A three-dimensional view of structural changes caused by deactivation of fluid catalytic cracking catalysts

Since its commercial introduction three-quarters of a century ago, fluid catalytic cracking has been one of the most important conversion processes in the petroleum industry. In this process, porous composites composed of zeolite and clay crack the heavy fractions in crude oil into transportation fuel and petrochemical feedstocks. Yet, over time the catalytic activity of these composite particles decreases. Here, we report on ptychographic tomography, diffraction, and fluorescence tomography, as well as electron microscopy measurements, which elucidate the structural changes that lead to catalyst deactivation. In combination, these measurements reveal zeolite amorphization and distinct structural changes on the particle exterior as the driving forces behind catalyst deactivation. Amorphization of zeolites, in particular, close to the particle exterior, results in a reduction of catalytic capacity. A concretion of the outermost particle layer into a dense amorphous silica–alumina shell further reduces the mass transport to the active sites within the composite

To be continued: the ASHT II project [Abstract]

Objective: Within the European Union there is a mesh of rapid alert systems (RAS) for different hazards, e.g. food and feed (RASFF), dangerous consumer products (RAPEX) and communicable diseases (EWRS = early warning and response system). The abbreviation RAPEX stands for the rapid alert system for all dangerous consumer products, with the exception of food, pharmaceutical and medical devices. These systems link national and European public health authorities. Although the rapid alert system for biological and chemical attacks (RAS-BICHAT) connects national focal points in case of confirmed terror attacks with chemicals, there is still a gap for chemical hazards in cases of mere suspicion: in the future poisons centres and the EAPCCT will play an important role in the process of exchanging warnings concerning these hazards within the European Union. The ASHT research project prepares tools for these important new functions. The scope of the ASHT I projects was the creation of an EUwide alerting system to detect covert release of chemicals with a criminal or terrorist intent. The acronym “ASHT” stands for “Alerting System and Development of a Health Surveillance System for the Deliberate Release of Chemicals by Terrorists”. In ASHT II this task expands to all chemical incidents. Methods: Description of political, financial, toxicological and technical aspects of the project. Results: In the first phase of the project, ASHT I, two major tasks were accomplished: the feasibility of both a rapid alert system for chemicals (RAS-CHEM) by creating DEV RAS-CHEM, a preliminary “developmental” version, and a European surveillance system between poisons centres. Like ASHT I the second phase of the project is funded by the European Commission, the EAPCCT and the other project members. The duration of the project is 36 months. In ASHT II several tasks will have to be accomplished. Firstly, the DEV RAS-CHEM draft version must be converted into an EU-wide operating rapid alert system for chemicals (RAS-CHEM). The data base must be accessible via the internet. The data base shall carry out the delivery of “chemical event” alerting. The member states’ public health surveillance authorities are to be integrated in the process. On the other hand the ‘EU PC Forum’ as a means of emergency communication between European poisons centres is to be created. This includes the testing of a prototype toxicosurveillance tool using automated data sampling in poisons centres. Toxicological aspects include the refinement of lists of chemicals, symptoms or toxidromes as important bases for mutual data exchange. Concerning the information technology level, several requirements are to be taken into consideration: for the creation of an event and for retrieval functions an appropriate relational data base structure is essential. National Public Health Authorities of the member states of the European Union and the WHO are integrated into the project as associate partners. Conclusion: The early warning system for chemicals (RAS-CHEM) will be integrated into the suite of other pre-existing EU early warning systems in the near future. There is a chance that poisons centres and the EAPCCT could upgrade their role for chemical alertness in Europe

The DeNaMiC Project: description of the nature of accidental misuse of chemicals and chemical products [Abstract]

Objective: To determine the availability of information from poisons centres and other sources that would characterise the nature of accidental exposure to household chemical products to improve risk management. The DeNaMiC project was funded by European Chemical Industry Council (CEFIC) and was carried out by the poisons centres in Göttingen, Lille, London and Prague, the German Federal Institute for Risk Assessment, the World Health Organization and the Health Protection Agency (UK). Method: The project involved developing an analytical tool to compare data on accidental poisoning obtained from the published literature, poisons centre annual reports and official mortality and morbidity statistics, and comparing and mapping the data collection and product classification schemes used by three poisons centres (Göttingen, Lille and London). A retrospective analysis of 3 years of enquiry data from Göttingen and Lille was also carried out to determine routinely available data on circumstances of exposure. European poisons centres were surveyed to determine the availability of data useful for product risk assessment. In addition, an analysis of published literature on toxicovigilance and a survey of toxicovigilance activities of European poisons centres was carried out. Finally, the project explored the feasibility of using poisons centres to obtain additional information about circumstances of exposure through a prospective followup study. Results: A range of publicly available data on accidental exposures was found; however, this provided little on the circumstances of exposure and could only be compared qualitatively. The product classification schemes used by three poisons centres showed some degree of comparability for household products. European poisons centres collected the same base data set but varied in collecting data relevant for risk assessment. European poisons centres varied in their understanding of ‘toxicovigilance’ but most stated that they perform it. It was possible to collect additional prospective data on exposures to household products relevant for risk assessment and management. Conclusions: Poisons centres are an important potential source of data useful for product risk assessment and management. In most cases, however, this requires additional work that needs to be resourced. Cooperation between poisons centres and industry can contribute to improving product safety