Inherent Safety Evaluation for Process Flowsheets of Natural/Shale Gas Processes

摘要

Inherent safety aims to reduce the source of risk in chemical processes. Its application in early design stages represents an advantage due to the flexibility to make changes at that stage of the process development. A relevant application is presented in this work as part of the design of transformation processes for shale gas, since the increasing availability of natural gas due to shale gas extraction has raised the interest in developing processes that use natural gas as a feedstock. Two alternatives for the production of ethylene and four processes for the production of methanol, with natural gas as a feedstock, are analyzed to rank them according to inherent safety levels. The comparison of the technologies is complemented with economic and environmental issues. The results show that from the technologies for ethylene production, oxidative coupling of methane shows better inherent safety levels than the methanol to olefins route, although it offers a low profitability. For the methanol alternatives, the use of steam methane reforming resulted in the safest technology, while partial oxidation offered the highest profit and the autothermal reforming option showed the lowest CO2 emissions. In addition, the most hazardous streams or sections for each process, as provided by the safety indices, were detected.