EPA Safety

Hazard Assessment and Procedures
The chemicals involved in this process are benzene, propylene, benzene and p-diisopropylbenzene. Although each chemical posed a hazard, benzene is the most hazardous. All chemicals should be utilized with safety in mind however; benzene must be handled with care. The health effects of benzene range from dizziness to cancer. Therefore, special precautions must be taken to ensure safety within the facility. In fact, in any workplace where benzene is used, stored or transported, workers must be aware of benzene’s properties, toxicity and safety procedures to meet the requirements of the OSHA Benzene Standard (29 CFR 1910.1028). Therefore, an annual training program will be implemented at the facility that ensures that all employees are knowledgeable of benzene policies and procedures. The OSHA Benzene Standard also provides permissible exposure limits for employees. In the event of an accidental release of benzene, the release must be reported to the appropriate authority, cleaned immediately while removing all sources of ignition. The storage and handling of feed chemicals has been responsible for some many explosions, including the Bhopal disaster in 1984. The plant accidently released methyl isocyanate gas into the environment. The accident stole the lives of 3,787 people. The effects of the gas leak are still seen today in Bhopal. The use of internal floating roof storage tanks are recommended for benzene bulk storage to ensure that the facility is safe from accidental releases and the tanks will be maintained according to state and local regulations.

First, source reduction was considered to reduce the amount of benzene released. Therefore, most of the benzene used in the process is recycled back into the process. The stream was then minimized and analyzed to determine if the direct release of benzene to the environment was a feasible option. Unfortunately, the risk was not in the allowable range therefore, waste treatment must be used. Gas adsorption was considered as a method of treating the recycle stream. However, the purge stream in conjunction with waste removal was more financially sound than utilizing carbon in a gas adsorber to remove the cumene in the recycle stream.

Production of cumene is a vital process for the use of phenol in industry. The recommended design of a cumene plant is to feed pure propylene and benzene to a reactor at molar flow rates of 102.3 and 105.6 kmol/h, respectively followed by two distillation columns. The yield of cumene produced is in accordance with the design specifications given. An economic analysis of the process yielded a net present value of $53.11 million after 12 years with only a 30% probability of failure.
The proposed process has been evaluated for environmental and safety hazards. It has been designed in accordance to all EPA standards and regulations with minimal release of toxic chemicals. This process is believed to be an economically and environmentally sound investment.