Used oil, according to a report published by the Ministry of Health Environment in New Zealand, is the largest non watery waste stream in the country, generating about 30 million litres each year. The oil then becomes contaminated with different substances that are hazardous to people and the environment.
The good news is, it is possible to reuse and repurpose oil in a number of ways. In fact, some companies collect used oil for reuse, and many markets exist for the product. Environmental agencies around the world also make efforts to recycle the waste and prolong its usefulness. The options for repurposing and reusing used oil include re-refining, reprocessing, burning and road oiling.
Waste Petroleum Combustion Limited provides a quick overview of the processes for repurposing the oil.
The re-refining process takes away the impurities and contaminants to use the oil again as vehicle lubricant. In this option, the oil is treated or distilled to modify the structure of the liquid, and make it virtually identical to virgin oil stock. Certain countries use re-refined oil, but cost of setting up a new plant that meets environmental controls is substantial.
This process involves filtering the oil to remove contaminants and produce a partially cleaned fuel. Certain processors operate in the country, and most of them have different way of processing the oil. Some may only eliminate water fraction, while others will remove a large amount of contaminants to produce cleaner oil.
The burning process involves filtering used oil to remove the water and contaminants. It is then burned to make heat or substitute fuel for coal and diesel. In New Zealand, there are a number of burning applications for used oil. Some of them incorporate ash residues into the final product, while others require special handling of residual waste.
In some other cases, people apply oil to unsealed roads for dust suppression. This option, however, has been a subject of debate, as alternative dust suppression products exist. Some also consider the process as a convenient waste disposal route, and may only be pursued with resource consent.
When done properly, oil repurposing/recycling will benefit the environment and the economy. It is important for consumers and business to understand the value of disposing oil properly to spare the ecosystem of the dangerous waste.