Two-stage Fractionation Research Articles

Geochemical characteristics of natural gas in tight sandstone of the Chengdu large gas field, Western Sichuan Depression, Sichuan Basin, China

SINOPEC has made significant progress in natural gas exploration in terrigenous tight sandstone in the Western Sichuan Depression, making it one of the predominant exploration areas in the Sichuan Basin. Although the Chengdu large gas field was located in the main reservoirs of Upper Jurassic tight sandstone, few geochemical proofs were presented to support the explanation of the gas source, and regional differences in natural gas have been poorly investigated. The Jurassic tight gas in the Chengdu large gas field has a dryness coefficient (C1/C1-5) of 0.939–0.982, and the δ13C1, δ13C2, and δD1 values range from −33.7‰ to −30.7‰, −25.4‰ to −22.3‰, and −162‰ to −153‰, respectively, with positive carbon and hydrogen isotopic series of gaseous alkanes. The carbon and hydrogen isotopic compositions of the Jurassic tight gas indicate that it is typically coal-derived gas. The measured vitrinite reflectance (RO) values of source rocks of Member 5 of the Xujiahe Formation, which are demonstrated as the main source of Jurassic tight gas, are consistent with the calculated RO values according to the two-stage fractionation model of coal-derived gas. Effective source rocks are rare in the Lower Jurassic Baitianba Formation of the study area, which is considered to have only a minor contribution to the Jurassic gas reservoirs. The geochemical characteristics of Jurassic natural gas from various gas fields in the Western Sichuan Depression vary depending on the effect of different gas sources and accumulation processes.

O21 - Topic: AS02-Epidemiology: CONDITIONAL RELATIVE SURVIVAL IN MYELODYSPLASTIC SYNDROMES REVEALS A PERMANENT EXCESS MORTALITY RISK FOR LONG-TERM SURVIVORS: A POPULATION-BASED STUDY IN THE NETHERLANDS

SINOPEC has made significant progress in natural gas exploration in terrigenous tight sandstone in the Western Sichuan Depression, making it one of the predominant exploration areas in the Sichuan Basin. Although the Chengdu large gas field was located in the main reservoirs of Upper Jurassic tight sandstone, few geochemical proofs were presented to support the explanation of the gas source, and regional differences in natural gas have been poorly investigated. The Jurassic tight gas in the Chengdu large gas field has a dryness coefficient (C1/C1-5) of 0.939–0.982, and the δ13C1, δ13C2, and δD1 values range from −33.7‰ to −30.7‰, −25.4‰ to −22.3‰, and −162‰ to −153‰, respectively, with positive carbon and hydrogen isotopic series of gaseous alkanes. The carbon and hydrogen isotopic compositions of the Jurassic tight gas indicate that it is typically coal-derived gas. The measured vitrinite reflectance (RO) values of source rocks of Member 5 of the Xujiahe Formation, which are demonstrated as the main source of Jurassic tight gas, are consistent with the calculated RO values according to the two-stage fractionation model of coal-derived gas. Effective source rocks are rare in the Lower Jurassic Baitianba Formation of the study area, which is considered to have only a minor contribution to the Jurassic gas reservoirs. The geochemical characteristics of Jurassic natural gas from various gas fields in the Western Sichuan Depression vary depending on the effect of different gas sources and accumulation processes.

Two-Stage Fractionation of Sugarcane Bagasse by a Flow-through Hydrothermal/Ethanosolv Process

This work aimed to study the fractionation of sugarcane bagasse using a two-step hydrothermal and ethanosolv process in a flow-through reactor system. The effects of reaction temperature with or wi...

Isolation of guaiene from patchouli (Pogostemon cablin Benth.) oil using vacuum fractionation distillation

Guaiene is one component of patchouli oil, which is used in the flavor and pharmaceutical industries. It can be isolated using vacuum fractionation distillation. This study aim to study the effect of isolation stages on the performance of the distillation process. The method used is the descriptive method with two-stage fractionation and one-stage fractionation as its treatment. In one-stage fractionation, patchouli oil is fractionated with 8 temperature ranges: 249–261, 261–273, 273–280, 280–286, 286–291, 291–302, 302–319, and 319–321 °C. At two-stage fractionation, fractionation was carried out to obtain the patchouli alcohol component as the highest component of patchouli oil, then guaiene was isolated from the remaining fractions with 5 temperature ranges: 249–261, 261–274, 274–281, 281–287 and 287– 300 °C. Vacuum fractionation distillation was conducted using the BR 36–100 Spinning Bend Distillation System. The results showed that at one-stage fractionation produced 5 cut fractions, while the fractionation of two-stage fractions produced 2 cut fractions. One-stage fractionation takes longer time than two-stage fractionation (23.12 and 19.32 hours, respectively), with electricity consumption also being greater, 207.83 and 176.18 kWh, respectively.

Process Variable Optimization of Kenaf Two-Stage Fractionation Based on Dilute Hydrochloric Acid Followed by Ethanol Organosolv for Component Separation

Ethanol organosolv (EO) fractionation is a promising technology for producing high-purity lignin from kenaf, a lignocellulosic biomass. However, EO fractionation could not be used for the hemicellulose fraction because of the removal of hemicellulose into black liquor, which is a major drawback. Dilute hydrochloric acid (DHA) fractionation prior to EO fractionation has been proposed as a strategy to overcome this problem. In this study, the hemicellulose fraction of kenaf was maximally fractioned using 0.5% (w/w) HCl at 145 °C for 60 min. Subsequently, the non-washed and dried fibers, the cellulose-lignin fraction, were also fractionated to extract lignin using 60% (v/v) ethanol at 180 °C for 60 min through an optimization process. In each fractionation process, hemicellulose and lignin were removed at 86.11 and 68.86 % from untreated kenaf, respectively. Thus, DHA and EO fractionations are effective procedures to separate the lignin (94.73% purity) and hemicellulosic hydrolysate (19.65 g/L sugar) fractions in addition to cellulose-rich solid (glucan content 80.05%).

Source of the Upper Paleozoic natural gas in the Dingbei area, Ordos Basin, China

The Dingbei area is an important exploration area in the Ordos Basin for SINOPEC, and natural gas exploration in the Upper Paleozoic strata in the area achieved a great breakthrough in recent years. However, the origin and source of natural gas are weakly studied, wherein there is no consensus on whether the Upper Paleozoic gas in the basin has experienced large-scale lateral migration. Studies on the geochemical characteristics of natural gas indicate that the Upper Paleozoic natural gas in the Dingbei area is typically dry gas with the dryness coefficient (C1/C1-5) ranging from 0.977 to 0.986, and the δ13C1, δ13C2, and δD1 values range from −30.6‰ to −28.6‰, −25.9‰ to −24.1‰, and −191‰ to −177‰, respectively. The above has positive carbon and hydrogen isotopic sequence between CH4 and C2H6. Carbon and hydrogen isotope compositions of alkane gas suggest that the Upper Paleozoic gas in the Dingbei area is typically coal-derived gas. The calculated RO values according to the two-stage fractionation mode of coal-derived gas are consistent with the measured RO values of the Upper Paleozoic source rocks; this indicates that the Upper Paleozoic gas in the Dingbei area was mainly derived from in-situ source rocks in the Taiyuan and Shanxi formations. In comparison to the Dingbei area, natural gas from the Daniudi gas field in northeastern Ordos Basin displays lower δ13C1, C1/C1-5, and C1/C2+3 values and higher C2/C1 ratios, suggesting the lower maturity of source rocks rather than migration effect. The Upper Paleozoic natural gas in the Ordos Basin has not experienced large-scale lateral migration.

New two-stage pretreatment for the fractionation of lignocellulosic components using hydrothermal pretreatment followed by imidazole delignification: Focus on the polysaccharide valorization

The combination of hydrothermal pretreatment followed by delignification with imidazole was evaluated for the first time as a potential selective two-stage fractionation for elephant grass, aiming at obtaining pure fractions susceptible to conversion to high value-added products. In addition, the recovery of cellulose and hemicelluloses and enzymatic hydrolysis yield of pretreated elephant grass were evaluated. Hydrothermal pretreatment at 180 °C under non-isothermal conditions allowed obtaining a liquor rich mainly in xylo- and glucooligosaccharides, as well as pentoses. Subsequent treatment of the recovered solid fraction with imidazole at 140 °C for 182.5 min resulted in 83.8 wt% delignification and cellulose enrichment of 97.7 wt%. The solids obtained from the two-stage pretreatment process also permitted high glucan to glucose conversion through enzymatic hydrolysis using Cellic CTec2 (99.0 mol%) or an enzymatic complex of Penicillium echinulatum (96.3 mol%).

Study of selective condensation for woody biomass pyrolysis oil vapours

The quality of oil produced from the pyrolysis of biomass is a function of many factors, including the type and extent of the condensing system. In this work, we designed a two-stage fractionation system intermediate/fast pyrolysis in a 2–4 kg/h auger reactor to determine the impact of removal of water and low molecular weight acidic compounds on the quality of the oil and the nature of the fractions recovered. The auger reactor two-stage fractionation system consists of two shell and tube condensers in series with an ESP. The first condenser coolant temperature was varied between 50 and 90 °C, while the second condenser temperate was kept constant at 4 °C. GC-FID analysis show that acetic acid which contributes to bio-oil acidity and other light ends such as methanol, glycolaldehyde, and acetol are entirely removed from the first condenser product at a coolant temperature of 90 °C. The product has a low water content (6 wt%), a low acid content (34 mg KOH/g), and a high heating value (approximately 28 MJ/kg). The two-stage fractional system improves bio-oil fuel quality compared to a bio-oil produced from a traditional condenser system. However, the viscosity of the bio-oil approximately doubled as the first condenser coolant temperature increased from 50 to 70 °C and subsequently limits its applications.

Consecutive Recovery of Non-Structural Sugars and Xylooligomers from Corn Stover using Hot Water and Acidified Calcium Chloride

Corn stover, which has a high non-structural sugar content, was treated by two-stage fractionation using water and acidified CaCl2 for the consecutive recovery of non-structural sugars and xylooligomers. In this process, water treatment under mild conditions (60 °C to 140 °C) was used for the recovery of non-structural sugars in the first stage, followed by the recovery of xylooligomers using acidified CaCl2 in the second stage under severe conditions (160 °C to 180 °C). For the recovery of non-structural sugars, a water treatment at 80 °C was observed to be effective, recovering 95.6% of the non-structural sugars. With a non-structural sugar-free solid, the reaction conditions for the second stage of treatment using acidified CaCl2 were statistically optimized. The highest recovery yield of xylooligomers (72.5%) was obtained under optimum conditions (172.9 °C, 22.2 min, 4.7% CaCl2). With the two-stage fractionation process, the glucan digestibility of treated solid was enhanced from 34.0% for untreated corn stover to 91.0% for the treated solid (with 15 FPU/g-glucan).

Lignin valorization: lignin nanoparticles as high-value bio-additive for multifunctional nanocomposites

BackgroundAlthough conversion of low value but high-volume lignin by-product to its usable form is one of the determinant factors for building an economically feasible integrated lignocellulose biorefinery, it has been challenged by its structural complexity and inhomogeneity. We and others have shown that uniform lignin nanoparticles can be produced from a wide range of technical lignins, despite the varied lignocellulosic biomass and the pretreatment methods/conditions applied. This value-added nanostructure lignin enriched with multifunctional groups can be a promising versatile material platform for various downstream utilizations especially in the emerging nanocomposite fields.ResultsInspired by the story of successful production and application of nanocellulose biopolymer, two types of uniform lignin nanoparticles (LNPs) were prepared through self-assembling of deep eutectic solvent (DES) and ethanol-organosolv extracted technical lignins derived from a two-stage fractionation pretreatment approach, respectively. Both LPNs exhibited sphere morphology with unique core–shell nanostructure, where the DES–LNPs showed a more uniform particle size distribution. When incorporated into the traditional polymeric matrix such as poly(vinyl alcohol), these LPN products displayed great potential to formulate a transparent nanocomposite film with additional UV-shielding efficacy (reached ~80% at 400 nm with 4 wt% of LNPs) and antioxidant functionalities (reached ~160 μm mol Trolox g−1 with 4 wt% of LNPs). At the same time, the abundant phenolic hydroxyl groups on the shell of LNPs also provided good interfacial adhesion with PVA matrix through the formation of hydrogen bonding network, which further improved the mechanical and thermal performances of the fabricated LNPs/PVA nanocomposite films.ConclusionsBoth LNPs are excellent candidates for producing multifunctional polymer nanocomposites using facile technical route. The prepared transparent and flexible LNPs/PVA composite films with high UV-shielding efficacy, antioxidant activity, and biocompatibility are promising in the advanced packaging field, which potentially provides an additional high-value lignin product stream to the lignocellulose biorefinery. This study could open the door for the production and application of novel LNPs in the nascent bioeconomy.Graphical abstractLignin nanoparticle for transparent nanocomposite film with UV-shielding efficacy

Two-stage fractionation of sugarcane bagasse by autohydrolysis and glycerol organosolv delignification in a lignocellulosic biorefinery concept

Bioethanol production from lignocellulose biomass offers a solution to current environmental challenges caused by fossil fuel energy resources, while satisfying the biorefinery concept. In this study, two-stage fractionation (autohydrolysis (AH) followed by glycerol organosolv delignification (GOD)) of sugarcane bagasse (SCB) was studied as a function of temperature, time, glycerol content and liquid-to-solid (LSR) ratio using experimental designs. The effect of three different AH pretreatment severities on delignification extents (DE) of the solid fractions were also evaluated. Scanning electron microscopy was used to examine the changes in the surface of SCB pretreated by AH. Energy balances of four fractionation conditions were estimated, and the use of pure and crude glycerol in GOD was evaluated based on DE and lignin contents. A DE of ∼64% was obtained at 210.3°C, 40min, LSR of 6.5 (v/w) and 80% (v/v) pure glycerol for GOD of SCB pretreated by AH at 175.8°C, 49min and LSR of 5.3 (v/w), which resulted in an energetic profitability (EP) of 141.48MJ/kgSCB. The use of crude glycerol at 80% (v/v) under the same process conditions optimized for pure glycerol also proved to be feasible (DE of ∼64% and EP of 142.67MJ/kgSCB), widening the possibilities for its direct use in GOD of SCB pretreated by AH in a 2G bioethanol integrated plant.

Barium stable isotopes in the global ocean: Tracer of Ba inputs and utilization

Barium has been used as a biogeochemical tracer for alkalinity, productivity, and riverine inputs in the ocean, but its oceanic cycle remains poorly constrained. Barium stable isotope measurements may improve the use of Ba as a tracer and better constrain the cycling of Ba, but data are only available in limited regions of the oceans. In this study, we present dissolved seawater Ba isotopic compositions in a sample collection spanning the North Atlantic, South Atlantic, North Pacific and Southern Oceans. Compiled global upper-ocean [Ba] data show a relatively constant [Ba] (35–45 nM) in the near-surface waters throughout the global ocean, with the exception of areas near river inputs or strong upwelling. The relatively uniform distribution of [Ba] in the upper ocean seawater indicates that Ba removal is slow relative to supply and mixing, and implies that near-surface Ba isotope values are controlled by basin-scale balances rather than by regional or short-term processes. Seawater Ba isotopic compositions show a large variation of δ138/134Ba values ranging from 0.24 to 0.65‰, and a tight relationship with [Ba]. This global relationship can be simply modelled assuming a primary deep Southern Ocean source for Ba to yield a maximum isotope fractionation of α=1.00058±0.00010 (α=Baseawater138/134/Baparticle138/134). This suggested isotope fractionation during Ba removal from seawater is larger than implied by laboratory measurement during barite formation, suggesting additional fractionating phases or a two-stage fractionation process. Riverine input from the Rio de la Plata to the South Atlantic has a signature of δ138/134Ba=−0.06–0.11‰, which is too light to explain the heavy values (>0.58‰) observed in the surface open ocean. Globally, the Ba isotope composition of the upper ocean waters is correlated with the fraction of Ba utilization at the basin scale (which varies from <15 to 70% at sites studied here). In the deep Atlantic Ocean, distinct δ138/134Ba signals in the northern-sourced (≈0.45‰) and the southern-sourced water (≈0.25‰) trace mixing and allow identification of non-conservative behaviour of Ba, reflecting additional inputs or sinks of Ba during transport (most likely addition from sediment or hydrothermal). Ba isotopes may be useful to trace such inputs in the present and past ocean.

Two-stage, acetic acid-aqueous ammonia, fractionation of empty fruit bunches for increased lignocellulosic biomass utilization

Fractionation of EFB was conducted in two consecutive steps using a batch reaction system: hemicellulose hydrolysis using acetic acid (AA; 3.0–7.0wt.%) at 170–190°C for 10–20min in the first stage, and lignin solubilization using ammonium hydroxide (5–20wt.%) at 140–220°C for 5–25min in the second stage. The two-stage process effectively fractionated empty fruit bunches (EFB) in terms of hemicellulose hydrolysis (53.6%) and lignin removal (59.5%). After the two-stage treatment, the fractionated solid contained 65.3% glucan. Among three investigated process parameters, reaction temperature and ammonia concentration had greater impact on the delignification reaction in the second stage than reaction time. The two-stage fractionation processing improved the enzymatic digestibility to 72.9% with 15 FPU of cellulase/g of glucan supplemented with 70 pNPG of β-glycosidase (Novozyme 188)/g-glucan, which was significantly enhanced from the equivalent digestibility of 28.3% for untreated EFB and 45.7% for AAH-fractionated solid.

Transformation of wood industry waste into key intermediates for pharmaceutical substances: Biotechnological study

Selective microbial conversion of plant sterols allows direct production of 9α-hydroxyandrost-4-ene-3,17-dione (9-OH-AD), a key intermediate in the synthesis of important pharmaceutical substances from the steroid glucocorticoid group. As substrates for bioconversion, sterol-enriched wastes of local pulp-and-paper industry, particularly, unsaponifiable tall pitch residue and its derivatives can be used. A series of simple and effective one- or two-stage fractionation procedures yielded the derivatives containing 51–88 wt % of convertible sterols. The analysis of the bioconversion dynamics of the sterol-enriched samples demonstrated that while the 9-OH-AD accumulation rates were 2–2.5 times lower than with commercial phytosterol, acceptable molar yields of 53–57% of the product were obtained. The obtained results make it possible to optimize the technological chain starting from the primary products of processing of renewable raw materials (by-products of wood processing) and ending with the desired steroid pharmaceutical substances via 9-OH-AD.

Two-stage fractionation of polar alkaloids from Rhizoma coptidis by countercurrent chromatography considering the strategy of reactive extraction

Separation of polar alkaloids by countercurrent chromatography (CCC) is challengeable due to their close partition behaviors in solvent system. In this paper, a two-stage method for isolation of epiberberine, jatrorrhizine, palmatine, coptisine, and berberine from Rhizoma coptidis was presented. The first stage separation performed on CCC was based on the principle of reactive extraction. Trifluoroacetic acid was acted as a modulator to selectively react with alkaloids, which changed their partition coefficients in solvent system. Purified epiberberine and other partially separated targets were eluted by ammonium adjusted mobile phase. In the second stage, four alkaloids were purified in pH-zone-refining CCC mode. All the targets collected were over 97% pure determined by HPLC. The method developed demonstrates performing of reactive extraction on standard CCC as an option for separation of polar alkaloids from medicinal plants.

Two-Stage Fractionation and Fiber Production of Lignocellulosic Biomass for Liquid Fuels and Chemicals

In the current study, a simple two-step fractionation process was developed for utilization of hardwood biomass without forming troublesome sticky lignin condensation products. The four product streams generated are a hemicellulose extract, a lignin extract, separated wood fibers (pulp) and wood fiber bundles (rejects). All four product streams can be further utilized for production of transportation fuel, chemicals, and biomaterials. The optimum fractionation conditions for mixed southern hardwood chips are the following: extraction with 10 g/L formic acid (FA) at 160 °C for 90 min followed by extraction with 50% (w/w) EtOH at 80 °C for 90 min. The yield of pulp and reject fibers that are produced from the FA and EtOH pre-extracted wood chips by mechanical action are 38% and 28%, respectively. Cellulose to glucose conversion yield of the FA treated wood, as well as that of the final pulp and fiber bundles by enzymes, are strongly improved compared to that of the original hardwood chips.

Two-Stage Fractionation of Hardwoods

A two-stage lignocellulosic biomass fractionation process consisting of a formic- or acetic acid-reinforced wood autohydrolysis step followed by an ethanol-water treatment was applied to a mixture of Southern hardwood chips. The wood products in the hydrolysate were mostly monomeric xylose, other monomeric sugars, polymeric hemicelluloses, acetic acid, and a relatively small amount of lignin. The second step mostly dissolves sulfur-free lignin, while the fibrous residue consists mainly of cellulose fibers, which may be used for liquid fuels or pulp production. The yield composition, and quality of these products were determined as a function of treatment conditions, with the aim to develop an economic and robust biorefinery fractionation technology.

Biorefinery process for production of paper and oligomers from Leucaena leucocephala K360 with or without prior autohydrolysis

Lignocellulosic material from Leucaena leucocephala was subjected to a two-stage fractionation process to obtain a valorized effluent containing hemicellulose derivatives and a solid phase for producing cellulose pulp by conventional soda-anthraquinone delignification. This solid phase allows the production of cellulose pulp, under less rigorous conditions from NaOH-AQ process (177°C, 21%, 120min) than without pretreatment delignification (185°C, 25%, 150min) and better or similar properties in the paper sheets obtained (yield 27.6 and 34.0%, brightness 39.3 and 31.6% ISO, tensile index 7.8 and 10.5Nm/g, burst index 0.43 and 0.29MPam2/kg with and without previous autohydrolysis) have be found. Also, the first autohydrolysis stage allows up to 46.6% of the initial hemicellulose in the raw material to be extracted as xylooligomers, xylose and furfural into the liquid phase.

Improved enzyme efficiency of rapeseed straw through the two-stage fractionation process using sodium hydroxide and sulfuric acid

Two-stage fractionation process using sodium hydroxide and sulfuric acid was conducted to remove lignin and hemicellulose from rapeseed (Brassica napus) straw. This process consists of two stages; using sodium hydroxide, the first stage solubilized 35.54% of lignin and increased the glucan content in the treated solid from 32.86% to 38.13%. The second stage solubilized 85.85% of the lignin and 91.56% of the XMG (Xylan+Mannan+Galactan) into hydrolyzate. After the two-stage process, merely 2.53% of glucan and 3.81% of XMG were lost due to excessive decomposition. Despite the reduction in enzyme loading by 50%, the enzymatic digestibility with the two-stage treated straw was approximately 23% higher than that of the single stage acid fractionation process.

Optimization of two-stage fractionation process for lignocellulosic biomass using response surface methodology (RSM)

A two-stage process using aqueous ammonia and hot-water has been investigated to fractionate corn stover. To maximize hemicelluloses recovery and purity in the liquid hydrolyzate by optimizing the fractionation process, the experiments were carried out employing response surface methodology (RSM). A central composite design (CCD) was used to evaluate and confirm the effectiveness and interactions of factors. The optimal fractionation conditions were determined to be as follow: (1) First-stage reactor operated in batch mode using a 15% NH4OH solution (wNH3 = 15%) at 1:10 solid:liquid ratio, 60 °C, and 24 h; (2) second stage percolation reactor operated using hot-water at 20 cm3 min−1, 200 °C, and 10 min. The model predicted 51.5% xylan recovery yield and 82.4% xylan purity under these conditions. Experiments confirmed the maximum xylan recovery yield and purity were 54.7% and 83.9% respectively under the optimal reaction conditions. With the solids resulting from the two-stage treatment, 87%–98% glucan digestibilities were obtained with 15 FPU of GC 220 per g-glucan and 30 CBU of Novo 188 per g-glucan enzyme loadings. Xylan digestibility of xylooligomer hydrolysates reached 76% with 8000 GXU per g-xylan of Multifect-Xylanase loading. In the simultaneous saccharification and fermentation (SSF) test using treated solids and Saccharomyces cerevisiae (D5A), 86 % to 98% of ethanol yield was obtained on the basis of the glucan content in the treated solids.