scholarly journals Assessment of Renewable Alternatives to Coal, Based on Their High Heating Value and Global Warming Potential

Author(s):  
V. Dhivakhar ◽  
Maju Varghese ◽  
Keerthi M. S. ◽  
S. Kaviya

About 40% of the Global Electricity produced is fuelled by coal. Although Coal has various advantages like good High Heating Value, easy availability etc., it also has various disadvantages. Green House Gas Released from Coal Thermal Power Plants is the single major contributor to Global warming. Coal is also nonrenewable. Hence it is important to analyze the viability of potential alternatives and reduce the usage of coal. In this assessment, various potential replacements of coal have been analyzed based on their High heating value (HHV) and their Global Warming Potential. The Global warming Potential (GWP) of the assessed fuels have been calculated by the Respiratory Quotient (RQ) Factor method. Hence a direct comparison between Coal and other replacements based on their HHV and GWP has been performed.

Author(s):  
Cássio Florisbal de Almeida ◽  
Vinícius Gonçalves Maciel ◽  
Luiz Fernando de Abreu Cybis

O setor energético é de suma importância para o crescimento estratégico de qualquer país. Isso não é diferente no Brasil, o qual apresenta uma matriz energética diversificada, mas que tem um predomínio do setor hidrelétrico. No entanto, o setor termelétrico tem crescido nos últimos anos para garantir a segurança energética e, nos sistemas isolados, a termeletricidade é predominante. Este é o caso do estado do Amazonas, o qual recebe energia prioritariamente de usinas termelétricas da região. As usinas da região utilizam, em sua maioria, combustíveis fósseis tais como diesel, óleo combustível pesado (HFO, em inglês). Atualmente, tem sido incorporada a este sistema a utilização do gás natural proveniente da bacia petrolífera amazônica, localizada em Urucu. Nesse sentido, para analisar a influência ambiental desta mudança nas usinas termelétricas, este emprega a metodologia de Avaliação do Ciclo de Vida (ACV) da eletricidade entregue ao grid por uma usina termelétrica, localizada em Manaus, que utiliza óleo combustível pesado e gás natural como combustível. O estudo foi conduzido do berço ao portão da usina a partir de dados primários da própria usina e dados secundários de bibliografia da área. Para a observação das diferenças, fez-se um estudo comparativo entre a mesma usina em duas situações: utilizando somente óleo combustível pesado e o uso concomitante deste combustível com o gás natural. A Avaliação do Impacto de Ciclo de Vida foi calculada pelo método CML IA baseline com o uso do software SimaPro e escolheu-se a categoria de impacto de Aquecimento Global para análise. A conversão bicombustível resultou em redução do impacto da usina, que antes era de 590,50 kg CO2eq/MWh e passou para 521,11 CO2eq/MWh, no entanto ao longo do ciclo de vida o resultado se manteve no mesmo patamar. Resumen El sector energético es de suma importancia para el crecimiento estratégico de cualquier país. Esto no es diferente en Brasil, que tiene una matriz energética diversificada, pero que tiene un predominio del sector hidroeléctrico. Sin embargo, el sector termoeléctrico ha crecido en los últimos años para garantizar la seguridad energética y, en sistemas aislados, termoelectricidad es predominante. Este es el caso de estado del Amazonas, que recibe energía principalmente de centrales térmicas de energía en la región. Las plantas de la región utilizan, sobre todo, combustibles fósiles como el diesel, fuelóleo pesado (HFO en inglés). En la actualidad, se ha incorporado a este sistema, el uso de gas natural de la cuenca petrolífera del Amazonas, situado en Urucu. En este sentido, para analizar el impacto ambiental de este cambio en las centrales térmicas, este estudio emplea la metodología del Análisis de Ciclo de Vida (ACV) de la electricidad entregada a la red por una central térmica, que se encuentra en Manaus, que utiliza fuelóleo pesado y gas natural como combustibles. El estudio se realizó a partir de datos primarios de la central térmica y datos secundarios de literatura del área. Para observar las diferencias, se hizo un estudio comparativo de la misma planta en dos situaciones: utilizando sólo el fuelóleo pesado y el uso concomitante de este combustible con gas natural. La evaluación del impacto del ciclo de vida se calculó por el método de CML IA baseline usando el software SimaPro y optó por categoría de impacto del calentamiento global para análisis. La conversión bi-combustible resultó en una redución del impacto de la planta, que antes era de 590.50 kg CO2eq / MWh y aumentó a 521.11 CO2eq / MWh. Sin embargo a lo largo del ciclo de vida, el resultado se mantuvo en el mismo nivel. Abstract The electric sector is very important to the strategic growing of any country. It isn’t different in Brazil, which shows a diversified energy matrix, but has a predominance of hydropower sector. However, the thermoelectric sector has grown in the last years to guarantee the electrical safety and, in isolated systems, the thermoelectricity is predominant. It is the case of Amazonas State, which receives energy priority from thermal power plants in the region. They use, mostly, fossil fuels such as Diesel, Heavy Fuel Oil (HFO). Nowadays, it has been incorporated into this system the natural gas use from Amazon oil basin, located in Urucu. In this sense, to analyze the environmental influence of this change on the thermal power plants, this study intends to employ the methodology of Life Cycle Assessment (LCA) of the electricity delivered to the grid by one thermal power plant (TPP), located in Manaus, which uses HFO and Natural Gas as fuel. For observation of differences, it was performed a comparative study of this power plant in two situations: using only HFO and using HFO and Natural gas concomitant. The study was conducted from cradle to gate of the power plant from specific primary data, provided by the power plant and secondary data from the literature. The Life Cycle Impact Assessment (LCIA) was calculated from the CML IA baseline with the use of SimaPro software and it was chosen the impact category of Global Warming Potential (GWP) for analysis. The conversion bifuel resulted in reduction of the impact of the TPP, which previously was 590.50 kg CO2eq / MWh and passed to 521.11 CO2eq / MWh. However, the bifuel power plant has, along the lifecycle, when compared the operation with only HFO, the same magnitude of GWP due to contributions of, for example, natural gas production.


Author(s):  
Yang Yang ◽  
Nicholas Eisenbarth ◽  
Xiaoxu Song ◽  
Meng Zhang ◽  
Donghai Wang

The U.S. is sustainably producing of over 1 billion dry tons of biomass annually. This amount of biomass is sufficient to produce bioenergy that can replace about 30 percent of the nation’s current annual consumption of conventional fossil fuels. This then gives us the opportunity to turn waste into bioenergy that can assist in meeting the U.S. Renewable Fuel Standard (RFS). Besides being converted into bioethanol through the biochemical platform, biomass can also be utilized solid fuels to generate bioenergy through the thermochemical platform. Co-firing power plants use torrefied biomass pellets combined with coal for electricity generation. A two-step process, torrefaction followed by pelleting, is the prevailing technique that the industry is currently using to produce torrefied biomass pellets. Torrefaction converts biomass into biochar with high heating value, and pelleting densifies torrefied biochar into pellets with high durability and density. For the same purpose, we developed the ultrasonic pelleting and synchronized torrefaction of cellulosic biomass process, which is a single-step process to generate high quality solid fuel pellets with high heating value together with good durability and density. This study reports the first experimental investigation to demonstrate the feasibility of the novel process. Key process parameters have been identified, and their effects on the feasibility of generating quality torrefied biomass pellets are reported. Pellets are evaluated from the aspects of feasibility, durability, heating value, and thermal stability.


Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7979
Author(s):  
Mateus Mendes Campos ◽  
Luiz Eduardo Borges-da-Silva ◽  
Daniel de Almeida Arantes ◽  
Carlos Eduardo Teixeira ◽  
Erik Leandro Bonaldi ◽  
...  

This paper presents a ultrasonic-capacitive system for online analysis of the quality of fuel oils (FO), which are widely used to produce electric energy in Thermal Power Plants (TPP) due to their elevated heating value. The heating value, in turn, is linked to the quality of the fuel (i.e., the density and the amount of contaminants, such as water). Therefore, the analysis of the quality is of great importance for TPPs, either in order to avoid a decrease in generated power or in order to avoid damage to the TPP equipment. The proposed system is composed of two main strategies: a capacitive system (in order to estimate the water content in the fuel) and an ultrasonic system (in order to estimate the density). The conjunction of the two strategies is used in order to estimate the heating value of the fuel, online, as it passes through the pipeline and is an important tool for the TPP in order to detect counterfeit fuel. In addition, the ultrasonic system allows the estimation of the flow rate through the pipeline, hence estimating the amount of oil transferred and obtaining the total mass transferred as a feature of the system. Experimental results are provided for both sensors installed in a TPP in Brazil.


2007 ◽  
Vol 58 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Vladica Čudić ◽  
Dragica Kisić ◽  
Dragoslava Stojiljković ◽  
Aleksandar Jovović

Ash From Thermal Power Plants as Secondary Raw MaterialThe basic characteristic of thermal power plants in the Republic of Serbia is that they use low-grade brown coal (lignite) as a fuel. Depending on the location of coal mines, lignite may have different properties such as heating value, moisture, and mineral content, resulting in different residue upon combustion. Because of several million tonnes of ash and slag generated every year, their granularmetric particle size distribution, and transport and disposal methods, these plants have a negative impact on the environment. According to the waste classification system in the Republic of Serbia, ash and slag from thermal power plants are classified as hazardous waste, but with an option of usability. The proposed revision of waste legislation in Serbia brings a number of simple and modern solutions. A procedure is introduced which allows for end-of-waste criteria to be set, clarifying the point where waste ceases to be waste, and thereby introducing regulatory relief for recycled products or materials that represent low risk for the environment. The new proposal refocuses waste legislation on the environmental impacts of the generation and management of waste, taking into account the life cycle of resources, and develops new waste prevention programmes. Stakeholders, as well as the general public, should have the opportunity to participate in the drawing up of the programmes, and should have access to them.


2012 ◽  
Vol 16 (2) ◽  
pp. 605-612
Author(s):  
Slavko Djuric ◽  
Petko Stanojevic ◽  
Dragan Djuranovic ◽  
Sasa Brankov ◽  
Srdjan Milasinovic

In this paper we have looked into the qualitative analysis of coals in Bosnia and Herzegovina (B-H). The analysis includes the following characteristics: moisture (W), ash (A), combustible matter (Vg) and lower heating value (Hd). From the statistic parameters we have determined: absolute range (R), arithmetic mean (X), standard deviation (S) and variations coefficient (Cv). It has been shown that the coal characteristics (W, A, Vg, Hd) have normal distribution. The analysis show that there are considerable deviations of ash characteristics: moisture (36.23%), ash (34.21%), combustible matter (16.15%) and lower heating value (25.16%) from the mean value which is shown by the variations coefficient (Cv). Large oscilations of mass portions: W, A, Vg and Hd around the mean value can adversely influence the function of a boiler plant and an electric filter plant in thermal power plants in B-H in which the mentioned types of coal burn. Large ash oscilations (34.21%) around the mean value point out to the inability of application of dry procedures of desulphurisation of smoke gasses (FGD) due to the additional quantity of ash. It has been shown that the characteristics of Bosnian types of coal do not deviate a lot from the characteristics of coal in the surrounding countries (coals of Serbia and Monte Negro). The results can be used in analysis of coal combustion in thermal power plants, optimisation of electrical-filtre, reduction of SO2 in smoke gas and other practical problems.


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