- Email: [email protected]
Solid state chemistry and catalysis workshop in Villeurbanne
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of lung function, hospital admissions, asthma, and other respiratory problems. PM is the only air pollutant regulated by the EPA in the United States that does not specify a particular chemical composition. Many different types of particles are included in the term PM including naturally occurring windblown dust (generally the coarser particles) and anthropogenic combustion products (generally the finer ones). PM25 for example, includes acid aerosols such as sulfates from the burning of sulfur containing fuels. Fine particles form by chemical reaction, nucleation, condensation, coagulation, evaporation of fog and cloud droplets in which gases have dissolved and reacted. Particles generally are composed of sulfate, nitrate, ammonium, hydrogen ion, elemental carbon, organic compounds, PNA, Pb, Cd, V, Ni, Cu, Zn, particle-bound water or biogenic organics. Generally they are largely soluble, hygroscopic, and deliquescent. The major sources are combustion of coal, oil, gasoline, diesel, wood; atmospheric transformation products of NO,, Son, and organics including biogenic organics such as terpenes; high-temperature processes, smelters, steel mills. Their lifetime in the atmosphere is generally measured in days and they can travel over hundreds of kilometres. EPA has wide range of options in setting a new PM standard. It could merely reaffirm the existing standard for PM10 or it could establish a new standard for PM2.5, either for short-term exposure, long-term exposure, or both. Setting a new standard for PM2.5 would require that those particles be monitored systematically. If the epidemiological results collected to date are confirmed, setting a new PM standard could be difficult. Although
applied catalysis B: environmental
today’s 24-hour health standard for exposure to PM10 is 150yg/m3, health effects appear in the studies at levels below 50 pg/m3. In fact, the research has yet to identify a clear threshold below which the effects do not occur. Better NO, Removal from Gas Burners Field tests of a new deNOx catalyst, developed by Tokyo Gas Co. (Tokyo), and made of silver supported on an alumina honeycomb, for gas engine co-generation units have shown three times the removal capacity of conventional deNOx catalysts. The catalyst works in conjunction with an alcohol or ammonium acetate to remove more than 80% of the NO,. Tested at a gas temperature of 380°C and an O2 concentration of 10% on the emissions from a 300-kW lean-burn gas engine with P-propanol as reducing agent, 150 mm3 of the catalyst removed in excess of 80% of the 100-ppm NO, feed at a space velocity of 50,000 h-‘. The reductant:NOx ratio was 3:l. Field tests of the catalyst system are scheduled to continue until March 1996, with commercialization planned for the following month. Source: Chemical Engineering/July 1995 Solid State Chemistry and Catalysis Workshop in Villeurbanne The Euroxycat network of the Human Capital and Mobility Programme of the European Union held its second workshop on the theme “Solid State Chemistry and Surface Studies in Catalytic Oxidation” at the lnsitut de Recherches sur la Catalyse, Villeurbanne, France on 20 and 21 October 1995. The network gathers together research groups from Berlin, Bochum, ComVolume 7 No. l-2 - 7 December 1995
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piegne, Trontheim, Thessaloniki, Eindhoven, Patras, Villeurbanne and Limerick, each of which presented a paper at the workshop. In addition there was a guest contribution from the University of Twente. Further details of the Network composition were given previously in News Brief (Appl. Catal A: News Brief 121 (1995) N19). A large number of personnel exchanges between members of the network have been arranged in the last two years. A total of 9 presentations were made at Villeurbanne, covering the relationship between the solid state structure of pure or doped catalysts, the surface composition, the nature of chemisorbed species and the stability of reactants and products, with particular emphasis on propane oxidative dehydrogenation and the partial oxidation of methane into synthesis gas. The workshop was attended by 25 doctoral and post-doctoral workers from within the network. The last workshop planned for the network will be held in Greece in June or July 1996. Propylene Epoxidation with Hydrogen Peroxide L.T. Nerneth et al. of UOP report that titania-supported titanosilicates are effective catalysts for propylene epoxidation with hydrogen peroxide (U.S. Patent 5 354 875). An autoclave charged with 30% aq H202 (40 g) methanol (200 g), and catalyst (25-l 0 g) is heated to 4060°C and pressurized (500 psig) with propylene and nitrogen (propylene:hydrogen peroxide mole ratio of 5:l). Propylene oxide yield (from H202) increases from 81% in 3 h to 95% after 6 h. Hydrogen peroxide conversion is 100%.
applied catalysis 8: environmental
The disclosure also impliesthat the system is applicable to epoxidation of propylene with ethylbenzene hydroperoxide (a-methylbenzyl hydroperoxide); this technique is used commercially by Shell and Arco. Shell reportedly uses a silica-supported titania catalyst. The advantage of the Arco and Shell technology is the coproduction of about 4 lb styrene/lb propylene oxide, the value of which largely offsets the raw material costs for the process. The hydrogen peroxidebased route, however, has much lower capital investment. A key economic factor is the cost of hydrogen peroxide, which reportedly has been available to largescale users (pulp mills) at 25-35$/lb (100% basis). At a yield of 95%, this price corresponds to 0.62 lb H*O$lb propylene oxide or 15.5-21.7 C/lb of product, Global capacity for propylene oxide is nearly equally divided between chlorohydrin and alkylhydroperoxide systems. Current worldwide demand (3.5 million tons/year) is growing at an annual rate of 3%. Its primary end use is production of polyether polyols for polyurethanes. Source: ChemTech, July 1995
Environmental Protection and Process Safety
From January 1996, The Royal Society of Chemistry and the DECHEMA will publish the monthly abstracts publication Environmental Protection and Process Safety (EPPS). Formerly called Safety, Environmental Protection, and Analysis, this publication is one of five produced from the Chemical Engineering and Biotechnology Abstracts (CEABA) database. Environmental Protection and Process Safety monitors over 500 journals and many more sources, in more than five difVolume 7 No. l-2 - 7 December 1995
of lung function, hospital admissions, asthma, and other respiratory problems. PM is the only air pollutant regulated by the EPA in the United States that does not specify a particular chemical composition. Many different types of particles are included in the term PM including naturally occurring windblown dust (generally the coarser particles) and anthropogenic combustion products (generally the finer ones). PM25 for example, includes acid aerosols such as sulfates from the burning of sulfur containing fuels. Fine particles form by chemical reaction, nucleation, condensation, coagulation, evaporation of fog and cloud droplets in which gases have dissolved and reacted. Particles generally are composed of sulfate, nitrate, ammonium, hydrogen ion, elemental carbon, organic compounds, PNA, Pb, Cd, V, Ni, Cu, Zn, particle-bound water or biogenic organics. Generally they are largely soluble, hygroscopic, and deliquescent. The major sources are combustion of coal, oil, gasoline, diesel, wood; atmospheric transformation products of NO,, Son, and organics including biogenic organics such as terpenes; high-temperature processes, smelters, steel mills. Their lifetime in the atmosphere is generally measured in days and they can travel over hundreds of kilometres. EPA has wide range of options in setting a new PM standard. It could merely reaffirm the existing standard for PM10 or it could establish a new standard for PM2.5, either for short-term exposure, long-term exposure, or both. Setting a new standard for PM2.5 would require that those particles be monitored systematically. If the epidemiological results collected to date are confirmed, setting a new PM standard could be difficult. Although
applied catalysis B: environmental
today’s 24-hour health standard for exposure to PM10 is 150yg/m3, health effects appear in the studies at levels below 50 pg/m3. In fact, the research has yet to identify a clear threshold below which the effects do not occur. Better NO, Removal from Gas Burners Field tests of a new deNOx catalyst, developed by Tokyo Gas Co. (Tokyo), and made of silver supported on an alumina honeycomb, for gas engine co-generation units have shown three times the removal capacity of conventional deNOx catalysts. The catalyst works in conjunction with an alcohol or ammonium acetate to remove more than 80% of the NO,. Tested at a gas temperature of 380°C and an O2 concentration of 10% on the emissions from a 300-kW lean-burn gas engine with P-propanol as reducing agent, 150 mm3 of the catalyst removed in excess of 80% of the 100-ppm NO, feed at a space velocity of 50,000 h-‘. The reductant:NOx ratio was 3:l. Field tests of the catalyst system are scheduled to continue until March 1996, with commercialization planned for the following month. Source: Chemical Engineering/July 1995 Solid State Chemistry and Catalysis Workshop in Villeurbanne The Euroxycat network of the Human Capital and Mobility Programme of the European Union held its second workshop on the theme “Solid State Chemistry and Surface Studies in Catalytic Oxidation” at the lnsitut de Recherches sur la Catalyse, Villeurbanne, France on 20 and 21 October 1995. The network gathers together research groups from Berlin, Bochum, ComVolume 7 No. l-2 - 7 December 1995
N5
piegne, Trontheim, Thessaloniki, Eindhoven, Patras, Villeurbanne and Limerick, each of which presented a paper at the workshop. In addition there was a guest contribution from the University of Twente. Further details of the Network composition were given previously in News Brief (Appl. Catal A: News Brief 121 (1995) N19). A large number of personnel exchanges between members of the network have been arranged in the last two years. A total of 9 presentations were made at Villeurbanne, covering the relationship between the solid state structure of pure or doped catalysts, the surface composition, the nature of chemisorbed species and the stability of reactants and products, with particular emphasis on propane oxidative dehydrogenation and the partial oxidation of methane into synthesis gas. The workshop was attended by 25 doctoral and post-doctoral workers from within the network. The last workshop planned for the network will be held in Greece in June or July 1996. Propylene Epoxidation with Hydrogen Peroxide L.T. Nerneth et al. of UOP report that titania-supported titanosilicates are effective catalysts for propylene epoxidation with hydrogen peroxide (U.S. Patent 5 354 875). An autoclave charged with 30% aq H202 (40 g) methanol (200 g), and catalyst (25-l 0 g) is heated to 4060°C and pressurized (500 psig) with propylene and nitrogen (propylene:hydrogen peroxide mole ratio of 5:l). Propylene oxide yield (from H202) increases from 81% in 3 h to 95% after 6 h. Hydrogen peroxide conversion is 100%.
applied catalysis 8: environmental
The disclosure also impliesthat the system is applicable to epoxidation of propylene with ethylbenzene hydroperoxide (a-methylbenzyl hydroperoxide); this technique is used commercially by Shell and Arco. Shell reportedly uses a silica-supported titania catalyst. The advantage of the Arco and Shell technology is the coproduction of about 4 lb styrene/lb propylene oxide, the value of which largely offsets the raw material costs for the process. The hydrogen peroxidebased route, however, has much lower capital investment. A key economic factor is the cost of hydrogen peroxide, which reportedly has been available to largescale users (pulp mills) at 25-35$/lb (100% basis). At a yield of 95%, this price corresponds to 0.62 lb H*O$lb propylene oxide or 15.5-21.7 C/lb of product, Global capacity for propylene oxide is nearly equally divided between chlorohydrin and alkylhydroperoxide systems. Current worldwide demand (3.5 million tons/year) is growing at an annual rate of 3%. Its primary end use is production of polyether polyols for polyurethanes. Source: ChemTech, July 1995
Environmental Protection and Process Safety
From January 1996, The Royal Society of Chemistry and the DECHEMA will publish the monthly abstracts publication Environmental Protection and Process Safety (EPPS). Formerly called Safety, Environmental Protection, and Analysis, this publication is one of five produced from the Chemical Engineering and Biotechnology Abstracts (CEABA) database. Environmental Protection and Process Safety monitors over 500 journals and many more sources, in more than five difVolume 7 No. l-2 - 7 December 1995