The most Advanced Technologies for ... - CASALE GROUP

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quantities of heat in different parts of the converter. Pseudo-isothermal methanol synthesis converter The amount of cooling fl uid fed to the different parts of the plates can be controlled, so that it is possible to modify the temperature profi le in the catalyst bed, adapting it to specifi c needs and making possible to combine, in a single design, the same operating fl exibility of a quench converter with the high effi ciency of an isothermal design with indirect cooling. The catalyst beds can be designed either according to the standard axial confi guration or to the axial-radial bed concept, depending on requirements. With this design, Methanol Casale can cope with increasing demands for very large increases in plant capacity and of grass root plants with mega capacities, offering a very cost-effective solution. Four pseudo-isothermal methanol converters are in operation with capacity up to 3,400 t/d, and one has been designed for a new plant under construction to produce 7,000 t/d in a single vessel. ATR unit In order to drastically increase the capacity of conventional synthesis gas generation units in methanol plants, one of the most effi cient ways is the installation of an additional autothermal reformer (ATR) unit. Methanol Casale has developed a proprietary design for ATR units, which is based on a very effi cient burner design. The Casale ATR design is conceptually very simple: the oxygen stream is introduced at a high velocity axially at the top of the cylindrical combustion chamber, while the process gas is introduced from one side at the top of the cylindrical chamber, prior to the burner tip, and perpendicular to the oxygen tube. To reduce the non-uniformities introduced by the asymmetric inlet of the process gas, the burner is provided with a distributor placed upstream of the burner tip. The main features of the Casale design for ATR burners are: • fast and even mixing between oxygen and process gas; • uniform temperature and composition with better approach to equilibrium; • shorter fl ame length, with low risk of damage to the catalyst resulting in maximum catalyst performance over a longer period, together with lower pressure drop. • low temperature of the reformer refractory lining, with no hot spots on the lining surface. • a water-cooled burner tip to ensure high fl exibility in operation and high reliability (an almost unlimited operating life is expected). This technology is already operating in four methanol plants and in two ammonia plants. ATR burner Large capacity increase using Methanol Casale technologies Utilising the most appropriate of its proprietary technologies, combined with the correct modifi cation to the process steps, Methanol Casale makes drastic capacity increases in existing plants possible. In two of the most recent projects, a capacity increase 7 of 25% has been obtained, with fi nal capacities between 3,000 t/d and 3,500 t/d. Furthermore, Methanol Casale is presently studying a capacity increase of almost 100%. 4. New plant construction Boosted by the creativity necessary to improve existing plants and by the experience gained from the successful applications of many new concepts, in recent years the Casale Group has developed innovative processes for grass-roots fertilizer and methanol plants to respond to the growing demand for new plants in low gas cost areas. Ammonia Casale has traditionally been involved in designing grass-roots ammonia plants, with more than 200 units build in the fi rst half of its history. More recently, even though it has been mostly focused on plant revamping, it has also increasingly developed and supplied technologies for grass-roots plants. Ammonia Casale has participated to the design to 7 grass-roots plants through its licensees and designed 36 coalbased plant, supplying the design of the synthesis loops. Some of these loops have been designed to run with syngas coming from gasifi cation plants making use of alternative feedstocks. Ammonia Casale has also completely designed a 2,050 t/d grass-roots plant that is in operation since more than two years. Four more 2050 MTD plants have been designed by Casale and are work on them is in progress. This plant has been designed around conventional steam reforming technology, but incorporates all the most advanced technologies of Ammonia Casale to make it as effi cient as possible. Through a joint development with Lurgi, Ammonia Casale has also developed a very innovative process that allows the design of single trains plants with capacities of 4,000 t/d and higher. In the fi eld of methanol, Methanol Casale has designed and supplied two grass-roots plants, of 1,350 and 1,600 t/d capacity, as well as the world’s largest methanol plant, currently at an early stage of realisation, with a capacity of 7,000 t/d. Thanks to its pseudo-isothermal converter and to its innovative ATR design Methanol Casale is in a position to design very large methanol units, 7,000 t/d and more, in a real single train with a single vessel converter.
Casale grass-roots urea plant Casale grass-roots methanol plant. Casale grass-roots ammonia plant For grass-roots urea plants, Urea Casale has developed a new process, the Split- Flow-Loop process, based on its Split- Flow-Loop technology (see above) and incorporating all of its most advanced technologies, such as the Casale-Dente high effi ciency trays, the Full-Condenser design, and the HEH. Three plants are operating according to this process and one grass-root plants is being started-up. 5. Syngas production and new gas based routes to olefi ns and fuels Two other chemicals deriving from synthesis gas are becoming more and more important; hydrogen and carbon monoxide. Casale is therefore now working to develop innovative processes and equipment for these two products. For hydrogen this is via improving the traditional steam reforming route, while for carbon monoxide the focus is on the development of better partial oxidation reactors. One Casale improved POX burner for the production of CO is already in operation and a second one is under construction. Casale is also working on the development of two new processes downstream of methanol plants: the production of dimethyl-ether, DME, and of light olefi ns from methanol, MTO, where ethylene and propylene are produced with high yields and a variable production ratio to cope with market demand. Olefi ns and DME may become, in the very near future, new large and profi table uses for methanol, contributing to the sales of methanol plants. For these two processes, Casale is applying its well established know-how and experience in the synthesis area to the design of the reactors, refl ecting their importance within the overall technology. 6. R&D activities As can be seen from the large number of innovative technologies developed, the Casale Group has invested and is still signifi cantly investing in technology development. The Casale R&D department is also putting a lot of effort into developing the right process design models. For investigating, analysing and visualising complex phenomena, the R&D department avails itself of the right specialists and of advanced tools, such as computer-aided techniques with applications ranging from chemical process design to fl uid dynamics evaluations. Several of the technologies developed by Casale are typical examples of how the combination of these tools and this expertise can lead to the development of innovative concepts. At present, to shape future Casale technologies, various R&D programs are being implemented in different fi elds (see previous sections), involving also the construction of pilot facilities. In addition to new technologies, Casale has also developed, and continue to develop, innovative mechanical designs for very critical equipment, such as 8 HP process boilers, to improve their reliability. 7. Conclusion So far, Casale’s traditional fi eld of excellence has been the revamping of existing units, which has contributed to saving large amounts of natural resources in terms of increased effi ciency of natural gas use. Such excellence has also secured for Casale the position of a modern and reliable participant in licensing the process design of new plants for the production of ammonia, urea, methanol and downstream products. ■
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The most Advanced Technologies for ... - CASALE GROUP

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