Development of fluidized bed combustion—An overview of trends, performance and cost

Abstract

The goal of this article is to chart and analyse the development and economical performance of fluidized bed combustion (FBC) and its derivates circulating fluidized bed (CFB) and bubbling fluidized bed (BFB). A descriptive overview is given of the technology and the market penetration is discussed. To make further analysis possible a database is constructed. This database comprises technological and economical data on 491 FBC projects. Analysis of these projects shows that the technology variants (CFB and BFB) diffused differently over time. Drivers, which influenced the market diffusion and technological development are market regulation, environmental legislation and RD&D programs. Important drivers for FBC technology are fuel availability, required applications in the market, innovation spill over and competing technologies. In this article technical characteristics are charted, which show improvements in fuel diversification, technical availability, efficiency and emissions. In terms of economical performance the results show a decline in specific investment cost. Finally, the effect of technological learning and experience on the economical performance of FBC technology is analysed using the experience curve method and theory on economies of scale. A problem with applying the experience curve method is that it is not used often for large power plants like FBC plants and with it lacking a methodological standard. A method is therefore suggested. The analyses yielded progress ratios (PR) from 0.42 to 0.93 for different groups of projects (new plant, repower, retrofit, add-on and conversion) and different parts of the capital breakdown (total project price, engineering, procurement and construction price and boiler price). This means that the specific investment prices (in $/kWe) decline with, respectively, 58% and 7% with every doubling of cumulative installed capacity (in MWe). The progress ratio found for new FBC plants lies between 0.90 and 0.93. These values correspond with the average PR of 0.90 found for power plants in the literature. Further results show that economies of scale have a significant influence on the investment price. Scale factors are found in the range of 0.62-0.81 for different groups of projects. According to these scale factors specific investment price decreases, respectively, between 25% and 12% with every doubling of plant capacity (in MWe).

A Review of Factors Influencing the Cost Development of Electricity Generation Technologies

“…Manufacturers can use this information to improve their respective products [24][25][26]. Furthermore, companies, users, project developers and other stakeholders-such as research institutes and policymakers-can learn from one another through the formal and informal exchange of information [27][28][29].…”

“…Economies of scale at manufacturing level do not appear to have played a significant role in influencing the costs of fossil fuel plants in the past, even though some literature sources suggest that standardisation and the ensuing potential for mass production and economies of scale may have played a role in reducing the costs over time of fluidized bed combustion boilers [25,28]. The limited role played by economies of manufacturing scale in large-scale fossil fuel power plants can be explained by the much lower number of identical (or similar) plants required by these technologies, compared to small-scale renewable energy technologies, to achieve a certain level of electricity generation.…”

“…The same regulations also limited the size of installed circulating fluidized bed (CFB) technology to below 100 MW el until the year 2000. As the technology was already available for above 400 MW el , the regulatory size limit is likely to have prevented power producers from taking advantage of economies of unit scale [25].…”

The future challenges for “clean coal technologies”: Joining efficiency increase and pollutant emission control

“…Fluidized bed combustion represents a straightforward evolution of the circulating fluidised bed combustion, which has gained great attention from the Seventies [16]. Fluidization means that the solid coal particles are supported and mixed with air which is injected into the system.…”

Effect of the by-pass cement-kiln dust and fluidized-bed-combustion fly ash on the properties of fine-grained alkali-activated slag-based composites

“…It is usually concluded that a replacement of OPC higher than 5-10 % has an adverse effect on the compressive and tensile strengths. 4 FBC technology has many advantages in comparison with pulverized coal combustion, 5 but the ashes from FBC are very porous and they contain high amounts of very reactive free lime and anhydrite, which lead, on the one hand, to their self-cementing properties, but, on the other hand, to the problems with the workability and volume stability due to the formation of expansive-hydration products.…”