PROCESS SAFETY MANAGEMENT STANDARD (PSM)• PSM - Created by OSHA in 1992

- Outlines requirements for companies dealing with potentially hazardous chemicals.

• Information regarding process safety must be available to employees to help them accurately identify and fully understand all hazards in addition to process limitations, process chemistry, process diagrams, and deviations from all normal processes.

• Training program is implemented to ensure ensures employees understand all health and safety hazards.

• Mandatory Process Hazard Analysis (PHA) must be completed along with Hazards Operability Study (HAZOP).

• Every 5 years after an initial analysis, the employers of the plant must complete an updated PHA.

• Ethanol plant will have at least two PHA’s because its tentative run-length is ten years.

1st level

Primary Safety Features (Designs, Plans, Procedures)

Should rely more on design to prevent accidents as opposed to primarily operating procedures and equipment.

-Process safety management procedures along with a risk management plan-PHA and HAZOP -Emergency Plans

-Establish acceptable levels of risk -A risk assessment and analysis should be completed

2nd level

Secondary Safety Features

-Sprinkler systems to prevent the occurrence of fire. - Pressure relief systems to prevent overpressure (Rupture Discs, Safety Relief Valves) in the pipes, storage tanks, reactor, etc…

-Fire alarms, monitors, control systems-Gas detection systems which detect flammable gases at low concentrations.

-Backup generators (to support utilities and alarms).

3rd level

Containment Systems

Trenches, Extra Barriers

4th level

Emergency shutdown systems

Safety Features

Ethane C2H6 Ethanol CH3CH2OH Ethylene C2H4 Water H2O Zirconium tungstate (Zr(WO4)2)

Limits TLV = 1000 ppm TWA= 1000 ppm TWA= 200 ppm PEL= 5mg (Zr)/m3

Hazards Flammable, harmful if inhaled

Flammable, volatile, harmful if inhaled, ingested

Flammable, volatile, harmful if inhaled, contact with skin

Mechanical irritation

Safety Features in Ethanol Plant

-Pipes should not be placed in/near trenches should be avoided.

-Due to its density, it is possible for ethane to stick to ground level and flash back to their source if a source of ignition is encountered.

-Trenches built in appropriate areas within the plant to deal with ethanol spill.-Trenches minimize the amount of vapor released from spills and prevents the ethanol from collecting around the leaking tanks.

-Pipes must be corrosion resistant since high grades of ethanol can corrupt our piping system made of carbon steel.

-Gas detection systems which measure flammable gases such as ethylene at low concentrations must be installed to mitigate the risks posed by ethylene.

-Welded pipes should be used when dealing with hazardous chemicals. Usage of flexible connectors should be minimal.

-Steam causes burns, may rupture pipes, pressure relief system necessary.

-Thermal insulation must be installed on metallic equipment which heats to 60oC or higher to prevent burns.