Addition Of ZnCl2 Research Articles

Bis(iminopyridyl)phthalazine as a sterically hindered compartmental ligand for an M2 (M = Co, Ni, Fe, Zn) centre; Applications in ethylene oligomerisation

The new bis(iminopyridyl)phthalazine ligand, 1,4-{(2,6-i-Pr2C6H3)NCMe)C5H3N}2C8H4N2 (L), has been prepared in good yield using a combination of palladium-mediated cross coupling and condensation strategies. Reaction of L with three equivalents of CoX2 (X=Cl, Br) in n-BuOH at elevated temperature generates, on crystallisation from bench acetonitrile, the paramagnetic tetrahalocobaltate salts [(L)Co2X(μ-X)(NCMe)m(OH2)n](CoX4) (X=Cl, m=2, n=1 1a; X=Br, m=2, n=0 1b) as acetonitrile or mixed acetonitrile/aqua adducts; a similar product is obtained from the reaction of FeCl2 with L and has been tentatively assigned as [(L)Fe2Cl(μ-Cl)(OH2)3](FeCl4) (2). By contrast, reaction of L with NiX2(DME) (X=Cl, Br; DME=1,2-dimethoxyethane), under similar reaction conditions, affords the halide salts [(L)Ni2X2(μ-X)(OH2)2](X) (X=Cl 3a, X=Br 3b) as aqua adducts. Structural determinations on 1 and 3 reveal L to adopt a bis(tridentate) bonding mode allowing the halide-bridged metal centres to assemble in close proximity (M⋯M range: 3.437–3.596Å). Unexpectedly, on reaction of L with ZnCl2, the neutral bimetallic [(L)Zn2Cl4] (4b) complex is formed in which the ZnCl2 units fill inequivalent binding sites within L (viz. the Nphth,Npy,Nim and Npy,Nim pockets). Complex 4b could also be obtained by the sequential addition of ZnCl2 to L to form firstly monometallic [(L)ZnCl2] (4a) and then on further ZnCl2 addition 4b; the fluxional behaviour of diamagnetic 4a and 4b is also reported. On activation with excess methylaluminoxane (MAO), 1–3 display modest activities for ethylene oligomerisation forming low molecular weight waxes with methyl-branched products predominating for the nickel systems (3). On the other hand, the iron catalyst (2) gives exclusively α-olefins while the cobalt systems (1) are much less selective affording equal mixtures of α-olefins and internal olefins along with lower levels of vinylidenes and tri-substituted alkenes. Single crystal X-ray structures are reported for L, 1a, 1b, 3a, 3b and 4.

Application of zinc chloride precipitation method for rapid isolation and concentration of infectious Pectobacterium spp. and Dickeya spp. lytic bacteriophages from surface water and plant and soil extracts.

This is the first report describing precipitation of bacteriophage particles with zinc chloride as a method of choice to isolate infectious lytic bacteriophages against Pectobacterium spp. and Dickeya spp. from environmental samples. The isolated bacteriophages are ready to use to study various (ecological) aspects of bacteria-bacteriophage interactions. The method comprises the well-known precipitation of phages from aqueous extracts of the test material by addition of ZnCl2, resuscitation of bacteriophage particles in Ringer’s buffer to remove the ZnCl2 excess and a soft agar overlay assay with the host bacterium to isolate infectious individual phage plaques. The method requires neither an enrichment step nor other steps (e. g., PEG precipitation, ultrafiltration, or ultracentrifugation) commonly used in other procedures and results in isolation of active viable bacteriophage particles.

Thermal decomposition profile and product selectivity of analytical pyrolysis of sweet sorghum bagasse: Effect of addition of inorganic salts

Sweet sorghum is an important biomass in biofuels and value-added chemicals production. This work studied the effects of inorganic chlorides in the analytical pyrolysis of sweet sorghum bagasse. Two inorganic chlorides were used: ZnCl2 and MgCl2·6H2O. The thermal decomposition kinetics of this biomass was investigated by thermogravimetric analysis. The results indicated that the addition of inorganic salts modified the degradation profile of sweet sorghum bagasse. A decrease in the maximum degradation rate was observed for both hemicellulose and cellulose fractions in the assays with addition of ZnCl2. Tests with MgCl2 showed a significant decrease in the peak corresponding to hemicellulose. In the presence of both salts, a solid residues increase was observed. The large amount of non-oxygenated compounds (isoprene and limonene), which are obtained from the analytical pyrolysis of pure sweet sorghum bagasse, may indicate the formation of a bio-oil chemically more stable than the bio-oil produced from another biomass. On the other hand, the addition of salts led to an increase in the content of furfural, especially in the test with ZnCl2.

Potential interactions of calcium-sensitive reagents with zinc ion in different cultured cells.

BackgroundSeveral chemicals have been widely used to evaluate the involvement of free Ca2+ in mechanisms underlying a variety of biological responses for decades. Here, we report high reactivity to zinc of well-known Ca2+-sensitive reagents in diverse cultured cells.Methodology/Principal FindingsIn rat astrocytic C6 glioma cells loaded with the fluorescent Ca2+ dye Fluo-3, the addition of ZnCl2 gradually increased the fluorescence intensity in a manner sensitive to the Ca2+ chelator EGTA irrespective of added CaCl2. The addition of the Ca2+ ionophore A23187 drastically increased Fluo-3 fluorescence in the absence of ZnCl2, while the addition of the Zn2+ ionophore pyrithione rapidly and additionally increased the fluorescence in the presence of ZnCl2, but not in its absence. In cells loaded with the zinc dye FluoZin-3 along with Fluo-3, a similarly gradual increase was seen in the fluorescence of Fluo-3, but not of FluoZin-3, in the presence of both CaCl2 and ZnCl2. Further addition of pyrithione drastically increased the fluorescence intensity of both dyes, while the addition of the Zn2+ chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine (TPEN) rapidly and drastically decreased FluoZin-3 fluorescence. In cells loaded with FluoZin-3 alone, the addition of ZnCl2 induced a gradual increase in the fluorescence in a fashion independent of added CaCl2 but sensitive to EGTA. Significant inhibition was found in the vitality to reduce 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide in a manner sensitive to TPEN, EDTA and BAPTA in C6 glioma cells exposed to ZnCl2, with pyrithione accelerating the inhibition. Similar inhibition occurred in an EGTA-sensitive fashion after brief exposure to ZnCl2 in pluripotent P19 cells, neuronal Neuro2A cells and microglial BV2 cells, which all expressed mRNA for particular zinc transporters.Conclusions/SignificanceTaken together, comprehensive analysis is absolutely required for the demonstration of a variety of physiological and pathological responses mediated by Ca2+ in diverse cells enriched of Zn2+.

Synthesis and Metal Complex Formation of a Bis(terpyridine) Derivative with a Phenylacetylene Framework

A new bis(terpyridine) derivative with a phenylacetylene framework was synthesized via a stepwise terpyridine construction strategy. The addition of ZnCl2 to a solution of the bis(terpyridine) in chloroform resulted in UV/vis and 1H NMR spectral changes because of complex formation.

A comprehensive study on activated carbon prepared from spent shiitake substrate via pyrolysis with ZnCl2

Activated carbon was produced from spent shiitake substrate (SSS) via ZnCl2 activation. The product was studied by scanning electron microscopy (SEM), N2-adsorption, Fourier transform infrared spectroscopy and X-ray diffraction (XRD), and its adsorptive behavior was quantified using methylene blue. The pyrolysis of SSS with ZnCl2 was investigated by thermogravimetric analysis, XRD, SEM and energy dispersive X-ray spectrometry. Pyrolysis kinetic was analyzed via Coats–Redfern method. Experimental results demonstrated that the product had surface area of 1,743 m2 g−1 and total pore volume of 0.930 cm3 g−1. The adsorption equilibrium data followed Langmuir isotherm model with a monolayer adsorption capacity of 408.16 mg g−1, and pseudo-second-order kinetic model better described the adsorption kinetic. The adsorption mechanism was well described by the intraparticle diffusion model. SSS can transform into a plastic phase during activation, and zinc oxide chloride hydrate (Zn2OCl2·2H2O) was formed above 260 °C. The diffusion of the ZnCl2 gas generated from the decomposition of Zn2OCl2·2H2O around 500 °C was responsible for the porosity development. ZnO was the main zinc-containing matter in the carbon at high pyrolysis temperatures. With the addition of ZnCl2, the activation energy of the pyrolysis of the lignocellulose structure in SSS was reduced to 12.27 kJ mol−1.

Micropyrolysis of Tobacco Powder at 500°C: Influence of ZnCl2 and MgCl2 Contents on the Generation of Products

This work studied the influence of additive concentration on the analytical pyrolysis of tobacco powder at 500°C. Additive mass concentration of 5, 10, and 20% ZnCl2 and 5, 10, and 20% MgCl2 were studied. The addition of ZnCl2 and MgCl2 to tobacco powder promoted the formation of vapors with higher contents of acetic acid and furfural and for both, the higher the concentration the lower the nicotine content. However, there were some losses related to bio-oil quality, such as higher contents of oxygenated compounds, ketones and aldehydes, and carboxylic acids. Results indicate that bio-oils with higher acetic acid and phenolics contents will be generated from tobacco residue with 5% MgCl2, and bio-oils with higher furfural contents will be produced from the residue with 20% MgCl2. The pyrolytic reaction of tobacco residue with 10% ZnCl2 would result in a fuel oil with ignition quality.

The effect of ZnCl2 on green Spanish-style table olive packaging, a presentation style dependent behaviour.

Zinc chloride has been used previously as a preservative in directly brined olives with promising results. However, this is the first time that the effects of ZnCl2 addition (0-1 g L(-1) ) on green Spanish-style table olive (cv. Manzanilla) packaging has been studied. The presence of ZnCl2 affected the physico-chemical characteristics of the products; the presence of the Zn led to lower pH values (particularly just after packaging) and titratable and combined acidity values than the control but did not produce clear trends in the colour parameters. No Enterobacteriaceae were found in any of the treatments evaluated. At the highest ZnCl2 concentrations, the lactic acid bacteria were inhibited while, unexpectedly, its presence showed a lower effect than potassium sorbate against the yeast population. Regardless of the use of potassium sorbate or ZnCl2 , the packages had a reduced microbial biodiversity because only Lactobacillus pentosus and Pichia galeiformis were found at the end of the shelf life. With respect to organoleptic characteristics, the presentations containing ZnCl2 were not differentiated from the traditional product. Zinc chloride was less efficient than potassium sorbate as a yeast inhibitor in green Spanish-style olives, showing clear presentation style dependent behaviour for this property. Its presence produced significant changes in chemical parameters but scarcely affected colour or sensory characteristics.

Synthesis, structural characterization and photocatalytic application of ZnO@ZnS core–shell nanoparticles

ZnO nanoparticles were synthesized by co-precipitation with no capping agent followed by covering with ZnS using a solution-based chemical method at low temperature. By variation of the solution concentrations it was found that the fully-covering ZnS shell forms by a reaction of Na2S with ZnO NPs followed by the formation of ZnS nano-crystals by the reaction of Na2S with ZnCl2. The mechanism that led to full coverage of the ZnO core is proposed to be the addition of ZnCl2 at a later stage of the growth which guarantees a continuous supply of Zn ions to the core surface. Moreover, the ZnS nanocrystals that uniformly cover the ZnO NPs show no epitaxial relationship between the ZnO core and ZnS shell. The slow atomic mobility at the low reaction temperature is attributed to the non-epitaxial uniform ZnS shell growth. The rough surface of the ZnO grains provides initial nucleation positions for the growth of the ZnS shell nano-crystals. The low growth temperature also inhibits the abnormal growth of ZnS grains and results in the homogeneous coverage of ZnS nano-crystals on the ZnO core surface. The as-synthesized ZnO@ZnS core–shell nanoparticles were used as a photocatalyst to decompose Rose Bengal dye at three different pH values. ZnO@ZnS core–shell nanoparticles perform as a more active photocatalyst at a pH of 4, while pure ZnO nanoparticles are more efficient at a pH of 7.

Highly Porous Silica Glasses and Aerogels Made Easy: The Hypersaline Route

Through the addition of inorganic salts as porogens during an alcohol-based sol-gel process high surface area silica glasses and aerogels with varying pore sizes are synthesized. In the presence of ZnCl2 and CaCl2 respectively, tetraethyl orthosilicate (TEOS) dissolved in ethanol hydrolyzes also in the absence of any acid or base catalysts, eventually forming high surface area monolithic silica networks. The porosity can be controlled by the gel ageing step as well as the salt nature. Two different gel drying conditions were investigated, i.e., room temperature (RT) air drying at ambient pressure and supercritical (sc) CO2 drying. While a reference solution which only contains ethanol and TEOS does not gel at all, the addition of ZnCl2 leads to mesoporous aerogels with high surface areas of 1400 m2 g−1 after sc CO2 drying. Interestingly, the utilization of CaCl2 however, produces aerogel-like materials of high porosity for both drying methods under preservation of the nano-and macroscopic features. Thereby, it is shown that inorganic salts can influence the structure formation during the sol-gel process where the type of salt controls the framework connectivity/stability and tunes the porosity towards smaller pore sizes than usually obtained. At the same time, the herein presented hypersaline aerogel-synthesis is very simple, fast and in the case of CaCl2 drying can even be performed in air

Exploring the Programmable Assembly of a Polyoxometalate–Organic Hybrid via Metal Ion Coordination

The conformational flexibility and programmed assembly of a dumbbell-shaped polyoxometalate-organic hybrid molecule comprising two Dawson-type polyoxometalates linked by a 2,2'-bipyridine unit, which can be coordinate to metal ions, in this case of Zn(2+), are described. SAXS, UV/vis, and NMR spectroscopic techniques confirm that the hybrid molecules exist as the trans dumbbell in metal-ion-free solutions and can be reversibly transformed into the cis dumbbell through coordination upon the addition of ZnCl2 into a DMSO solution containing the hybrid. Subsequent addition of EDTA reverses the switching process by extracting the Zn(2+) cations from the hybrid. During the interchange process between trans and cis dumbbells, a further reorganization of the hybrid molecules occurs through bond rotation to minimize steric clashes between the polyoxometalate subunits, in order to stabilize the corresponding dumbbell conformation. The Zn(2+)-controlled conformational transformation of the hybrid can be further utilized to manipulate the hybrid's solvophobic interaction-driven self-assembly behavior in the metal-ion driven reversible formation of 140 nm sized vesicles, studied by laser light scattering techniques.

Enhancing thermochromic performance of VO2 films via increased microroughness by phase separation

Application of VO2 to smart windows calls for an enhancement of both luminous transmittance (Tlum) and solar transmittance modulation (ΔTsol). These two properties are related to optical constants, microstructure and film thickness. In this article, VO2-based films with increased microroughness are prepared by polymer assisted deposition, and ZnCl2 is added to the precursor solution to control the microstructure of the films. Addition of ZnCl2 increases the microroughness of films through phase separation, which largely decreases the refraction index and the reflectivity of the films, resulting in enhanced luminous transmittance and solar transmittance modulation; two films with balanced optical performance show Tlum=50.5% and ΔTsol=11.3%, and Tlum=59.3% and ΔTsol=10.5%, respectively. Moreover, this kind of microstructure control has no influence on doping VO2, which is proven by the deposition and characterization of W-doped VO2-based films. By the formation of a W-doped VO2/F:SnO2/glass multilayer stack, a film shows excellent thermochromic properties and low emissivities; typically, a film with a phase transition temperature, Tlum, ΔTsol of 43.4°C, 30.0%, 8.82%, respectively, and emissivity of 0.20 for monoclinic and 0.33 for rutile phase is successfully prepared.

Gadolinium‐containing magnetic resonance contrast media: investigation on the possible transchelation of Gd3+ to the glycosaminoglycan heparin

Retention of gadolinium (Gd) in biological tissues is considered an important cofactor in the development of nephrogenic systemic fibrosis (NSF). Research on this issue has so far focused on the stability of Gd-based contrast media (GdCM) and a possible release of Gd³⁺ from the complex. No studies have investigated competing chelators that may occur in vivo. We performed proton T(1) -relaxometry in solutions of nine approved GdCM and the macromolecular chelator heparin (250 000 IU per 10 ml) without and with addition of ZnCl₂. For the three linear, nonspecific GdCM complexes, Omniscan®, OptiMARK® and Magnevist®, 2 h of incubation in heparin at 37 °C in the presence of 2.0 mm ZnCl₂ led to an increase in T₁-relaxivity by a factor of 7.7, 5.6 and 5.1, respectively. For the three macrocyclic complexes, Gadovist®, Dotarem® and Prohance®, only a minor increase in T₁-relaxivity by a factor of 1.5, 1.6 and 1.7 was found, respectively. Without addition of ZnCl₂, no difference between the two GdCM groups was observed (factors of 1.4, 1.2, 1.1, 1.3, 1.5 and 1.4, respectively). The increase in T₁-relaxivities observed for linear GdCM complexes may be attributable to partial transchelation with formation of a macromolecular Gd-heparin complex. For comparison, mixing of GdCl₃ and heparin results in a 8.7-fold higher T₁-relaxivity compared with a solution of GdCl₃ in water. Heparin is a glycosaminoglycan (GAG) and as such occurs in the human body as a component of the extracellular matrix. GAGs generally are known to be strong chelators. Gd³⁺ released from chelates of GdCM might be complexed by GAGs in vivo, which would explain their retention in biological tissues. Plasma GAG levels are elevated in end-stage renal disease; hence, our results might contribute to the elucidation of NSF.

New zinc(II), palladium(II) and platinum(II) complexes of dl-piperidine-2-carboxylic acid; X-ray crystal structure of trans-[Zn2(μ-Ca)2(Hpa)2Cl6] and anticancer activity of some complexes

New complexes of dl-piperidine-2-carboxylic acid (dl-H2pa), [Zn(Hpa)(AcO)(H2O)2], trans-[Zn2(μ-Ca)2(Hpa)2Cl6], [M(bpy)(Hpa)]Cl and [M(pa)(PPh3)2] (M(II)=Pd, Pt) have been prepared and characterized on the basis of elemental analyses, molar conductivity and thermal measurements, IR, Raman, UV–Vis, NMR (1H and 31P) and mass spectroscopy. dl-Piperidine-2-carboxylic acids act as bidentate ligands, through the carboxyl oxygen and cyclic nitrogen atoms. The crystal structure of trans-[Zn2(μ-Ca)2(Hpa)2Cl6], obtained from the addition of ZnCl2 to dl-H2pa in either hard tap water or presence of CaCl2, has been determined by X-ray diffraction. It crystallizes in a triclinic lattice with space group symmetry P1. The complex has two zinc atoms in tetrahedral geometry, each ligated by a carboxyl oxygen and three chlorine atoms. The other carboxyl oxygen atoms from the two Hpa− ligands are bridged by two calcium atoms, i.e., there are two Zn(Hpa−)Cl3 units bridged by two calcium atoms. The free dl-H2pa and its complexes, trans-[Zn2(μ-Ca)2(Hpa)2Cl6], [Pd(bpy)(Hpa)]Cl and [M(pa)(PPh3)2] (M(II)=Pd, Pt) have been tested against the serous ovarian cancer ascites, OV 90 cell line.

Desiccation-induced non-radiative dissipation in isolated green lichen algae

Lichens are able to tolerate almost complete desiccation and can quickly resume metabolic activity after rehydration. In the desiccated state, photosynthesis is completely blocked and absorbed excitation energy cannot be used for electron transport, leading to a potential strong vulnerability for high light damage. Although desiccation and high insolation often occur simultaneously and many lichens colonize exposed habitats, these organisms show surprisingly little photodamage. In the desiccated state, variable chlorophyll fluorescence is lost, indicating a suspension of charge separation in photosystem II. At the same time, basal fluorescence (F (0)) is strongly quenched, which has been interpreted as an indication for high photoprotective non-radiative dissipation (NRD) of absorbed excitation energy. In an attempt to provide evidence for a photoprotective function of NRD in the desiccated state, isolated green lichen algae of the species Coccomyxa sp. and Trebouxia asymmetrica were used as experimental system. In contrast to experiments with intact lichens this system provided high reproducibility of the data without major optical artifacts on desiccation. The presence of 5mM trehalose during desiccation had no effect but culture of the algae in seawater enhanced F (0) quenching in T. asymmetrica together with a reduced depression of F (V)/F (M) after high light treatment. While this effect could not be induced using artificial seawater medium lacking trace elements, the addition of ZnCl(2) and NaI in small amounts to the normal growth medium led to qualitatively and quantitatively identical results as with pure seawater. It is concluded that NRD indicated by F (0) quenching is photoprotective. The formation of NRD in lichen algae is apparently partially dependent on the presence of specific micronutrients.

Development of a novel Zn fortified table olive product

This work explores novel Zn fortified table olive presentations, using “Aceituna Aloreña de Málaga” as the model matrix. The addition of ZnCl2 to the packing brine led to novel products with limited changes in colour and improved instrumental firmness. Partial Least Square (PLS) analysis linked the physicochemical characteristics and the sensory scores to the products, allowing for their characterization. The control had the highest scores for saltiness and bitterness as well as for the kinaesthetic sensations. The addition of 0.50 g/L ZnCl2 led to a product with average physicochemical and sensory characteristics. The product added with 0.75 g/L ZnCl2 had the highest titratable acidity and acid scores and the lowest pH while showing average values for the other variables. The olives prepared with 1.00 g/L ZnCl2 produced a presentation with high firmness and Zn content in flesh but the lowest scores for the kinaesthetic sensations, bitterness and saltiness. Overall, the product with 0.75 g/L ZnCl2 in the packing brine could be a good potential for novel Zn fortified table olive presentations. The consumption of 10 olives (50 g of flesh) of these fruits would supply around 79% of the recommended daily intake of Zn (or ∼12% in 15 g of an olive flesh serving size).

A high potential organophosphorus pesticide-degrading enzyme from a newly characterized, Pseudomonas aeruginosa NL01

Twenty seven bacterial isolates were obtained from diazinon-treated agricultural soils in North of Iran and amongst them, an isolate was found to grow in the mineral salt agar plates supplemented with diazinon at concentration of 200 mg L −1 as the sole carbon source. The bacterial isolate was identified by 16S rRNA gene sequence as Pseudomonas aeruginosa NL01. A 36 kDa organophosphorus hydrolase (OPH) enzyme, designated as OPH NL07, was purified by DEAE sepharose column chromatography. The purified enzyme showed a single band on SDS-PAGE. The Michaelis constant (Km) and maximal velocity (Vmax) values of enzyme for paraoxon as substrate were 10 µM and 66.67 µM/min, respectively. The effect of pH and temperature on enzyme activity indicated that the OPH NL07 had the highest activity at pH 8 and was active at a range of temperatures from 25 to 60°C, although, optimum temperature for enzyme activity was 37°C. Enzyme activity was enhanced by 1.28 and 1.09 fold in the presence of CoCl2 and CaCl2, each at 2 mM, while addition of ZnCl2, MgCl2, FeCl3, SDS and EDTA, each at 2 mM inhibited the enzyme by 0.93, 0.92, 0.51, 0.06 and 0.00 fold, respectively. The OPH NL07 seems to be suitable as biocatalyst for practical use in bioremediation of organophosphorus pesticides (OPs)-contaminated soils. Key words: Diazinon, organophosphorus pesticides, organophosphorus hydrolase,Pseudomonas aeruginosa.

Controllable Self‐Assembly of Organic–Inorganic Amphiphiles Containing Dawson Polyoxometalate Clusters

An organic-inorganic molecular hybrid containing the Dawson polyoxometalate, ((C(4)H(9))(4)N)(5)H[P(2)V(3)W(15)O(59)(OCH(2))(3)CNHCOC(15)H(31)], was synthesized and its surfactant-like amphiphilic properties, represented by the formation of bilayer vesicles, were studied in polar solvents. The vesicle size decreases with both decreasing hybrid concentration and with increasing polarity of the solvent, independently. The self-assembly behavior of this hybrid can be controlled by introducing different counterions into the acetonitrile solutions. The addition of ZnCl(2) and NaI can cause a gradual decrease and increase of vesicular sizes, respectively. Tetraalkylammonium bromide is found to disassemble the vesicle assemblies. Moreover, the original counterions of the hybrid can be replaced with protons, resulting in pH-dependent formation of vesicles in aqueous solutions. The hybrid surfactant can further form micro-needle structures in aqueous solutions upon addition of Ca(2+) ions.

Chemical composition of bio-oil produced by co-pyrolysis of biopolymer/polypropylene mixtures with K2CO3 and ZnCl2 addition

The chemical composition of liquid products of cellulose and lignin co-pyrolysis with polypropylene at 450°C with and without the potassium carbonate or zinc chloride as an catalyst was investigated. The yield of liquid products of pyrolysis was in the range of 26–45wt% and their form was liquid or semi-solid highly depending on the composition of sample and pyrolysis conditions. The potassium carbonate and zinc chloride addition to blends has also influenced the range of samples decomposition as well as the chemical composition of resulted bio-oils. All bio-oils from biopolymer and polypropylene mixtures were three-phase (water, oil and solid). While zinc chloride acted as catalyst, all bio-oils obtained from biopolymer and polypropylene mixtures were yellow liquids with well-separated water and oil phases. All analyses proved that the structure and quality of bio-oil strongly depends on both the composition of the blend and the presence of the additive. The FT-IR and GC–MS analyses of oils showed that oxygen functionalities and hydrocarbons contents highly depend on the composition of biomass/polypropylene mixture. Results confirmed the significant removal and/or transformation of oxygen containing organic compounds, i.e. levoglucosan, 1,6-anhydro-β-d-glucofuranose and phenol derivatives due to the zinc chloride presence during pyrolysis process. All analyses showed that zinc chloride as catalyst was generally much more effective for removal of hydroxyl and methoxy groups than was potassium carbonate. It was demonstrated in this study that catalysts used in present work lead to the increased char yield and improved the fuel quality of bio-oil.

Scale-up of microwave heating process for the production of bio-oil from sewage sludge

A pilot-scale microwave heating apparatus was constructed for the production of bio-oil from sewage sludge, and the effects of important microwave processing parameters and chemical additives on the quality and yield of bio-oils were investigated. It was found that bio-oil was mainly formed at the pyrolysis temperature range of 200–400°C. A higher heating rate (faster pyrolysis) not only increased the yield of bio-oil, but also improved the quality of bio-oil according to the elemental composition and calorific values. The maximum bio-oil yield was 30.4% of organic fraction, obtained from the pyrolysis of original sewage sludge at microwave radiation power of 8.8kW and final pyrolysis temperature of 500°C. All of five simple additives (KOH, H2SO4, H3BO3, ZnCl2, and FeSO4) reduced the bio-oil yield, but the composition and property of bio-oil varied with the additive types greatly. KOH, H2SO4, H3BO3 and FeSO4 were found to improve the quality of bio-oils remarkably according to the calorific value, density, viscosity and carbon content of bio-oils, but ZnCl2 treatment went against that. GC–MS analysis of the bio-oils showed that, alkali treatment promoted the formation of alkanes and monoaromatics, while acid treatment favored the formation of heterocyclics, ketones, alcohols and nitriles. Compared with sulfate slat FeSO4, chloride salt ZnCl2 was a better catalyst for selective catalytic pyrolysis of sewage sludge. The addition of ZnCl2 only promoted the formation reactions of a few kinds of nitriles and ketones remarkably. It is technologically feasible to produce bio-oil form microwave-induced pyrolysis of sewage sludge by optimizing pyrolysis conditions and selecting appropriate additives.