Hazards and Solutions
Hazards encountered in petroleum and petrochemical storage tanks include, fire or explosion, asphyxiation, toxicity, entrapment, falls, and physical and chemical hazards including steam, heat, noise, cold and electrical shock. These hazards can be a result of the presence of hazardous gases, vapors, fumes, cleaning chemicals, dusts, improper or insufficient lockout-tagout, or excessive heat or cold. Additionally, the creation of an oxygen-deficient or oxygen-rich atmosphere may cause serious injury or death.
Most storage tanks have restricted means of entry and egress and are not intended for continuous human occupancy. Because they may contain hazards when taken out of service, most storage tanks will be considered Permit-Required Confined Spaces (PRCS). PRCSs are recognized by Elimex Oil and the industry as presenting specific hazards that require special safety procedures in order to prevent accidents and injuries during entry. Elimex Oil and Gas Ltd’s permit-required confined spaces standards must be followed whenever employees enter permit spaces.
In addition, petroleum and petrochemical storage tanks present a unique classification of confined spaces. The American Petroleum Institute (API) and the National Fire Protection Association (NFPA) have developed a number of standards and codes that specifically address safe work practices while cleaning and entering petrochemical storage tanks.
Oil products (such as crude oil, gasoline, naphtha, diesel and fuel oil) are mainly stored in large-size tanks.
Chemical products (such as methanol, xylene, MEG and styrene) are typically stored in smaller tank sizes. Chemical products often require specific storage conditions such as controlled temperature conditions or atmospheres. LPG is a highly flammable product and is stored in refrigerated tanks at about minus 40°C or in bullets under high pressure.
Biofuels and vegetable oils storage
Biofuels and vegetable oils: bio-ethanol is often stored in the same size tanks as chemicals and requires similar specific tank storage conditions. Bio-diesel and vegetable oils are often stored in the same size tanks with less restricted storage conditions than chemicals.
LNG is stored in specially-designed full containment large tanks and is cooled at atmospheric pressure to about minus 160°C.