scholarly journals Catalysts for the Simultaneous Production of Syngas and Carbon Nanofilaments Via Catalytic Decomposition of Biogas

2022 ◽  
Author(s):  
Buthainah Ali Al-Timimi ◽  
Zahira Yaakob

The possibility of alleviation of methane and carbon dioxide levels in the atmosphere are of major global interest. One of the alternatives that attracts much scientific attention is their chemical utilization, especially because both of these gases are components of the biogas. Thus, the rapid and extensive shale gas development makes them abundant raw materials. The development of an effective catalytic process that could be scaled-up for industrial purposes remains a great challenge for catalysis. As well, understanding of the mechanisms of molecular activation and the reaction pathways over active centers on heterogeneous catalysts needs to be advanced. It has been shown that biogas is a very interesting source of renewable energy. Because of its elevated methane content, biogas has excellent potential, as reflected in its year-over-year rise in production. This is because its manufacturing promotes the use of organic waste, prevents uncontrolled dumping and minimizes atmospheric methane and carbon dioxide emissions. Moreover, its use as an energy source is in some cases an alternative to fossil fuels and can help to minimize energy dependence. Another aspect of interest is that it can be used in situ, allowing agro-livestock farms or small industrial plants to achieve energy self-sufficiency.

2020 ◽  
pp. 1-18
Author(s):  
Yu.V. Bilokopytov ◽  
◽  
S.L. Melnykova ◽  
N.Yu. Khimach ◽  
◽  
...  

CO2 is a harmful greenhouse gas, a product of chemical emissions, the combustion of fossil fuels and car exhausts, and it is a widely available source of carbon. The review considers various ways of hydrogenation of carbon dioxide into components of motor fuels - methanol, dimethyl ether, ethanol, hydrocarbons - in the presence of heterogeneous catalysts. At each route of conversion of CO2 (into oxygenates or hydrocarbons) the first stage is the formation of CO by the reverse water gas shift (rWGS) reaction, which must be taken into account when catalysts of process are choosing. The influence of chemical nature, specific surface area, particle size and interaction between catalyst components, as well as the method of its production on the CO2 conversion processes is analyzed. It is noted that the main active components of CO2 conversion into methanol are copper atoms and ions which interact with the oxide components of the catalyst. There is a positive effect of other metals oxides additives with strong basic centers on the surface on the activity of the traditional copper-zinc-aluminum oxide catalyst for the synthesis of methanol from the synthesis gas. The most active catalysts for the synthesis of DME from CO2 and H2 are bifunctional. These catalysts contain both a methanol synthesis catalyst and a dehydrating component, such as mesoporous zeolites with acid centers of weak and medium strength, evenly distributed on the surface. The synthesis of gasoline hydrocarbons (≥ C5) is carried out through the formation of CO or CH3OH and DME as intermediates on multifunctional catalysts, which also contain zeolites. Hydrogenation of CO2 into ethanol can be considered as an alternative to the synthesis of ethanol through the hydration of ethylene. High activation energy of carbon dioxide, harsh synthesis conditions as well as high selectivity for hydrocarbons, in particular methane remains the main problems. Further increase of selectivity and efficiency of carbon dioxide hydrogenation processes involves the use of nanocatalysts taking into account the mechanism of CO2 conversion reactions, development of methods for removing excess water as a by-product from the reaction zone and increasing catalyst stability over time.


Author(s):  
Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali

Because of increased demand for electrical energy in the Kingdom of Saudi Arabia, which has resulted in an increase in carbon dioxide emissions, the electricity system in the Kingdom of Saudi Arabia is the largest in the Gulf region and the Arab world, with approximately 61.7 gigatons (GW) of peak demand and 89.2 gigatons (GW) of available capacity in 2018 of electricity power. It has grown rapidly over more than 20 years and has almost doubled in size since 2000. Where we observe that the total carbon dioxide emissions in the Kingdom of Saudi Arabia from 1990 to 2020; where shows rapid growth in emissions of carbon dioxide and greenhouse gases, as it was found that CO2 emissions in 1990 amounted to 151 million metric tons compared to 2011 when it reached about 435 million metric tons, and the increase continued until 2020 when it reached about 530 million metric tons. The comprehensive study relied on time series analysis to carefully analyze the electric energy productivity rate from fossil fuels and the significant amount of carbon dioxide emissions typically resulting from promptly burning fossil fuels to naturally produce electric energy. Therefore, the Kingdom of Saudi Arabia, through Vision 2030 and the Paris Agreement on Climate Change, looks to reduce the rate of carbon dioxide emissions in the field of electric power generation by diversifying the fuels used or replacing them with clean and renewable energy such as solar and wind energy.


2021 ◽  
Vol 19 (5) ◽  
pp. 35-42
Author(s):  
Abdullah A. Abdullah

The element carbon Carbon dioxide emissions are increasing primarily as a result of people's use of fossil fuels for electricity. Coal and oil are fossil fuels that contain carbon that plants removed from the atmosphere by photosynthesis over millions of years; and in just a few hundred years we've returned carbon to the atmosphere. The element carbon Carbon dioxide concentrations rise primarily as a result of the burning of fossil fuels and Freon for electricity. Fossil fuels such as coal, oil and gas produce carbon plants that were photosynthesized from the atmosphere over many years, since in just two centuries, carbon was returned to the atmosphere. Climate alter could be a noteworthy time variety in weather designs happening over periods ranging from decades to millions of a long time. The permanent change in climatic conditions, or in the time period of long-term natural conditions, indicates irregularity in climatic conditions. Discuss toxins are pollutants that have an adverse impact on the ecosystem through interferometry's with the climatic environment, plant physiology, creature organisms, complete biological systems and human property in the form of agricultural or human crops. We list the best climate to represent the fact that global climate change has been identified as one of the major environmental problems facing humanity in the 21st century. In this context, the list of "classic" poisons must be included alongside substances such as oxides of nitrogen or sulfide. Certain environment limiting agents – the most crucial of them being carbon dioxide – which otherwise do not damage life formations. On the other hand, climate research has linked some compounds that have long been known to discuss toxin (occasionally dark CO2) with the warming of the climate.


2019 ◽  
Vol 239 ◽  
pp. 793-819 ◽  
Author(s):  
Nan Zhou ◽  
Lynn Price ◽  
Dai Yande ◽  
Jon Creyts ◽  
Nina Khanna ◽  
...  

2007 ◽  
Vol 25 (5) ◽  
pp. 357-392 ◽  
Author(s):  
Havva Balat ◽  
Cahide Öz

This article deals with review of technical and economic aspects of Carbon Capture and Storage. Since the late 1980s a new concept is being developed which enables to make use of fossil fuels with a considerably reduced emission of carbon dioxide to the atmosphere. The concept is often called ‘Carbon Capture and Storage’ (CCS). CCS technologies are receiving increasing attention, mainly for their potential contribution to the optimal mitigation of carbon dioxide emissions that is intended to avoid future, dangerous climate change. CCS technologies attract a lot of attention because they could allow “to reduce our carbon dioxide emissions to the atmosphere whilst continuing to use fossil fuels”. CCS is not a completely new technology, e.g., the United States alone is sequestering about 8.5 MtC for enhanced oil recovery each year. Today, CCS technologies are widely recognised as an important means of progress in industrialized countries.


2017 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Ali Eren Alper

Since the first days of its existence, the humanity had been using natural resources to meet its needs. Especially along with the globalization period as a result of the Industrial Revolution and the rapid development of communication technologies within the last fifty years, the production has increased significantly in the world and has created negative effects on the environment. The leading adverse effects involve the emission of greenhouse gases and the global warming, which stem from the energy supply of fossil fuels as the main inputs of production. The global warming can be described as an increase in temperature worldwide. Irreversibility is the most important feature of the global warming. Therefore, in the absence of objective measures, the future costs would be much higher than the current ones. For this reason, governments need to take various measures to reduce the volume of emissions. The most important of these measures is carbon taxes. Carbon taxation encourages individuals to use fewer fossil fuels and to find new sources of energy by increasing the cost of using fossil fuels that cause carbon dioxide emissions through the price mechanism. To this end, the impacts of carbon tax levied in 18 selected European countries on economic growth, urbanization, natural gas and petroleum usage, and CO2 emissions are examined by panel data analysis for the 1995-2015 period. The analysis results indicate that a 1% increase in environmental taxes reduces carbon dioxide emissions by 0.9%. Furthermore, it is reported that a 1% increase in natural gas and petroleum consumption among the variables included in the analysis increased carbon dioxide emissions by 0.1% and 0.7%, respectively; while a 1% increase in urbanization reduced carbon dioxide emissions by 0.9%.


AIMS Energy ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1170-1191
Author(s):  
Peter Schwartzman ◽  
◽  
David Schwartzman ◽  

<abstract> <p>First, we recognize the valuable previous studies which model renewable energy growth with complete termination of fossil fuels along with assumptions of the remaining carbon budgets to reach IPCC warming targets. However, these studies use very complex combined economic/physical modeling and commonly lack transparency regarding the sensitivity to assumed inputs. Moreover, it is not clear that energy poverty with its big present impact in the global South has been eliminated in their scenarios. Further, their CO<sub>2</sub>-equivalent natural gas emission factors are underestimated, which will have significant impact on the computed greenhouse gas emissions. Therefore, we address this question in a transparent modeling study: can the 1.5 ℃ warming target still be met with an aggressive phaseout of fossil fuels coupled with a 100% replacement by renewable energy? We compute the continuous generation of global wind/solar energy power along with the cumulative carbon dioxide equivalent emissions in a complete phaseout of fossil fuels over a 20 year period. We compare these computed emissions with the state-of-the-science estimates for the remaining carbon budget of carbon dioxide emissions consistent with the 1.5 ℃ warming target, concluding that it is still possible to meet this warming target if the creation of a global 100% renewable energy transition of sufficient capacity begins very soon which will likely be needed to power aggressive negative carbon emission technology. The latter is focused on direct air capture for crustal storage. More efficient renewable technologies in the near future will make this transition easier and promote the implementation of a global circular economy. Taking into account technological improvements in 2<sup>nd</sup> law (exergy) efficiencies reducing the necessary global energy demand, the renewable supply should likely be no more than 1.5 times the present level, with the capacity to eliminate global energy poverty, for climate mitigation and adaptation.</p> </abstract>


2003 ◽  
pp. 277-315 ◽  
Author(s):  
J. Timmons Roberts ◽  
Peter E. Grimes ◽  
Jodie L. Manale

Carbon dioxide is understood to be the most important greenhouse gas believed to be altering the global climate. This article applies world-system theory to environmental damage. An analysis of 154 countries examines the contribution of both position in the world economy and internal class and political forces in determining a nation's CO, intensity. CO, intensity is defined here as the amount of carbon dioxide released per unit of economic output. An inverted U distribution of CO, intensity across the range of countries in the global stratification system is identified and discussed. Ordinary Least Squares regression suggests that the least efficient consumers of fossil fuels are some countries within the semi-periphery and upper periphery, spe-cifically those nations which are high exporters, those highly in debt, nations with higher military spending, and those with a repressive social structure.


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