Contenido

En la actualidad se están construyendo numerosas centrales termoeléctricas de las denominadas de ciclo combinado, que son un tipo de central que utiliza gas natural, gasóleo o incluso carbón preparado como combustible para alimentar una turbina de gas. Luego los gases de escape de la turbina de gas todavía tienen una elevada temperatura, se utilizan para producir vapor que mueve una segunda turbina, esta vez de vapor. Cada una de estas turbinas está acoplada a su correspondiente alternador para generar energía eléctrica.[1]​.

Normalmente durante el proceso de partida de estas centrales solo funciona la turbina de gas; a este modo de operación se lo llama ciclo abierto.[2]​ Si bien la mayoría de las centrales de este tipo pueden intercambiar el combustible (entre gas y diésel) incluso en funcionamiento.

Como la diferencia de temperatura que se produce entre la combustión y los gases de escape es más alta que en el caso de una turbina de gas o una de vapor, se consiguen rendimientos muy superiores, del orden del 55 %.

Este tipo de centrales generaron el 32 % de las necesidades españolas de energía eléctrica en 2008.[3]​.

GICC

In recent times, a new technology has been developed, Integrated Gasification in Combined Cycle (IGCC), which, through a coal gasification system, significantly reduces polluting emissions into the atmosphere, by being able to apply the combined cycle to coal.[1]​.

The emission of waste into the atmosphere and the combustion processes that occur in thermal power plants have a significant impact on the environment. To try to alleviate, as far as possible, the damage that these plants cause to the natural environment, various elements and systems are incorporated into the facilities.

Some types of thermoelectric plants contribute to the greenhouse effect by emitting carbon dioxide. This is not the case with solar thermal power plants, which do not burn any fuel. It must also be considered that the mass of this gas emitted per unit of energy produced is not the same in all cases: coal is made up of carbon and impurities. Almost all the carbon that is burned is converted to carbon dioxide; It can also become carbon monoxide if combustion is poor in oxygen. In the case of natural gas, for each carbon atom there are four hydrogen atoms that also produce energy by combining with oxygen to become water, so they pollute less for each unit of energy they produce and the emission of harmful gases from the combustion of impurities - such as sulfur oxides - is much lower.

Negative impacts can occur during construction, as well as during operation of thermoelectric plants. Thermoelectric plants are considered important sources of atmospheric emissions and can affect air quality in the local or regional area. The combustion that occurs in thermoelectric projects emits sulfur dioxide (SO), nitrogen oxides (NO), carbon monoxide (CO), carbon dioxide (CO) and particles (which may contain metals). The quantities of each will depend on the type and size of the installation, the type and quality of the fuel, and the way it is burned. The dispersion and concentrations of these emissions, at ground level, are the result of a complex interaction of the physical characteristics of the plant stack, the physical and chemical qualities of the emissions, the meteorological conditions at or near the site during the time required for the emissions to travel from the stack to the ground level receptor, the topographic conditions of the plant site and surrounding areas, and the nature of the receptors.

Clean cooling water constitutes the most important effluent coming from thermoelectric plants. It can be recycled or discharged to the surface water body, without causing major effects in terms of its chemical quality. However, the effect of waste heat on the ambient water temperature must be considered.

The pollution problem is greatest in the case of conventional thermoelectric plants that use coal as fuel. Furthermore, the combustion of coal results in the emission of particles and sulfur oxides that greatly contaminate the atmosphere.[4] In fuel oil plants the emission levels of these pollutants are lower, although the emission of sulfur oxides and acid soot must be taken into account), practically zero in gas plants.

In any case, to a greater or lesser extent all of them emit carbon dioxide, CO, into the atmosphere. Depending on the fuel, and assuming a yield of 40% of the primary energy consumed, a thermal power plant emits approximately:

Natural gas plants can operate with the so-called combined cycle, which allows higher efficiency (up to a little more than 50%), which would still make the plants that run on this fuel less polluting.

Contenido

En la actualidad se están construyendo numerosas centrales termoeléctricas de las denominadas de ciclo combinado, que son un tipo de central que utiliza gas natural, gasóleo o incluso carbón preparado como combustible para alimentar una turbina de gas. Luego los gases de escape de la turbina de gas todavía tienen una elevada temperatura, se utilizan para producir vapor que mueve una segunda turbina, esta vez de vapor. Cada una de estas turbinas está acoplada a su correspondiente alternador para generar energía eléctrica.[1]​.

Normalmente durante el proceso de partida de estas centrales solo funciona la turbina de gas; a este modo de operación se lo llama ciclo abierto.[2]​ Si bien la mayoría de las centrales de este tipo pueden intercambiar el combustible (entre gas y diésel) incluso en funcionamiento.

Como la diferencia de temperatura que se produce entre la combustión y los gases de escape es más alta que en el caso de una turbina de gas o una de vapor, se consiguen rendimientos muy superiores, del orden del 55 %.

Este tipo de centrales generaron el 32 % de las necesidades españolas de energía eléctrica en 2008.[3]​.

GICC

In recent times, a new technology has been developed, Integrated Gasification in Combined Cycle (IGCC), which, through a coal gasification system, significantly reduces polluting emissions into the atmosphere, by being able to apply the combined cycle to coal.[1]​.

The emission of waste into the atmosphere and the combustion processes that occur in thermal power plants have a significant impact on the environment. To try to alleviate, as far as possible, the damage that these plants cause to the natural environment, various elements and systems are incorporated into the facilities.

Some types of thermoelectric plants contribute to the greenhouse effect by emitting carbon dioxide. This is not the case with solar thermal power plants, which do not burn any fuel. It must also be considered that the mass of this gas emitted per unit of energy produced is not the same in all cases: coal is made up of carbon and impurities. Almost all the carbon that is burned is converted to carbon dioxide; It can also become carbon monoxide if combustion is poor in oxygen. In the case of natural gas, for each carbon atom there are four hydrogen atoms that also produce energy by combining with oxygen to become water, so they pollute less for each unit of energy they produce and the emission of harmful gases from the combustion of impurities - such as sulfur oxides - is much lower.

Negative impacts can occur during construction, as well as during operation of thermoelectric plants. Thermoelectric plants are considered important sources of atmospheric emissions and can affect air quality in the local or regional area. The combustion that occurs in thermoelectric projects emits sulfur dioxide (SO), nitrogen oxides (NO), carbon monoxide (CO), carbon dioxide (CO) and particles (which may contain metals). The quantities of each will depend on the type and size of the installation, the type and quality of the fuel, and the way it is burned. The dispersion and concentrations of these emissions, at ground level, are the result of a complex interaction of the physical characteristics of the plant stack, the physical and chemical qualities of the emissions, the meteorological conditions at or near the site during the time required for the emissions to travel from the stack to the ground level receptor, the topographic conditions of the plant site and surrounding areas, and the nature of the receptors.

Clean cooling water constitutes the most important effluent coming from thermoelectric plants. It can be recycled or discharged to the surface water body, without causing major effects in terms of its chemical quality. However, the effect of waste heat on the ambient water temperature must be considered.

The pollution problem is greatest in the case of conventional thermoelectric plants that use coal as fuel. Furthermore, the combustion of coal results in the emission of particles and sulfur oxides that greatly contaminate the atmosphere.[4] In fuel oil plants the emission levels of these pollutants are lower, although the emission of sulfur oxides and acid soot must be taken into account), practically zero in gas plants.

In any case, to a greater or lesser extent all of them emit carbon dioxide, CO, into the atmosphere. Depending on the fuel, and assuming a yield of 40% of the primary energy consumed, a thermal power plant emits approximately:

Natural gas plants can operate with the so-called combined cycle, which allows higher efficiency (up to a little more than 50%), which would still make the plants that run on this fuel less polluting.