Environmental quality in India: Application of environmental Kuznets curve and Sustainable Human Development Index

This study explores the trend of selected air pollutants, carbon dioxide (CO₂), nitrogen dioxide NO₂), sulfur dioxide (SO₂) and particulate matter 10 microns in diameter (PM₁₀) in India. Environmental Kuznets curves (EKC), which show the association of the economy and pollution, are fitted for selected Indian states to understand whether EKC in India fits well with the inverted “U” shape. We observed that CO₂ and PM₁₀ are steadily increasing in India. The states of Kerala and Punjab follow the inverted “U” shape of EKC, while Bihar, Uttar Pradesh, West Bengal, and Maharashtra may take decades to reduce pollutants. A new Sustainable Human Development Index calculated in this paper indicates a diverse picture of Indian states, especially in regard to environmental parameters. The government needs to implement stringent, state‐specific laws and regulations to assist in curbing air pollutants. The time has also come to represent the rankings of states in terms of an environmentally inclusive development index.     

Comparison and application of different component municipal solid wastes based carbon on adsorption of carbon dioxide

The prepared different components municipal solid wastes based carbons were used to investigate the adsorption of CO₂. The optimum conditions for CO₂ adsorption were investigated firstly. And then, the CO₂ adsorption performance of different components based carbon adsorbents were compared with each other under the optimum parameters. The results illustrated that the triple components (pinewood, acrylic textile, and tire) based carbon exhibited the best adsorption performance, which is 1.522 mmol/g and its physical prosperity was also conducted to interpret the adsorption mechanism. Besides, to further approach to the actual gas, the influence of additional O₂ and SO₂ on CO₂ adsorption properties of ternary-component-based carbon was investigated. The results illustrate that O₂ concentration exerts little effect on adsorption capacity. SO₂ plays the dominated role in the competitive adsorption effect.     

Synthesis and characterization of zwitterionic carbon dioxide fixing reagents

The synthesis of three amine-based carbon dioxide fixing reagents is presented. The reagents were designed so that they would be able to bind CO₂ reversibly through the formation of the well known carbamates that was stabilized through forming a zwitterion. CO₂ fixing experiments were performed with ¹³CO₂ labeling and medium pressure NMR. The experiments showed that two of the three reagents were able to form carbamates and thus bind CO₂. In addition we investigated this particular class of molecules for the possible formation of neutrally charged spiro compounds and we show that these did not form under the conditions studied.     

Kinetics of sulfur dioxide- and oxygen-induced degradation of aqueous monoethanolamine solution during CO2 absorption from power plant flue gas streams

Studies of the kinetics of sulfur dioxide (SO₂)- and oxygen (O₂)-induced degradation of aqueous monoethanolamine (MEA) during the absorption of carbon dioxide (CO₂) from flue gases derived from coal- or natural gas-fired power plants were conducted as a function of temperature and the liquid phase concentrations of MEA, O₂, SO₂ and CO₂. The kinetic data were based on the initial rate which shows the propensity for amine degradation and obtained under a range of conditions typical of the CO₂ absorption process (3–7 kmol/m³ MEA, 6% O₂, 0–196 ppm SO₂, 0–0.55 CO₂ loading, and 328–393 K temperature). The results showed that an increase in temperature and the concentrations of MEA, O₂ and SO₂ resulted in a higher MEA degradation rate. An increase in CO₂ concentration gave the opposite effect. A semi-empirical model based on the initial rate, ?r_MEA = {6.74 × 10⁹ e^?(29,403/RT)[MEA]^0.02([O]^2.91 + [SO₂]^3.52)}/{1 + 1.18[CO₂]^0.18} was developed to fit the experimental data. With the higher order of reaction, SO₂ has a higher propensity to cause MEA to degrade than O₂. Unlike previous models, this model shows an improvement in that any of the parameters (i.e. O₂, SO₂, and CO₂) can be removed without affecting the usability of the model.     

Separation and recovery of carbon dioxide by a membrane flash process

A novel process for carbon dioxide (CO₂) separation, which was named a membrane flash process, was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The electric energy for CO₂ recovery in a membrane flash process using aluminum oxide and diethanolamine was lower than the thermal energy of the conventional chemical absorption process. Flashing at elevated temperature by the low temperature energy significantly reduced the electric energy and required much less membrane area. This process has potentiality of low cost capture of CO₂ when the low temperature energy, which is not available for other purposes, can be utilized to elevate flashing temperature.     

Experimental measurement and modeling of the rate of absorption of carbon dioxide by aqueous ammonia

In this work, the rate of absorption of carbon dioxide by aqueous ammonia solvent has been studied by applying a newly built wetted wall column. The absorption rate in aqueous ammonia was measured at temperatures from 279 to 304 K for 1 to 10 wt% aqueous ammonia with loadings varying from 0 to 0.8 mol CO₂/mol NH₃. The absorption rate in 30 wt% aqueous mono-ethanolamine (MEA) was measured at 294 and 314 K with loadings varying from 0 to 0.4 as comparison.It was found that at 304 K, the rate of absorption of carbon dioxide by 10 wt% NH₃ solvent was comparable to the rates for 30 wt% MEA at 294 and 314 K (a typical absorption temperature for this process). The absorption rate using ammonia was however significantly lower at temperatures of 294 K and lower as applied in the Chilled Ammonia Process. However, at these low temperatures, the rate of absorption in ammonia has only a small temperature dependency.The rate of absorption decreases strongly with decreasing ammonia concentrations and increasing CO₂ loadings.The rate of absorption of carbon dioxide by aqueous ammonia solvent was modeled using the measurements of the unloaded solutions and the zwitter-ion mechanism. The model could successfully predict the experimental measurements of the absorption rate of CO₂ in loaded ammonia solutions.     

Panel heterogeneous distribution analysis of trade and modernized agriculture on CO2 emissions: The role of renewable and fossil fuel energy consumption

In line with the global target of reducing climate change and its impact, this study explored the causal relationship between CO₂ emissions, modernized agriculture, trade openness, aggregate and disaggregate energy consumption in 14 African countries from 1990–2013 using a panel quantile estimation procedure. The empirical results showed that value addition to agricultural commodities declines CO₂ emissions in countries with high pollution levels. The study revealed a positive nexus between CO₂ emissions and energy consumption homogeneously distributed across quantiles. Trade openness was found to lower CO₂ emissions in countries with lower and higher levels of environmental pollution. While fossil fuel energy consumption was found to exacerbate CO₂ emissions, renewable energy consumption confirmed its mitigating effect on environmental pollution. The institution of climate‐smart agricultural options will sustainably increase productivity and income while adapting to climate change by reducing greenhouse gas emissions. Diversification of energy technologies with clean and modern energy sources like renewables avoid the over‐dependence on fossil fuels for agricultural purposes. Trade policies can stimulate flows of technology and investment opportunities for specialization in production and economies of scale. Hence, the consideration of policies that boost agricultural sector productivity and create an efficient market for international trade in Africa will help in improving livelihoods.     

Carbon dioxide capture and recovery by means of TSA and/or VSA

Experimental work is performed with a 5A zeolite on a small laboratory column with heating from the wall. Carbon dioxide adsorption occurs at atmospheric pressure and different CO₂ concentrations in nitrogen. Comparisons of different methods of desorption by heating, purge and/or vacuum are studied. Desorption by heating only leads to almost pure CO₂ (around 99% purity) and a recovery nearly linear to the heating temperature, ranging from 45% at 130 °C to 79% at 210 °C. Recovery can be subsequently increased with a nitrogen purge to more than 98% but the recovered carbon dioxide is diluted due to the dispersive character of the desorption wave and the operation time is long. Increasing the flow rate decreases the desorption time but has no effect on the purity because the total purge volume remains about the same. Substitution of the purge step with a vacuum step leads to pure CO₂ and almost total recovery. Desorption under vacuum only without heating leads to pure CO₂ (around 99% purity) but limited recovery (85% in the present work).Desorption under vacuum seems to be more simple for large-scale applications. When using a water liquid ring pump, the temperature of the ring must be kept as low as possible to provide a high operating capacity.     

A statistical analysis of the carbon dioxide capture process

Post combustion carbon dioxide (CO₂) capture is one of the most commonly adopted technologies for reducing industrial CO₂ emissions, which is now an important goal given the widespread concern over global warming. Research on amine-based CO₂ capture has mainly focused on improving effectiveness and efficiency of the CO₂ capture process. Our research work focuses on studying the relationships among the significant parameters influencing CO₂ production because an enhanced understanding of the intricate relationships among the parameters involved in the process is critical for improving efficiency of the CO₂ capture process. This paper presents a statistical study that explores the relationships among parameters involved in the amine-based post combustion CO₂ capture process at the International Centre for CO₂ Capture (ITC) located in Regina, Saskatchewan of Canada. A multiple regression technique has been applied for analysis of data collected at the CO₂ capture pilot plant at ITC. The parameters have been carefully selected to avoid issues of multicollinearity, and four mathematical models among the key parameters identified have been developed. The models have been tested, and accuracy of the models is found to be satisfactory. The models developed in this study describe part of the CO₂ capture process and can help to predict performance of the CO₂ capture process at ITC under different conditions. Some results from a preliminary validation process will also be presented.     

Intermediate storage of carbon dioxide in geological formations: A technical perspective

Enhanced oil recovery (EOR) through CO₂ flooding has been practiced on a commercial basis for the last 35 years and continues today at several sites, currently injecting in total over 30 million tons of CO₂ annually. This practice is currently exclusively for economic gain, but can potentially contribute to the reduction of emissions of greenhouse gases provided it is implemented on a large scale. Optimal operations in distributing CO₂ to CO₂-EOR or enhanced gas recovery (EGR) projects (referred to here collectively as CO₂-EHR) on a large scale and long time span imply that intermediate storage of CO₂ in geological formations may be a key component. Intermediate storage is defined as the storage of CO₂ in geological media for a limited time span such that the CO₂ can be sufficiently reproduced for later use in CO₂-EHR. This paper investigates the technical aspects, key individual parameters and possibilities of intermediate storage of CO₂ in geological formations aiming at large scale implementation of carbon dioxide capture and storage (CCS) for deep emission reduction. The main parameters are thus the depth of injection and density, CO₂ flow and transport processes, storage mechanisms, reservoir heterogeneity, the presence of impurities, the type of the reservoirs and the duration of intermediate storage. Structural traps with no flow of formation water combined with proper injection planning such as gas-phase injection favour intermediate storage in deep saline aquifers. In depleted oil and gas fields, high permeability, homogeneous reservoirs with structural traps (e.g. anticlinal structures) are good candidates for intermediate CO₂ storage. Intuitively, depleted natural gas reservoirs can be potential candidates for intermediate storage of carbon dioxide due to similarity in storage characteristics.     

Mineral sequestration of carbon dioxide in basalt: A pre-injection overview of the CarbFix project

In this paper we describe the thermodynamic and kinetic basis for mineral storage of carbon dioxide in basaltic rock, and how this storage can be optimized. Mineral storage is facilitated by the dissolution of CO₂ into the aqueous phase. The amount of water required for this dissolution decreases with decreased temperature, decreased salinity, and increased pressure. Experimental and field evidence suggest that the factor limiting the rate of mineral fixation of carbon in silicate rocks is the release rate of divalent cations from silicate minerals and glasses. Ultramafic rocks and basalts, in glassy state, are the most promising rock types for the mineral sequestration of CO₂ because of their relatively fast dissolution rate, high concentration of divalent cations, and abundance at the Earth's surface. Admixture of flue gases, such as SO₂ and HF, will enhance the dissolution rates of silicate minerals and glasses. Elevated temperature increases dissolution rates but porosity of reactive rock formations decreases rapidly with increasing temperature. Reduced conditions enhance mineral carbonation as reduced iron can precipitate in carbonate minerals. Elevated CO₂ partial pressure increases the relative amount of carbonate minerals over other secondary minerals formed. The feasibility to fix CO₂ by carbonation in basaltic rocks will be tested in the CarbFix project by: (1) injection of CO₂ charged waters into basaltic rocks in SW Iceland, (2) laboratory experiments, (3) studies of natural analogues, and (4) geochemical modelling.     

Energy Use and Sulphur Dioxide Emissions in Asia

This paper presents a review of energy use in 22 selected countries of Asia and estimates the anthropogenic emission of sulphur dioxide (SO₂) for the selected countries, both at national and disaggregated sub-country regional levels. The paper also makes a comparative assessment of the Asian countries in terms of SO₂emission intensity (i.e. emission per GDP), emission per capita and emission density (i.e. emission per unit area). Total SO₂emission in the region was estimated to be about 38 million tons in 1990. Five countries, China, India, South Korea, Japan and Thailand, accounted for over 91% of the regional SO₂emission. Coal use had the dominant share (81%) of the total emission from the region. Among the economic sectors, industry contributed the largest share (49%) to the total emissions of the selected countries as a whole, followed by the power sector (30%). These findings suggest the need for mitigation strategies focussed on the industry and power sectors of the major emitting countries in Asia.     

Limitations for brine acidification due to SO2 co-injection in geologic carbon sequestration

Co-injection of sulfur dioxide during geologic carbon sequestration can cause enhanced brine acidification. The magnitude and timescale of this acidification will depend, in part, on the reactions that control acid production and on the extent and rate of SO₂ dissolution from the injected CO₂ phase. Here, brine pH changes were predicted for three possible SO₂ reactions: hydrolysis, oxidation, or disproportionation. Also, three different model scenarios were considered, including models that account for diffusion-limited release of SO₂ from the CO₂ phase. In order to predict the most extreme acidification potential, mineral buffering reactions were not modeled. Predictions were compared to the case of CO₂ alone which would cause a brine pH of 4.6 under typical pressure, temperature, and alkalinity conditions in an injection formation. In the unrealistic model scenario of SO₂ phase equilibrium between the CO₂ and brine phases, co-injection of 1% SO₂ is predicted to lead to a pH close to 1 with SO₂ oxidation or disproportionation, and close to 2 with SO₂ hydrolysis. For a scenario in which SO₂ dissolution is diffusion-limited and SO₂ is uniformly distributed in a slowly advecting brine phase, SO₂ oxidation would lead to pH values near 2.5 but not until almost 400 years after injection. In this scenario, SO₂ hydrolysis would lead to pH values only slightly less than those due to CO₂ alone. When SO₂ transport is limited by diffusion in both phases, enhanced brine acidification occurs in a zone extending only 5 m proximal to the CO₂ plume, and the effect is even less if the only possible reaction is SO₂ hydrolysis. In conclusion, the extent to which co-injected SO₂ can impact brine acidity is limited by diffusion-limited dissolution from the CO₂ phase, and may also be limited by the availability of oxidants to produce sulfuric acid.     

Unveiling the liaison between human capital,trade openness,and environmental sustainability for BRICS economies: Robust panel-data estimation

Global warming and greenhouse gas emissions pose severe threats to environmental sustainability. A sustainable environment is a prerequisite for long-term socioeconomic growth and human survival. Green technology is brought about by a country's economic and financial openness, and education provides knowledge to the public and labor, contributing to environmental sustainability. Thus, this research aims to unveil the liaison between human capital, trade openness, and environmental quality for Russia, Brazil, India, China, and South Africa (BRICS) countries from 1998 to 2018. Several econometric methods, including the Driscoll–Kraay standard errors and the Dumitrescu–Hurlin causality approaches, reveal long-run and causal relationships among the modelled indicators. The Driscoll–Kraay standard error results show that human capital is negatively related to carbon dioxide emissions (CO₂ emissions). Imposing high tariffs and excise duties, changing tax structures, discouraging the inflow of polluted commodities, and encouraging green trade can help BRICS combat high environmental pollution. The results show that a one-point increase in human capital in models 1 and 2 can reduce CO₂ emissions by 1.5279 and 0.1538 points, respectively. In contrast, a 1% growth in trade can lead to a rise in CO₂ emissions of 0.3731% and 0.2384%, respectively. Similarly, financial development and energy consumption result in high CO₂ emissions in the long run. Moreover, a feedback effect of the human capital index on CO₂ emissions is discovered. As a result of the findings, the government and responsible authorities should provide financial support and encourage investments in the region's energy-resourceful and sustainable green projects.     

Reduction of CaSO4 oxygen carrier with coal in chemical-looping combustion: Effects of temperature and gasification intermediate

Chemical-looping combustion (CLC) has been suggested as an energy efficient method for the capture of carbon dioxide from combustion. Thermodynamics and kinetics of CaSO₄ reduction with coal via gasification intermediate in a CLC process were discussed in the paper, with respect to the CO₂ generating efficiency, the environmental factor and the surface morphology of oxygen carrier. Tests on the combined process of coal gasification and CaSO₄ reduction with coal syngas were conducted in a batch fluidized bed reactor at different reaction temperatures and with different gasification intermediates. The products were characterized by gas chromatograph, gas analyzers and scanning electron microscope. And the results showed that an increase in the reaction temperature aggravated the SO₂ emission. The CO₂ generating efficiency also increased with the temperature, but it decreased when the temperature exceeded 950 °C due to the sintering of oxygen carrier particles. The use of CO₂ as gasification intermediate in the fuel reactor had a positive effect on the sintering-resistant of oxygen carrier particles. However, increasing the steam/CO₂ ratio in gasification intermediate evidently enhanced CO₂ generating efficiency and reduced SO₂ environmental impact.     

Toward sustainable use of natural resources: Nexus between resource rents,affluence, energy intensity and carbon emissions in developing and transition economies

Sustainable use of natural resources would entail ensuring that derived economic benefits today do not undermine the welfare of generations to come. On this basis, this study examines the nexus between natural resource rents and carbon dioxide (CO₂) emissions disaggregated into production and consumption-based (i.e., trade-adjusted) CO₂ emissions for a selected panel of 45 developing and transition economies over the period 1995–2017. The empirical model also incorporates the impacts of population, affluence, and energy intensity. The results show that affluence increases production-based CO₂ emissions by 1.407%, with the EKC's predicted inverted U-shaped curve only explaining consumption-based CO₂ emissions. Economic reliance on natural resource rents and energy intensification contribute 0.022% and 0.766%, respectively, to CO₂ emissions embedded in territorial production inventories and 0.035% and 0.583%, respectively, to CO₂ emissions embedded in consumption inventories. The bootstrap non-causality test shows that historical data on each variable has significant predictive power for future CO₂ emissions from both sources. The historical information about natural resource rents has significant predictive power over the future levels of affluence and energy intensity. Clearly, the results show that the environmental impact of natural resource rents is stronger when CO₂ emissions are adjusted for trade and varies among the countries, with Bangladesh, Guinea, India, Malaysia, Mexico, Nigeria, Pakistan, Saudi Arabia, Vietnam, and Zimbabwe among the most affected countries. Overall, this study provides motivation for policies to keep the use of natural resources within sustainable limits.     

Energy and carbon dioxide intensity of Thailand's steel industry and greenhouse gas emission projection toward the year 2050

The purpose of this article is to study the energy and carbon dioxide intensities of Thailand's steel industry and to propose greenhouse gas emission trends from the year 2011 to 2050 under plausible scenarios. The amount of CO₂ emission from iron and steel production was calculated using the 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines in the boundary of production process (gate to gate). The results showed that energy intensity of semi-finished steel product was 2.84 GJ/t semi-finished steel and CO₂ intensity was 0.37 tCO_2eq/t semi-finished steel. Energy intensity of steel finishing process was 1.86 GJ/t finished steel and CO₂ intensity was 0.16 tCO_2eq/t finished steel. Using three plausible scenarios from Thailand's steel industry, S1: without integrated steel plant (baseline scenario), S2: with a traditional integrated BF–BOF route and S3: with an alternative integrated DR-EAF route; the Greenhouse Gas emissions from the year 2011 to 2050 were projected. In 2050, the CO₂ emission from S1 (baseline scenario) was 4.84 million tonnes, S2 was 21.96 million tonnes increasing 4.54 times from baseline scenario. The CO₂ emission from S3 was 7.12 million tonnes increasing 1.47 times from baseline scenario.     

The impact of electric passenger transport technology under an economy-wide climate policy in the United States: Carbon dioxide emissions,coal use,and carbon dioxide capture and storage

Plug-in hybrid electric vehicles (PHEVs) have the potential to be an economic means of reducing direct (or tailpipe) carbon dioxide (CO₂) emissions from the transportation sector. However, without a climate policy that places a limit on CO₂ emissions from the electric generation sector, the net impact of widespread deployment of PHEVs on overall U.S. CO₂ emissions is not as clear. A comprehensive analysis must consider jointly the transportation and electricity sectors, along with feedbacks to the rest of the energy system. In this paper, we use the Pacific Northwest National Laboratory's MiniCAM model to perform an integrated economic analysis of the penetration of PHEVs and the resulting impact on total U.S. CO₂ emissions. In MiniCAM, the deployment of PHEVs (or any technology) is determined based on its relative economics compared to all other methods of providing fuels and energy carriers to serve passenger transportation demands. Under the assumptions used in this analysis where PHEVs obtain 50–60% of the market for passenger automobiles and light-duty trucks, the ability to deploy PHEVs under the two climate policies modelled here results in over 400 million tons (MT) CO₂ per year of additional cost-effective emissions reductions from the U.S. economy by 2050. In addition to investments in nuclear and renewables, one of the key technology options for mitigating emissions in the electric sector is CO₂ capture and storage (CCS). The additional demand for geologic CO₂ storage created by the introduction of the PHEVs is relatively modest: approximately equal to the cumulative geologic CO₂ storage demanded by two to three large 1000 megawatt (MW) coal-fired power plants using CCS over a 50-year period. The introduction of PHEVs into the U.S. transportation sector, coupled with climate policies such as those examined here, could also reduce U.S. demand for oil by 20–30% by 2050 compared to today's levels.     

Adsorption of carbon dioxide using impregnated activated carbon promoted by Zinc

The effect of impregnation of activated carbon with Cr₂O and Fe₂O₃ and promotion by Zn²⁺ on its adsorptive properties of carbon dioxide was studied using a volumetric adsorption apparatus at ambient temperature and low pressures. Slurry and solution impregnation methods were used to compare CO₂ capture capacity of the impregnated activated carbon promoted by Zinc. The obtained adsorption isotherms showed that amount of CO₂ adsorbed on the samples impregnated by Cr₂O was increased about 20% in compare to raw activated carbon. The results also showed that Fe₂O₃ was not an effective impregnating species for activated carbon modification. Moreover slurry impregnation method showed higher CO₂ adsorption capacity in comparison with solution impregnation method. Samples prepared by co-impregnation of two metal species showed more adsorption capacity than samples impregnated by just one metal species individually. Washing the impregnated samples by metal oxide resulted in 15% increase in CO₂ adsorption capacities of activated carbons which can be attributed to the metal oxides removal covering the adsorption surface. Decreasing impregnation temperature from 95 to 25 °C in solution method showed a significant increase in CO₂ adsorption capacity. Sips equation was found a suitable model fitting to the adsorption data in the range studied.     

Hollow fiber membrane separation process in the presence of gaseous and particle impurities for post-combustion CO2 capture

The membrane separation process for CO₂ capture can be interfered by the gaseous components and the fine particles in flue gas, especially in desulfurized flue gas. In this work, the pint-sized Polyimide(PI) hollow fiber membrane contactors were self-packed to investigate the membrane CO₂ separation from flue gas containing fine particles and gaseous contaminants (SO₂,SO₃,H₂O). First, the effects of SO₂, SO₃, water vapor, and gypsum particles on the CO₂ capture were studied independently and synergistically. The results showed that the effect of SO₂ on the membrane separation properties is indistinctive; however, the membrane performance was damaged seriously with the addition of SO₃. The high humidity promoted the CO₂ separation initially before inhibiting the PI membrane performance. Moreover, the decrease of the CO₂/N₂ selectivity and the permeation rate were accelerated with the coexistence of SO₂. The membrane performance showed an obvious deterioration in the presence of gypsum particles, with a 21% decrease in the CO₂/N₂ selectivity and 51% decrease in the permeation rate. Furthermore, the gypsum particles exerted dramatic damage. Under the WFGD conditions, the combined effects of SO₂, water vapor, and the gypsum particles influenced the stability of the membrane significantly. This tendency is mainly attributed to the deposition of fine particles and aerosol on the membrane surface, which occupied the effective area and enhanced the mass transfer resistance. This study of impurities’ influence could play an important role in further industrial application of membrane CO₂ capture.