In this work, hydrolysis lignin with nickel compounds deposited on the surface was prepared. The resulting material was introduced into the process of carbon dioxide assisted conversion and the catalytic activity of the deposited nickel compounds in this reaction was evaluated. Use of the obtained catalytic system increases CO2 conversion by more than 30% in the temperature range 450−800 °C. After the conversion process, the material was subjected to a study using a variety of physico-chemical analysis methods (TEM, SEM-EDX, and X-ray phase analysis). Physico-chemical methods of analysis of a sample calcined at 300 °C to decompose nickel nitrate revealed NiO nanoparticles with an average particle size of 16.9 nm.

In this work, a novel ejector design concept of a swirl-bypass nozzle is proposed to improve off-design performance of CO2 two-phase ejectors. The swirl-bypass nozzle allows part of the flow to bypass into the ejector mixing chamber to generate swirl. The design of such a device is investigated using a 3D multiphase CFD model. An extensive experimental test campaign is conducted to validate the baseline homogeneous equilibrium CFD model. The model’s prediction motive mass flow rate within 2−12% error and suction mass flow rate was predicted with 3−50% error. Based on the tested ejector geometry, simulations of different ejector swirl-bypass inlets are conducted. The results show that, for the current design, total entrainment of the ejector is reduced by 2−20% with the swirl-bypass inlet. The axial position of the bypass inlet plays a primary role in the bypass inlet flow rate, and, consequently, in suction flow reduction. This is found to be due to the bypass flow blocking off the suc... [more]

This work presents a multiscale experimental and numerical investigation of CO2 foam generation, strength, and propagation during alternating injection of surfactant solution and CO2 at reservoir conditions. Evaluations were conducted at the core-scale and with a field-scale radial simulation model representing a CO2 foam field pilot injection well. The objective of the experimental work was to evaluate foam generation, strength, and propagation during unsteady-state surfactant-alternating-gas (SAG) injection. The SAG injection rapidly generated foam based upon the increased apparent viscosity compared to an identical water-alternating-gas (WAG) injection, without surfactant. The apparent foam viscosity of the SAG continually increased with each subsequent cycle, indicating continued foam generation and propagation into the core. The maximum apparent viscosity of the SAG was 146 cP, whereas the maximum apparent viscosity of the WAG was 2.4 cP. The laboratory methodology captured transi... [more]

This paper presents the results of an experimental study of the emission levels of selected greenhouse gases (CO2, CH4, NOx) arising from the combustion of different forms of biomass, i.e., solid biomass in the form of pellets and liquid biomass in the example of engine biofuel (biodiesel). Both types of biomass under study are rape-based biofuels. The pellets are made from rape straw, which, as a waste product, can be used for energy purposes. Additionally, biodiesel contains rape oil methyl esters (FAME) designed to power diesel engines. The boiler 25 kW was used to burn the pellets. Engine measurements were performed on a dynamometer bench on an S-4003 tractor engine. An analyzer Testo 350 was used to analyze the exhaust gas. CO2 emission studies do not indicate the environmental benefits of using any alternative fuels tested compared to their conventional counterparts. In both the engine and boiler tests for NOx emissions, no environmental benefits were demonstrated from the use of... [more]

The effective displacement of the shale oil from organic nanopores plays a significant role in development of the shale oil reservoirs. In order to deeply understand the microscopic displacement mechanism of alkane of shale oil by CO2 in organic nanopores, microscopic pore model of organic matter and molecular model of CO2 and n-dodecane were established to investigate the influences of key parameters on the displacement process by using the Monte Carlo and molecular dynamics simulation method. The instantaneous adsorption of molecules demonstrates that the displacement of n-dodecane and the adsorption of CO2 are proportional to the increase of the injection pressure of CO2 as well as the pore size. In addition, the results also show that the adsorption capacity of CO2 first increases and then decreases with the increase of the temperature, which indicates that the optimum temperature exists for the adsorption of CO2. This work can provide critical insights into understanding the micro... [more]

Bioadsorbent, obtained as a result of the processing of bio-waste, has recently gained popularity as a material that adsorbs greenhouse gases, mainly carbon dioxide. Bio-waste, mainly residues from food industry operations, is a waste to be landfilled or composted and can be a potential substrate for bioadsorbent production. Bioadsorbents used for carbon capture must, above all, have low production costs and high adsorption efficiency. This review covers popular bioadsorbents that have been tested for their ability to adsorb carbon dioxide. The paper compares bioadsorbent production methods, physicochemical properties, adsorption isotherms, surfaces, and their porosity. There is a lack of data in the literature on the topic of carbon dioxide adsorption on large-scale plants in the target environment. Therefore, further research needs to fill in the gaps to identify the promised potential of these bioadsorbents.

This study presents a simple indoor air quality diagnosis program for school office spaces, which are occupied for long durations by teachers, and indoor sports facilities, whose utilization has been on the rise in response to high concentrations of pollutants in outdoor air. The proposed program was made with Visual Basic for Applications (VBA) and Microsoft Excel. This program requires inputs which can be easily determined or measured even by nonexperts and can check the current status of indoor air quality such as CO2 and PM2.5 concentrations and predict the effect if changes are made. In addition, it is possible to diagnose indoor air quality before and after class and compare it with the initial plan so that if it exceeds the indoor air quality maintenance standard range, it can be improved by using a ventilation system and an air purifier. The development of the program was divided into four stages. First, prior research on the influencing factors was investigated. Second, influe... [more]

One of the primary difficulties we have recently is environmental degradation. The deterioration of the environment was visible in the rise in carbon dioxide emissions, which has a detrimental impact on various life matters. A variety of factors caused this growth. Inappropriate human behaviors caused the majority of them. This study aimed to ascertain how energy consumption and economic growth with its components in the Czech Republic, affected CO2 emissions. The relationship between CO2 emissions, economic growth, agriculture, and energy consumption was studied using econometric analysis, specifically the Johansen, Vector Error Correction (VEC) Model, and granger causality. The findings revealed that all variables are cointegrated. Economic growth, agricultural, and energy consumption output are all positively correlated with CO2 emissions. There is a unidirectional Granger Causality between economic growth, and Agriculture towards carbon dioxide emissions. A unidirectional Granger C... [more]

This paper numerically models the thermal performance of offshore hydro-pneumatic energy storage (HPES) systems composed of a subsea accumulator pre-charged with a compressed gas. A time-marching numerical approach combining the first law of thermodynamics with heat transfer equations is used to investigate the influence of replacing air within an HPES system with carbon dioxide (CO2). The latter is able to experience a phase change (gas−liquid−gas) during the storage cycle in typical subsea temperatures when limiting the peak operating pressure below the critical point. The influences of integrating a piston and an inner liner within the accumulator to mitigate issues related to gas dissolution in seawater and corrosion are explored. It is found that the energy storage capacity of subsea HPES accumulators increases substantially when CO2 is used as the compressible fluid in lieu of air, irrespective of the accumulator set up. It is also noted that the length-to-diameter ratio of the a... [more]

Recent advancements in the Internet of Things and Machine Learning techniques have allowed the deployment of sensors on a large scale to monitor the environment and model and predict individual thermal comfort. The existing techniques have a greater focus on occupancy detection, estimations, and localization to balance energy usage and thermal comfort satisfaction. Different sensors, actuators, and analytic data methods are often non-invasively utilized to analyze data from occupant surroundings, identify occupant existence, estimate their numbers, and trigger the necessary action to complete a task. The efficiency of the non-invasive strategies documented in the literature, on the other hand, is rather poor due to the low quality of the datasets utilized in model training and the selection of machine learning technology. This study combines data from camera and environmental sensing using interactive learning and a rule-based classifier to improve the collection and quality of the dat... [more]

Carbon dioxide and combustion products are among the main waste streams deriving from the energy sector. Efficient and cost-effective methods of solid waste valorization and carbon capture, storage and utilization are needed in the transition period towards carbon neutrality in light of the recent scenarios forecasting energy demand and energy supply mix under dynamic social, economic and political circumstances. Within this paper, the current advances in carbon dioxide mineralization, combining carbon dioxide utilization and combustion products valorization, are presented in terms of the recognized methodological options of carbonation methods, process efficiency and effects on the process product properties. Special attention is given to the studies on the valorization of fluidized bed boilers fly ash, differing in a range of parameters from the conventional boilers fly ash, as well as the effects of the carbonation process on the stabilization and improvement of its properties and t... [more]

Multiphase flow properties of fractures are important in engineering applications such as hydraulic fracturing, evaluating the sealing capacity of caprocks, and the productivity of hydrocarbon-bearing tight rocks. Due to the computational requirements of high fidelity simulations, investigations of flow and transport through fractures typically rely on simplified assumptions applied to large fracture networks. These simplifications ignore the effect of pore-scale capillary phenomena and 3D realistic fracture morphology (for instance, tortuosity, contact points, and crevasses) that lead to macro-scale effective transport properties. The effect of these properties can be studied through lattice Boltzmann simulations, but they require high performance computing clusters and are generally limited in their domain size. In this work, we develop a technique to represent 3D fracture geometries and fluid distributions in 2D without losing any information. Using this innovative approach, we pres... [more]

is a species distributed worldwide. Its seeds are used to produce castor oil, which can be used for the production of biofuels; yield improvement can be achieved with elicitors that are substances of biological origin that can induce increased productivity of primary and secondary metabolism, when applied to plants. Salicylic acid (SA) is a natural constituent of plants, and applied exogenously acts as an elicitor. The aim of this work is to evaluate the oil content of castor bean plants elicitated with 900, 600, 300, and 100 µM of salicylic acid and its emissions derived from biodiesel made with the oil in blends (0, 10 and 20%) with commercial fuel in a 296 cc diesel cycle engine; elicitation was foliar sprayed. The oil content increased 39% when 900 µM SA was applied compared to control, and the evaluation of emissions showed the maximum reduction with 20% of Ricinus communis biodiesel (RCB) in all different RPM rates. Otherwise, the use of SA could be a method to increase oil conte... [more]

In an era where sustainability is becoming the main driving force for research and development, supercritical fluids-based techniques are presented as a very efficient alternative technology to conventional extraction, purification, and recrystallization processes. Supercritical antisolvent (SAS) precipitation is a novel technique that can replace liquid antisolvent precipitation techniques. Additionally, through the optimization of precipitation operating conditions, morphology, particle size, and particle size distribution of nanoparticles can be controlled. As an antisolvent, supercritical carbon dioxide (scCO2) is far more sustainable than its conventional liquid counterparts; not only does it have a critical point (304 K and 73.8 bar) on its phase diagram that allows for the precipitation processes to be developed so close to room temperature, but also its recovery and, consequently, the precipitated solute purification stage is considerably simpler. This technique can be used eff... [more]

The perspective of the emerging environmentally friendly and economically efficient detonation gun technology for the high-temperature gasification of organic wastes with ultra-superheated mixture of steam and carbon dioxide is discussed. The technology is readily scalable and allows the establishment of a highly reactive atmospheric-pressure environment in a compact water-cooled gasifier due to very high local temperature (above 2000 °C), intense in situ shock-induced fragmentation of feedstock, and high-speed vortical convective flows enhancing interphase exchange processes. These unique and distinctive features of the technology can potentially provide the complete conversion of solid and liquid wastes into syngas, consisting exclusively of hydrogen and carbon monoxide; microparticles, consisting of environmentally safe simple oxides and salts of mineral residues, as well as aqueous solutions of oxygen-free acids such as HCl, HF, H2S, etc., and ammonia NH3. A small part of the synga... [more]

The injection of carbon dioxide (CO2) into gas reservoirs has become an important way to enhance gas recovery and reduce CO2 emissions. Large discrepancies are observed when predicting natural gas compressibility factors with high CO2 content by several well-known empirical correlations. An explicit correlation is proposed to improve the prediction accuracy in the estimation of compressibility factors on condensate gases with variable CO2 contents. The analysis of the results is carried out on the basis of 202 experimental data from 9 various mixtures of natural gases. The results show that relative deviations of compressibility factors predicted by conventional empirical correlations increase with the increase in CO2 mole fraction with an average error of 8%. The average error of the new method is less than 4%. The effect of compressibility factors on the estimations of dynamic reserves is studied and the compressibility factor causes a 3% reduction in dynamic reserves estimation. The... [more]

Ni-based catalysts supported on alumina derived from the pseudo-boehmite prepared by the impregnation method were employed for catalytic dry reforming of methane reaction at the temperature of 550−750 °C. The effect of calcination temperature on physicochemical properties such as the Ni dispersion, reduction degree, nickel crystallite sizes, and metal−support interaction of the catalysts was investigated. The characterization results show that increasing the catalyst calcination temperature leads to the formation of nickel-alumina spinel, which enhances the metal−support interaction and increases the reduction temperature. The nickel nanoparticle size decreases and the effective dispersion increases with the increasing calcination temperature from 450 °C to 750 °C due to the formation of nickel aluminate. The catalyst calcined at 750 °C exhibits the highest CH4 and CO2 conversion owing to the small Ni0 active sites and high Ni dispersion. In a 200 h stability test in dry reforming of m... [more]

Protic ionic liquids have been regarded as promising materials to capture CO2, because they can be easily synthesized with an attractive capacity. In this work, we studied the CO2 absorption mechanism by protic ionic liquids (ILs) composed of diamino protic cations and azolide anions. Results of 1H nuclear magnetic resonance (NMR), 13C NMR, 2-D NMR and fourier-transform infrared (FTIR) spectroscopy tests indicated that CO2 reacted with the cations rather than with the anions. The possible reaction pathway between CO2 and azolide-based protic ILs is proposed, in which CO2 reacts with the primary amine group generated from the deprotonation of the cation by the azolide anion.

The simulation of carbon dioxide (CO2)-methane (CH4) mixed gas adsorption and the selectivity on zeolite 4A using Aspen Adsorption were studied. The influence of temperature ranging from 273 to 343 K, pressure up to 10 bar and various compositions of CO2 in the binary system were simulated. The findings of the study demonstrate that the models are accurate. In addition, the effects of various key parameters such as temperature, pressure, and various compositions of binary gases were investigated. The highest CO2 and CH4 adsorption are found at 273 K and 10 bar in the Langmuir isotherm model with 5.86 and 2.88 mmol/g, respectively. The amount of CO2 adsorbed and the selectivity of the binary mixture gas depends on the composition of CO2. The kinetics of adsorption for pure components of CO2 at high temperatures can reach saturation faster than CH4. The influence of the physical properties of zeolite 4A on kinetic adsorption were also studied, and it was observed that small adsorbent par... [more]

The main purposes of this project are to assess and to optimize the solubility of carbon dioxide (CO2) in an aqueous 30 wt% monoethanolamine-tetrabutylphosphonium methanesulfonate (MEA-[TBP][MeSO3]) new hybrid solvent. In this study, the viscosity and density of aqueous MEA-[TBP][MeSO3] hybrid solvents containing different amounts of [TBP][MeSO4] were determined. Meanwhile, Fourier Transform-Infrared (FT-IR) Spectroscopy was used to determine the presence of carbamate in aqueous MEA-[TBP][MeSO3] to prove that CO2 was absorbed by aqueous MEA-[TBP][MeSO3]. Response Surface Methodology (RSM) based on central composite design (CCD) was used to design the experiments and explore the effects of three independent parameters on the solubility of CO2 in aqueous MEA-[TBP][MeSO3]. The three independent parameters are concentration of [TBP][MeSO3] (2−20 wt.%), temperature (30−60 °C) and pressure of CO2 (2−30 bar). The experimental data was found to fit a quadratic equation using multiple regressio... [more]

In this work, a lipophilic ophthalmic drug, lutein, has been entrapped in liposomes, using a supercritical assisted process. Effects of pressure, temperature, and drug to lipid ratio variation were studied on mean diameters and lutein encapsulation efficiency. Liposomes with diameters between 153 ± 38 and 267 ± 56 nm were produced, and lutein encapsulation efficiencies between 86.5 ± 0.4% and 97.8 ± 1.2% were obtained. A Scanning Electron Microscope confirmed spherical shape and mean dimensions of vesicles. The variation of temperature for the production of liposomes showed a significant impact on lutein retention time in the double lipidic layer. Lutein drug release from liposomes produced at 35 °C ended in almost 4.5 days; whereas, liposomes produced at 40 °C showed a faster lutein release in 3 days; then, vesicles obtained at 45 °C released their lutein content in only 2 days. Drug release raw data were well-fitted using Weibull model (R2 up to 99%).

The effective separation of CO2 and CH4 mixtures is essential for many applications, such as biogas upgrading, natural gas sweetening or enhanced oil recovery. Membrane separations can contribute greatly in these tasks, and innovative membrane materials are being developed for this gas separation. The aim of this work is the evaluation of the potential of two types of highly CO2-permeable membranes (modified commercial polydimethylsiloxane and non-commercial ionic liquid−chitosan composite membranes) whose selective layers possess different hydrophobic and hydrophilic characteristics for the separation of CO2/CH4 mixtures. The study of the technical performance of the selected membranes can provide a better understanding of their potentiality. The optimization of the performance of hollow fiber modules for both types of membranes was carried out by a “distance-to-target” approach that considered multiple objectives related to the purities and recovery of both gases. The results demonst... [more]

Argon oxygen decarburization stainless steel slag (AOD slag) has high mineral carbonation activity. AOD slag carbonation has both the resource utilization of metallurgical waste slag and the carbon reduction effect of CO2 storage. This paper aimed to study carbonation reaction characteristics of AOD slag. Under the slurry-phase accelerated carbonation route, the effect of stirring speed (r) and reaction temperature (T) on AOD slag’s carbonation was studied by controlling the reaction conditions. Mineral composition analysis and microscopic morphology analysis were used to explore the mineral phase evolution of AOD slag during the carbonation process. Based on the unreacted core model, the kinetic model of the carbonation reaction of AOD slag was analyzed. The results showed that the carbonation ratio of AOD slag reached its maximum value of 66.7% under the reaction conditions of a liquid to solid ratio (L/S) of 8:1, a CO2 partial pressure of 0.2 MPa, a stirring speed of 450 r·min−1, an... [more]

Currently, one of the biggest concerns of human beings is greenhouse gas emissions, especially carbon dioxide emissions in developed and under-developed countries. In this study, connectionist models including LSSVM (Least Square Support Vector Machine) and evolutionary methods are employed for predicting the amount of CO 2 emission in six Latin American countries, i.e., Brazil, Mexico, Argentina, Peru, Chile, Venezuela and Uruguay. The studied region is modelled based on the available input data in terms of million tons including oil (million tons), gas (million tons oil equivalent), coal (million tons oil equivalent), R e w (million tons oil equivalent) and Gross Domestic Product (GDP) in terms of billion U.S. dollars. Moreover, the available patents in the field of climate change mitigation in six Latin American countries, namely Brazil, Mexico, Argentina, Peru, Chile, Venezuela and Uruguay, have been reviewed and analysed. The results show that except Venezuela, a... [more]

Clean methanol can play an important role in achieving net zero emission targets by decarbonizing the energy and chemical sectors. Conventionally, methanol is produced by using fossil fuel as raw material, which releases a significant amount of greenhouse gases (GHGs) into the environment. Clean methanol, which is produced by hydrogen (H2) from renewable sources (green H2) and captured carbon dioxide (CO2), is totally free from the influence of fossil fuel. Due to its vast applications, clean methanol has potential to substitute for fossil fuels while preventing further GHGs emissions. This review addresses the feasibility of producing clean methanol from renewable resources, i.e., green H2 and captured CO2. Availability of these raw materials is the main factor involved in establishing the circular economy of methanol, therefore, their potential sources and the possible pathways to access these sources are also summarized. Renewable energy sources such as solar, wind and biomass shoul... [more]