CO2 Gas Emissions Research Articles

A preliminary study of mechanical treatments’ effect on the reactivation of hydrated cement paste

More than 4.4 billion metric tons of cement were produced in 2021 [1], making it one of the most common building materials. Unfortunately, excessive cement use brings up several environmental concerns, one being the enormous volumes of CO2e (carbon dioxide equivalent) created as a by-product. CO2e is a standard unit for measuring carbon footprint and can be calculated for all greenhouse gases using global warming potential. Reducing CO2 and other greenhouse gas emissions is crucial in modern cement manufacturing, as 0.9 kg of CO2e is produced for every kg of cement. Cement manufacturing contributed by releasing 3.96 Gt of CO2e into the atmosphere in 2021. This issue is often remedied using recycled materials in the fresh concrete mix as supplementary or pozzolanic additives. Some researchers have focused on regaining the activity of hydrated cement paste by grinding and thermally activating it [2–5], but a low-strength binder would also work for many applications. A low-strength binder recovered with as little energy as possible (only grinding, no heat treatment) could be considered a more sustainable and less energy-intensive way of recovery of the cement binder matrix. This study investigated a technique for recycling hydrated cement paste by mechanical treatment to disintegrate the hydrated cement conglomerate to reveal the unhydrated cement particles [6] that can be used as a recovered cementitious binder from processing waste from the production of wood-cement boards. Processing waste is defined as cement particles containing hydrated and unhydrated cement [7] and spruce wood fibres. The partly hydrated cement in the waste stream was mechanically processed in a planetary mill to reactivate it and restore its cementitious characteristics. The binder was characterized by density and mechanical compressive strength.

Characteristics of SI engine fueled with BE50-Isooctane blends with different ignition timings

The effect of various ignition timing on spark ignition (SI) engines with bioethanol-isooctane mixtures has been widely studied. In the present studies, we used three different ignition angle positions, namely 9°, 12°, and 15° BTDC to increase the combustion pressure in the combustion chamber. In addition to macroscopic observations through engine performance, observations are also carried out from a molecular perspective, i.e.; atomic, bond, and bond angle properties of bioethanol-isooctane fuel. The result shows that more atoms of the isooctane carbon chain are non-rotatable (23 atomic bonds) than the 8 bonds of the bioethanol carbon chain. Furthermore, isooctane also has a wider bond angle (around 121.1745°) than the bond angle of ethanol (around 110.0476°). The unique properties of the atoms in the carbon chains of these two fuels have a direct impact on engine performance. The results show that the viscosity of bioethanol is lower when compared to isooctane, which indicates that the bioethanol molecules are more reactive and flammable. The result also found that at an ignition angle of 12° the BE50 engine has the best performance. Moreover, the test results also show that bioethanol produces clean combustion as evidenced by the lowest CO and HC gas emissions.

Utilization of Biopertalite for Fuel Efficiency and Reduction in CO and CO2 Gas Emissions in Four-Wheel Motor Vehicles

Emissions of carbon monoxide (CO) and carbon dioxide (CO2) gases are the main problem that must be rectified as they are harmful and contribute to global warming through the greenhouse gas effect. In Indonesia, motor vehicles, especially four wheelers, are one of the biggest contributors with up to 71 million tons of CO2 emissions and energy consumption of 179 million barrel of oil equivalent. Bioethanol has octane rating >100, which is higher than that of gasoline; and emission contribution of only 0.02 kg/L, which is lower than that from gasoline (2.23 kg/L). Accordingly, a mixture of gasoline and bioethanol is the solution proposed in this study to solve the issues of CO and CO2 emissions. Gasoline and bioethanol mixture consists of six products, namely E-0, E-5, E-10, E-15, E-20, and E-25, which have different percentage values of bioethanol mixture (0%–25%). This study was conducted through engine testing with different rpm values (500–2500 rpm) to identify the concentration and mass of CO2 emissions, fuel efficiency, and cost efficiency. Based on the test results, this product succeeded in reducing CO emissions by up to 86% and CO2 emissions up to 30.6% from Pertalite (E-0) and increasing the fuel efficiency up to 51.76% for 1 L and cost efficiency up to 33.6% after considering the actual price of Pertalite. Therefore, the proposed product can be a solution to the existing problems.

Effects of split injection strategy on combustion stability and GHG emissions characteristics of natural gas/diesel RCCI engine under high load

Natural gas/diesel RCCI mode is considered as a high-efficiency clean low-temperature combustion strategy with great application prospects. In order to solve the problem that RCCI engines are prone to knock combustion under high load, the effects of diesel start of main-injection (SOImain), start of pilot-injection (SOIpilot) and pilot-injection quantity (PIQ) on in-cylinder combustion and pollutant emissions of RCCI engine were systematically investigated. Results show that the advance of SOImain effectively reduces CO, HC, soot and CH4 emissions of RCCI engine, but increases knock tendency and NOx emissions. Split injection strategy makes combustion exothermic of RCCI mode present two-stage heat release phenomenon. When SOIpilot is advanced from −15°CA ATDC to −27°CA ATDC, the IMEP and combustion pressure peak increase, the knock tendency significantly decreases, and CO, HC, soot and CH4 emissions are reduced by 55.6%, 43.1%, 28.8% and 39.1% respectively. With the increase of PIQ, the in-cylinder combustion of RCCI engine gradually changes from single-stage to two-stage heat release, the ignition delay is shortened, and the knock tendency is enhanced. Compared with single injection strategy, split injection strategy can simultaneously reduce HC, CO and greenhouse gas emissions, as well as maximum pressure oscillation amplitude and pressure rise rate in RCCI mode.

Green Concrete: An Eco-Friendly Alternative to the OPC Concrete

The popularity of concrete has resulted in the considerable consumption of natural resources and significant emission of CO2 gas into the atmosphere. The key constituents of the concrete are the cement and the natural aggregates. These major concrete elements are recommended to be replaced with other materials to solve sustainability issues. Hence, by-products like pulverized granular blast-furnace slag, fly ash, rice husk ash, silica fume, recycled coarse aggregates etc., are added to the concrete to utilize the waste products and produce sustainable concrete. Cement manufacturing accounts for 8 to 10% of total global CO2 emissions. The construction industry is progressively adopting green concrete use in buildings because of its inherent benefits and limitations of traditional concrete. Green concrete is available in a variety of forms such as high-volume fly ash concrete, alkali-activated concrete, recycled aggregate concrete, ultra-high performance concrete, geopolymer concrete etc. Green concrete has various environmental, technical, and economic advantages i.e., greater durability, enhanced workability, and pumpability, decreased permeability, controlled bleeding, higher acid resistance, and decreased plastic shrinkage cracking. These properties encourage faster concrete production, shorter curing times, lower construction costs, earlier project completion, lower maintenance costs, and longer service life of construction projects. This review article aims to comprehensively explain the fresh, hardened, and durability properties of green concrete and knowledge gaps in green concrete. The literature revealed that further research is needed to accurately assess the long-term properties, notably creep and shrinkage behaviour of structural or reinforced elements of green concrete.

The Effect of CO2 Gas Emissions on the Market Value, Price and Shares Returns

One thing that should be considered in environmental considerations and climate change is the transportation sector’s contribution to producing carbon dioxide. Unfortunately, in developing countries such as Iran, due to high tariff support, manufacturers have no incentive to improve the combustion quality of their products. Most likely, significant restrictions on CO2 emissions will be applied in the coming years, and companies whose activities or products are related to high-level greenhouse gas emissions will be affected by these restrictions. Therefore, due to the application of these restrictions, investors are most concerned about the risk associated with the return of purchased shares. Considering these cases, it can be expected that the risk related to carbon emissions will be reflected in the yield level and, thus, the stock price. Therefore, the present study deals with the effect of CO2 gas emissions on the market value, price and stock returns of Iranian automobile companies. The data collected as tabular data include six automobile companies from 2018–2019. By conducting various tests and panel data estimations, especially the dynamic panel data method, it was determined that CO2 emissions reduce stock prices, returns and market value of automobile companies. In addition, the results of the causality test indicate that the direction of causality is only from CO2 emissions to stock returns.

Using the IPCC Formula to Calculate CO2 Emissions from Everyday Motorized Vehicles as the Baseline for Climate Change Mitigation Policies

Climate change has attracted the attentions of every nation on earth, including Indonesia. Indonesia’s commitment to minimize greenhouse gas emissions through the ratification of the Kyoto decree in Law no. 17 / 2004. Other regulations for the National Action Plan for Reducing Carbon dioxide are regulated in Presidential Regulation No. 61/2011 and No. 7/2021 for the National Greenhouse Gas Inventory. The East Java provincial government adopted this policy through East Java’s Province Regulation No. 67/2012. This article predicted an increase in carbon dioxide from the daily vehicles. The study will be done in Jember, a third city in East Java Province. Data is calculated using IPCC formula. The secondary data from 2018 to 2020 was analyzed, as well as predictions for 2030. The number of motorized vehicles growth is 4.5% each year. CO2 emissions from the daily transportation sector will reach 3,846,049.49 tons in 2030. Motorcycles contribute 2,055,244.87 tons. CO2 gas emissions from the 8 main streets of the Jember Gold Triangle are 62,190.52 tons.

Evaluation of the technical parameters of the generator for efficient electricity generation in low-speed wind and water flows

This article analyzes the literature on the choice of generators for power devices that can work effectively with wind and water currents in the climatic conditions of Uzbekistan. In most of the territory of our republic, low-speed winds and water currents prevail. Efficient use of these flows makes it possible to save fuel and energy resources and thereby reduce the emission of CO2 gas into the atmosphere. Based on the analysis of the literature, the factors of using an electric generator capable of operating efficiently even at low rotation speeds are analyzed. The article deals with scientific research carried out in recent years on generators with radial and axial magnetic flux

LESSONS FROM VIETNAM’S SOLAR POWER PLANT GROWTH DEVELOPMENT FOR INDONESIA TO REACH NET ZERO EMISSION

CO2 gas emissions are increasingly massive, one of which is caused by the generation of energy from fossils in many countries that poses a threat to climate change. The global world has agreed on the Paris Agreement in 2016 to reduce carbon emissions in 2050. ASEAN countries are also taking concrete steps, especially in the electricity sector by seeking renewable energy sources. At present Vietnam has succeeded in becoming the leading country in ASEAN in the solar power development sector in order to meet its electricity needs and also in order to reduce carbon emissions. Indonesia is one of the countries that has ratified the agreement has made a "grand strategy" for the development of solar power plant which aims to reduce the use of fossil energy and national carbon emissions by 2060. This paper aims to provide a comparative study between Vietnam and Indonesia in terms of policy and implementation of solar power plant development to date. The methodology that the authors use in this study is a qualitative research with a descriptive approach to provide a holistic picture. The method of this study applied two steps, i.e. systemic literature review and comparative observation between Vietnam and Indonesia. The data obtained was also reviewed from state documents, academic literature, to media bold that are relevant to this research. Conclusively, the author managed to review that Vietnam is far more successful with several advantages that Indonesia can emulate which is still hampered from developing solar power plant in the near future.

The Impact of Technology and Government Policies on OECD Carbon Dioxide Emissions

This study investigated the effect of technology and government policies on carbon dioxide (CO2) emissions in 36 Organisation for Economic Co-operation and Development (OECD) countries from 1994 to 2015. This empirical investigation uses econometric models, such as panel quantile regression and ordinary least squares (OLS). The research uses the method proposed by Lin and Ng in 2015 to deal with parameter heterogeneity across countries that identified two separate groups. The empirical results indicated that Gross Domestic Product (GDP), fossil fuel consumption, industrialisation and taxation to GDP intensify CO2 emissions. In contrast, urbanisation (% of the total population), environmental patents, and environmental tax as a percentage of total tax reduce CO2 gas emissions. Estimates with homogeneity preserve the signs of the parameters but reveal substantial differences in intensity and that environmental tax revenues (as % of GDP and % of tax) are only statistically significant for our studied group 1. The conclusions of this study have important policy implications. The effect of industrialisation on environmental degradation is an observable fact. When the country reaches the allowable thresholds, it needs to maximize energy consumption. Policymakers should design policies that help them to promote environmentally sustainable economic growth by imposing and accumulating environmental taxes. In addition, environmental taxes, the discharge system and credit could support the modification of in-industrial structures and modes of economic growth. Policymakers should also use policies that encourage trade in nuclear-generated electricity to neighbouring OECD countries.

Sustainable production of cement masonry blocks with the combined use of fly ash and quarry waste

Cement-sand block is a primary construction material used for masonry house units. River sand and cement are the two main ingredients in cement block construction; however, cement is notoriously unfriendly to the environment due to excessive energy consumption during cement manufacture and considerable CO2 and other greenhouse gas emissions. Overusing river sand has several adverse effects on the environment and society, including a deepening of the riverbed, a decline in the water table, and the extinction of freshwater aquatic life. Therefore, finding substitutes for cement and river sand has received much attention in recent years. It would be beneficial to use fly ash and quarry refuse for making masonry blocks since it would use less energy and cause less environmental damage. The present study emphasizes the combined use of quarry waste (100% substitute for river sand) and fly ash (0, 10, 20, 30 and 40% substitute for cement) for sustainable masonry block production. The physical, mechanical, and durability properties of cement blocks made using fly ash and quarry waste underwent a thorough investigation. Results showed that, even though the compressive strength and impact strength of masonry blocks decreased with fly ash content, the strength of masonry blocks with quarry waste and 40% fly ash was higher than that of conventional masonry blocks. The substitution of fly ash for cement potentially increased the alkaline and acid resistance and also improved the thermal performance. Also, the replacement of fly ash for cement in the masonry blocks significantly reduced the total cost, embodied energy and CO2 emission. It can be inferred from the study that using quarry waste as a full river sand substitute and fly ash as a partial cement substitute in masonry blocks is a cost-effective and sustainable method.

The Effects Energy Consumption, Export, GDP, and Import on Indonesia’s Emission of CO2

The purpose of this study is to examine the connection between exports, imports, GDP, and energy consumption on Indonesia's CO2 emissions used the World Bank data. This research is a type of quantitative research using VAR (Vector Autoregression) estimation. The data used comes from secondary data in a time series from 1971-2014. The data analysis technique in this study used the Vector-Autoregression (VAR) method. The tests performed include the optimum lag, Granger causality test, cointegration test, stationary test, VAR stability test, Impulse Response Function, and Variance Decontamination test. This study found that an increase in economic activity, in general, will affect an increase in CO2 gas emissions, which is caused by the large energy consumption of the economy. The increase in CO2 emissions will cause climate change, thus causing environmental damage. The Granger causality test analysis demonstrates the exports no one has any effect on CO2 emissions.So with imports, there is also no causality to CO2. The VAR analysis test also explains that export and import activities have no significant effect on increasing CO2 because both variables' values are higher than with the t-statistics' values. So, international trade has no effect on increasing CO2 and environmental degradation. According to the study's findings, CO2 emissions can rise as a result of energy usage.

Type-B Energetic Processes and Their Associated Scientific Implications

Recently, our work has identified two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth: Type-A energy processes such as the classical heat engines, ATP hydrolysis, and many of the known chemical, electrical, and mechanical processes apparently well follow the second law of thermodynamics; and Type-B energy processes, such as the newly discovered thermotrophic function that isothermally utilizes environmental heat energy to do useful work in driving ATP synthesis, which follows the first law of thermodynamics (conservation of mass and energy), but does not necessarily have to be constrained by the second law, owing to their special asymmetric functions. In mitochondria, their special asymmetric functions associated with Type-B processes comprise: 1) The transmembrane asymmetry of inner mitochondrial membrane structure with the protonic outlets of redox-driven proton-pumping protein complexes protruded away from the membrane surface by about 1-3 nm into the bulk liquid p-phase while the protonic inlet of the F0F1-ATP synthase located rightly at the transmembrane electrostatically localized proton (TELP) layer; and 2) The lateral asymmetry of mitochondrial cristae with an ellipsoidal shape that enhances the density of TELP at the cristae tips where the F0F1-ATP synthase enzymes are located in supporting the TELP-associated thermotrophic function. The identification of Type-B energy processes indicates that there is an entirely new world of physical and energy sciences yet to be fully uncovered. Innovative efforts on Type-B processes to enable isothermally utilizing endless environmental heat energy could help to liberate all peoples from their dependence of fossil fuel energy, thus helping to reduce greenhouse gas CO2 emissions and control climate change toward a sustainable future for the humanity on Earth.

Pyrolysis of four waste biomasses and elucidation of reaction kinetics and pyrolytic products

With the increase of bioenergy crops and the rapid development of agriculture, the total amount of solid waste is increasing rapidly. This study quantified the pyrolytic performance and gaseous products of spent coffee grounds (SCG), Chinese medicine residue (CMR), vinasse (VI) and camellia oil shell (COS) by using (derivative) thermogravimetric ((D)TG), Fourier transform infrared spectrometry (FTIR) and mass spectrometry (MS) analyses. There are two main stages of mass loss: volatilisation of volatiles and continuous decomposition of macromolecules. At a heating rate of 20°C/min, COS has the slowest pyrolysis rate compared to the other three. Model-free methods: Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were used to calculate the activation energy (E) of samples with different conversion rates (α). SCG and VI have the highest average activation energy (about 240kJ/mol), followed by CMR (200kJ/mol), and COS the lowest (175kJ/mol). FTIR was mainly used to detect functional group types (including hydroxyl, carbonyl, aldehyde and ester groups, etc.), while MS co-detected the characteristics of condensable/non-condensable gases (including H2O, CO2, NOx, SOx, C6H6, C7H8, C9H8 and other major gas emissions, pollutants and hydrocarbons). Nitrogen oxides are produced in the range of 500–800°C. SCG and VI emit more gas pollutants than CMR and COS.

The Impact of Transportation Restructuring on the Intensity of Greenhouse Gas Emissions: Empirical Data from China.

Adjusting transportation structure to reduce the intensity of greenhouse gas emissions is an effective way to address climate change issues. This paper selects six transport sectors and constructs a hybrid input-output model to study the impact of transportation restructuring on the intensity of CO2 and non-CO2 greenhouse gas emissions in each sector during different periods. The results show that the effect of transportation restructuring on greenhouse gas emissions is manifested differently in different time periods. After 2008, transportation restructuring had a significant effect on reducing the intensity of greenhouse gas emissions in all sectors. However, the impact of transportation restructuring on the intensity of non-CO2 greenhouse gas emissions is limited. It is also found that the railway transport sector has been a low-impact transport sector in terms of greenhouse gas emissions since 2004, which provides insights for the optimization of China’s transportation structure.

Optimization of Pulsed Polarization Condition for Efficient Electrochemical CO2 Reduction

Introduction Massive emission of CO2 gas from fossil fuel combustion causes the severe global greenhouse effect. Electrochemical reduction of CO2 using renewable energy has been attractive due to its simple methodology, while the conversion efficiency may be lessened due to undesirable side reactions such as water decomposition. In this study, CO2 was covered to CO on Ag electrode in aqueous KHCO3 solution using potentiostatic pulse polarization, and optimal pulse condition to improve the conversion efficiency was explored. Experiment An electrochemical cell was composed of a cathode compartment containing an Ag working electrode (W.E.) and an Ag/AgCl reference electrode and an anode compartment containing a Pt counter electrode. Two compartments were separated by a Nafion membrane. An Ag-W.E. was mechanically polished and potentiostatically pulse-polarized in a CO2-saturated 0.1 M KHCO3 solution to form CO. After some polarization period, the conversion efficiency ( η=[CO]/([CO]+[H2]) ) of CO2 to CO was evaluated by using gas chromatography as a function of various parameters such as cathodic polarization potential (E c) and time (t c), rest potential (E a) and time (t a), KHNO3 concentration, etc. Result and discussion When E c was varied, the highest η was obtained around –1.5 to –1.6 V. When t c was varied at E c = –1.6 V, the highest η was obtained around t c = 3 s, as shown in Fig. 1. The t a did not affect η. These results reveal that the t c influences the conversion efficiency viacontrolling the diffusion layer thickness of reactants such as CO2 molecular. The highest η at the optimal pulse condition was ca. 0.9 and is comparable to the value obtained by the previous work using ionic liquid solution (T. Oguma et al., Electrochemistry, 88 (2020) 451–456). Fig. 1. Relationship between the cathodic polarization time t c and reduction efficiency Figure 1

SUSTAINABLE UTILIZATION OF CROP RESIDUE AS BRIQUETTES

Reducing anthropogenic emission of CO2 and other greenhouse gases are important strategies for mitigating the greenhouse effect. Sustainable use of crop residue as a possible source of feedstock should be adequately assessed because of its potential impacts on soil carbon sequestration and good soil quality maintenance. Crop residue plays an important role in climate change mitigation without harming the food security. In the present work, an attempt to evaluate the CO2 emission released from the biomass briquettes compared to that from the coal and their cost benefit analysis has been carried out. The suitability of using biomass briquettes to substitute coal is debatable, as coal gives more production in the industry in less time than briquettes.

Evaluate consumption of electric energy of residential sector and its environmental and economic effects

The demand for electric power in Iraq increased significantly after 2003, The residential sector is the most consumption according to the statistics of the iraqi ministry of electricity (ICME) and the data published by the international energy agency (IEA). In this paper, a survey was applied for a sample of the population; whereby questionnaire models were used for some of the most energy consuming devices to determine the estimates of supply and demand for energy, and some data from the Iraqi Ministry of Electricity available until 2020 was relied on to predict the consumption of electrical energy for next ten years. Five Scenarios have been implemented for energy saving, CO2 gas emission and electricity production cost that reduce the accumulative energy consumed for the coming years.

Modeling and Analysis of Deforestation Prevention by Uncrewed Aerial Vehicles-based monitoring systems

The Brazilian Amazon is suffering from serious deforestation that may lead to catastrophic consequences for the world's climate and biodiversity. Preventing illegal deforestation activities is an emergent and crucial mission for the world. Recently, automated monitoring systems using Uncrewed Aerial Vehicles (UAVs) appear as a promising solution to combat deforestation. However, the quality design of such systems considering the deforestation prevention impacts remains under-explored. In this paper, we propose a socio-ICT (Information Communication Technology) model that enables to analyze the deforestation prevention impacts of a UAV-based monitoring system quantitatively. The socio-ICT model uses a causal loop diagram to formulate the relations among system quality measures and key performance indicators (KPIs) associated with deforestation prevention. Through the numerical study, we estimate the effectiveness of the UAV monitoring system by annual deforestation rate and CO2 gas emissions. Our analysis shows important design trade-offs need to be considered when planning UAV-based monitoring systems.

Composition of Flue Gases during Oxy-Combustion of Energy Crops in a Circulating Fluidized Bed

In recent years, global warming and climate change associated with emissions of CO2 from fossil fuel-fired power systems are a big worry for authorities in many countries worldwide. The utilization of biomass as an alternative, carbon-neutral fuel can reduce emissions of CO2 and other greenhouse gases. Furthermore, the coupling of oxy-combustion of biomass with CO2 capture is an option for carbon-negative power generation technology. In this study, emissions of NOx, SO2, and CO from the air- and oxy-combustion of three energy crops (Miscanthus giganteus, Sida hermaphrodita, and Salix viminalis) are presented and compared with emissions from other biomass fuels and reference coal. Combustion tests in air and O2/CO2 mixtures were conducted in a 12-kW bench-scale CFB combustor at 850 °C. Measurements of flue gas compositions were taken using an FTIR spectrometer. In all tested atmospheres, emissions of SO2, N2O, and CO for biomass were lower than those for the reference coal. The oxidation of volatile nitrogen compounds was behind high emissions of NOx from biomass burned in air and O2/CO2 mixtures. The lowest concentrations of NO were found in the 21% O2/70% CO2 mixture. Combustion in mixtures containing more oxygen (30% and 40% O2) led to a decrease in emissions of N2O and CO and an increase in emissions of NO and SO2.