scholarly journals On Some New Indicators for the Energo-Ecological Assessment of Thermo-Power Plants Operation

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Mircea Cârdu ◽  
Arina Speranţa Negoiţescu ◽  
Dana Sandu

The authors offer a critical analysis of pollution indicators currently applied for the ecological assessment of the thermo power plant's operation. They forward new “energo-ecological” indicators to highlight both the qualitative aspect of polluting emissions and their quantitative aspect, by relating their concentration in the flue gases purged into the atmosphere to the energy produced during the same interval. The application of these indicators contributes to the attenuation of the global warming phenomenon and to the protection of the world's resources of fossil fuels.

Author(s):  
Kazuo Onda ◽  
Takuya Taniuchi ◽  
Daisuke Sunakawa ◽  
Mitsuyuki Nagahama ◽  
Takuto Araki ◽  
...  

A major factor in global warming is CO2 emission from thermal power plants, which burn fossil fuels. One technology proposed to prevent global warming is CO2 recovery from combustion flue gas and the sequestration of CO2 underground or near the ocean bed. Solid oxide fuel cell (SOFC) can produce highly concentrated CO2, because the reformed fuel gas reacts with oxygen electrochemically without being mixed with air in the SOFC. We therefore propose to operate multi-staged SOFCs with high utilization of reformed fuel to obtain highly concentrated CO2. In this study, we estimated the performance of multi-staged SOFCs considering H2 diffusion and the combined cycle efficiency of a multistage SOFC / gas turbine / CO2 recovery power plant. The power generation efficiency of our CO2 recovery combined cycle is 68.5%, whereas the efficiency of a conventional SOFC/GT cycle with the CO2 recovery amine process is 57.8%.


Author(s):  
Matthys P. Levy

This chapter summarizes the history and evolution of various forms of infrastructure and the current state of their technology as a basis for exploring the anticipated effects of global warming on existing infrastructure facilities and for developing a strategy that adapts to these effects. Infrastructure encompasses all of the physical structures that support the functioning of a community or enhance the quality of life of its members. These structures are part of systems that provide the basic services of an industrial society: transportation, energy, water management, communications, and solid waste management. There are numerous other facilities that will also experience the impact of climate change, such as those for flood control, but in this chapter I consider only the major systems. For a thousand years, the world’s average temperature remained relatively constant; in fact, it was very slowly decreasing. Then, at the end of the 19th century, it began to rise dramatically. This change was concurrent with an explosive increase in the world’s population—from less than 1 bil­lion to today’s almost 7 billion. This change spurred rapid industrialization. The insatiable appetite of a growing population for goods and services required the burning of ever-increasing amounts of fossil fuels to support power plants (starting with coal and then oil and gas) as well as ever more complex transportation networks (Randers 2012). Today, our planet’s atmosphere is overburdened by the increasing amounts of CO2 spewing from these plants, and nature’s equilibrium as it existed for millennia has been destroyed. The world’s oceans and plants are no longer able to absorb any more CO2. Concentrations in the atmosphere have reached 400 parts per million (ppm) and are still rising at an annual rate of 2 ppm. As a consequence, we now have a blanket of CO2 in the upper atmosphere that traps heat in the way that the roof of a glass-enclosed greenhouse does, and it raises both the planet’s air and sea temperatures. These are the essential facts of what is popularly called global warming.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Peter Durcansky ◽  
Stefan Papucik ◽  
Jozef Jandacka ◽  
Michal Holubcik ◽  
Radovan Nosek

Combined power generation or cogeneration is a highly effective technology that produces heat and electricity in one device more efficiently than separate production. Overall effectiveness is growing by use of combined technologies of energy extraction, taking heat from flue gases and coolants of machines. Another problem is the dependence of such devices on fossil fuels as fuel. For the combustion turbine is mostly used as fuel natural gas, kerosene and as fuel for heating power plants is mostly used coal. It is therefore necessary to seek for compensation today, which confirms the assumption in the future. At first glance, the obvious efforts are to restrict the use of largely oil and change the type of energy used in transport. Another significant change is the increase in renewable energy—energy that is produced from renewable sources. Among machines gaining energy by unconventional way belong mainly the steam engine, Stirling engine, and Ericsson engine. In these machines, the energy is obtained by external combustion and engine performs work in a medium that receives and transmits energy from combustion or flue gases indirectly. The paper deals with the principle of hot-air engines, and their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element.


2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Romdhane Ben Slama

The global warming which preoccupies humanity, is still considered to be linked to a single cause which is the emission of greenhouse gases, CO2 in particular. In this article, we try to show that, on the one hand, the greenhouse effect (the radiative imprisonment to use the scientific term) took place in conjunction with the infrared radiation emitted by the earth. The surplus of CO2 due to the combustion of fossil fuels, but also the surplus of infrared emissions from artificialized soils contribute together or each separately,  to the imbalance of the natural greenhouse effect and the trend of global warming. In addition, another actor acting directly and instantaneously on the warming of the ambient air is the heat released by fossil fuels estimated at 17415.1010 kWh / year inducing a rise in temperature of 0.122 ° C, or 12.2 ° C / century.


2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Made Dirgantara ◽  
Karelius Karelius ◽  
Marselin Devi Ariyanti, Sry Ayu K. Tamba

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat  Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate 


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3860
Author(s):  
Mária Hagarová ◽  
Milan Vaško ◽  
Miroslav Pástor ◽  
Gabriela Baranová ◽  
Miloš Matvija

Corrosion of boiler tubes remains an operational and economic limitation in municipal waste power plants. The understanding of the nature, mechanism, and related factors can help reduce the degradation process caused by corrosion. The chlorine content in the fuel has a significant effect on the production of gaseous components (e.g., HCl) and condensed phases on the chloride base. This study aimed to analyze the effects of flue gases on the outer surface and saturated steam on the inner surface of the evaporator tube. The influence of gaseous chlorides and sulfates or their deposits on the course and intensity of corrosion was observed. The salt melts reacted with the steel surface facing the flue gas flow and increased the thickness of the oxide layer up to a maximum of 30 mm. On the surface not facing the flue gas flow, they disrupted the corrosive layer, reduced its adhesion, and exposed the metal surface. Beneath the massive deposits, a local overheating of the inner surface of the evaporator tubes occurred, which resulted in the release of the protective magnetite layer from the surface. Ash deposits reduce the boiler’s thermal efficiency because they act as a thermal resistor for heat transfer between the flue gases and the working medium in the pipes. The effect of insufficient feedwater treatment was evinced in the presence of mineral salts in the corrosion layer on the inner surface of the tube.


Author(s):  
Khasan Nasriddinov ◽  
Ji-Eun Min ◽  
Hae-Gu Park ◽  
Seung Ju Han ◽  
Jingyu Chen ◽  
...  

Direct CO2 hydrogenation to long-chain hydrocarbons can mitigate global warming by extensively replacing fossil fuels. However, designing a suitable catalyst with high catalytic activity and C5+ hydrocarbon selectivity continues to...


2016 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Jan Erik Lane

The implementation process of the global accord on climate change has to start now in order to be implementable. The decentralized process if implementation should take the lessons from the theory of policy implementation into account (Pressman & Wildavsky, 1984; Wildavsky, 1987). The dependency upon various forms of coal (wood, stone) and fossil fuels is so large in the Third World that only massive financial assistance from the First World can mean a difference for the COP21 objectives. And many advanced countries (except Uruguay) also need to make great changes to comply with COP21.


Sign in / Sign up

Export Citation Format

Share Document