Sulfur Content in Gasoline

Sulfur content in gasoline is an important regulatory constraint for refiners. Many schemes are in use to reduce the sulfur content in refinery products. In the case of the FCC unit, a significant portion of the sulfur in the feed leaves the process as a dry gas. However, the remaining sulfur leaves through the key liquid products. 

Let us consider the situation where a cheaper feedstock. Vacuum Residue (VR) is available. The refiner may want to maximize the profitability of the unit by blending in VR with the existing vacuum gas oil (VGO) feed. Currently, 5.7 wt.% of the feed to the FCC unit is VR type feed. We would like to know how much VR we can blend into the VGO feed while meeting the constraint of stabilized gasohne. 

We vary the feed ratio of VR from 0% to 11.3% and the associated sulfur content in the VGO. The corresponding sulfur limit for FCC gasoline in this refinery is 800 ppm wt We use the model to predict the sulfur content in different cases of feed ratio and sulfur in VGO. We note that for the base case of 0.71 wt% sulfur in feed VGO, we could blend in more than 10% VR while still meeting the sulfur constraint However, if the sulfur in the VGO increases to 0.78 wt.%, we cannot blend in more than 4.5 wt% of VR if we want to meet the sulfur constraint 

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Influence of sulfur content in gasoline (from 500 to 50 ppm) in the reduction of pollutant emissions. j... 

By 1999, General Motors, Daimler-Clirysler, Toyota, and Nissan all had demonstration fuel cell vehicles operating on niethanol, with plans to start introducing vehicles into the market by 2005. Auto makers have shown a preference for methanol over gasoline primarily because of the likelihood of the sulfur content in gasoline poisoning some of the catalysts used in the fuel cell. 

Figure 5.31. Sulfur removal (ASR) process developed by an H2-free technology it reduces the sulfur content in gasoline and diesel fuel from 300 to 3000ppm to less than 5ppm.133...

Organic sulfur compounds are present in gasoline and diesel. With the increased emphasis on the requirement for more environmentally friendly transportation fuels [1], oxidative desulfurization, using H202 and redox-molecular sieves [2,5,6,7], has been studied and shown to significantly reduce the sulfur content of gasoline and diesel. The reaction of thiophene and its derivatives were successfully converted to oxidized compounds, but the identification of oxidized compounds was not simple because the concentrations of individual sulfur compounds were low. Most of the previous literature has reported sulfone formation. 

The specifically formulated CGP-1 catalyst plays a vital role in the MIP-CGP process. Unique catalyst design, such as metal promoted MFl zeolite, phosphorus modified Y zeolite, and a novel matrix with excellent capability to accommodate coke [12] were involved to ensure the primary cracking and secondary reactions to proceed within a defined path. The commercial trial results of the MIP-CGP process in SINOPEC Jiujiang Company showed that, in combination with CGP-1 catalyst, the propylene yield was 8.96 wt%, which increased by more than 2.6% as compared with FCC process. The light ends yield and slurry yield are basically equal. The olefin content of the gasoline produced by MIP-CGP process was 15.0 v%, which was 26.1% lower than that of FCC gasoline. The sulfur content of gasoline was decreased from 400 to 270 pg/g. 

Sulfur Poisoning. - Many conventional liquid hydrocarbon feeds contain large quantities of sulfur. For example, military diesel may contain as much as 3,000 ppm. Currently in the European Union the sulfur content in diesel is limited to 350 ppm, which was reduced to 50 ppm for both diesel and gasoline in 2005. Even with the pending limits on the sulfur content for U.S. fuels, deactivation by sulfur will be an ongoing concern. 

The results on gasoline and fuel oil are presented in Tables XII and XIII, respectively. The results on gasoline for six elements are based on six aliquots. These results show that sulfur content of gasoline can be determined by INAA. The fuel oil results for 16 elements are based on seven aliquots. The sulfur content reported, 2.04%, agreed well with the NBS true value of 2.035% for the round-robin fuel sample. 

Marshall stability of asphalt concrete dropped 72% after immersion testing in gasoline compared with only a 21% loss with 35-vol % sulfur-asphalt concrete. Jet and diesel fuels had a lesser effect on the Marshall stabilities than did gasoline. The solvent effect on sulfur-asphalt concrete materials decreased with increasing sulfur content in the asphaltic binder in the O-35-vol % substitution range. The greater resistance of sulfur-... 

As in the US, member nations of the European Community will introduce further specifications for transportation fuels over the next few years. Besides other components, the sulfur content of transportation fuels and gasoline in particular will be limited.FCC gasoline can contribute up to 90% of the sulfur in the gasoline pool. The parameters thatcontrol the sulfur levels in gasoline have been described by various authors in the past. The main determinant of sulfur levels in the FCC gasoline is the feedstock. Researchers found that the reactions that converted the feed sulfur compounds in the FCCU were kinetically controlled and were dominated more by catalyst contact time than by catalyst-to-oil ratio [1]. 

In this way the sodium hydroxide is regenerated for further use, and the disulfides, which are not soluble in sodium hydroxide, form an oily layer that can be removed. This is one way in which the sulfur content of gasolines is kept below the 0.1% limit required for marketing. 

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