Environmental Assessment of Used Oil Management Methods

Abstract

The 1 billion gal of used oil generated in the U.S. each year are managed in three primary ways: rerefined into base oil for reuse, distilled into marine diesel oil fuel, and marketed as untreated fuel oil. Management of used oil has local, regional and global impacts. Because of the globally distributed nature of fuel markets, used oil as fuel has localized and regional impacts in many areas. In this paper, the human health and environmental tradeoffs of the management options are quantified and characterized. The goal of this study was to assess and compare the environmental impacts and benefits of each management method in a product end-of-life scenario using a life-cycle assessment (LCA) approach. A life-cycle inventory showed that 800 mg of zinc and 30 mg of lead air emissions may result from the combustion of 1 L of used oil as fuel (50−100 times that of crude-derived fuel oils). As an example, up to 136 Mg of zinc and 5 Mg of lead air emissions may be generated from combustion of over 50 M gal of California-generated used oil each year. While occurring elsewhere, these levels are significant (of the same magnitude as reported total stationary source emissions in California). An impact assessment showed that heavy metals-related toxicity dominates the comparison of management methods. Zinc and lead emissions were the primary contributors to the terrestrial and human toxicity impact potentials that were calculated to be 150 and 5 times higher, respectively, for used oil combusted as fuel than for rerefining or distillation. Low profits and weak markets increasingly drive the used oil management method selection toward the untreated fuel oil market. Instead, both the rerefining and distillation methods and associated product markets should be strongly supported because they are environmentally preferable to the combustion of unprocessed used oil as fuel.

Effect of Operating Variables on Regeneration of Base-Oil from Waste Oil by Conventional Acid-Clay Method

“…In extreme cases, these contaminants damage the furnace, leading to increased environmental pollution [3]. Emission of Zn can be as high as 600 times and Cu can be 2100 times if waste oil is burnt instead of rerefining [6].…”

Applying environmental policy instruments to used oil

“…While the increase in recycling undoubtedly signifies that more is being conserved than before, at present most of the recovered oil is ultimately reprocessed for bunker fuel rather than re-refined oil, even though re-refining is generally acknowledged to be more conserving and less of a risk to public health and the environment (Boughton and Horvath 2004). Furthermore, until recently, California's used oil programme gave relatively little attention to the possibility of reducing the rate at which used oil is generated, i.e.…”

Compound changes in re-refined used lubricating oils using fabricated Packed-bed reactor

“…Since motor oil does not degrade, used motor oil as the potential to be recycled safely and productively, saving energy and circumventing environmental pollution. 2,3,4 The conventional approaches of recycling used motor oil either entail a high-cost technology such as vacuum distillation or the use of toxic materials such as sulphuric acid, contaminating by-products with high sulphur concentrations may be made. Blend of vacuum distillation and hydrogenation systems had been used for recycling used engine oil.…”