摘要:

At the KEMA laboratories, three types of corrosion concerning heat exchangers in coal gasifiers were studied in detail: (1) resistance of materials to general corrosion (sulfidation); (2) down-time corrosion; and (3) interaction between stress/strain and corrosion (corrosion-assisted cracking). A combination of optical and scanning electron microscopy and special sample preparation techniques gave excellent information about the corrosion mechanisms of sulfidation and down-time corrosion. The slow strain rate testing technique was applied to classify materials according to resistance to corrosion-assisted cracking. Critical temperatures for cracking were determined.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689440

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

High temperature corrosion tests were done for 1.25Cr-0.5Mo steel and 347H and 31OS stainless steels in simulated syngases of various compositions at atmospheric and high pressures. For 1.25Cr-1Mo steel, the weight gain increases linearly for 100h and is accelerated by total gas pressure. For stainless steels, the weight gain is accelerated with increase of H2S content and suppressed with increase of H2O content of the simulated syngas. The corrosion of 31 OS stainless steel is one-half to one-third that of 347H stainless steel.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689441

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Corrosion is a major factor affecting the selection, efficiency and safety of many processes operating at elevated temperatures. This is particularly the case in coal gasification plant where a number of contaminants derived from the coal feedstock can cause severe degradation through corrosive attack. Testing of materials for inclusion in such plant can be undertaken eitherin situor in the laboratory under simulated plant conditions. The latter method is commonly used owing to the need to establish, in a controlled manner, the mechanisms governing the mode and rate of the corrosion degradation processes. The paper describes the development of laboratory test methodologies that simulate specific elements of corrosion processes occurring under real plant conditions, allowing predictive models for materials behaviour to be developed. An important aspect of the laboratory studies is the development of test methodologies that permit close control of experimental parameters and have the capability of being reproduced not only in the same laboratory but in other laboratories. Fully reproducible test methodologies could eventually be used as standards. If accepted standard test methods for obtaining commercially relevant data can eventually be established, the database for candidate and new materials should grow and, as a result, better provide for future plant design and operating requirements.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689442

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The purpose of this paper is to take an objective look at the laboratory corrosion studies that have been done and to identify key technical accomplishments in terms of their contributions to the industry. In addition, the future of laboratory testing with respect to the purpose it can serve will be assessed based on the results of work to date and the needs of the industry.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689443

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The main purpose of this paper is to review existing knowledge on metal alloy behaviour in contact with highly reducing syngas in coal gasification plants, presently close to commercialization. A secondary purpose is to compare laboratory and plant corrosion data. Present commercial practice indicates that most metal alloys will be used as heat exchangers to evaporate steam at 350–450°C. Smaller but significant future applications may be superheaters or hot-gas clean-up equipment exposed at 500–600°C. The alloys will probably be in contact with non-equilibrium gases quenched from much higher gasification temperatures in the range 1000–1500°C. Under these conditions the formation of chromia- rich protective oxide scales is rarely observed. The growth rate of less protective oxide/sulfide scales varies considerably with temperature, gas composition and alloy composition. For most applications, available Fe-Cr-Ni alloys can be found to provide adequate service life, provided carburization after long exposures can be avoided.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689444

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Coal-fired combined cycle power generation systems, based on fluidized bed combustion and/or gasification, are being introduced that offer significant advantages over pulverized fuel (pf) firing. Materials selection and performance are key factors in determining the availability of these systems. This paper reports the approach to materials testing adopted for gasifier hot gas path components in British Coal's Topping Cycle Development Programme’and outlines some of the findings. This testing is aimed at generating a database of corrosion and other materials performance data from the exposure of alloys and coatings in gasifier fuel gas environments at a range of temperatures from 300 to 900°C. Detailed characterization of the fuel gas environment has been carried out in an atmospheric gasifier using selected elements and compounds. Activity windows have been defined for sulfur and oxygen in the required temperature ranges and compared with those predicted from calculations based on the fuel gas composition. Materials performance data for four alloys, including 310ss and Haynes HR 160, are also presented. These data illustrate the similarities and differences between results obtained from atmospheric pressure and pressurized conditions, the types of corrosion damage morphologies observed and the effect of changes in gas chemistry on the extent of the damage.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689445

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

In-plant corrosion tests were carried out in two coal gasification plants. This research was sponsored by the Agency of Industrial Science and Technology and the New Energy and Industrial Technology Development Organization (NEDO). At the HYBRID pilot plant (fluidized-bed gasifier), the test programme was conducted to evaluate the low temperature corrosion behaviour of construction alloys. The corrosion rate is strongly dependent on the temperature and peaks at about 300°C. At the HYCOL pilot plant (entrained-bed gasifier), the main purpose of the test programme was to obtain corrosion data on candidate heat exchanger tubing alloys. The test alloys were carbon steel, Cr-Mo steels, austenitic stainless steels, Ni-base alloys and diffusion coatings. According to the first examination results from the heat recovery boiler, the corrosion resistance of the test alloys increases with Cr content in the alloy. Cr-Mo steels are severely attacked through sulfidation and austenitic stainless steels are slightly attacked through oxidation and internal sulfidation.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689446

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

In the PRENFLO plant in Fürstenhausen, Germany, experience of materials exposure was acquired over more than 10000 operating hours. The PRENFLO process is based on the entrained-flow principle with dry fuel dust feeding. The PRENFLO development—based on the Koppers-Totzek process—received funding from the Federal Ministry of Research and Technology (BMFT) and the Commission of the European Communities (CEC). Within the operating time we elaborated two special materials programmes together with the Electric Power Research Institute (EPRI, USA). In the second materials programme KEMA (The Netherlands) was also involved to a large extent. This paper mainly describes some results from the second test series with uncooled samples.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689447

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The Cool Water Coal Gasification Program built and operated the first commercial-scale prototype of an integrated gasification combined cycle (IGCC) power plant. This Program demonstrated the economic and technical feasibility of IGCC technology and provided a foundation for future construction and operation of coal gasification-based power plants.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689448

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Various components in the 40 tpd fluidized-bed IGCC gasifier were inspected at the site and some of them were analysed destructively in the laboratory to reveal the damage accumulated on the components and to verify the reliability of the materials used.

ISSN:0960-3409    

DOI:10.1080/09603409.1993.11689449

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor