De katalytische dehydrogenatie van ethylbenzeen tot styreen: Verslag van het processchema

Document(en) uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science

Omzettingen van koowaterstoffen door middel van gasontladingen

Applied Science

Trends, problems and outlook in process industry risk assessment and aspects of personal and process safety.

Process industry brings economic activity and provides us with unique materials. Inherent to it are risks of loss of containment of hazardous substances and the ensuing risks of explosions, fires and toxic spread. Risk assessment as an instrument to describe and delimit the risk of chemical process operations was introduced to the community of Loss Prevention in the process industry in the mid-seventies. Many data have been collected and much has been said about interpretation of results. The latter has been an infinite source of quarrels. Meanwhile, the use of risk assessment has become rather widespread and more decision making depends on it. Not only installations bound to a certain location, but also transportation routes have been object of risk analysis and assessment. Yet, the methodology produces still unsatisfactory results. This paper will start off presenting a statistical study on petrochemical accidents over the long period to evidence the need of developing and strengthening control barriers to prevent catastrophic consequences to people or environment resulting from accidental releases of hydrocarbons. The paper will continue describing what is meant with risk assessment, where it is used for and why and what trends can be seen. It will briefly summarise experiences in the Netherlands and elsewhere. It will then try to analyse the underlying problems as there are the subjectivity in hazard identification, oversimplification in release models, assumptions in environmental conditions (weather, terrain), the large uncertainties in failure mechanisms and failure rates, and the deficiencies in consequence modelling. The paper will further try to give a perspective of promising developments, highly needed cooperative efforts on e.g. a European scale to give relief to the larger demands in a more complex and economically striving society which puts a high value to overall safety and security. At last, an approach to process and personal safety management is presented, derived from a process industry case-study and including human behaviour evaluation, as well as the implementation of a set of lagging and leading safety indicators

Social risk assessment of large technical systems

A probabilistic approach to engineering advances. Since risk adhering to a technical structure can be determined quantitatively easier and more accurately than before, criteria for decision making are becoming more important. If the structure is in the public domain, and benefits are not felt, the voluntariness of being subjected to the risk becomes low. Decisions become, in such a case, a political issue on the basis of considerations of ethics, law, and social justice. For a specific case, the comparison of the economic benefits with the total costs, including risk reduction in a worst case scenario, play a major role as we have seen over and over again in, for example, planning nuclear power generation. A criterion for individual risk of 10-5 per year for the purpose of "external safety" is generally accepted. For social risk assessment, however, a group risk criterion is essential and much more difficult to define. An analysis is made. Examples of inconsistency are given. Further dialogue is encouraged

Trends, problems and outlook in risk assessments: Are we making progress?

Process industry brings economic activity and provides us with unique materials. Inherent to it are risks of loss of containment of hazardous substances and the ensuing risks of explosions, fires and toxic spread. Since for several reasons industry favours locations near crossways of trade and traffic and thus vicinity to population is inevitable, risk assessment has in many places become a routine based on legislation. The paper will review the state of the art and will call for improvements