Termocentrala fara emisie de carbon

In the Texas city of La Porte, about 30 miles outside of Houston, the power plant of the future generates enough electricity to power 5,000 homes simultaneously. It burns old-fashioned fossil fuels. And yet it produces no carbon emissions.

Sound impossible?
Net Power, the Durham, North Carolina-based startup behind the plant, is on a mission to prove it's not only possible but also a potential solution to one of the biggest contributors to climate change.

If all goes well, the plant will be the first of many like it around the globe.

Founded in 2008, Net Power has been on a long journey to create a new type of power plant that will appeal to established energy companies. The hope is this first plant serves as the proof of concept necessary to show the industry a path to zero emissions--and, for Net Power, a path to profitability.
For years, the energy industry has experimented with an environmentally friendly process known as carbon capture and storage (CCS). It does exactly what it sounds like: produces energy and sequesters the carbon dioxide byproduct so it can't escape into the atmosphere. In theory, this would offset the climate-altering effects of burning fossil fuels.

While scientifically plausible, the process usually is prohibitively expensive. First, it requires the construction of extra facilities for capturing carbon. Then, once those facilities are built, they use so much power that they end up offsetting many of the environmental benefits they're designed to achieve.

Allam developed a new fuel-burning process that entails capturing carbon dioxide at the combustion stage.

The process that makes Net Power so innovative, now dubbed the Allam Cycle, allows much of the carbon dioxide released during combustion to be recycled. The carbon that isn't reused is captured.

It can then be injected underground, where it's permanently absorbed by rock, or sold to companies that can use it for other purposes like manufacturing plastics or extracting oil.

The net result is an emissions-free process that can generate electricity on a large scale.

The Texas plant, which first fired up in May, can produce 25 megawatts, enough to power all the homes in a medium-size town simultaneously. It isn't yet sending electricity to the local grid; Brown hopes that will happen within the next several months, once the plant completes an extensive series of tests and gets connected with Texas utility company Ercot.

Meanwhile, the company is looking to partner with an energy company on its first full-size plant, which will be capable of producing 12 times as much energy. Net Power's goal is to complete that project by 2022.

The Texas plant cost $150 million to build, and Brown says the price of running it will be on par with that of a conventional power plant--clearly, a critical factor for wide adoption. The goal is to go even further.

Even though only one turbine is used, the Allam cycle can potentially achieve efficiencies up to about 59 percent (LHV) for natural gas and 51–52 percent (LHV) for gasified coal. This is due to the use of carbon dioxide as the main constituent of the working fluid. In its supercritical state, which it reaches in the combustion unit, carbon dioxide is very efficient for driving a turbine.

Also, energy losses from phase transitions of water are avoided, which allows Allam cycle plants to recover more energy in their heat exchangers than combined cycle plants can do. At this efficiency, carbon dioxide capture is already a part of the Allam cycle, whereas if desired in conventional plants, the capture has to be added as an external function that may decrease the overall efficiency by around 10 percent

Din ce inteleg de pe Wikipedia sunt de fapt doua avantaje:

1. Procesul tehnologic necesita componente mai mici/ieftine/putine (ceea ce insemna mai ieftin si usor de scalat)

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Cum sa fie mai ieftin daca este de 6 ori mai scump ?

Au incercat recent sa faca o termocentrala minune din asta, care sa arate ca si carbunele poate fi ecologic si eficient; a costat foarte mult fata de cat estimasera initial si costurile de operare erau mari (trebuia sa consumi mai mult carbune pentru a produce aceeasi candtitate de energie ca una "normala"). S-a dovenit a fi un fiasco si nu au mai construit altele. Uite si link - https://en.wikipedia.../Kemper_Project . Uitasem toate detaliile; se pare ca pana la urma, dupa ce au tocat 7 miliarde, au renuntat de tot la carbune si au inceput sa arda gazu' Producea 500MW dar a costat cat o centrala nucleara care produce 2500MW.
Unii americani incearca sa salveze industria carbunelui, pentru ca produce locuri de munca, si o treime din energia electrica din America; dar, e greu; daca o sa incepa sa puna taxe pe carbonul aruncat in aer, centralele nucleare o sa devina chiar ieftine.
Dar, cine stie, poate pe viitor poate o sa apara modalitati de a arde carbunele ecologic.

Sursa

Aparent este posibil, fara sa implice alchimie sau costuri exorbitante de captare ca carbonului.
Procesul a fost demonstrat in laborator, iar tespectiva termocentrala este prima punere in practica la scara larga.
Combustibilul ar fi gazele naturale.

Cine vrea sa studieze Ciclul Allam, gaseste informatie pe Wikipedia.