Facile Desulfurization Research Articles

Fe-functionalized walnut shell–activated carbon for the facile desulfurization of liquid fuels

Fe-functionalized walnut shell–activated carbon for the facile desulfurization of liquid fuels

Acidity Controlled Desulfurization of Biogas by Using Iron (III) and Ferrosoferric (II, III) Oxide

Abstract Removal of hydrogen sulfide (H2S) from raw biogas is essential for feeding the refined gas with high methane (CH4) content in engines and combustion units. In small-scale farmhouses and power plants, a cheap, inexpensive, and facile desulfurization process is needed. Herein, the desulfurization process of biogas by treating with Fe2O3 and nanoscaled Ferrosoferric oxide (FeF) suspension is presented. The treatment process includes both the chemical reaction and physical adsorption phenomena. With variable pH and treatment duration, efficient desulfurization of the biogas was achieved. The optimum pH for H2S removal was 5 at which the removal efficiency was 97% for Fe2O3 solution and 95% for FeF solution. Respectively, CH4 content increased above 75%. The H2S-concentration dropped by 50 ppm from the initial value. The H2S content in the purified gas is thus reduced below the recommended limit for running internal combustion engines. We suggest some physicochemical elimination of the H2S fraction. The process might be feasible to utilize in small farmhouses and power units.

Enhanced and Facile Desulfurization of Commercial Oil Using Air-Assisted Performic Acid Oxidation System

Abstract Heavy oil is a low-cost fuel and is extensively used in the industries, however, it contains high sulfur content, which creates serious environmental problems. Conventional hydrodesulfuriz...

A selective and sensitive “turn-on” fluorescent chemodosimeter for Hg2+ in aqueous media via Hg2+ promoted facile desulfurization–lactonization reaction

A novel highly selective and sensitive "turn-on" fluorescent chemodosimeter for Hg(2+) in pure aqueous media has been developed.

Formation of Dihydrouracils (III) via Cyclization of N‐Substituted 3‐Thioureidopropanoic Acids and Facile Desulfurization.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Formation of dihydrouracils via cyclization of N-substituted 3-thioureidopropanoic acids and facile desulfurization

Cyclization of N-3 substituted 3-thioureidopropanoic acids in isobutyric anhydride at high temperature resulted in the unexpected formation of N-3, N-1-substituted dihydrouracils, as confirmed by thorough spectroscopic characterization. A mechanism based on the identification of intermediates observed at lower reaction temperatures is proposed.

Facile Desulfurization of Thioamides and Thioureas with Tetrabutylammonium Periodate under Mild Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Facile Desulfurization of Thioamides and Thioureas with Tetrabutylammonium Periodate under Mild Conditions

Thioamides and thioureas were reacted with tetrabutylammonium periodate at room temperature to afford the corresponding amides and ureas, respectively, under aprotic conditions.

Understanding base-assisted desulfurization using a variety of disulfide-bridged peptides.

A recently rediscovered reaction of base-assisted lanthionine formation has been applied to several systems of disulfide-bridged peptides. In addition to previously described nonapeptides consisting of i, i+3 cystine linkages, the reaction has now been extended to systems consisting of shorter (i, i+2) and longer (i, i+4) disulfide bridges. The desulfurization reaction is also compatible with disulfide bridges formed through homocysteines and penicillamines, yielding unusual amino acids such as cystathionine and beta,beta-dimethyl lanthionine (referred to as "penthionine") in a peptide chain, respectively. Systematic study of this transformation has provided several new insights into its mechanism. We have observed formation of dehydroalanine and dehydrovaline residues resulting from i, i+2-bridged cysteines and i, i+3-bridged cysteine/penicillamine peptides, respectively, thereby supporting a beta-elimination/Michael-addition mechanism for this transformation. Amino acid analysis and NMR data from total correlation spectroscopy (TOCSY) and (1)H-(13)C heteronuclear single quantum correlation (HSQC) experiments show three diastereomeric lanthionine-bridged peptides in the product mixture. But in the case of desulfurization of a cysteine/homocysteine containing disulfide-bridged peptide, Michael addition appears to be stereoselective, yielding a single stereoisomer of cystathionine within the peptide. According to molecular modeling and CD spectroscopy, constrained peptides such as those containing penicillamine are less likely to undergo facile desulfurization. Flexibility of the torsional angles (C(alpha)H-C(alpha)-C(beta)-S) corresponding to the cysteine residues and temperature appear to be contributing factors determining the extent of desulfurization.

ChemInform Abstract: Facile Desulfurization of Cyclic Thioureas by Hydrogen Peroxide in Acetic Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Facile desulfurization of cyclic thioureas by hydrogen peroxide in acetic acid.

A simple, mild and synthetically useful method for the desulfurization of cyclic thioureas and related compounds, existing as thiol-thione tautomeric mixtures, by hydrogen peroxide in acetic acid is proposed. The effect of substituting different solvents for the acetic acid was investigated.

ChemInform Abstract: Facile Desulfurization of Tris(2,6‐dimethoxyphenyl)phosphine Sulfide by Acids.

ChemInform Abstract: Facile Desulfurization of Tris(2,6‐dimethoxyphenyl)phosphine Sulfide by Acids.

α-methoxyallyl sulfides as a novel homoenolate dianion equivalent

α-Methoxyallyl sulfides 1 proved to serve a novel homoenolate dianion equivalent. Introduction of two electrophiles into 1 was realized by successive regiospecific reaction of an allylic moiety with electrophiles intervened by an acid-catalyzed thioallylic rearrangement. Facile desulfurization of the products under mild conditions afforded a variety of (α,β- unsaturated carbonyl compounds and 2,3,4-trisubstituted furans.

Facile desulfurization of thiocarbonyl groups to carbonyls by superoxide. A model of metabolic reactions.

Several types of thioamides and thioureas including thiouracils were readily desulfurized to the carbonyl compounds by superoxide, generated by KO2 and 18-crown-6 or electrolysis of oxygen in aprotic solvent at room temperature. Such desulfurization may provide a model of metabolic reactions catalyzed by oxygenases.

A Facile Desulfurization Reaction with a Combination of Two Kinds of Metals in Acidic Media. The Synthesis of Hypoxanthine

Abstract A facile desulfurization procedure has been presented for the method that synthesizes hypoxanthine in one step by heating 4,5-diamino-6-hydroxy-2-mercaptopyrimidine with a desulfurizing agent in formic acid. When Raney nickel prepared in the usual way was used as the desulfurizing agent, it was necessary for the ratio of nickel atoms to sulfur atoms (the Ni/S ratio) to be more than 2.6 : 1. On the contrary, when the Raney alloy per se was used, the amount of nickel could be diminished to a catalytic amount (Ni/S 0.2–0.3). The higher the content of aluminum in the alloy, the smaller the Ni/S ratio required for the desulfurization. In contrast with usual desulfurization reactions carried out in neutral media, most of the sulfur was released from the reaction mixture as hydrogen sulfide. Although aluminum or iron powder by itself had little desulfurizing activity, its addition to the Raney alloy was useful in diminishing the Ni/S ratio. Furthermore, combinations of nickel or cobalt salts and aluminum or iron powder were as effective as the Raney alloy as desulfurizing catalysts. In the case of a combination of nickel formate and aluminum powder, a large portion of the nickel ion was proved to be reduced to metallic nickel. The desulfurization reaction also proceeded smoothly in an aqueous solution of hydrochloric or sulfuric acid. On the basis of these facts, a mechanism was proposed with which the active nickel catalyst is regenerated by such auxiliary metals as aluminum or iron.