant species was carried out over a soil contaminated with five heavy metals lead (Pb), cadmium (Cd), chromium (Cr), cobalt (Co) and nickel (Ni). The experimental setup was designed in such a manner that the effluent stream passed intermittently for 60 days through the plant species Acalypha indica and Amaranthus viridis grown on-site after which the species were uprooted and processed further to check the heavy metal concentration in several parts of the plant such as roots, stem, leaves and flowers as well as the soil. The flowers of A. indica accumulated a maximum amount of Pb and least in the stem with a Translocation Factor (TF) of 21.49 and a Bioconcentration Factor (BCF) value of 2 and the highest concentration of Cr in flowers followed by leaves, root and stem regions with a TF of 11.5 and BCF value of 244.59. Co accumulation in A. indica was noted to be maximum in the flowers and least in the stem with a TF of 12.03 and a BCF value of 3.77, while it was highest in the flowers and least in the root with 8.2 and 0.9 TF and BCF values respectively, for Cd, whereas for Ni it was highest in the flowers and least in stem with 18.19 TF and 11.04 BCF. A. viridis accumulated maximum amount of Pb in leaves followed by flowers and least in stem with a TF of 8.64 and BCF of 259.93. It accumulated highest amount of Cr in the leaves followed by flowers, stem and root region with a TF of 10.55 and BCF of 212.49. The leaves of A. viridis accumulated a maximum amount of Co and the least in the stem region with a TF of 7.05 and BCF of 4.95 while the concentration of Cd was highest in leaves and least in roots with 18.37 and 1.61 TF and BCF respectively. A. viridis accumulating trend for Ni was leaves > flowers > root > stem with a TF of 8.15 and BCF of 10.48. Hence as per the values obtained both the species exhibited successful phytoextraction of all the five heavy metals in their aerial parts making both of them good bioaccumulator species.

One-Pot Synthesis of Copper-Embedded Nitrogen-Doped Carbon Nanofiber Catalysts for Cascade Electroreduction of Carbon Dioxide to Ethylene

Electrochemical reduction reaction of CO2 (CO2 RR) to valuable products offers potential for storing excessed renewable energy as well as chance to close the carbon loop, displacing the fossil fuel in chemical industries. Major efforts have been made to direct conversion of CO2 to ethylene which is widely used building blocks for chemical industries with large market size. Recently, tandem electrocatalysts composed of Cu and promoter metals which produces CO such as Au, Ag, and Zn have been investigated to enhance ethylene selectivity by increasing local concentration of CO*, overcoming limitation of pure Cu. However, these catalysts fabricated by sequential deposition of promoter metals on copper have limits in difficulty of controlling proximity between activated CO production sites and copper surfaces. Carbon is known for good supporter for the electrocatalyst due to the good electrical conductivity and electrochemical stability. In addition, Doped nitrogen in the pyridinic or pyrrolic configurations acts as the active site of CO2 reduction to CO. However, many researches have been reported carbon as supporter or catalyst producing CO gas, not as CO supplying co-catalyst with Cu. This may be caused by difficulty of composing nitrogen uniformly in carbon and in the proximity of Cu. Here, we have developed a new organic-metal hybrid tandem catalyst composed of Cu particles embedded in N-doped carbon nanofiber (Cu/N-CNF) and N atoms located on the periphery of Cu particles via “one-pot selective oxidation”. In order to fabricate Cu/N-CNF, electrospun copper acetate (CuAc: Cu(CO2CH3)2)/polyacrylonitrile (PAN: (C3H3N)n) nanofibers were calcinated at thermodynamically designed oxygen-controlled conditions based on Ellingham diagram. Cu-embedded undoped carbon nanofiber (Cu/CNF) catalysts were also synthesized by same process as Cu/N-CNF using polyvinyl alcohol (PVA : (C2H4O)n) instead of PAN. During calcination, temperature was maintained at 800 ºC for 5 h under 50 mTorr of pO2 at which the carbon is combusted and the copper is reduced, besides, the nitrogen hardly reacted with oxygen during calcination. It was confirmed that metallic Cu particles are successfully formed in all catalysts by SEM and TEM analysis. Also, Cu/N-CNFs contains pyridinic N predominantly than other N species by SEM and XPS analysis. The activity and faradaic efficiency (FE) of each product were examined by flow cell reactor with 5 M KOH electrolyte. Cu/N-CNFs show higher current densities compared to Cu/CNF catalyst at measured potential range (-0.2 ~ -0.8 V vs. RHE). Furthermore, Cu/N-CNF shows maximum C2H4 selectivity (62%) at much lower overpotential of -0.57 V vs. RHE compared to undoped Cu/CNF (-0.75 V vs. RHE). It can be inferred that increased CO production by doped N promotes CO* dimerization, whereas, without doped N, lower CO* generation limits the maximum amount of CO* dimerization. Furthermore, decrease of the CO dimerization energy barrier by CO production of doped N around Cu particles also will be discussed by DFT calculations.

Optimization of Catalytic Sites in Cobalt‐Modified Nitrogen‐Doped Carbon towards High‐Performance Oxygen Reduction Electrocatalysts for Zinc‐Air Batteries

AbstractEfficient yet low‐cost electrocatalysts for the oxygen reduction reaction (ORR) are highly desirable for energy systems such as metal‐air batteries and fuel cells. Herein, we report the synthesis of efficient cobalt‐modified nitrogen‐doped carbon (N−C/Co) electrocatalysts by using a one‐pot pyrolysis. The abundant source of N in g‐C3N4 contributes to the in situ N doping in the carbon matrix, which favors the formation of Co‐related catalytic active sites. The N−C/Co‐1 (prepared with 1 mmol Co salt) sample exhibits the best performance towards the ORR, with a positive half‐wave potential of 0.86 V (vs. the reversible hydrogen electrode, RHE), high stability and excellent methanol tolerance, which outperforms the commercial Pt/C catalyst. We find that the high performance is dependent on the optimal content of Co that can achieve the maximum amount of Co−Nx catalytic species. In addition, we reveal that the size effect of Co nanoparticles is not the determining factor for the ORR activity in the current system, as the kinetics of the ORR reaction is dominantly determined by the active sites derived from Co−Nx species. By exploiting the N−C/Co‐1 sample as an air cathode catalyst, the assembled Zn‐air battery presents a maximal power density of 153 mW cm−2 as well as good durability during continuous cycle tests.

Carbon capture induced changes in Deccan basalt: a mass‐balance approach

AbstractPrevious studies on the Deccan basalt–water–CO2 interaction were focused on numerical simulations and experimental validation that revealed carbonate formation, but restricted to low temperatures and for a shorter period. However, during prolonged interactions, silicates restricted carbonates from forming, and thus necessitated for comparative mass‐balance calculations of parent basalt, neo‐formed mineral and dissolution products to understand apposite parameters that control the reaction extent and optimal geochemical conditions. To examine these interactions, mass‐balance calculations have been attempted. A gradual increase in HCO3− concentration and basalt dissolution is concomitant with the increase in experimental run time; thus, the pH of the solution is affected. X‐ray diffraction and scanning electron microscope–energy dispersive X‐ray spectrometer analyses revealed the presence of carbonates in the post‐experiment residue (run for a shorter period). Owing to gradual carbonate decrease in the residue, Ca2+, Fe2+ and Mg2+ released from basalt gradually increased in the leachate at 100°C. But with the progression of time at 200°C, more secondary silicates were formed and incorporated Mg2+ and Si4+, which led to a decrease in Mg2+ and Si4+ concentrations in the leachate. Mass‐balance calculations revealed that the maximum amount of CO2 is mineralized (22.88 mol%) from the ions derived from the parent basalt at 100°C under 5 bar CO2 and 70 h of experiment running time. But, for longer periods of experiments, the rate of ionic interactions as well as CO2 mineralization is almost ceased. Thus, the rate of dissolution is affected by temperature, but the amount of CO2 mineralization is directly a function of the basalt–water–CO2 interaction time. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Functionalization of SBA-15 by dithiooxamide towards removal of Co (II) ions from real samples: Isotherm, thermodynamic and kinetic studies

In this study, mesoporous SBA-15 was functionalized by dithiooxamide ligand through sodium dodecyl sulfate as intermediate. The obtained nanocomposite was considered as a strong adsorbent towards selective removal of the cobalt (II) ions from the industrial wastewater samples. Transmission Electron Microscopy (TEM) analysis, Brunauer-Emmett-Teller (BET) analysis, elemental CHNS (carbon, hydrogen, nitrogen, and sulfur) analysis, and thermo-gravimetric analysis (TGA) were used for characterization, particle size determination, confirming the presence of the used ligand, and measuring the nanocomposite stability, respectively. Effective parameters on the removal of the cobalt (II) ions such as pH, adsorbent dosage, concentration, and contact time have been evaluated. Results showed that the Freundlich isotherm has a bit better correlation coefficient compared to Langmuir isotherm (0.96 versus 0.94, respectively). The maximum amount of Co (II) ions adsorption on 1 g of nanocomposite (qm) is calculated to be 2500 mg/g that points to the excellent adsorption. Kinetic analyses were conducted using pseudo-first and second-order models and the regression results showed that the pseudo-second-order model is more accurate for the study of the cobalt adsorption due to the higher correlation coefficient (0.99 versus 0.83) compared to the pseudo-first-order model. The result of the present study points that the suggested nanocomposite can be positively used in treating industrial effluents containing cobalt ions.

Electronic structure, pore size distribution, and sorption characterization of an unusual MOF, {[Ni(dpbz)][Ni(CN)4]}n, dpbz = 1,4-bis(4-pyridyl)benzene

The monoclinic (Ni(L)[Ni(CN)4] (L= 1,4-Bis(4-pyridyl) benzene) compound (defined as Ni-dpbz) is a flexible metal organic framework which assumes a pillared structure with layers defined by 2D Ni[Ni(CN)4]n nets and dpbz ligands as pillars. The structure features an entrapped dpbz ligand that links between the open ends of four-fold Ni sites from two neighboring chains. This arrangement results in an unusual 5-fold pseudo square-pyramid environment for Ni and a significantly long Ni-N distance of 2.369(4) Å. Using Density Functional Theory calculations, the different bonding characteristics between the 5-fold and 6-fold Ni's were determined. We found that there is weak covalent bonding between the 5-fold Ni and N in the entrapped ligand, and the 6-fold Ni-N bonds provide effective electronic conduction. The disordered dimethyl sulfoxide (DMSO) solvent molecules are not bonded to the framework. The material has a single pore with a diameter of 4.1 Å. This pore includes approximately 55% of the total free volume (based on a zero-diameter probe). The accessible pore surface area and pore volume were calculated to be 507 m2/g and 6.99 cm3/kg, respectively. The maximum amount of CO2 that can be accommodated in the pores after DMSO is removed was found to be 204 mg/g, agreeing with the results of adsorption/desorption experiments of about 220 mg/g.

CO2 Capture by Injection of Flue Gas or CO2-N2 Mixtures into Hydrate Reservoirs: Dependence of CO2 Capture Efficiency on Gas Hydrate Reservoir Conditions.

Injection of flue gas or CO2-N2 mixtures into gas hydrate reservoirs has been considered as a promising option for geological storage of CO2. However, the thermodynamic process in which the CO2 present in flue gas or a CO2-N2 mixture is captured as hydrate has not been well understood. In this work, a series of experiments were conducted to investigate the dependence of CO2 capture efficiency on reservoir conditions. The CO2 capture efficiency was investigated at different injection pressures from 2.6 to 23.8 MPa and hydrate reservoir temperatures from 273.2 to 283.2 K in the presence of two different saturations of methane hydrate. The results showed that more than 60% of the CO2 in the flue gas was captured and stored as CO2 hydrate or CO2-mixed hydrates, while methane-rich gas was produced. The efficiency of CO2 capture depends on the reservoir conditions including temperature, pressure, and hydrate saturation. For a certain reservoir temperature, there is an optimum reservoir pressure at which the maximum amount of CO2 can be captured from the injected flue gas or CO2-N2 mixtures. This finding suggests that it is essential to control the injection pressure to enhance CO2 capture efficiency by flue gas or CO2-N2 mixtures injection.

Parametric effect of adsorption variables on CO<SUB align="right">2 adsorption of amine-grafted polyaspartamide composite adsorbent during post-combustion CO<SUB align="right">2 capture: a response surface methodology approach

In this study, effect of operating variables (e.g., temperature, flue gas flow rate and pressure) on the CO2 adsorption capacity of an amine-grafted polymer composite adsorbent, PAA, was investigated using a statistical approach (response surface methodology). A set of 25 experiments were designed using the central composite design (CCD) and six regression models were proposed to describe the behaviour of the materials for CO2 capture under the influence of the operating variables considered in this study. The best model that adequately described the behaviour of the material displayed a mean error, a variance and a p-value of –2.6375 × 10–12, 29 and 0.0006, respectively, indicating the statistical significance of the model to describe the behaviour of the material during CO2 adsorption. In addition, results of the cross-validation of the model showed an error of about 5%, strengthening further the validity of the model. Under the main and interaction effects of the considered variables, a maximum amount of CO2 adsorbed was approximately 45 mg CO2/g adsorbent at a gas flowrate of 60 ml/min, a temperature of about 40°C, and at a pressure of 1.6 bar. [Received: October 5, 2016; Accepted: March 30, 2017]

The Application of Hybrid RSM/ANN Methodology of an Iron-based Catalyst Performance in Fischer-Tropsch Synthesis

In this research, the performance and kinetics of an iron/manganese oxide catalyst in a fixed-bed reactor by Fischer-Tropsch Synthesis is studied. The range of operating conditions are; P = 1 – 12 bar, T = 513 - 553 K, H2/CO ratio = 1 - 2 and GHSV = 4200 – 7000 ((〖cm〗^3 (STP))/h/g_cat). The effect of these independent variables, on Fischer-Tropsch product were performed by using a statistical model based on experimental data. Two models, response surface methodology and artificial neural network, were applied for modeling and predicting of the experimental points for carbon monoxide conversion (CO% conversion) and catalytic kinetic for the consumption rate of CO (-rco). Some statistical parameters such as correlation coefficient and mean square error were calculated to capability and sensitivity analysis of two models. Results show that two models, have good agreement with experimental data but artificial neural network model was stronger and more accurate than the response surface method model. To achieve the optimum condition, optimization must be done. It was obtained that maximum amount of CO% conversion was achieved in P = 8 bar, T = 559.5 K, H2/CO = 2.5 and GHSV = 7325.2 ((〖cm〗^3 (STP))/h/g_cat) and maximum amount of consumption rate of CO was in P = 8 bar, T= 568 K, H2/CO = 2.5 and GHSV = 2800 ((〖cm〗^3 (STP))/h/g_cat). Finally, all of quadratic equations and optimum conditions for any variable and responses will be concluded.

Removal of Co2+, Ni2+, and Pb2+ by Manganese Oxide-Coated Zeolite: Equilibrium, Thermodynamics, and Kinetics Studies

AbstractThe removal of Co2+, Ni2+, and Pb2+ from aqueous solutions using a modified zeolite was investigated because of the need to eliminate toxic contaminants from wastewaters. In the present study the ways in which equilibrium, thermodynamics, and kinetics parameters affected the removal of heavy metals were evaluated and compared. An Iranian clinoptilolite with a Si/Al ratio of 6.5 was used as an adsorbent. In order to increase the adsorption capacity of the adsorbent, it was converted to a manganese oxide-coated zeolite (MOCZeo) using various Mn solutions. The initial concentration of metals, pH, contact time, and temperature were the variables studied and optimal conditions were established. The maximum amount of Co2+, Ni2+, AND Pb2+ adsorption on MOCZeo was ascertained. A thermodynamics study, using ΔG, ΔH, and ΔS state functions showed that adsorption of Pb2+ was more spontaneous than that of Co2+, Ni2+ ions. The adsorption of these ions on MOCZeo was an endothermic reaction. Investigation of the adsorption models revealed that the adsorption of Pb2+, Co2+, and Ni2+ on MOCZeo followed both the Langmuir and Freundlich models. Kinetics studies showed that the adsorption of Pb2+, Co2+, and Ni2+ on MOCZeo followed the pseudo-second order kinetics model with a high correlation coefficient.

Visible light photoactivatable CO releasing manganese (I) tricarbonyl complexes: Experimental and DFT studies

The reaction between [Mn(CO)5Br] and antibacterial drugs (Nifuroxazide (NIF) and Nitazoxanide (NTZ)) afforded fac-[MnBr(CO)3(NIF)] (1) and fac-[MnBr(CO)3(NTZ)2] (2) complexes, which were characterized by different analytical and spectral tools. The photo-induced CO releasing properties and the ability of the metal carbonyls to drive CO to the myoglobin solution were investigated. The green-light (525 nm) illumination of the DMSO solution of 1 for 20 min gave rise to the maximum amount of CO. Compared with the DMSO solution of 1, the rate of CO release from the 80% aqueous-DMSO mixed media is slower, and the plateau is reached upon the illumination for 140 min. On the contrast, a clear isosbestic point is developed during the storing of the DMSO solution of 2 for 6 h, which reflects its instability. To drive CO from 2 to myoglobin solution, the energy of the green light was not sufficient. However, the grown of the bands corresponding to the formation of carboxy-myoglobin species is stopped after 50 min of the irradiation at 468 nm and 36 min at 410 nm. The electronic structures and the related electronic transitions have been calculated by TD-DFT/B3LYP (or CAM-B3LYP)/LANL2DZ methods. The spectra calculated by the hybrid exchange-correlation functional CAM-B3LYP with a long range correction term are more closed to the experimental findings. The remarkable toxicity of 2 against the tested microbes, with respect to the free drug, may be attributed to the change of the lipophilicity of free NTZ upon the complex formation as well as the releasing of CO upon the incubation in dark.

Ln0.5 A0.5 MnO3 (Ln=Lanthanide, A= Ca, Sr) Perovskites Exhibiting Remarkable Performance in the Thermochemical Generation of CO and H2 from CO2 and H2 O.

Perovskite oxides of the Ln0.5 A0.5 MnO3 (Ln=lanthanide, A=Sr, Ca) family have been investigated for the thermochemical splitting of H2 O and CO2 to produce H2 and CO respectively. The amounts of O2 and CO produced strongly depend on the size of the rare earth ions and alkaline earth ions. The manganite with the smallest rare earth possessing the highest distortion and size disorder as well as the smallest tolerance factor, gives out the maximum amount of O2 , and, hence, the maximum amount of CO. Thus, the best results are found with Y0.5 Sr0.5 MnO3 , which possesses the highest distortion and size disorder. Y0.5 Sr0.5 MnO3 shows remarkable fuel production activity even at the reduction and oxidation temperatures as low as 1200 °C and 900 °C, respectively.

Analysis of carbon dioxide, water vapour and energy fluxes over an Indian teak mixed deciduous forest for winter and summer months using eddy covariance technique

In the present study, we report initial results on analysis of carbon dioxide (CO2), water vapour (H2O), and energy fluxes (sensible and latent heat flux) over teak mixed deciduous forests of Madhya Pradesh, central India, during winter (November 2011 and January 2012) and summer (February–May 2012) seasons using eddy covariance flux tower datasets. During the study period, continuous fast response measurements of CO2, H2O and heat fluxes above the canopy were carried out at 10 Hz and averaged for 30 minutes. Concurrently, slow response measurements of meteorological parameters are also being carried out. Diurnal and seasonal variations of CO2, H2O and heat fluxes were analysed and correlated with the meteorological variables. The study showed strong influence of leaf off and on scenario on the CO2, H2O and energy fluxes due to prevalence of deciduous vegetation type in the study area. Maximum amount of CO2 was sequestered for photosynthesis during winter (monthly mean of $-25~\upmu $ mol/m2/s) compared to summer (monthly mean of $-2~\upmu $ mol/m2/s). Energy flux analysis (weekly mean) showed more energy being portioned into latent heat during winter (668 W/m2) and sensible heat during summer (718 W/m2).

A Numerical Simulation Study of Carbon-Dioxide Sequestration into a Depleted Oil Reservoir

Utilization of CO2 for enhanced oil recovery and sequestration processes not only reduces greenhouse emissions but also awards economical benefits. Enhancing oil recovery in a sequestration is an optimization process that requires careful analysis. In CO2-enhanced oil recovery the main purpose is to maximize oil recovery with the minimum quantity of CO2 while a maximum amount of CO2 is aimed to store in a sequestration. Kartaltepe field having 32° API gravity oil in a carbonate formation from southeast Turkey has been considered in this study. Reservoir rock and fluid data were evaluated and merged into CMG/STARS simulator. History matching study was done with production data to verify the results of the simulator with field data. From the results of simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering of a high amount of CO2 was found to be inappropriate for Kartaltepe field. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of original oil in place in 2006 for the field, it reached to 43% of original oil in place by injecting CO2 after defining production and injection scenarios properly.

Simulating Oil Recovery During CO2 Sequestration Into a Mature Oil Reservoir

Abstract Utilization of CO2 for enhanced oil recovery (EOR) and sequestration processes not only reduces greenhouse emissions, but also awards economic benefits. Enhancing oil recovery using sequestration is an optimization process that requires careful analysis. In CO2 EOR, the main purpose is to maximize oil recovery using the minimum quantity of CO2, while at the same time, sequestering the maximum amount of CO2 in the field. The Kartaltepe Field, having 32 ºAPI gravity oil in a carbonate formation, in southeast Turkey has been considered in this study. Reservoir rock and fluid data were evaluated and merged into CMG's STARS simulator. A history matching study was done with production data to verify the results of the simulator with field data. From the results of the simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering high amounts of CO2 was found out to be inappropriate for the Kartaltepe Field. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of OOIP for the field in 2006. It reached 43% of OOIP by injecting CO2 after properly defining production and injection scenarios. Introduction Global warming is a term used to describe the observed increases in the average temperature of the Earth's atmosphere and oceans. The average global temperature rose 0.6 ± 0.2 ºC over 150 years, and the scientific opinion on climate change is that it is likely that " most of the warming observed over the 20th century is attributable to human activities."(1,2) Factors that may be contributing to global warming are the burning of coal and petroleum products (sources of anthropogenic greenhouse gases (GHG) such as carbon dioxide, methane, nitrous oxide, ozone) and deforestation(3). It is estimated that the global radiative forcing of anthropogenic carbon dioxide (CO2) is approximately 60% of the total due to all anthropogenic greenhouse gases so that climate change is mainly driven by emissions of CO2(4). The United Nations Framework Convention on Climate Change (UNFCCC) was drafted in 1992 by a majority of the world's nations in response to global concern over human-induced climate change. A central, and often controversial, issue in these negotiations has been the use of terrestrial carbon sinks (e.g. forests, agricultural soils) to reduce CO2 emission levels(5). The Kyoto Protocol to the UNFCCC included provisions for industrialized nations to manage carbon sinks in order to meet specified emissions-reduction targets. Under the Kyoto Protocol to the UNFCCC, adopted in December 1997, industrialized nations agreed on a target to reduce their greenhouse gas emissions on an average of 6 to 8% below 1990 levels between the years 2008 and 2012(6). Deep ocean and geologic sequestration are the only choices to dispose of large amounts of CO2 safely and economically for long-term periods. Geologic sequestration, a prospective technology to reduce large amounts of CO2 released into the atmosphere, involves the capture of CO2 from hydrocarbon emissions, transportation of compressed CO2 from the source to the field, and injection and storage of CO2 into the subsurface.

The CO2-EOR sequestration equation: recovery, dynamic monitoring, and co-optimization

Industry has recognized the usefulness of injecting CO2 in geological formations for the past fifty years. The aim of this injection has not been for sequestration/storage, but to displace/dissolve oil, enhancing oil production (EOR). Though a lot of the injected CO2 remains trapped in an oil reservoir, the majority of the floods cannot be considered sequestration/storage projects since the CO2 source is another geological formation. The CO2-EOR operation aims at recovering the maximum amount of oil while consuming the minimum amount of CO2. The sequestration goal is to store the maximum amount of CO2 and to guarantee that it is safely stored.

Transformations of biomass internal oxygen at varied pyrolysis conditions

Pine bark, characterized by high oxygen content (41 wt.%) typical of biomass, was submitted to pyrolysis at varied conditions in order to follow the regularities of oxygen transformation. The effect of water, a catalyst and molecular hydrogen on the yield and composition of pyrolysis products, and their oxygen content were studied. The volatiles, liquid fractions soluble in selected solvents, and solid products of pyrolysis were characterized by ultimate analysis, FTIR-spectroscopic and chromatographic methods. It was demonstrated that, depending on pyrolysis conditions, 46–79 wt.% of oxygen of the original biomass can be transformed into water and 17–43 wt.% into CO 2. The maximum amount of water is produced at catalytic hydropyrolysis, and the maximum amount of CO 2 at pyrolysis with supercritical water. The yields of total bio-oil and charcoal with considerably reduced oxygen content were 11–19 and 30–41 wt.%, respectively. Though a significant portion of oxygen compounds was separated by extraction with polar solvents like water and acetone, the benzene-soluble oil fraction was characterized by a wide spectrum of oxygenates as well. As for the biomass, the role of oxygen in both quantitative and qualitative pyrolytical transformations is dominant being strongly influenced by pyrolysis conditions.

Mechanochemical synthesis of Co, Ni, Fe nanoparticles in polymer matrices

We report on synthesis of Co, Ni, and Fe nanoparticles by the action of elastic wave pulses on solid phase sandwich type samples containing metal salt, reducing agent, polyethylene, and polyacrylamide. The formation of metal nanoparticles is evidenced by ferromagnetic resonance and scanning electron microscopy. The product yield for the nanoparticles formation has a threshold character with the pressure in the elastic wave pulse. The maximum amount of Co, Ni, and Fe nanoparticles is observed around 20 kbar of pressure in elastic wave pulses. The presence of polyacrylamide in reaction composites increases the stability of metal nanoparticles to oxidation by two orders of magnitude.