Experimental study on sulfur removal from ladle furnace refining slag in hot state by blowing Air

In view of the present problem of sulfur enrichment in the metallurgical recycling process of ladle furnace （LF） refining slag, a simple and efficient method of removing sulfur from this slag was proposed. The proposed method is compatible with current steelmaking processes. Sulfur removal from LF refining slag for SPHC steel （manufactured at a certain steel plant in China） by blowing air in the hot state was studied by using hot-state experiments in a laboratory. The FactSage software, a carbon/sulfur analyzer, and scanning electron micros- copy in conjunction with energy-dispersive X-ray spectroscopy were used to test and analyze the sulfur removal effect and to investigate factors influencing sulfur removal rate. The results show that sulfur ions in LF refining slag can be oxidized into SO2 by O2 at high tempera- ture by blowing air into molten slag; SO2 production was observed to reach a maximum with a small amount of blown O2 when the tem- perature exceeded 1350℃. At 1370℃ and 1400℃, experimental LF refining slag is in the liquid state and exhibits good fluidity; under these conditions, the sulfur removal effect by blowing air is greater than 90wt% after 60 min. High temperature and large air flow rate are benefi- cial for removing sulfur from LF refining slag; compared with air flow rate, temperature has a greater strongly influences on the sulfur re- moval.

Removal of sulfur in coke oven gas by mixing ZnO-based additive into coal

A new technology for recycling EAF dust and removal of sulfur from coking oven gas was investigated. The new technology does not need to set up special equipment to treat COG (coke oven gas), and it is only acquired by mixing the ZnO base additive into the coke coal. In the stage of pyrolysis of the coal volatile, ZnO of the additive combines with H 2S, CS 2, COS and C 2H 2SH of coal gas, forming ZnS in coal char. In the stage of coking of the coal char, Zn is gasified with S, then the gas Zn react with H 2S, CS 2, COS and C 2H 2SH, forming ZnS in coal gas and depositing as dust. After the collected ZnS dust was regenerated, it can be recycling as the additive again. The sulfur in coal gas can be completely removed if the mole ratio of the added Zn to the volatilized S is more than 1, and the sulfur in coke is also slightly decreased comparing with the coke without the additive. The EAF dust containing ZnO and Fe 2O 3 can be the base material of the desulfurizing additive.

Separation of Sulfur/Gasoline Mixture with Polydimethylsiloxane/ Polyetherimide Composite Membranes by Pervaporatlon

Worldwide environment has resulted in a limit on the sulfur content of gasoline.It is urgent to investigate the desulfurization of gasoline.The polydimethylsiloxane(PDMS)/polyetherimide(PEI)composite membranes were prepared by casting a PDMS solution onto porous PEI substrates and characterized by scanning electron microscope(SEM).The membranes were used for sulfur removal from gasoline by pervaporation.The effects of feed temperature,sulfur content in the feed and PDMS layer thickness on membrane performance were investigated,and an activation energy of permeation was obtained.Experimental results indicated that higher feed temperature yielded higher total flux and lower sulfur enrichment factor.The total flux varied little with the increase of sulfur content in the feed,but the sulfur enrichment factor first increased with the amount of thiophene added into the gasoline,and then the variation was little.The increase of PDMS layer thickness resulted in a smaller flux but a larger sulfur enrichment factor.The result indicates that the PDMS/PEI composite membranes are promising for desulfurization by pervaporation.

Wet Desulfurization of High-Sulfur Petroleum Coke Improved via Pre-calcination,H_(2)O_(2) Treatment,and Ultrasound

This work reports an improved method for the wet desulfurization of high-sulfur petroleum coke(petcoke)powder based on the combination of pre-calcination,H_(2)O_(2),and ultrasound.The results demonstrated that over 45%of the sulfur atoms were efficiently removed from Tianjin coke and Qilu coke(particle size<0.1 mm)by pre-calcination at 800℃ for 6 h followed by desulfurization with HNO3(8 mol/L)and H_(2)O_(2)(2 mol/L)solution at a reaction temperature of 60℃,a reaction time of 6 h,a liquid-to-solid ratio of 10 mL/g,and a 40 kHz ultrasonic power of 400 W.In addition,the specific surface area of the petcoke particles increased from 0.7 to 301.49 m^(2)/g.After desulfurization,the pore size distribution of the petcoke particles was more concentrated on micropores compared with the samples prior to petcoke treatment.Reactive force field molecular dynamics simulation results indicated that HNO_(3) continuously oxidized the carbon atoms adjacent to sulfur atoms in the petcoke macromolecules and promoted sulfur removal from petcoke via the cleavage of C-S bonds.The sulfur transformation mechanism can be summarized as follows:thiophene sulfur→branched chain carbon sulfur→CO_(2)S→C_(2)O_(2)S→C_(2)O_(3)NS→C_(2)O_(4)S→CO_(2)S.

Optimization of a continuous ultrasound assisted oxidative desulfurization(UAOD) process of diesel using response surface methodology(RSM) considering operating cost

A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken design.Considering the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of 8.24.In these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,respectively.By drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to 10.Therefore,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.

Study on Reduction of Sulfur Content in FCC Gasoline

Reduction of sulfur content in FCC gasoline was studied in a fixed fluid bed (FFB) unit by using metal-modified LV-23 FCC catalyst. The results showed that the sulfur content in FCC gasoline could be reduced with LV-23 catalyst modified with zinc, palladium, zinc-palladium, zinc-cobalt, and zinc-nickel. Among these metals or metal combinations, palladium-containing catalyst was the most effective. Desulfurization of the heavy fraction of FCC gasoline was more effective than full-range gasoline under the same conditions with palladium-containing catalysts. A high reaction temperature was favorable to desulfurization, but it would reduce the yield of liquid product. After desulfurization reaction, the olefin content of product gasoline decreased while the aromatic and iso-alkane contents increased. Removal of thiophene and benzothiophene is higher.

Optimization of dispersed carbon nanoparticles synthesis for rapid desulfurization of liquid fuel

Stringent regulations and environmental concerns make the production of clean fuels with low sulfur content compulsory for the petroleum refining industry.Because of ease of operation without high energy consumption,the adsorption of sulfur compounds seems the most promising process.Central composite design was used to optimize parameters influencing the synthesis of dispersed carbon nanoparticles（CNPs）,a new class of sorbents,in order to obtain an excellent adsorbent for desulfurization of liquid fuel.The optimized dispersed CNPs,which are immiscible in liquid fuel,can effectively adsorb different benzothiophenic compounds.Equilibrium adsorption was achieved within 2 min for benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiophene with removal efficiency values of 75 %,83 %,and 52 %,respectively.The rate of desulfurization by the prepared CNPs in the present work is seven times higher than the previously reported CNPs.Optimized CNPs were characterized by different techniques.Finally,the effect of the mass of CNPs on the removal efficiency was studied as well.

酸洗除锈工艺的试验研究

讨论了硫酸和盐酸的除锈性能 。

Production of high-purity hydrogen from paper recycling black liquor via sorption enhanced steam reforming

Environmentally friendly and energy saving treatment of black liquor(BL),a massively produced waste in Kraft papermaking process,still remains a big challenge.Here,by adopting a NieCaOeCa_(12)Al_(14)O_(33) bifunctional catalyst derived from hydrotalcite-like materials,we demonstrate the feasibility of producing high-purity H_(2)(~96%)with 0.9 mol H_(2) mol^(-1) C yield via the sorption enhanced steam reforming(SESR)of BL.The SESRBL performance in terms of H_(2) production maintained stable for 5 cycles,but declined from the 6th cycle.XRD,Raman spectroscopy,elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst.It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL,while deposition of Na and K from the BL might also be responsible for the declined performance.On the other hand,it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO_(3).Our results highlight a promising alternative for BL treatment and H_(2) production,thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.

Desulfurization using the 1,2-dimethylimidazolium ionic liquid as an adsorbent

The aim of this study is to investigate the possible use of a 1,2-dimethylimidazolium ionic liquid,2,2-bis（（1,2-dimethylimidazolium）methyl）propane-1,3-diol hexafluorophosphate（1）,as an adsorbent to selectively remove aromatic heterocyclic sulfur compounds from model fuels.The result indicates that adsorbent 1 is insoluble in model fuels.The spent IL saturated sulfur compounds could be regenerated by a water dilution process.The influence of extraction time or temperature as well as the molar ratio of 1 to aromatic heterocyclic sulfur compound was also studied.