Natural gas combined cycle

Table 4. Cost estimates of alternative mitigation technologies in the power generation sector compared to baseline pulverized coal-fired power plant and natural gas Combined Cycle with Gas Turbine (CCGT) power stations and the potential reductions in C02 emissions to 2020 [14]...

In a Natural Gas Combined Cycle (NGCC) or an Integrated Gasification Combined Cycle (IGCC), the steam produced from the waste heat boiler is converted into extra electrical power in the steam turbines. Consequently, for hydrogen production, the steam use must be kept as low as possible. 

Natural gas combined cycle power plants with highest efficiencies (NCCC) and pre-and postcombustion capture of COj. 

Supply side efficiency measures. Here we mean primarily increasing the efficiency of electricity production. Natural gas combined cycle power plants (NGCC) emit less C02 than single-cycle coal-fired power plants first, because natural gas emits about one-half the amount of C02 per fuel heating value than coal, and secondly, because the thermal efficiency of combined-cycle power plants is in the 45-50% range compared with the 35-38% range of single-cycle plants. In the... 

NEI NETPATH NFC NGCC NMR NOx NPP NRA NRC Development Nuclear Energy Institute Interactive code for modelling net geochemical reactions along a flow path Nuclear fuel cycle Natural gas combined cycle Nuclear magnetic resonance NO + N02 Nuclear power plant Nuclear reaction analysis National Research Council... 

Existing capture technologies, however, are not cost-effective when considered in the context of sequestering C02 from power plants. Most power plants and other large point sources use air-fired combustors, a process that exhausts C02 diluted with nitrogen and excess air. Flue gas from coal-fired power plants contains 10%-12% C02 by volume, while flue gas from natural gas combined cycle plants contains only 3%-6% C02. For effective carbon sequestration, the C02 in these exhaust gases must be separated and concentrated. 

Currently, global hydrogen production is 48% from natural gas, 30% from oil, and 18% from coal water electrolysis accounts for only 4%. The distribution of production reflects the effects of thermodynamic constraints on economic choices of the four processes for obtaining hydrogen, partial combustion of natural gas in a natural gas combined cycle power plant offers the most efficient chemical pathway and the greatest off-take of usable heat... 

NGCC/GTCC, Natural gas combined cycle (often termed gas-turbine combined cycle) PC, Pulverized-coal-fired power plant IGCC, Integrated gasification combined cycle, Oxy-fuel (PC boiler) plant. Flue-gas desulfurization and air particulate control is included in the total cost, but not in the separation unit cost. 

H2/power coproduction = C02 in the steam/natural gas combined cycle stack gas... 

It is assumed that high-efficiency, natural gas combined-cycle units would be installed to replace retired power generation. 

Spath, P.L. and Mann, M.K. Life cycle assessment of a natural gas combined-cycle power generation system. September 2000, NREL/TP-570-27715. http //www.nrel.gov/docs/fy00osti/27715.pdf. 

NexTech Materials, 323 NGCC. See natural gas, combined cycle (NGCC)... 

A number of combustion installations with integrated municipal waste/natural gas combined cycle exist in the Danish energy system. As municipal waste is not covered by the Directive, but natural gas is, these installations had to be split into two parts. This was done pro rata, using fuel consumption as the key. Even though this appears unique, there was complex discussions with some operators on how to apply the pro-rata principle. 

For the power production scenario, the hydrogen is co-fired in a turbine at a natural gas combined-cycle (NGCC) plant. Two options were examined ... 

NGCC Natural Gas Combined-Cycle PGM Platinum Group Metal... 

The primary source of CO2 is the burning of fossil fuels - specifically gas, oil, and coal - so stabilization of atmospheric CO2 concentration will clearly require substantial reductions in CO2 emissions from these sources. For example, one commonly discussed scenario to stabilize at 500 ppm by the mid-twenty-first century suggests that about 640 Gt CO2 (c. 175 GtC) would need to be avoided over 50 years, with further emission reductions beyond 50 years. As references, a 1000 MW pulverized coal plant produces 6-8MtC02 c. 2MtC) per year, while an oil-fired single-cycle plant produces about two-thirds this amount and a natural gas combined cycle plant produces about half this amount. Thus the above scenario would require that the atmospheric emissions from the equivalent of 2000-4000 large power plants be avoided by approximately the year 2050. 

For the ZEPP system presented in Fig. 2.7 the allowable installed costs for the capture plant have been estimated to be in between 80 and 120M for a 1.4GWthermai input natural gas combined cycle (NGCC) plant. To meet the cost targets, an ITM based ZEPP power plant should have an electric efficiency of at least 52%. Capture ratios (carbon captured/carbon fed to the process) of 100% result in plant efficiencies lower than 50%. Capture ratios of the order of 85% are accompanied with plant efficiencies of about 52%. The allowable installed costs window is satisfied when the oxygen flux is at least 20 ml/cm min and the costs of the ITM tubes should be less than 1,500 /m. This clearly sets the targets for materials and turbine development in order for the system to be economically viable within the capture cost boundary conditions. 

Assumes use of electricity from natural gas combined cycle without transmission and distribution costs. 

Dijkstra et al. [56] compared membrane WGS reaction with membrane reforming in the natural gas combined cycles with CO2 capture. Their simulation results indicate that membrane WGS reaction suits well for CO2 capture compared to the membrane reforming. The lower hydrogen partial pressure in a membrane reformer compared to membrane WGS causes high investment... 

Nowadays, natural gas combined cycle (NGCC) power plant represents the most efficient thermodynamic cycle for power production. The modern unit achieves more than 60% of net electrical efficiency. NGCCs have been discussed with pre-combustion and post-combustion capture leading to around 8-10 percentage points of efficiency penalty [70]. 

Manzolini, G., Macchi, E Binotti, M. and Gazzani, M. (2011) Integration of SEWGS for carbon capture in Natural Gas Combined Cycle. Part B Reference case comparison. International Journal of Greenhouse Gas Control, 5, 214-225. 

Figure 6.1 Natural gas combined cycle with pre-combustion CO2 capture on the basis of the SERF concept [5, 6]. (Source Reproduced from Ref [5], with permission from Elsevier and reproduced with permission from Ref [61, Copyright 2006, american chemical society)...

Gazzani, M Macchi, E. and Manzolini, G. (2012c) COj capture in natural gas combined cycle with SEWGS. Part A Thermodynamic performances. InternationalJour-nal of Greenhouse Gas Control, doi 10.1016/j.ijggc.2012.06.010. 

Electricity Price 0.0977 /kWh Ecoinvent 3, electricity production, natural gas, combined cycle power plant. Comment for electricity produced in steam turbine... 

Layout of a natural gas combined cycle with CO2 pre-combustion capture based on air-blown ATR reactor. 

Total installation costs depends on type of plant and its complexity 80% is a correct figure for power plants with CO2 capture or coal based plant as Integrated Gasification Combined Cycles for Natural Gas Combined Cycles, this coefficient decreases to 68%. 

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