Innovative approaches for metal removal from petroleum desalter effluent using biological systems

点击翻译按钮获取中文摘要

Desalting and dewatering of crude oil upstream of the crude distillation unit (CDU) is an important unit operation for the removal of salt and other undesirable components from crude oil. The desalter effluent stream arising from this unit operation contains many contaminants such as hydrocarbon emulsions, heavy metals, salts such as chlorides and carbonates, suspended solids, hydrogen sulfide (H2S), ammonia, and phenolic compounds. Current approaches to desalter effluent treatment include sedimentation to remove sludge and suspended solids, dissolved air flotation to remove oil and/or membrane/reverse osmosis to remove metals.**However these techniques are inefficient and expensive. The presence of heavy metals in the desalter effluent impacts biological treatment strategies. An approach is urgently needed which can economically remove the heavy metals before biological treatment. In this proposal, the removal of heavy metals is investigated from desalter streams by using specific biological ligands such as metal binding proteins and metal reducing bacteria. This project is in collaboration with Imperial Oil Limited. The current research efforts in the ongoing project involve a two step approach: (i) investigation of a halophilic yeast Debaryomyces hansenii for the removal of hydrocarbons and emulsions and subsequently (ii) the use of halophilic micro-algae Dunaliella salina to remove the remaining nitrogen and phosphorus and produce nutraceuticals such as beta-carotene and clean water for recycle to the refinery. These nutraceuticals are emerging as valuable materials in a new health food sector.The significant benefit envisioned for the industrial partner in this project, Imperial Oil Limited, will be better management of effluent streams with strong potential for clean water recycle into refinery operations. Water recycling in the refinery industry can be a major benefit due to the large volumes of water**utilized.