Steam technology, developments

Heat Recovery and Seed Recovery System. Although much technology developed for conventional steam plants is appHcable to heat recovery and seed recovery (HRSR) design, the HRSRhas several differences arising from MHD-specific requirements (135,136). First, the MHD diffuser, which has no counterpart ia a conventional steam plant, is iacluded as part of the steam generation system. The diffuser experiences high 30 50 W/cm heat transfer rates. Thus, it is necessary to allow for thermal expansion of the order of 10 cm (137) ia both the horizontal and vertical directions at the connection between the diffuser and the radiant furnace section of the HRSR. 

Wood was the easiest fuel to use in early steam locomotives, but it was soon realized that the logistics of wood fuel were limiting. Steam engines were developed that could burn coal, peat, or (later) oil where those fuels were more abundant. For intercity railroads (especially in the Americas, Asia, Australia, and Africa), coal remained the fuel of choice for one hundred years. Despite impressive technology development, steam locomotives never could achieve thermal efficiencies greater than about 6 to 8 percent. 

Steam reforming using natural gas in a central station or distributed facility could reduce C02 emissions on the order of 200 million metric tons per year by 2050, in either state of technology development. Also, sharp reductions in C02 emissions would occur if all of the hydrogen was generated using biomass as a feedstock, or nuclear power as a heat source, or if the C02 from a coal-based or a natural-gas-based technology was separated and sequestered. 

A number cf processescombine both the above techniques in order to compensate for the endothennicity of steam treatment by combustion with oxygen or air. These include the technology developed jointly in the 1950s by SBA (Society Beige del Azote) and Haldor Topsoe, and the low-pressure techniques subsequently proposed by 0.N7A, BASF (Badiiche Anilin und Soda Fabrik) eta... 

Furnaces with very short residence time (Short Residence Time technolog> developed b> Lummus) adapt ideally to the cracking of gas oils on account of their tube diameter, which is larger than that of standard equipment, the low partial pressure of steam, and decreased coking. 

There have been many cholesterol-reduction technologies developed all over the world because of high interest by the dairy industry. However, there are only a few technologies available for technology transfer. Fractionation by thermal crystallization, steam stripping, short-path molecular distillation, supercritical fluid extraction, selective absorption, and crystallization using solvents or enzymatic modification can achieve fat alterations of significance to the dairy industry. 

In its original version, this process operates on naphtha, which is cracked by injection into a hot medium, achieved by the combustion of the same naphtha with oxygen in the presence of steam. The latest technological developments, achieved jointly with Union Carbide and Chivoda. are designed to convert crude ofl in a reactor whose operation can be directed towards the preferential production of ethylene (see Section 21.3.4), or towards that of an acetylene/ethylene mixture in a molar ratio close to 1 (see Section 3.4.2). This possibility is exploited to produce vinyl chloride monomer in a process (Fig. 11.6) whose main stages are discussed below ... 

Application Advanced Pygas Upgrading (APU) is a catalytic process technology developed by SK Corp. and is exclusively offered by Axens to convert pyrolysis (ex steam cracking) gasoline to a superior steam-cracker feed (LPG), and benzene, toluene and xylene (BTX) aromatics. 

China Petrochemical Technology Co., Ltd. Ethylene Ethane to heavy-vacuum gasoil CBL cracking technology is a steam-cracking technology developed by SINOPEC. 44 NA... 

---