摘要:

AbstractCharacteristic process parameters and variables in catalytic fluidized bed cracking. Catalytic fluidized‐bed cracking occupies a distinctive position among the various conversion processes. With regard to its favorable product range, the process is characterized by low processing costs coupled with flexibility of raw materials. A number of independent process parameters are available for control of the reactions involved in catalytic cracking and for influencing the product range. The cracking reactions taking place and the interplay of the independent and dependent variables are described. Apart from the actual cracking process, particular importance attaches to the regeneration of the catalyst charged with coke since it has a decisive influence on the thermal economy of the plant. Depending upon the desired product yield or the raw materials a suitable catalyst must be chosen. Considerable progress has recently been made in catalyst developmen

ISSN:0009-286X    

DOI:10.1002/cite.330540202

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractHeat, mass and momentum transfer in separated flows. The simple model of a backward‐facing step in flat plate boundary layers provides basic information on heat, mass and momentum transfer in local separated regions. These new investigations cover nearly the whole range of existence of incompressible separated flows with laminar as well as turbulent boundary layers at separation, including the two main parameters Reδ1and Res: The Reynolds number Reδ1represents the boundary layer at separation, the Reynolds number Resthe shape of the body. It is demonstrated that independently of the state of the boundary layer at separation, there exist three types of local separated regions. Therefore a new general valid classification of local separated flows is introduced based on the actual state of the separated boundary (shear) layer from separation to reattachement. The new results presented are limited to the case where no temperature or concentration boundary layers exist at separation, i.e. to the case of unheated or inert starting length before separation: Only then can the analogy of heat, mass and momentum transfer give useful results over the whole range of existence of local separated regions. A new shear layer model is introduced to facilitate transfer of the results obtained for backward‐facing steps to arbitrary shaped bodies. A compilation and comparison of available literature values shows that this shear layer model for the step also permits the calculation of heat and mass transfer in separated areas on arbitrarily shaped b

ISSN:0009-286X    

DOI:10.1002/cite.330540203

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractProduction of a combustible for coal‐fired power stations based on sewage sludge. This article describes various means of achieving more extensive mechanical dewatering of sewage sludges. The heat content of the sludge solids can become available for combustion processes. The sludge filter cakes obtained by the “CarboSed” process can be disposed of with minimum energy consumption by fluidized bed combustion or be used after appropriate work‐up as a combustible in coal‐fired power stations with full exploitation of their heat content for generation of steam and electric current. Partial substitution of primary energy sources such as coal and fuel oil by sludge filter cake is feasible in all cases. The processes thus make a contribution to the saving of energy resources and the disposal

ISSN:0009-286X    

DOI:10.1002/cite.330540204

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractManufacture of light hydrocarbons from heavy oils – processes and developments. High quality crude oils are running short and their price continues to increase. At the same time there is a trend towards light petroleum products for use as transportation fuels or petrochemical raw materials. Consequently, the conversion of heavy oils, i.e., particularly distillation residues but also heavy oils from tar sands, is gaining increasing commercial importance. The cracking processes currently used in the refining industry are reviewed. Emphasis is placed on their application to metal‐and asphaltene‐containing heavy oils. Feed pretreatment by solvent deasphalting is discussed and the manufacture of syncrude from tar sands is considered. New developments for conversion of heavy oils are outlined. The future production of shale oil and of transportation fuels from oil shale is briefly tr

ISSN:0009-286X    

DOI:10.1002/cite.330540205

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractDevelopments of metallic materials in view of their use for chemical plants. The demands placed on materials of construction for chemical plants are becoming more and more stringent due to the steady increase in mechanical, thermal, and chemical loading. Molten metallurgical improvements, alloying steps, new methods of plastic deformation and heat treatment, and facilitation of workability are implemented in attempts to optimize the properties of construction materials and to achieve better adaptation to the service conditions. Progress achieved by research and developments during recent years in the above mentioned field is apparent in practical applications of some groups of materials which are important for construction of apparatus; these are high‐strength fine grained steels, high‐alloyed ferritic and austenitic stainless steels, as well as duplex steels. Moreover, the improvements – especially in corrosion restistance – are considered which can be obtained by special melting techniques and new fabrication processes. In addition, the advantages of electroslag remelting (ESR) and powdermetallurgical fabrication of semi‐finished products of corrosion resistant alloys and the possibilities of hotisostaticpressing (HIP) of structural components are

ISSN:0009-286X    

DOI:10.1002/cite.330540206

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSolvent extraction (SX). SX is widely used to separate metals from diluted leaching liquors, wastes, and effluents. The composition of the organic phase has great influence in this type of extraction with chemical reaction. Some trends and rules can be given. Another major problem is the aqueous phase. A systematic study is undertaken to up‐date the parameters which are changing with aqueous phase composition. Step‐by‐step development of a process is

ISSN:0009-286X    

DOI:10.1002/cite.330540207

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractProduction of petrol from coal and natural gas. This article assumes an adequate knowledge of the Fischer‐Tropsch process in its original form and as its modern variant, the Synthol process, and adopts the view that coal hydrogenation will only become implementable on an industrial scale in the early 1990. In detail, it considers the integration of the Mobil MTG process in the proven area of methanol production; operation of pilot plant has shown that this process is indeed suitable for industrial scale operation. The production of methanol from natural gas and coal is discussed, as is the subsequent conversion of methanol to petrol; emphasis is placed on the best possible integration of all process plant. Apart from the conventional steam reforming route for methanol production from natural gas, the alternative approach of combing a steam reforming plant with an autothermal cleavage step is also considered; the latter leads to a significant increase in efficiency and a reduction in investment costs. It is also shown for coal as raw material that simultaneous generation of petrol and SNG has considerable advantages of a thermal and financial nature. The principal process steps are described after the manner of keywords and the product costs are presented as functions of the various raw material cost

ISSN:0009-286X    

DOI:10.1002/cite.330540208

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractPresent tendency in rectification: energy economizing. Rectification columns are the greatest consumers of energy in many chemical plants. Decreasing their energy consumption has been a long term aim in process engineering. These considerations have culminated, for example, in the splitting of a separation between two columns operating at different pressures to make an energy match feasible, the application of heat pumps, of intermediate evaporators and condensers, and also the joint execution of different separations in one column with several feeds and side streams. These ideas were formerly often thwarted by high investment costs and (supposed) reduced flexibility; in recent years, however, the design of complex plants with extensive energy matching has become commonplace. A prerequisite is the feasibility of calculating sufficiently exactly the necessary separation units; moreover, there is also a need for efficient column intervals and heat exchangers which can operate with small pressure drops and modest temperature gradients. A general energy‐saving strategy also leads to process modifications in other separation techniques such as liquid‐liquid extract

ISSN:0009-286X    

DOI:10.1002/cite.330540209

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540210

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540211

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY