Presence Of Metal Chlorides Research Articles

Effects of Metal Chlorides on the Hydrothermal Carbonization of Grape Seeds

In this study, hydrothermal carbonization (HTC) of grape seeds, a lignocellulosic biomass, was carried out at various temperatures (200, 225, and 250 °C), different reaction times (6, 12, and 24 h), and different biomass:water ratios (0.025, 0.05, and 0.1). The most important parameter affecting the yields and characteristics of hydrochars was found to be temperature. The HTC of grape seeds was then conducted in the presence of metal chlorides (i.e., CsCl, ZnCl₂, and SnCl₂) at temperatures of 200, 225, and 250 °C for 12 h. SnCl₂ behaved very differently in the HTC process than the other catalysts (or no catalyst). A major difference among these catalysts was the extent to which they were incorporated within the hydrochar structure. SnCl₂ was much more readily incorporated than was CsCl or ZnCl₂. Carbon microspheres were observed in hydrochars from obtained biomass without a catalyst and with CsCl and ZnCl₂ catalysts; agglomerated carbon nanospheres were observed in hydrochars produced with SnCl₂. Hydrochars obtained at 225 and 250 °C by using SnCl₂ and ZnCl₂ catalysts were in the lignite class, while hydrochars obtained from biomass without a catalyst, and using CsCl, were in the peat coal class.

Conversion of sugars (sucrose and glucose) into 5-hydroxymethylfurfural in pyridinium based dicationic ionic liquid ([C10(EPy)2]2Br−) with chromium chloride as a catalyst

In this work, conversion of sucrose and glucose has been studied with pyridinium based dicationic ionic liquid as solvent and CrCl2 as a catalyst. They have shown good performance and gave good yield for 5HMF. Highly efficient and selective dehydration of sugars to 5-hydroxymethylfurfural (HMF) was achieved in [C10(EPy)2]2Br− (1,1′-decane-1,10-diylbis (3-ethylpyridinium) dibromide) with 2.3mol% CrCl2 under mild conditions with a sucrose conversion of 78.5% and 83.9%, HMF selectivity was achieved in 60min reaction time at 110°C. HMF yield of 47% obtained from glucose in the presence of metal chloride (2.1mol% CrCl2) at 110°C in 120min reaction time. The effect of the reaction temperature, time, and catalyst concentration was investigated in detail. The results strongly suggested that an ionic liquid with CrCl2 can play an important role in exploring new efficient and easy to use processes for the dehydration of 5HMF.

Bio-oil production by fast pyrolysis of cellulose/polyethylene mixtures in the presence of metal chloride

Cellulose/polyethylene mixture (3:1 w/w) and Tetra Pak wastes with and without metal chloride (ZnCl2, AlCl3, CuCl2, FeCl3) addition were subjected to a fast pyrolysis process at 350–500 °C and heating rate 100 °C/s to evaluate the possibility of liquid product formation with a high yield. The addition of zinc, aluminum, iron and copper chlorides has influenced the range of samples decomposition as well as the chemical composition of resulting pyrolytic oils. It was found that formation of levoglucosan, the main product of cellulose thermal decomposition, and phenol and its derivatives decreased in a presence of metal chlorides. Non-catalytic fast pyrolysis of polyethylene leads to the formation of solid long chain hydrocarbons, whereas the addition of metal chlorides promotes the formation of more liquid hydrocarbons.

Efficient and selective conversion of sucrose to 5-hydroxymethylfurfural promoted by ammonium halides under mild conditions

The highly efficient and selective production of 5-hydroxymethylfurfural (HMF) from sucrose has been achieved in the presence of metal chlorides and ammonium halides under mild conditions. Notably, an 87% yield of HMF from sucrose was obtained with a catalyst system composed of CrCl 3 and NH 4Br at 100 °C for 1.0 h in N, N-dimethylacetamide (DMAc) solvent. The effect of the reaction temperature and time was investigated in detail, and a possible mechanism for this catalytic process has been proposed. In addition, NH 4Br is an effective promoter in the conversion of glucose and fructose to HMF.

Spectral characterization of metal complexes derived from glycine (Gly) and 2-acetylpyridine (2-APy)

New metal complexes of Cu(II), Co(II), Ni(II), Zn(II), Cd(II), Cr(III) and Fe(III) chlorides and/or acetates with glycine and 2-acetylpyridine have been synthesized and characterized by, elemental analyses, spectral analyses (IR, UV–Vis., 1H NMR), thermal analyses (TGA and DTG), conductance and magnetic measurements. The results showed that, in presence of metal acetates both glycine and 2-acetylpyridine are condensated to form the Schiff-base ligand. While, in presence of metal chlorides both glycine and 2-acetylpyridine react separately to form binary compounds. The Schiff-base ligand acts as mono-negative tridentate coordinating via pyridyl nitrogen, azomethine nitrogen and carboxylate oxygen after displacement of hydrogen. In case of Ni(II), Cr(III) and Fe(III) chloride complexes glycine acts as mono-negative bidentate and 2-acetylpyridine acts as neutral tridentate.

Diels–Alder Reaction of Cyclopentadiene and Alkyl Acrylates in the Presence of Pyrrolidinium Ionic Liquids with Various Anions

The conversion and stereoselectivity of transformation to endo and exo norbornene derivatives was determined in the Diels–Alder reaction of cyclopentadiene with alkyl acrylates. The reactions were carried out in the pyrrolidinium ionic liquids in the presence of metal chlorides and trifluoromethanesulfonates as the catalysts. Shorter reaction times and higher conversions of dienophile were observed in a comparison with analogous cycloadditions carried out in the presence of conventional organic solvents. A higher stereoselectivity to the endo isomer was found in the majority of cases. The ionic liquids composed of 1-butyl-1-methylpyrrolidinium cation (Pyrr1.4) and various anions were used. The influence of ionic liquid anion and several metal chlorides and metal triflates used as the catalysts on the conversion was determined. The conversion and stereoselectivity of transformation to endo and exo norbornene derivatives was determined in the Diels–Alder reaction of cyclopentadiene with alkyl acrylates. The reactions were carried out in the pyrrolidinium ionic liquids in the presence of metal chlorides and trifluoromethanesulfonates as the catalysts. Shorter reaction times and higher conversions of dienophile were observed in a comparison with analogous cycloadditions carried out in the presence of conventional organic solvents. A higher stereoselectivity to the endo isomer was found in the majority of cases. The ionic liquids composed of 1-butyl-1-methylpyrrolidinium cation (Pyrr1.4) and various anions were used. The influence of ionic liquid anion and several metal chlorides and metal triflates used as the catalysts on the conversion was determined.

Synthesis and Characterization of Some Group 12 Metal Complexes with Tellurium Containing 10‐Membered Tetraazamacrocyclic Ligands

A new series of 10‐membered tellurium containing tetraazamacrocyclic complexes, [ML1Cl2], [ML2Cl2] and [ML3Cl2], where [M=Zn(II), Cd(II), Hg(II); L1, L2 and L3=10‐membered tellurium containing tetraazamacrocyclic ligands] have been prepared via the template condensation of ethylenediamine and diaryltellurium dichlorides, R2TeCl2, (R=p‐hydroxyphenyl, 3‐methyl‐4‐hydroxyphenyl, p‐methoxyphenyl) in the presence of metal chlorides. These complexes have been characterized by elemental analyses, conductivity measurements, infrared, electronic absorption and proton magnetic resonance spectral studies. IR and PMR spectra confirm the formation of 10‐membered tetraazamacrocycle skeleton and their tetradentate nature. An octahedral geometry has been assigned to all the metal complexes on the basis of various physicochemical studies.

Pyrolysis of polymer materials in the presence of metal chlorides of the iron subgroup

Catalytic activity of metal chlorides of the iron subgroup is studied during pyrolysis of polymer cord obtained during processing of worn automobile tires by mechanical grinding. It is established that use of metal chlorides of the iron subgroup increases the rate of hydrocarbon formation by about a factor of four to five. It is established that in order to obtain gaseous pyrolysis products with a high heat of combustion and hydrocarbon content the most suitable catalytic system is CoCl 2 (2% of substrate weight) at 450°C.

Kinetic Assessment of Catalysts for the Methanolysis of Sodium Borohydride for Hydrogen Generation

The efficacy of metal chlorides and platinum-coated lithium cobalt oxide as catalysts for the methanolysis of sodium borohydride over 45 to −20 °C was investigated. Among the metal chlorides tested, cobalt chloride exhibited maximum activity. In the presence of metal chlorides, the methanolysis reaction exhibited first-order kinetics with respect to the borohydride concentration. The rate constant for methanolysis reaction at −20 °C for 10 wt% cobalt chloride was determined to be 0.00136 s−1, which represents an over 100 times increase compared to the kinetics of the noncatalyzed methanolysis reaction. Platinum-coated lithium cobalt oxide also exhibits a significant rate increase compared to uncatalyzed methanolysis reaction at at 20 °C; however, no measurable activity was noticed at −20 °C. Further, the reaction kinetics appear to be zeroth-order with respect to borohydride concentration. In addition to the rate enhancement, all potential catalysts tested in this study showed a significant reduction in t...

The influence of temperature and moisture on the physical properties of cellulose in the presence of metal chlorides and glucuronic acid

Article The influence of temperature and moisture on the physical properties of cellulose in the presence of metal chlorides and glucuronic acid was published on January 1, 2008 in the journal Nordic Pulp & Paper Research Journal (volume 23, issue 1).

The influence of temperature and moisture on the optical properties of cellulose in the presence of metal chlorides and glucuronic acid

The influence of temperature and moisture on the optical properties of cellulose in the presence of metal chlorides and glucuronic acid

Effect of Metal Compounds on Pyrolysis Profiles of Douglas Fir

Pyrolysis of Douglas fir with metal compounds has been carried out to examine the effect of metal compounds on the pyrolysis profiles. The profiles dramatically shifted into lower or higher temperatures by adding some metal compounds. On the other hand, the presence of metal chlorides promoted the decomposition of Douglas fir at low temperature. The metal compounds having high hydrophilicity, by which Douglas fir decomposition was shifted toward lower temperatures, caused an increase in char and a decrease in tar through promoting the cross-linking reaction at low temperature. From these results, it can be said that the control of dehydration at low temperature is an essential factor to achieve high char yield with minimizing tar formation.

Effect of metal chlorides on thermal degradation of (waste) polycarbonate

In this study, we investigated how to treat (waste) polycarbonate efficiently to reduce its degraded residue. The study was carried out in an isothermal reactor under continuous nitrogen flow at atmospheric pressure to pyrolyze polycarbonate (PC) alone and in the presence of metal chloride. Some metal chlorides were shown to be catalytic active for the degradation of PC at 400 °C, which increased degradation conversion from 8.5% to more than 58.3%. Among those active metal chlorides, ZnCl 2 and SnCl 2 can produce higher liquid product yields. Effects such as particle size of PC, temperature, the weight ratio of metal chloride/PC, and degradation time on the degradation conversion of PC without and with these two most active metal chlorides were studied. Results of the liquid product analysis by GC/MS demonstrated the product composition of PC degradation over the metal chlorides is much simpler than that of degradation alone. The main liquid product is phenol, p-isopropylphenol, diphenyl carbonate, and bisphenol A for all cases.

Formation of PCDD/Fs from heating polyethylene with metal chlorides in the presence of air

This paper investigated the effect of inorganic chlorine on the formation of PCDD/Fs from heating polyethylene (PE) in the presence of air. There was an increase in the formation of PCDD/Fs with an increasing amount of metal chlorides except NaCl, which was not observed to have any effects on the formation of PCDD/Fs without the presence of catalysts. Although the levels of PCDD/Fs formation in this study have no relevance to full scale municipal solid waste incineration, the results of the present experiments can aid understanding of the mechanisms of the formation of PCDD/Fs from heating PE in the presence of metal chlorides.

Synthesis and thermal studies of poly(N‐acryloyl,N′‐cyanoacetohydrazide) complexes with Co(II), Fe(III), and UO2(II) ions

AbstractPolymer complexes with uranium, cobalt, and iron chlorides were synthesized and investigated by elemental analysis, electronic (uv–visible), IR vibration, and magnetic moment measurements. The thermal stabilities of N‐acryloyl,N′‐cyanoacetohydrazide (ACAH) homopolymers and polymer complexes of poly(ACAH) (PACAH) with metal chlorides were studied thermogravimetrically. The rates of polymerization of PACAH in the absence and presence of metal chlorides were studied. The activation energies of the degradation of the homopolymer and polymer complexes were calculated using the Arrhenius equation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3354–3358, 2003

Catalytic pyrolysis of polyvinylchloride in the presence of metal chloride

Catalytic pyrolysis of polyvinylchloride in the presence of metal chloride

Catalytic pyrolysis of polyvinylchloride in the presence of metal chloride

The pyrolysis of polyvinylchloride (PVC) was studied in a quartz reactor with and without the addition of metal chlorides as catalysts. The results indicated that the addition of metal chlorides such us ZnCl2 or BaCl2 decreased the temperature of dehydrochlorination of PVC. The introduction of H2 in pyrolysis enhanced the degradation of PVC at 400°C or higher and decreased the amount of solid residue. Gas chromatography/mass spectroscopy analysis indicated that Zn and Ba chlorides reduced the formation of high molecular weight products. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2464–2471, 2000

Electric resistance of chitosan derivatives

Direct compression of partially deacetylated chitin (DAC) and its derivatives gave tablets, which were found to be very convenient for the simple and swift estimation of the specific resistance under the various temperature and moisture conditions. The specific resistance ( ρ) value of the 86% deacetylated chitin (DAC-86) tablet decreased with increasing the water content and temperature. The presence of metal chloride in the DAC-86 acetate tablet decreased the ρ value. The utilization of polyionic DAC derivatives such as N-carboxymethylated DAC-86, N, O-sulfated DAC-95, and O-methyl- N-trimethylated DAC-86 chloride gave improved ρ values (ca. 10 6–10 7 Ω cm at 20°C and RH=40%) without the addition of acidic dopant and inorganic salts that would be easily lost by dissolution in water. These chitosan derivatives might be regarded as polyelectrolytes, which partially showed ionic conductivity.

Formation of aromatics during pyrolysis of PVC in the presence of metal chlorides

The effect of metal chlorides that can be formed from metals or metal oxides during pyrolysis of PVC and other chlorinated plastics via reaction with HCl on the decomposition process of PVC was investigated. Experiments with a reactor on a gram-scale have been run using admixtures of Lewis acids FeCl 3, GaCl 3, SbCl 3, BiCl 3 and ZnCl 2 as well as Cu-halides. PAH in the pyrolyzate were analysed quantitatively with HPLC and fluorescence detector, methyl-PAH, mainly naphthalenes and in lower quantities phenanthrenes and anthracenes, with HPLC-UV. While the coke fraction increases linearly with increasing proportion of metal chlorides approaching finally a maximum value, the yield of aromatics (PAH, methyl-PAH) tends nearly exponentially to a minimum value decreasing practically to zero with increasing Lewis acidity. The maximum coke fraction increases with Lewis acidity. Cu(I)-halides (CuCl, CuBr, CuJ) also favour the formation of coke and reduce the formation of aromatics via a radical mechanism. No considerable influence of metal chlorides on the yield of chlorinated compounds such as hexa- and pentachlorobenzene as well as PCB 209 and 206 was observed.

Synthesis and properties of novel dialkylaminocarbenium salts

Novel dialkylaminocarbenium salts with metallocomplex counter ions were prepared by the reaction of phosgene with either DMF or tetramethylurea in the presence of metal chlorides. Reactions of organosilicon amides with phosgene gave corresponding carbenium salts, while organosilicon ureas yielded aminoiminocarbenium salts. Dialkylaminochlorocarbenium salts were reduced with hydrosilanes to give dialkylaminocarbenium, salts and can be easily hydrolyzed to afford either amides or ureas. Pathways of the reaction with water and alcohols depend on the nature of reagent and the reaction conditions.