Environmental

A conventional coal plant’s CO2 emissions can be reduced either after combustion (see Part I of this article in POWER, June 2008) or before. In the latter case, typified by integrated gasification combined-cycle (IGCC) plants, the fuel used is synthesis gas (syngas), which contains mostly hydrogen (H2) and CO. A water-shift reactor converts the CO […]

It is rare indeed to witness, at an otherwise staid industry forum, the public rebuke of the country’s most prominent supplier to the electric power industry. But at the Keynote session and Power Industry CEO Roundtable of the 2008 ELECTRIC POWER Conference & Exhibition in Baltimore this May, Milton Lee, general manager and CEO of […]

“Once it’s enacted, the impact of climate change legislation on the electric power industry will be ten times bigger than that of the Clean Air Act,” said Dan Adamson, an attorney with the law firm of Davis Wright Tremaine and chair of the opening session at the 2nd Annual Carbon Constraint Conference (Figure 1). 1. […]

No doubt some power plant engineers feel that tackling environmental problems is a lot like dealing with the Hydra, the ancient mythological serpent monster with multiple heads. When an attacker would cut off one of the Hydra’s numerous heads, two new ones would grow back in place of the head that was removed. All too […]

Senate legislation to cap U.S. greenhouse gas (GHG) emissions beginning in 2012 would have generally modest cost impacts on the national economy, leading to reductions in gross domestic product (GDP) by 2030 that range from 0.2%, or $444 billion, to 0.6%, or $1.3 trillion, according to an Energy Information Administration analysis.

But the analysis, which concluded that the costs of the legislation would depend largely on the availability of advanced nuclear and coal-fired generation technologies, drew criticism from Republicans for its projection of a massive buildup of nuclear generation.

Reducing NO_x, SO₂, and other air pollutants continues to be a challenge for the power generation industry. The technologies are well-understood, but the devil is always in the details, especially when a complex treatment system is retrofitted to an existing plant.

The most common method for reducing SO₂ from plant emissions is the conventional lime- and limestone-based flue gas desulfurization (FGD) system. Material-handling systems for limestone and gypsum present specific challenges and opportunities that differ from those of coal-handling systems. This article looks at factors to consider  before and during the design of a new material-handling system. The choices you make about these many variables will determine the cost and longevity of your system.

By Editor-in-Chief Dr. Robert Peltier, PE
Zhou Dadi, director general (emeritus) of the Energy Research Institute at China’s National Development and Reform Commission, recently spoke at a panel discussion sponsored by the Carnegie Endowment for International Peace. Zhou boasted that China has set aggressive short-term goals for improved energy efficiency and that his country understands that it needs to make significant reductions of CO₂ in the future. This is a remarkable statement considering that China installed over 100 GW of new coal-fired generation in 2006 and another 75 GW in 2007.

In early June, New York Gov. David Paterson proclaimed that his state would commit $6 million to buttress a carbon capture and sequestration (CCS) viability study for the development of a new 50-MW clean coal plant in Jamestown, in western New York. The circulating fluidized-bed (CFB) project, which would use pure oxygen to combust coal and subsequently capture and sequester 90% of emitted carbon dioxide (CO₂), would be “the first of its kind in the world” and could potentially enable New York firms to launch exports of the technology worldwide, Paterson promised.

The mere mention of the words "New Source Review" (NSR) will immediately capture the full attention of any utility executive and might cause the cancellation of even the best power plant "upgrade" project. The effects of those three words have nothing to do with project economics or whether a project increases or decreases emissions. It’s all about the lawsuits.

Caps on greenhouse gas emissions are imminent in the U.S., and they will change how we design tomorrow’s coal-fired power plants. Efforts are already under way to develop alternative capture and sequestration technologies, mainly for CO2. Unfortunately, the proposed processes all consume lots of energy, reducing plants’ net output and efficiency. In Part I of our look at these technologies, we list and quantify the negative impacts of postcombustion removal of CO2 from a coal plant’s flue gas. Next month, in Part II, we’ll do the same for four other CO2 reduction techniques: oxyfuel combustion, using higher-temperature and higher-pressure boilers, cofiring biomass, and replacing some coal-fired capacity with renewable capacity.