Residue desulfurization

Because of the increased sulfur and impurity levels in crudes currently being processed, refiners in recent years have been considering residue desulfurization units upstream of the delayed coker. In addition to the reduction in sulfur content, residue desulfurization units also lower the metals and carbon residue contents. Due to the reduction in the carbon residue, the liquid product yield is increased and the coke yield reduced. In addition, the coke produced from a desulfurized residue may be suitable for use as anode grade coke. Table I shows the yields and product properties after coking Medium Arabian vacuum residue, with and without upstream residue desulfurization. 

Figure 10. Long-term deactivation during residue desulfurization.

Dautzenberg, F.M. van Klinken, J. Pronk, K.M.A. Sie, S.T. Wijffels, J.-B. Catalyst Deactivation through Pore Mouth Plugging during Residue Desulfurization presented at the 5th International Symposium on Chemical Reaction Engineering Houston, March 13-15,1978. 

ARDS [Atmospheric Residue DeSulfurization] A process for upgrading petroleum residues by catalytic hydrogenation. 

The Bureau of Mines in August 1971 (3) in its study on Oil Availability by Sulfur Levels estimated the additional U. S. and Caribbean residual desulfurization capability would be about 300 million bbl. When this is added to the 59 million bbl of low sulfur oil which already meets the standards, a total of 359 million bbl of low sulfur oil will be available in 1975. If this quantity is deducted from the total utility requirement of 565 million bbl, then about 206 million bbl will be burned in utilities with control devices, or must be processed to low sulfur content in the absence of devices. 

Operating Conditions for Residuum Desulfurization. Temperature, space velocity, hydrogen partial pressure, and catalyst consumption (or cycle life for flxed beds) are the essential operating conditions considered in residual desulfurization. These normally range from 700 to 800°F (6), 0.3 to 3.0 V/hr/V (8), and 0.02 to 1.0 Ib/bbl, respectively. The ranges do not necessarily represent technical limits but are based on judgment and economic considerations. 

MINA ABDULLA REFINERY EXPERIENCE WITH ATMOSPHERIC RESIDUE DESULFURIZATION (ARDS)... 

VGO, vacuum gas oil ARDS, atm. residue desulfurization VGO HCR, vacuum gas oil hydrocracking Residue HCR, residue hydrocracking. 

In order to reduce air pollution, most industrialized countries have restricted the sulfur content of residual fuel. Such regulations have led to the design and construction of residual desulfurization units or cokers in modem refineries to produce fuels that meet these restrictions. 

Besides the aforementioned conventional applications, there are many other HDT technologies that have emerged in the changing environment of the oil industry. The majority of these are focused on the upgrading of the heaviest feedstocks. The atmospheric residue/vacuum residue desulfurization processes (RDS/VRDS), which have been developed to meet a variety of objectives such as preparing feed for FCC, residue FCC, coker, and residue HCR, are cases in point [14, 15]. 

Catalyst Deactivation through Pore Mouth Pluming during Residue Desulfurization... 

The present paper deals with the development of a simple two-parameter model describing the deactivation behaviour of residue-desulfurization catalysts. The validity of the model is being checked against the results of a large number of experiments with a variety of catalysts, two feedstocks and under different operating conditions. 

Possible applications of brown coal coke are seen in small generating units and in large power plants where desulfurization fadhties have already been installed. In the former case brown coal coke can be used for complete desuUurization and for removal, in the latter one, however, it serves the purposes of residual desulfurization and NOj removal. Brown coal coke s big price advantage over other activated cokes, e g. those prodnced from hard coal, makes an expensive regeneration of the laden coke superfluous. It can be used as a fuel with a high heating valne in power plants equipped with flue gas desulfurization facilities or as a valuable sulfur-containing material in other appropriate plants. 

Lababidi, H.M.S., Shaban, H.I., Al-Radwan, S., Alper, E. 1998. Simulation of an atmospheric residue desulfurization unit by quasi-steady state modeling. Chem. Eng. Technol. 21(2) 193-200. 

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