ENBC: Yes! Look at this. Everything you ever wanted to know about Biodesulfurization.
The Sulfur Penalty:
The environmental driver for diesel sulfur reduction is well-established. Sulfur is the key diesel fuel property that has to be changed to allow auto manufacturers to achieve the Tier 2 vehicle emission reduction targets of the U. S. Environmental Protection Agency (EPA). In fact, there is widespread belief that if fuel sulfur levels are reduced in order to enable efficient after-treatment, the after-treatment device will become the primary driver on tailpipe emissions and all other fuel properties will have only minor or secondary effects. This is according to a recent Society of Automotive Engineers (SAE) review paper [1].
Meeting sulfur regulations on petroleum products is driving up the cost of refining, because conventional hydrodesulfurization becomes increasingly expensive and less efficient in handling sulfur removal as lower and lower sulfur levels are reached [2, 3] At last fall's SAE International Fuel & Lubes meeting, at least one refiner estimated that the potential cost to U.S. refiners of investing in low-sulfur diesel could reach $30 billion [4]. Biodesulfurization, which focuses on sulfur removal and doesn't necessarily attack other aromatics, is expected to provide refiners worldwide a cost-effective method of meeting new lower-sulfur standards while lowering energy consumption and, thus, CO2 emissions.
New opportunity:
Additionally, EBC researchers discovered that the enzymes offered the potential to produce high-value chemical products. Sulfones which concentrate in oil, and sulfinates and/or sulfonates which concentrate in water can be selectively produced. Any of these oxidized products are easily recoverable and have much greater chemical value than elemental sulfur produced by HDS, and are even more valuable than the diesel fuel itself.
Selectivity:
The most recent advances in EBC's biocatalyst technology have occurred within the past 12 months. Selectivity issues are being addressed and resolved. EBC resumed screening of soil isolates and also initiated an aggressive program of directed evolution and gene shuffling to discover or produce new enzymes that are capable of removing a broader range of sulfur types from petroleum. The overall goal of this research is to broaden selectivity to the point where the technology can achieve the full extent of desulfurization required by refiners, i.e., reduce diesel sulfur to less than 50 ppm. To this end, EBC scientists are building a library of catalysts with broader selectivity than IGTS8.
Commercialization Status:
As of the writing of this report (January 1999), EBC and its alliance partner Kellogg, Brown & Root were preparing the basic process design basis for the first commercial licensee to build a diesel BDS unit. The licensee is Petro Star Refining, and the unit is planned for construction at the company's refinery in Valdez, Alaska. Target for the unit to be operational is third quarter, 2001. The Petro Star process installation is expected to be the first commercial scale demonstration of diesel biodesulfurization. In addition to upgrading the refinery's 5 MBPD diesel stream, this plant will produce approximately 10 MM lbs/year of the new aromatic sulfonate commodity, which will be available for commercial use.
Go here for the rest of the article:
news.hydrocarbononline.com
I like the outlook for this one. |
