It's liquid gold and worth more every day! Considering heating costs, the uncertainty of fuel availability and haul-off costs, waste oils can be worth up to $3.00 per gallon!
Though not classified as hazardous waste, used oil is the responsibility of the generator—in this case, the maintenance shop that created it—from the moment it is created until it is processed or burned. If you produce it, you own it. Better to burn it on site and never ship it out.
The Federal EPA and state regulatory agencies approve the "recycling" of used oils on-site. Waste oils can be burned nationwide except in California and New York City. The EPA has three requirements: 1. Units are not to exceed 500,000 BTU input; 2. Units must be vented to the outside of the facility; 3. The used oil that is burned is to be generated onsite or delivered to the site by "do-it-yourself" oil changers.
A waste oil heater is a sound investment for fleet maintenance shops, truck and heavy equipment dealerships, municipalities, quick lube facilities and other firms generating used oils and having a need for heating air or water. The colder the weather, the longer the heating season, the more one saves. Boilers are not as seasonal and can fill various needs for hot water year round.
Major advances in burner technology and design features assure dependable performance and significantly lower maintenance.
The oils are delivered to a burner specifically designed for their combustion. They are usually pre-heated and then mixed with compressed air to create an atomizing condition. Primary combustion is accomplished in the heater combustion chamber area with resultant heat being passed into the heat exchanger part of the unit. Shop air is brought into the heater and circulated over/through the heat exchanger area. This air picks up the heat from the exchanger and is then delivers it into the shop through vents on the heater or through attached ductwork. Boilers are similar, however, instead of ambient air, water is brought into the boiler. Heat is passed from the boiler heat exchanger into the water. The water exits the unit as hot water.
Heaters and boilers range in BTU input from approximately 140,000 to 500,000. Units are thermostatically controlled. Oil consumption varies depending on the model and the range of shop temperature or water temperature desired.
Heaters and furnaces (ducted heaters) are designed primarily for shop air heating. Boilers may heat shop air through use of remotely located hydronic units or utilize hot water for various services such as in-floor heating, vehicle washes or other processes.
Consistent maintenance is the key to dependable and efficient operation. This includes cleaning ash from the heat exchanger as needed. An annual tune-up of the burner is recommended, possibly including cleaning or replacement of the nozzle and electrodes. Other than this, oil filters need to be cleaned or replaced as necessary.
Usually, a return on investment can be calculated with available heating and haul-off cost figures. However, the most basic part of the equation is whether or not one has used oils available and in what quantity. "On-spec" lubricants—used oils that have been processed or cleaned—are available in many areas at a much lower cost than conventional fuels. These lubricants are no longer considered "waste" or "used" oil and are an excellent supplement for firms that do not produce enough used oils to justify a unit purchase. Even though these fuels are not "free," as with used oil, the return on investment can still be very appealing as they are much less expensive than typical heating oils, natural gas or propane. Paybacks can actually be one year or less, depending on cost of standard fuels, used oil disposal and the actual hours of usage.
Designs vary from manufacturer to manufacturer by configuration and air movement. Basic sizing depends on the quantity of oils available for recycling and the size and layout of the facility. Pricing can play into the decision but isn't the major concern since paybacks are usually very acceptable. Purchasers should look for atomizing type equipment, designed and assembled by long-term manufacturers in ISO shops. Units should be completely packaged, including on-board air compressors, metering pumps (for consistent fuel delivery regardless of oil mixture or viscosity) and factory-tested, including pre-firing.
Ron Foskey has 24 years experience in the environmental industry, all centered on combustion products. Since 1990, his concentration has been on energy reclamation from combustion of used oils with waste-oil-fired heaters and boilers, as Division Manager Waste-Oil-Fired Products Group for Thomas & Betts-HVAC (Reznor), Memphis, TN.