Calcining effort

Normally, the best activities observed during the development process are found for catalysts prepared in the laboratory where special attention is paid to each preparation step and where better control of e.g. impregnation and calcination temperature history can be achieved. This should be kept in mind when comparing activities of new lab-prepared catalysts with standard products from a production facility. As a consequence, it is seldom worth the effort to continue with a test production if the activity of the lab-prepared catalyst fails to meet the requirements. Important results for the test-produced catalysts are activity measurements covering the full range of operating conditions in the industrial converter and the mechanical strength. 

Much effort has been devoted to aluminophosphates with isomorphous Co2+ substitution (Co-AlPOs) (162). These structures are of interest for two reasons. First, Co is immobilized at lattice sites, and formation of clusters of Co is therefore impossible. Such clusters, which are catalytically less active, can in contrast be formed in materials with mobile Co, for example, Co-exchanged zeolite Y. Second, calcination of Co-AlPOs brings at least... 

A major effort was devoted to the characterization of these catalysts by vibrational and electronic spectroscopies [28i]. Use of IR and Raman spectroscopies confirmed that the monolayer consisted of vanadyl complexes, exhibiting both Lewis and Bronsted sites, and suppressing nucleophilic sites on the support. According to UV-VIS spectra, most of the vanadium in the calcined catalysts is in the Vv state, but part is easily reducible. Evidence for electronic interaction between vanadium and titanium ions was also presented. The monolayer is effective in suppressing Raman bands due to the anatase support, and an explanation for this effect has been offered [30]. 

For all these reasons, the guanine building blocks and the sol-gel chemistry were used as molecular precursor to conceive hybrid chiral materials at nanometric and micrometric scales. Our efforts involved the synthesis and the self-assembly of a guaninesiloxane monomer Gsi (Fig. 3) in the G-quartet and G-quadruplex supramolecular architectures (Fig. 6), which are fixed in a hybrid organic-inorganic material by using a sol-gel transcription process, followed by a second inorganic transcription in silica, by calcination. 

Process and equipment development will continue at Harwell with a concentrated effort on a modification of the FINGAL Process called HARVEST which features an annular calcining and vitrification unit. 

U.S. vitrification processes. In the United States [M2] development efforts are focused on two processes, a spray-calcine/in-can melting process and a ceramic melter process that may be... 

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