Solid Residue Fractions Research Articles

Fractionation of Winemaking Grape Stalks by Subcritical Water Extraction to Obtain Added-Value Products

Grape stalks (GSs) from winemaking were submitted to a green process to valorise its lignocellulosic biomass that applied subcritical water extraction (SWE) at 170 °C and 180 °C to obtain active extracts and cellulose-enriched fractions. The sum of the total phenolic content of the soluble extract and the solid residue fractions from the SWE exceeded that of the GS, which suggests the generation of compounds with antioxidant properties through SWE. All SWE fractions showed high antioxidant power. The increased temperature promoted the extraction of polyphenolic compounds, enhancing the antioxidant power of both extracts and solid residues. These solid residue fractions were bleached with alkaline hydrogen peroxide solutions (4 and 8% v/v) to purify cellulose. After two bleaching cycles, no notable delignification progress was observed, as the bleaching yield or whiteness index did not significantly change in the further cycles. The first bleaching cycle led to a significant reduction in the lignin content at both SWE temperatures. The cellulose purity was higher in the samples obtained at 170 °C and bleached with 4% alkaline hydrogen peroxide. SWE at 180 °C led to greater cellulose oxidation during the bleaching step regardless of the hydrogen peroxide concentration.

АНАЛИЗ ЗАВИСИМОСТЕЙ РАСПРЕДЕЛЕНИЯ РАДИОНУКЛИДОВ ОТ СПОСОБА ПЕРЕРАБОТКИ НЕФТЕСОДЕРЖАЩИХ ОТХОДОВ

In this paper main regularities of distribution of radionuclides in dependence of the method of treatment of oil-containing wastes have been analyzed. Calculation of limit values of the specific effective activity of natural radionuclides have been carried out. Results of experiments are showing that during the burning of oil sludges samples the analyzed radionuclides behave the same in all cases. The relationship between migration coefficients and ash content has been also established. For the samples with more high ash content during the burning the coefficients of migration of radionuclides into the remaining ashes were high than for the samples with the lower values of ash. Estimation of migration of natural radionuclides 226Ra, 232Th and 40Kin the processes of treatment of oil-containing wastes (burning, extraction of oil products, distillation of the diesel fraction) has been carries out. It was determined that during the carrying out of these processes the radionuclides are concentrated in more solid processes products: in ash, solid residue and bitumen fraction. As result, it increases their specific effective activity. The dependence of the coefficients of migration of radionuclides from the ash and the con tent of the mechanic impurities during the treatment by the methods of burning and extraction of oil products has been also received. Using of the results of work is allowing us to select the most appropriate methods of treatment of oil-containing wastes and to reach significant reduction of radioactive nuclides negative impact to the humans and to the environment.

Elucidating the role of NiMoS-USY during the hydrotreatment of Kraft lignin

Major hurdles in Kraft lignin valorization require selective cleavage of etheric and C–C linkages and subsequent stabilization of the fragments to suppress repolymerization reactions to yield higher monomeric fractions. In this regard, we report the development of efficient NiMo sulfides and ultra-stable Y zeolites for the reductive liquefaction and hydrodeoxygenation of Kraft lignin in a Parr autoclave reactor at 400 °C and 35 bar of H2 (@25 °C). Comparing the activity test without/with catalyst, it is revealed that NiMo sulfides over ultra-stable Y zeolites (silica/alumina = 30) achieved a significant reduction (∼50 %) of the re-polymerized solid residue fraction leading to a detectable liquid product yield of 30.5 wt% with a notable monocyclic and alkylbenzenes selectivity (∼61 wt%). A physical mixture counterpart, consisting of hydrothermally synthesized unsupported NiMoS and Y30, on the other hand, shows lower selectivity for such fractions but higher stabilization of the lignin fragments due to enhanced access to the active sites. Moreover, an extended reaction time with higher catalyst loading of the impregnated NiMoY30 facilitated a remarkable alkylbenzene (72 wt%) selectivity with an increased liquid yield of 38.9 wt% and a reduced solid residue of 16.4 wt%. The reason for the high yield and selectivity over NiMoY30, according to the catalyst characterization (H2-TPR, XPS, TEM) can be ascribed to enhanced stabilization of depolymerized fragments via H2-activation at a lower temperature and high hydrodeoxygenation ability. In addition, the better proximity of the acidic and deoxygenation sites in NiMoY30 was beneficial for suppressing the formation of polycyclic aromatics.

Efficient Fractionation of Corn Stover for Biorefinery Using a Sustainable Pathway

This study presents a sustainable pathway for fractionating corn stover to produce glucose, high-quality lignin nanoparticles (LNPs), and levulinic acid (LA) based on the use of p-toluenesulfonic acid (p-TsOH), a solvent having strong acidity and surface activity at a high concentration. At a moderate pretreatment temperature (100 °C), 85% of xylose, 88% of arabinose, and 83% of lignin were removed from the substrate and present in the hydrolysate, while the cellulose yield in the solid residue fraction was 93%. The cellulose fraction exhibited much reduced “biomass recalcitrance” and was readily enzyme-hydrolyzed, with its glucose yield reaching up to 93% at a high solid concentration of 15% (w/w). The hydrolysate, involving the p-TsOH catalyst, was recycled for further hydrolysis of fresh corn stover: after recycling the hydrolysate four times, the cellulose fraction still had a high glucose yield of 81%. The lignin fraction in the hydrolysate was utilized in the form of LNPs, which were prepared as a result of diluting the recycled hydrolysate. The as-prepared LNPs were spherical and uniform, with an average particle size of 147 nm. The application of LNPs in the preparation of chitosan film significantly improved its strength. After LNP preparation, the diluent containing monomeric sugars was directly heated to 180 °C to produce LA in the presence of p-TsOH (an effective catalyst) with an LA yield of 57.1%. The LA was easily separated from the spent acid based on methyl isobutyl ketone (MIBK) extraction, and the p-TsOH/water mixture was recycled in the process.

Study of the Composition of the Mining Industry Rubber Waste Pyrolyzates

The study of the composition of the mining industry rubber waste pyrolyzates is an urgent research task. The study of the rubber waste pyrolyzates: solid carbon residue and various fractions of the pyrolysis liquid is presented in the work. A high content of sulfur compounds in all fractions of the pyrolysis liquid was found. The possibilities of improving the quality characteristics of the solid carbon residue and reducing sulfur- containing substances in the fractions of the pyrolysis liquid, which will allow their use as adsorbents and motor fuels, are considered.

ОЧИСТКА ПРОДУКТОВ СГОРАНИЯ ТОПЛИВА УСТАНОВКИ ПЕРЕРАБОТКИ ТВЕРДЫХ БЫТОВЫХ ОТХОДОВ

This paper considers the use of pyrolysis for the disposal of solid domestic and industrial wastes without residues or threat to public health. A pilot semi-industrial waste processing plant with a capacity of up to 1000 kg/day as part of the thermolysis unit of a waste recycling complex is presented. The advantages of using microwave radiation for decomposition of carbon-containing wastes, including food, polymer, plastic, wood, vegetable and paper fractions having a 30-40% moisture content per solid carbon-coke residue and gaseous fraction, are shown. A system for purification of exhaust flue gases is described. This system involves the stages of catalytic adsorption in a fixed bed adsorber, chemisorption in a wet scrubber by flushing flue gases with lime water and chemisorption in a wet scrubber by washing with an aqueous solution of carbamide. The samples of dust and gas emissions are analysed in terms of the content of polychlorinated dibenzo-p-dioxins, dibenzofurans, polyaromatic hydrocarbons and oxides. It is shown that the concentrations of these harmful substances do not exceed the maximum permissible values. The potential and efficiency of the developed technology that meets modern international standards of environmental safety are demonstrated.

Preparation of upgraded bio‐oil using two‐step catalytic pyrolysis of fresh, putrefied, and microbe‐treated biomass

In this study, water hyacinth was converted into highly flammable bio‐oil via two‐step catalytic pyrolysis. The upgradation of bio‐oil was based on the pretreatment of biomass, second‐step pyrolysis and use of clinkered material as a catalyst. This three‐prong approach was found effective for improving the nature and yield of the oil by lowering the water and oxygen content in the product. The yield of oil was investigated as a function of pyrolysis temperature and weight of the catalyst in addition to pretreatment of biomass. Optimum time for the reaction was also investigated for all three types of biomass. In the preliminary pyrolysis, each of the sample was pyrolyzed into an aqueous liquid, gas, and solid residue fractions. The liquid fraction of each of the sample was separated into combustible and non‐combustible liquids in addition to residue using fractional distillation. The residue of the fractional distillation for each of the fresh, putrefied, and microbe‐treated biomass was re‐pyrolyzed and the gas produced during 1st and 2nd steps of the pyrolysis was analyzed using chemical analysis. The upgraded oils were analyzed for their composition with GC‐MS technique. The oil products of the tested samples were significantly differing from each other in terms of nature and number of the compounds. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1836–1844, 2018

New materials from solid residues for investigation the mechanism of biomass hydrothermal liquefaction

Advanced analysis technologies cannot be applicable to structural characterization of solid residue from biomass hydrothermal liquefaction due to its insoluble characteristics in organic solution. In this investigation, the milled solid residue fractions were isolated from the solid residues producing during cypress hydrothermal liquefaction at 220, 260, and 300°C. Their fractions structural characteristics were comparatively investigated by advanced analysis technologies such as liquid state Nuclear Magnetic Resonance. Dichloroethane/ethanol insoluble fractions were firstly found during the liquefaction process at 260–300°C and results showed that the fractions were the intermediate component of biomass carbonization and mainly produced from the re-polymerization reactions of lignin during hydrothermal liquefaction process. The presence of crosslinking reactions between carbon-carbon which lead to the formation of a highly crosslinked structure resulting in the formation of milled solid residue fractions, which made the fractions be not insoluble in dichloroethane/ethanol and have high thermal stable and molecular weight. Ether structures scission, de-methylation reactions, re-polymerization between carbon-carbon, and fragmentation of large molecular fractions have been occurred in lignin during hydrothermal liquefaction process. The result showed that characterization of milled solid residue fractions provided some new information of the mechanisms of biomass hydrothermal liquefaction.

Fuel Recovery from Thermal Processing of Post-consumer Footwear Waste

ABSTRACTCurrently, almost 25 billion pairs of shoes are annually manufactured worldwide. Logically, a large amount of footwear waste is generated. Economically and environmentally acceptable disposal of the waste is needed. In the present work, fuel recovery from thermal processing of shoe waste is considered. Energetic content of shoe waste was estimated. Thermal degradation characteristics and distribution and yields of the products were analyzed. They were carried out using a macro scale, thermogravimetric analyzer and gas chromatography. It was found that the calorific value of the shoe waste was high (21 MJ/ kg). Analysis revealed that the pyrolysis of shoe waste at atmospheric pressure started around 100°C and finished at about 700°C. Three degradation temperature regions during pyrolysis of the shoe waste were recorded. Products of pyrolysing waste comprised solid residue (around 26%), liquid (around 34%) and gas fraction (around 40%). Product gases contained fractions of combustible components, i....

Cornstalk liquefaction in sub- and super-critical ethanol: Characterization of solid residue and the liquefaction mechanism

Cornstalk liquefaction in sub- and super-critical ethanol was carried out in an autoclave at various temperatures. The characteristics of solid residue were investigated by XRD and sugar analysis. Milled solid residue fraction was isolated from the solid residue, and its chemical characteristics were comparatively investigated with milled wood lignin of cornstalk by gel permeation chromatography, FT-IR, and 2D HSQC NMR. The results showed that the structure of xylan in cornstalk was not broken down completely under the reaction temperatures and those liquefaction conditions were unable to break effectively apart the inter/intra chain hydrogen bonding in cellulose fibrils. Characterization of milled solid residue showed that the de-polymerization of lignin was more dominant than the re-polymerization as reaction temperature increased from 180 to 300 °C. The β-O-4, ferulate, tricin substructures almost disappeared from the spectrum of milled solid residue, which indicated the re-polymerization or decomposition of those bonds in lignin during cornstalk liquefaction process. The result showed that characterization of solid residue fractions provided some new information of the mechanisms about cornstalk liquefaction in ethanol.

Hydrothermal liquefaction of macro algae: Effect of feedstock composition

Due to the increasing thrust on third generation biofuels, algal research has gained a lot of importance in the recent years. Effective utilization of algal biomass in a single step is necessary as it can produce fungible hydrocarbons in addition to a variety of valuable products.Hydrothermal liquefaction does not require the energy intensive drying steps and is an attractive approach for the conversion of algae which has high moisture content. The objective of this study is to understand the effect of compositional changes of macro algae samples Ulva fasciata (MA’UF), Enteromorpha sp. (MA’E) and Sargassum tenerrimum (MA’ST) on product distribution and nature of products. Various macro algae samples were converted to bio-oil by hydrothermal liquefaction in a batch reactor at 280°C for 15min with biomass:water ratio of 1:6. The liquefaction products were separated into ether soluble fraction (bio-oil1), water-soluble fraction, solid residue and gaseous fraction. Maximum conversion of 81% was observed with macro algae (MA) UF. The effect of varying feedstock compositions were reflected in the bio-oil and bio-residue yields. The maximum conversion and bio-oil yield was observed with MA’UF due to the presence of higher carbohydrate content than other feeds. FTIR and NMR spectra showed high percentage of aliphatic functional groups for all bio-oils.

Hydrothermal conversion of bamboo: identification and distribution of the components in solid residue, water-soluble and acetone-soluble fractions.

Hydrothermal conversion is an important thermochemical process to upgrade low-cost lignocellulose into valuable chemicals or fuels. Studies on hydrothermal products compositions and their distributions are of great significance in lignocellulose upgradation. In this work, the major products of bamboo hydrothermally treated at 180-240 °C for 3-60 min and their distributions were comparatively studied. According to the hydrothermal conditions, the hydrothermal products were composed of 37.11-89.98% of solid residues, 4.51-20.41% of water-soluble fractions (WS), and 4.23-16.17% of acetone-soluble fractions (AS). The products in WS fractions mainly consisted of furfural (FF), 5-hydroxymethylfurfural (HMF), and phenolic compounds, while the products in AS fractions were mainly 4-hydroxy-4-methyl-2-pentanone and complex aromatic compounds with multibenzene rings. Additionally, the highest yields of FF (33.4%) and HMF (15.6%) were observed at 200 °C for 60 min and 240 °C for 60 min, respectively.

Integration of Ambient Formic Acid Process and Alkaline Hydrogen Peroxide Post-Treatment of Furfural Residue To Enhance Enzymatic Hydrolysis

A novel integrated process with ambient formic acid combining alkaline hydrogen peroxide was developed to achieve efficient delignification of furfural residue. Furfural residue was treated with 88% formic acid at room temperature for 0.5 h followed by post-treatment with 1% alkaline hydrogen peroxide at 80 °C for 1.5 h. Results showed that 87.9% of the original lignin was removed and the solid residue obtained contained 84.6% cellulose. The glucose yield of the solid residue increased to 83.7% after 96 h enzymatic hydrolysis under a low enzymatic loading of 7 FPU/g cellulose. The analysis of the physicochemical property of the solid residue and lignin fractions indicated that there was an unapparent effect on formylation of cellulose during the ambient formic acid treatment, and the lignin rich in phenolic and carboxylic OH was easily removed. The insoluble-formsovl lignin in solid residue was effectively removed by alkaline hydrogen peroxide treatment.

Impact of ball milling on maize (Zea mays L.) stem structural components and on enzymatic hydrolysis of carbohydrates

The impact of ball milling on structural components of maize (Zea mays L.) stem was investigated in relation to enzymatic hydrolysis of carbohydrates. Ball milling of extractive-free maize stem material was carried out with different milling times up to 12h. Carbohydrate conversion from ball-milled maize stem material with cellulolytic preparation Onozuka R-10 increased to 79% with increasing ball milling time up to 4h, but did not thereafter increase further. Ball milling caused drastic depolymerization of hemicelluloses as revealed by increasing amounts of monosaccharides released in absence of enzymes. Infrared spectroscopy showed that cellulose crystallinity decreased within the first 6h milling thereafter reaching a plateau. Thioacidolysis of solid residue fractions obtained after treatment of ball-milled samples with Onozuka R-10 suggested that no extensive degradation of lignin occurred during the milling. The effect of lignin structure on enzymatic hydrolysis of associated carbohydrates was further studied independently of cellulose crystallinity. Two lignin-carbohydrate fractions comprising hemicellulose and lignin with either high or low amount of aryl ether linkages were used as model materials. Lignins abundant in aryl ether linkages appeared more detrimental than condensed lignins to enzymatic hydrolysis of associated carbohydrates.

Distribution and Characterizations of Liquefaction of Celluloses in Sub- and Super-Critical Ethanol

Effects of reaction conditions (temperature, retention time, and cellulose/ ethanol ratio) on biomass liquefaction in sub- and super-critical ethanol were investigated in this work. The liquefaction system was divided into the following fractions: a volatile organic compounds fraction, a gas fraction, a heavy oil fraction, a water-soluble oil fraction, and a solid residue fraction. Results showed that for three samples, the SR yield of microcrystalline cellulose was highest compared with corn stalk cellulose and rice straw cellulose at the same temperature, while the HO yield was lowest in the liquefaction process. At the same retention time in super-critical ethanol, the SR yield of microcrystalline cellulose was highest, suggesting that the microcrystalline cellulose was difficult to liquefy. The effect of different samples on liquefaction in ethanol with various cellulose/ethanol ratios can be clearly seen from the distribution yields. The FT-IR analysis of the solid residues showed that the structure of celluloses changed after liquefaction. The GC-MS analysis showed that the volatile organic compounds, water-soluble oil, and heavy oil comprised a mixture of organic compounds, which mainly included furfural, acids, furans, esters, and their derivatives. XRD analysis revealed that the decomposing reaction primarily occurred within amorphous zones of the celluloses at the low temperatures.

Hydrothermal pre-treatment and enzymatic hydrolysis of sunflower stalks

The production of fermentable sugars by biochemical conversion of pretreated sunflower stalks is studied in this work. Liquid hot water pre-treatment, in a temperature range from 180 to 230°C was used. After pre-treatment, solid residue and liquid fractions are separated by filtration. Pretreated solids are further submitted to enzymatic hydrolysis for glucose release using a commercial enzyme preparation. Enzymatic hydrolysis yields show that 90% glucose conversion can be obtained after 72h enzyme action on pretreated sunflower stalks at 220°C. Nevertheless, under such pre-treatment conditions most of the hemicellulosic sugars are lost due to solubilisation and degradation reactions. Taking into account all sugars that can be obtained from this agricultural residue, the best results in terms of potential ethanol production is found when pretreating sunflower stalks at 190°C. The characterization of hydrolysate composition is also discussed as inhibitor compounds are also found in liquid fractions issued from pre-treatment.

Potential uses for cuphea oil processing byproducts and processed oils

Cuphea spp. have seeds that contain high levels of medium chain fatty acids and have the potential to be commercially cultivated. In the course of processing and refining cuphea oil a number of byproducts are generated. Developing commercial uses for these byproducts would improve the economics of growing cuphea. Oil fractions and byproducts were obtained from processed seeds of cuphea germplasm line PSR 23 ( Cuphea viscosissima × Cuphea lanceolata). We investigated the employment of oil byproducts as growth regulators and solid residues as organic soil amendments on Calabrese broccoli ( Brassica oleracea L, family Brassicaceae) seedling growth. Seed processing solid residue fractions, included presscake, bin trash, stem trash and seed trash. These fractions were ground and mixed into soil to obtain concentrations of 0, 0.5, 1, 3, and 10% (w/w). Ground presscake and bin trash could be employed as an organic soil amendment up to 1% without detrimental effects on broccoli. Ground seed meal (seed trash) was detrimental to seedling growth at all concentrations tested. Stem trash employed at 1% caused fresh and dry weights to increase 26.8 and 29.8%, respectively, compared to untreated broccoli seedlings. Stem trash could be employed up to 10% without a detrimental effect on broccoli seedlings. Solvent extraction to remove residual oils from residue fractions was also conducted to generate improved soil amendments. Generally, solvent extraction of seed-processing residue fractions improved the broccoli seedling growth responses. Administration of processed oils and their byproduct fractions as foliar sprays on broccoli seedlings was conducted at rates of 0, 10, 30, and 50 g L −1. Plants were evaluated 72 h after spraying. Refined and crude oils had no effect on broccoli seedlings; gums and soapstock sprays had no effect at 10 or 30 g L −1 concentrations but at 50 g L −1 it killed seedlings. Distilled fatty acid fraction sprays killed broccoli seedlings at all tested concentrations. Certain oil byproduct fractions from cuphea oil processing can be employed as “environmentally-friendly” herbicidal sprays. Calorific evaluation of cuphea ag-wastes were conducted and found to compare well to other biomass energy sources.

Cytotoxic Activity of Paris quadrifolia Extract and Isolated Saponin Fractions Against Human Tumor Cell Lines

Steroidal saponins isolated from many plant species belonging to Monocotyledones display potent cytotoxic activity towards many human tumor cells. We examined the cytotoxic effects of crude Paris quadrifolia extract for the first time, testing isolated saponin-rich fractions against four different human cell lines using the [(3-(4,5dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay. Cytotoxic activity was tested against human promyelocytic leukemia (HL-60) cells, human cervical adenocarcinoma (HeLa) cells and human breast cancer (MDA-MB-468) cells. Human skin fibroblasts were used as non-neoplastic control cells. Our results show significant activity of the weakly water-soluble solid residue and butanolic fraction against HL-60 and HeLa cells. The solid residue exerted cytotoxicity against all tested cell lines.

Hydrothermal Liquefaction of Macroalgae Enteromorpha prolifera to Bio-oil

Marine macroalgae Enteromorpha prolifera, one of the main algae genera for green tide, was converted to bio-oil by hydrothermal liquefaction in a batch reactor at temperatures of 220−320 °C. The liquefaction products were separated into a dichloromethane-soluble fraction (bio-oil), water-soluble fraction, solid residue, and gaseous fraction. Effects of the temperature, reaction time, and Na2CO3 catalyst on the yields of liquefaction products were investigated. A moderate temperature of 300 °C with 5 wt % Na2CO3 and reaction time of 30 min led to the highest bio-oil yield of 23.0 wt %. The raw algae and liquefaction products were analyzed using elemental analysis, Fourier transform infrared (FTIR) spectroscopy, gas chromatography−mass spectrometry (GC−MS), and 1H nuclear magnetic resonance (NMR). The higher heating values (HHVs) of bio-oils obtained at 300 °C were around 28−30 MJ/kg. The bio-oil was a complex mixture of ketones, aldehydes, phenols, alkenes, fatty acids, esters, aromatics, and nitrogen-containing heterocyclic compounds. Acetic acid was the main component of the water-soluble products. The results might be helpful to find a possible strategy for use of byproducts of green tide as feedstock for bio-oil production, which should be beneficial for environmental protection and renewable energy development.

Application of chemical fractionation methods for characterisation of biofuels, waste derived fuels and CFB co-combustion fly ashes

In the important efforts to decrease the net CO 2 emissions to the atmosphere, new, alternative fuels are being included in the fuel mixes used in utility boilers. However, these fuels have ash properties that are different from those of the traditionally used fuels and in some cases technical problems, such as ash fouling and corrosion occur due to this. Therefore, diagnostic and predictive methods are developed and used to avoid such problems. Determination of the chemical association forms of important elements, such as potassium and sodium, in the fuel by chemical fractionation is a method well defined for coal and biofuels, such as wood pellets, bark and forest residues. Chemical fractionation is a step by step leaching method extracting water soluble salts in the first step, ion exchangeable elements, such as organically associated sodium, calcium and magnesium in the second step and acid soluble compounds such as carbonates and sulfates in the third step. The solid residue fraction consists of silicates, oxides, sulfides and other minerals. The compound extracted in the two first steps is considered reactive in the combustion with a few exceptions. In this work, it has been applied to some waste fuels, i.e. sewage sludge, straw and refuse derived fuel (RDF), as well as to coal and wood. The present work also includes results from combustion tests in a fluidised bed boiler where three blends of the investigated fuels were used. The fractionation results for the fuel blends are weighted results of the fractionations of the pure fuels discussed above which are compared with fractionations of their corresponding fly ashes. The co-combustion strategy gave very good results in reducing ash problems. Possible chemical mechanisms involved are discussed in the article.