UC SULFUR RECOVERY PROCESS APPLIED TO DIRECT DESULFURIZATION OF HIGH-PRESSURE SOUR GAS STREAMS

摘要

A process for treating amine offgas from natural gas, "UCSRP" and petroleum refinery/petrochemical and similar applications was disclosed previously. UCSRP has costs, on the order of 40% lower than Claus-plus-SCOT for producing sulfur from H2S. In the UCSRP excess H2S reacts with SO2 in a solvent to make molten sulfur. Research at UC Berkeley, coupled with experimental work at Gas Technology Institute (GTI), shows that UCSRP can also be used for direct desulfurization of high-pressure sour gas streams. The sour gas (e.g., syngas or natural gas) and 10% ? 20% excess SO2 are contacted at high pressure with the UCSRP solvent in an absorber-reactor column at about 260° - 280℉. Substantially all of the H2S reacts to form liquid sulfur, leaving the excess SO2 in the treated gas. The unreacted SO2 is recovered in a separate absorber-stripper system, which may also serve to dry the treated gas. The recovered SO2 is combined with SO2 produced by burning one-third of the liquid sulfur in a furnace, compressed and perhaps liquefied, and fed to the reactor column. The furnace employs either air or oxygen. All of the sulfur formed in the reactor is vaporized as it passes through the furnace; the unburned two-thirds condenses in the waste-heat boiler. Any organic components dissolved in the sulfur will also be burned. The product sulfur has only a small amount of dissolved SO2 as impurity. This paper will discuss this new application of the UCSRP to treating sour natural gas and sour syngas, present the results of exploratory experiments conducted at GTI and highlight the potential economic benefits of the process.