Lignosulfonate Research Articles

Sulfonated lignin intercalated graphene oxide membranes for efficient proton conduction

Graphene oxide (GO) membrane has triggered great attention in proton conduction, benefitting from the well-aligned interlayer nanochannels and oxygen-containing groups. However, GO membrane exhibited a relatively low proton conductivity because of the deficiency of proton-conducting groups on basal plane. Herein, sulfonated lignin (SL) was explored as a multifunctional intercalator to prepare highly conductive GO/SL membranes. The resultant GO/SL membrane with the SL mass fraction of 100% exhibits the highest proton conductivity of 346 mS cm−1 at 80 °C, 100% RH and 7.5 mS cm−1 at 80 °C, 40% RH, which are 3 times and 13 times higher than that of pristine GO membrane, respectively. Bearing abundant sulfonic acid groups and ether bonds, SL acts as both proton donors and acceptors, affording additional proton hopping sites and forming continuous hydrogen bond network for proton transfer. The continuous interlayer nanochannels along with the low-energy-barrier proton hopping pathways render GO/SL membranes highly elevated proton conductivity. Moreover, the GO/SL membrane with the SL mass fraction of 100% achieves a significantly increased maximum power density by 162.7% up to 169.2 mW cm−2 at 60 °C, 100% RH.

Production of Urea/Acetylated-lignin Sulfonate Matrix as SRFs and an Investigation on the Effect of Hydrodynamic Conditions on Release Rate Using the Biot Number

Background: This study aimed to investigate the effect of hydrodynamic conditions on the release rate of urea/acetylated lignin sulfonate (Ac-LS) matrix as slow-release fertilizers (SRFs). Therefore, two models were developed using the mass transfer balance for the determination of finite/infinite volume of fluids and solving finite integral transformation/separation of a variable. The Biot number, validating the hydrodynamic condition, was found in these models. Methods: In this study, the urea/Ac-LS matrix fertilizer was prepared. The morphological, thermal, chemical, and mechanical properties of the LS, Ac-LS, urea, and urea/Ac-LS matrix were analyzed using Fe-SEM, TGA, XRD, and SANTAM. Finally, the nitrogen release of the matrix fertilizer was investigated at 25°C for different impeller speeds. The models were also validated using the experimental data. Results: The results showed that the thermal and mechanical resistance of urea/Ac-LS due to strong interaction increased compared to pure urea or Ac-LS. The results further showed that the external resistance on the mass transfer decreased as the impeller speed increased, and the nitrogen release rate increased as the Biot number increased in both the states, i.e., finite and infinite. Conclusion: It was also observed that the release rate in the finite environment was less than that of the infinite one in the given hydrodynamic condition initially; however, the type of environment did not affect the release rate after a while.

A high-performance electrode based on reduced graphene oxide/lignosulfonate/carbon microspheres film for flexible supercapacitors

Reduced graphene oxide (RGO) flexible film pillared with lignosulfonate (LS) and carbon microspheres (CM) was fabricated via a facile vacuum-filtration process to serve as a high-performance electrode material for supercapacitors. Composite electrodes comprising graphene and biomass materials have the advantages of being flexible, lightweight, cheap, and environmentally friendly. The addition of LS and CM between the RGO layers mitigated the self-restacking of reduced graphene oxide flakes. Composite film electrode displayed a high specific capacitance of 641 mF cm-2 at 0.2 mA cm-2, which was much higher than that of the RGO film (117.9 mF cm-2). The present findings indicate a great potential of the graphene films composited with biomass materials in fabricating flexible supercapacitor electrodes.

Design of Fe3+-Rich, High-Conductivity Lignin Hydrogels for Supercapacitor and Sensor Applications.

Preparation of natural polymer-based highly conductive hydrogels with tunable mechanical properties for applications in flexible electronics is still challenging. Herein, we report a facile method to prepare lignin-based Fe3+-rich, high-conductivity hydrogels via the following two-step process: (1) lignin hydrogels are prepared by cross-linking sulfonated lignin with poly(ethylene glycol) diglycidyl ether (PEGDGE) and (2) Fe3+ ions are impregnated into the lignin hydrogel by simply soaking in FeCl3. Benefiting from Fe3+ ion complexation with catechol groups and other functional groups in lignin, the resultant hydrogels exhibit unique properties, such as high conductivity (as high as 6.69 S·m-1) and excellent mechanical and hydrophobic properties. As a strain sensor, the as-prepared lignin hydrogel shows high sensitivity when detecting various human motions. With the flow of moist air, the Fe3+-rich lignin hydrogel generates an output voltage of 162.8 mV. The assembled supercapacitor of the hydrogel electrolyte demonstrates a high specific capacitance of 301.8 F·g-1, with a maximum energy density of 26.73 Wh·kg-1, a power density of 2.38 kW·kg-1, and a capacitance retention of 94.1% after 10 000 consecutive charge-discharge cycles. These results support the conclusion that lignin-based Fe3+-rich, high-conductivity hydrogels have promising applications in different fields, including sensors and supercapacitors, rendering a new platform for the value-added utilization of lignin.

Synthesis of cationic biomass lignosulfonate hydrogel for the efficient adsorption of Cr(VI) in wastewater with low pH

ABSTRACT In the present study, we synthesized a cationic lignosulfonate hydrogel (LS-g-P (AM-co-DAC)) by grafting acrylamide (AM) and acryloxyethyl trimethyl ammonium chloride (DAC) onto sodium lignosulfonate (LS) via free radical copolymerization. The solution pH, contact time, initial concentration, and temperature were comprehensively investigated through the static adsorption method for the adsorption behaviours of Cr(VI) by the hydrogel. The experimental results show that the best conditions were a temperature of 30°C, a dosage of 0.1 g, pH = 3, a concentration of 50 mg / L, and contact time = 2 h with removal efficiencies of above 70% and adsorption capacity of 18.14 mg·g−1. The adsorption process followed the Langmuir isothermal model, indicating monolayer adsorption, and the maximum adsorption capacity was 58.86 mg·g−1. Adsorption kinetics results show that the pseudo-second-order kinetic model dominated the adsorption process, and the adsorption activation energy was 5.489 kJ·mol−1. In addition, the adsorption involved spontaneous exothermic and entropy reduction. The combination of FT-IR, SEM, and XRD was used to characterize the structure and properties of the prepared hydrogel, and the adsorption mechanism was the result of electrostatic attraction, physical and chemical adsorption, and hydrogen bond. The hydrogel has good regenerative properties after desorption. Overall, this work synthesized an environmentally friendly biomass lignin-based hydrogel, which can be used as an adsorbent for the treatment of anionic pollutants, and explored a new method for the high-value utilization of industrial lignin. Highlights Novel cationic lignosulfonate hydrogel (LS-g-P (AM-co-DAC)) was synthesized by a free radical method. SEM and XRD results confirmed the surface of the obtained hydrogel shows a 3D network structure and does not have a crystal structure. LS-g-P (AM-co-DAC) hydrogel adsorbent can selectively adsorb Cr6+ at pH 3.0. The adsorption conditions and the adsorption mechanism were studied in detail. Electrostatic interaction plays a key role in the adsorption of Cr6+.

Lignosulfonate properties and reaction conditions enhance precipitation and affect ensuing quality of proteins from green biomass juice for monogastric animal feed

This is the first study investigating the effects of lignosulfonate (LS) properties and reaction conditions on the precipitation of proteins from green biomass juice for producing monogastric animal feed. Both the improvement in the protein precipitation yield and the resulting impact on the quality of the protein pellets were investigated with new methods and approaches. High molecular weight (MW) LS gave the highest precipitation yield, 21–33% higher than traditional heat and isoelectric methods. Electrostatic interaction between LS and soluble proteins was observed to be higher in high MW LS than others, and likely improved the precipitation. A response surface design experiment showed that pH was more important than LS concentration for precipitation. The optimum conditions predicted by the model improved precipitation by up to 61% compared to traditional methods. Using high MW LS at near optimum conditions resulted in more LS being retained in the pellet, with a final LS content of up to 60 g/kg dry matter (DM). The improved precipitation yield came at the expense of lower crude protein (CP) content of the pellet. Despite reduced pellet protein purity, the total CP recovery from the juice was improved by up to 800 g/kg DM. The in vitro protein digestibility (IVPD) and amino acid composition were not significantly affected by the presence of LS. Using high MW LS at optimum reaction conditions can significantly improve protein precipitation yield from green biomass juice without compromising digestibility. However, finding the compromise between yield and protein purity is necessary to improve feasibility.

Effects of three surfactants on co-conversion of endogenous carbon and nitrogen of dairy wastewater in mesophilic hydrolytic acidification coupled microalgae culture system.

To determine the feasibility of enhancing co-conversion of endogenous C and N in dairy wastewater by surfactants, the effects of varying dosages of sodium lignosulfonate (LS), sodium dodecyl sulfate (SDS), and Tween-80 on mesophilic hydrolytic acidification coupled microalgae culture system were investigated. Tween-80 had a positive effect on hydrolytic acidification, while LS had no clear effect and SDS had a negative effect. Tween-80 significantly increased the C/N ratio in hydrolytic acidification liquor (HAL) (maximum HAc/NH4+-N rate reached 7.90 in 2.9% Tween-80 test). Pyrosequencing analysis demonstrated that community richness and diversity decreased and the proportion of acidobacteria increased with increasing Tween-80 dosage. Furthermore, the effect of Tween-80-enhanced HAL on microalgae (Chlorella pyrenoidosa) growth and nitrogen removal and the assimilation of C and N on the microalgae culture system were investigated. The biomass concentration and a C and N assimilation yield of 4.8% Tween-80 test (1.75 g/L, 825.01 mg/L, 126.68 mg/L) were significantly higher than those of both the low-concentration Tween-80 tests and control. The yield of protein and carbohydrates and higher heating value in the microalgae culture system were also promoted by Tween-80.

Lignin reinforced hydrogels with fast self-recovery, multi-functionalities via calcium ion bridging for flexible smart sensing applications

Hydrogels have found applications in many different fields. However, poor mechanical properties, such as low elasticity and lack of rapid recovery under large deformation, can severely limit their applications. In this study, we developed lignin reinforced hydrogels made of calcium ion containing ternary polymers (lignosulfonate (LS), alginate (Alg), and polyacrylic acid (PAA)). The resultant hydrogel has excellent elasticity, rapid self-recovery, and multi-functionalities. The covalent PAA network acts as the elastic scaffold of hydrogel, while calcium bridging networks of LS, Alg, and PAA, as well as the strong hydrogen bonding network in the system, function as sacrifice bonds to dissipate energy and transfer stress. The PAA/LS/Alg/Ca hydrogels exhibit rapid and durable elastic recovery ability under large deformation with the highest compressive stress of 835 kPa (95% strain), highest tensile fracture stress of 357 kPa, and highest tensile strain of 1144%. In addition, these tough hydrogels show UV resistance, self-healing, antifreeze, and excellent electro-conductivity. When assembled into a strain sensor, stable and reliable electrical responses with 375 ms response time are demonstrated. The PAA/LS/Alg/Ca hydrogel strain sensors can monitor human movements with responsive and accurate physiological signals. These results support the conclusion that the PAA/LS/Alg/Ca hydrogel strain sensors have great application potential in flexible wearable electronics and smart devices.

Promoting h-BN dispersion in cellulose-based composite by lignosulfonate for regulatable effectual thermal management

Hexagonal boron nitride (h-BN) is an excellent thermally conductive and electrically insulative material. However, the formation of heat transfer pathways of h-BN in thermal interface materials is restricted due to its poor aqueous dispersity. Herein, water-soluble lignosulfonate (LS) is used to promote the dispersion of h-BN, the phenolic hydroxyl and three-dimensional structure of LS could form hydrogen bonding or steric hindrance with h-BN under ultrasound treatment. After mixing with cellulose nanofiber (CNF), the three-dimensional thermally conductive pathways are built in LS-BN/CNF aerogel through freeze-drying. The results show that the through-plane thermal conductivity of LS-BN/CNF/PVA composite with 0.2 wt% LS (LS0.2-BN/CNF/PVA) exceeds 1.22 W/mK when the h-BN/CNF ratio is 3:1 (w/w), which is 6.1-fold of that of PVA film (0.20 W/mK). The initial decomposition temperature and tensile strength of LS0.2-BN/CNF/PVA composite are 205 °C and 38.5 MPa, respectively, demonstrating acceptable thermal stability and mechanical properties for electronics as thermal interface and packing material. Overall, this work put forwards an effective approach to disperse h-BN and paves the way in developing high-performance thermal interface materials.

Sulfonated lignin modified with silane coupling agent as biodegradable shale inhibitor in water-based drilling fluid

A series of sulfonated lignin (SL) samples modified with a silane coupling agent (Si–SL) was investigated as a biodegradable shale inhibitor for water-based drilling fluid (WBDF). Cutting dispersion, linear swelling, bentonite inhibition, and mud ball tests were used to evaluate the inhibition performance of the Si–SL series of and compared with conventional shale inhibitors including potassium formate (HCOOK), polyethylene alycol (PEA), Ultrahib polymer, and polyacrylamide potassium salt (K-PAM). The results showed that the inhibition performance of a series of Si–SL was similar to that of Ultrahib and was significantly better than that of HCOOK, PEA and K-PAM at normal temperature. In addition, compared with other inhibitors, Si–SL showed optimal temperature resistance. The inhibition mechanism of Si–SL was studied by particle distribution, rock compressive strength measurement, shale micro-fracture propagation synthesis, X-ray diffraction (XRD) measurement, adsorption measurement, contact angle measurement, scanning electron microscopy (SEM) observation and atomic force microscopy observation. At high temperature, Si–SL can be strongly adsorbed on the surface of clay particles, while phenyl in molecular chain of Si–SL is conducive to improving the temperature resistance and reducing the hydrophilicity of the surface of clay particles, thus effectively preventing the migration of water molecules to the clay layer. More importantly, through biotoxicity and biodegradability test, the results showed that Si–SL had no toxicity and was easy to be biodegraded. In field application of Bei 213-21HF well, the Si–SL effectively inhibits the hydration of water-sensitive cuttings and maintains the wellbore stability of the shale formation, providing a guarantee for safe and fast drilling. • The new shale inhibitor was tested in water-based drilling fluids. • It shows a better inhibition performance than the most of available inhibitors. • It shows excellent temperature resistance and environmental friendliness. • The mechanism of the inhibitor was investigated. • The product was successfully applied on Bei 213-21HF well (Jilin, China).

Structural basis for lignin recalcitrance during sulfite pulping for production of dissolving pulp from pine heartwood

Dissolving pulps are technically produced by prehydrolysis kraft, one-stage or two-stage acid sulfite pulping. Like other pulping methods, the delignification process is incomplete and bleaching is required for complete lignin removal. Here, we explored the molecular aspects of lignin recalcitrance during the pulping, in order to gain insights that could inform future pulping efforts. For this purpose, we adopted a protocol for the controlled fractionation of pulp into soluble fractions that could be analyzed by spectroscopic methods including size exclusion chromatography (SEC) and 2D NMR methods. In addition, lignosulfonates (i.e. technical lignin) was analysed as a reference to gain insights on the structural basis for dissolution. Overall, the results identify a sequence of reactions responsible for the dissolution of lignin. In the first stage, the sulfonation of lignin begins and occurs at the α-carbon of β-O-4 and β-5 sub-structures. In the second stage the cleavage of lignin carbohydrate bonds (LCC) of benzyl ether, gamma ester and phenylglycosides types, all of which were detected in the residual lignin of the earlier phases, occurs and enhances lignin dissolution. Finally, condensation reactions of benzylic cations with activated positions on aromatic ring were detected in lignosulfonates. This suggest that a competing reaction mode to the sulfonation at C-α position in lignin was occurring at prolonged pulping conditions, here considered to be unproductive.

Effect of the addition of lignin on the physical-mechanical properties of particleboards made with pine/hydrangea stems

ABSTRACT The effect of adding different lignins on the physical and mechanical properties of particleboards made with stems of hydrangea and pine using the urea–formaldehyde (UF) resin was evaluated. Four types of lignin were characterized by Fourier-transform infrared spectroscopy and Klason lignin: Cane Bagasse lignin, Pine China lignin, Kraft Brazil lignin, and ammonium lignosulfonate (LSA). Particleboards were prepared with four types of lignin in a 1:1 (w/w) UF/lignin ratio and compared with those prepared with the UF resin without lignin (control sample). Water absorption, thickness swelling, rupture modulus, and modulus of elasticity were measured. The type of lignin used does not have a statistically significant difference in the physical and mechanical properties and also a decrease in the physical properties of the particleboards compared with the control sample. The use of LSA in the 3:1 (w/w) UF/lignin ratio allows to elaborate particleboards with mechanical properties like those found in the control sample.

Acidolysis mechanism of lignin from bagasse during p-toluenesulfonic acid treatment

Lignin was efficiently separated from lignocellulosic biomass using p-toluenesulfonic acid (p-TsOH) treatment. However, lignin depolymerization and acidolysis have not been studied to date. In this study, the mechanism of lignin acidolysis was investigated. The structure of lignin in bagasse before and after the p-TsOH treatment was analyzed. The efficiency and selectivity of lignin depolymerization were evaluated. The lignin removal rate reached 88.81%. Hemicellulose was completely removed from lignin, and cellulose destruction was inhibited. The structure of lignin in bagasse was analyzed using nuclear magnetic resonance (NMR). The results revealed that α-methoxylated β-O-4 intermediates were formed during lignin depolymerization. This indicated that the benzyl ether bonds were effectively catalyzed and broke, thereby promoting lignin dissolution. The lignin–carbohydrate complex structure was destroyed. The insoluble and soluble lignin in the hydrolysate were analyzed using NMR and gas chromatography–mass spectrometry. The results indicated that the catalyst promoted breaking of the Cβ–O bonds in the β-O-4 structures. Phenols and Hibbert ketones were formed. In addition, lignin sulfonation was confirmed by the presence of di-o-tolusulfone and di-p-tolusulfone. The low contents of β-β and β-5 bonds in the reaction products indicated that lignin condensation was inhibited. The results demonstrated that lignin acidolysis was synergistically catalyzed by H+ and p-TsOH. It provides important theoretical support for efficient and clean separation of lignin using the p-TsOH treatment.

Synthesis of Lignosulfonate-Based Dispersants for Application in Concrete Formulations.

Lignosulfonates (LS) are products from the sulfite pulping process that could be applied as renewable environmentally-friendly polymeric surfactants. Being widely used as plasticizers and water-reducing admixtures in concrete formulations LS compete in the market with petroleum-based superplasticizers, such as naphthalene sulfonate formaldehyde polycondensate (NSF) and copolymer polycarboxylate ethers (PCE). In this work, different chemical modification strategies were used to improve LS performance as dispersants for concrete formulations. One strategy consisted in increasing the molecular weight of LS through different approaches, such as laccase and polyoxometalate-mediated polymerization, glyoxalation, and reversible addition-fragmentation chain transfer (RAFT) polymerization. The other strategy consisted of preparing LS-based non-ionic polymeric dispersants using two different epoxidized oligomer derivatives of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG). Modified LS were used to prepare cement pastes, which were examined for their fluidity. Results revealed that the most promising products are PPG-modified LS due to the introduction of PPG chains by reaction with phenolic moieties in LS. The enhanced dispersant efficiency of the ensuing products is probably related not only to electrostatic repulsion caused by the sulfonic ionizable groups in LS but also to steric hindrance phenomena due to the grafted bulky PPG chains.

Dispersion performance of hydroxypropyl sulfonated lignin in aluminum oxide suspension

• Hydroxypropyl sulfonated kraft lignin was compared with lignosulfonate as a dispersant. • The adsorption of the biopolymers on the aluminum oxide surface was studied. • The dispersion, sedimentation, and particle size of the system were studied. • The results confirmed that both biopolymers behaved very similarly in the suspension. • Hydroxypropyl lignin can replace lignosulfonate due to its attractive production process. In this work, the adsorption and dispersion characteristics of hydroxypropyl sulfonated lignin (HSL) were assessed and compared with those of lignosulfonate (LS). HSL was synthesized in an environmentally friendly manner by reacting kraft lignin (KL) with 3-chloro-2-hydroxypropansulfonic acid (CHPS) under alkaline conditions. This reaction produced HSL with a charge density (-2.48 mmol/g) and molecular weight (42,000 g/mol) that were similar to those of LS. The adsorption behavior of HSL and LS on the aluminum oxide surface was fundamentally analyzed using a quartz crystal microbalance with dissipation monitoring (QCM-D). HSL and LS formed films of similar thickness, though the HSL films exhibited looser and more viscous structures. The dynamic and static dispersion behaviors of HSL and LS in an aluminum oxide suspension were investigated via ζ potential, particle size, and sedimentation analyses. HSL and LS decreased the suspended particle size and improved suspension stability via electrostatic repulsion similarly. The similar properties, adsorption behavior, and stabilizing performances of HSL and LS indicate that HSL may be an effective substitute for commercial LS dispersants. Furthermore, its environmentally friendly synthesis and use of widely available KL as a starting material make HSL production a commercially attractive option.

Синтез коллоидного серебра с использованием лигносульфонатов

Colloidal silver solutions can be used as catalysts for carrying out various chemical transformations of organic substances and solving the problems of disposal of toxic compounds, as well as antibacterial agents for combating pathogenic microflora, in the manufacture of lubricants and light-absorbing materials, coatings, sensors, conductive pastes, and high-performance electrode materials. The research purpose is to study the synthesis of colloidal silver using a solution of technical lignosulfonates (LST) as a stabilizer. Colloidal silver was synthesized as a result of the reduction-oxidation (redox) reaction of Ag(I) cations with glucose at 100 °C in the presence of lignosulfonates. The reaction was carried out in an alkaline medium, which is provided by the addition of ammonia water. Electronic spectroscopy was used to control the synthesis of colloidal silver. After the reaction, the solution turned dark brown and an intense absorption band with a maximum at 400 nm appeared on the electron spectra. The effects of reagent consumption and synthesis duration were studied. It was found that the optimal reagent consumption in the colloidal silver synthesis is as follows: 2.5–5 g glucose / g Ag, 0.3–1 g LST / g Ag, and 3–5 g NH3 / g Ag. The synthesis duration is 2–5 min. The resulting colloidal silver solution is stable for several months. Partial stratification without precipitation is observed during the solution storage. It is shown experimentally that the stratification is followed by a redistribution of colloidal silver particles. Electron spectroscopy confirmed the absence of colloidal silver particles in the upper layer. The reaction kinetics has been studied in experiments carried out under thermostatically controlled conditions at temperatures from 50 to 100 °C. The kinetic dependence is described by a first-order equation at the initial stage of the reaction, the duration of which depends on the temperature. The duration of the active part of the kinetic curves is 15–90 % of the total reaction time. The logarithm of the rate constant on the active section was proved to depend linearly on the reverse thermodynamic temperature (pair correlation coefficient is 0.9887). The activation energy was 47 kJ/mol. For citation: Plakhin V.A., Khabarov Yu.G., Veshnyakov V.A. Synthesis of Colloidal Silver Using Lignosulfonates. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 184–195. DOI: 10.37482/0536-1036-2021-6-184-195

Lignosulphonates as an Alternative to Non-Renewable Binders in Wood-Based Materials.

Lignin is a widely abundant renewable source of phenolic compounds. Despite the growing interest on using it as a substitute for its petroleum-based counterparts, only 1 to 2% of the global lignin production is used for obtaining value-added products. Lignosulphonates (LS), derived from the sulphite pulping process, account for 90% of the total market of commercial lignin. The most successful industrial attempts to use lignin for wood adhesives are based on using this polymer as a partial substitute in phenol-formaldehyde or urea-formaldehyde resins. Alternatively, formaldehyde-free adhesives with lignin and lignosulphonates have also been developed with promising results. However, the low number of reactive sites available in lignin’s aromatic ring and high polydispersity have hindered its application in resin synthesis. Currently, finding suitable crosslinkers for LS and decreasing the long pressing time associated with lignin adhesives remains a challenge. Thus, several methods have been proposed to improve the reactivity of lignin molecules. In this paper, techniques to extract, characterize, as well as improve the reactivity of LS are addressed. The most recent advances in the application of LS in wood adhesives, with and without combination with formaldehyde, are also reviewed.

Ligno Sulphonate [SLS] Laboratory Testing For the Recovery of Residual Oil at Ledok Oil Field

Fossil energy much still needed and exhalated in demand every year on industrial sector, household, and transportation in Indonesia. In the other hand, oil gas production has decreases as many of oil and gas reservoirs have saturated with water breakthrough. Therefore, Enhance Oil Recovery [EOR] as one of proposed solution is adopted to optimize the remaining reserves of oil wells exploitation, especially from mature field that has lesser production capacity towards production problems. Ledok field Cepu district, Central Java Indonesia has many mature wells that produce liquids with its water cut higher than 90 %. The objective of study is to determine which variables that are involve on black liquor or Sodium Ligno Sulphonate [SLS] application as surfactant for EOR on laboratory measurements. Core flooding measurements had been developed and measured. Crude, formation water, and SLS surfactant were injected into the artificial cores. FTIR test show appearance of Sulphonate and Ether alkyl in its composition. Preliminary results show the surfactant has optimum performance to recover oil up to 79% with IFT value 10-1 dyne/cm.

Numerical study on stability of lignosulphonate-based stabilized surficial layer of unsaturated expansive soil slope considering hydro-mechanical effect

Numerous laboratory-based solutions have been proposed in the recent literature for the stabilization of unsaturated expansive soil by recycling lignosulphonate (LS). However, the practical assessments of these proposals for the treatment of the rainfall-induced surficial failure in unsaturated expansive soil slopes are required, considering the frequency of this failure and associated economic loss. Moreover, in conventional geotechnical practice, the slope stability is generally evaluated only with consideration of the hydraulic response of the soil, ignoring the hydro-mechanical coupling effect associated with the swelling behavior of soil. Since LS-based stabilizers mainly impart the reduction of the swelling potential of expansive soils, the assessment of the stability of the LS-treated surficial layer of unsaturated expansive soil slopes requires consideration of the hydro-mechanical effect. For this purpose, the uncoupled and hydro-mechanical coupled analyses were conducted for dealing with the hydraulic and hydro-mechanical responses of the surficial layer of soil slopes, respectively. Specialized experimentations and pertinent literature review were performed to acquire the required input data for these analyses. It is observed that the LS-based surficial layer treatment affects the pore water pressure (PWP) profiles as well as wetting front depth (WFD), which are the critical aspects for influencing the stability of unsaturated expansive soil slopes. Among all LS-based stabilizers, only the stabilizer named composite cementing admixture (CCA) reasonably ameliorated the PWP profiles and WFD of the slope considering disastrous environmental impacts (i.e., wetting–drying cycles). Moreover, the heave problem of expansive soil slopes was observed to be mitigated by LS-based treatment among which the CCA performed the most efficiently. Furthermore, the critical factor of safety (FS) required for slope stability was also affected by the LS-based treatment, whereas the CCA was observed to provide the safest critical FS for slope stability.

Lignosulfonate-Based Polyurethane Adhesives.

The feasibility of using lignosulfonate (LS) from acid sulphite pulping of eucalyptus wood as an unmodified polyol in the formulation of polyurethane (PU) adhesives was evaluated. Purified LS was dissolved in water to simulate its concentration in sulphite spent liquor and then reacted with 4,4′-diphenylmethane diisocyanate (pMDI) in the presence or absence of poly(ethylene glycol) with Mw 200 (PEG200) as soft crosslinking segment. The ensuing LS-based PU adhesives were characterized by infrared spectroscopy and thermal analysis techniques. The adhesion strength of new adhesives was assessed using Automated Bonding Evaluation System (ABES) employing wood strips as a testing material. The results showed that the addition of PEG200 contributed positively both to the homogenization of the reaction mixture and better crosslinking of the polymeric network, as well as to the interface interactions and adhesive strength. The latter was comparable to the adhesive strength recorded for a commercial white glue with shear stress values of almost 3 MPa. The optimized LS-based PU adhesive formulation was examined for the curing kinetics following the Kissinger and the Ozawa methods by non-isothermal differential scanning calorimetry, which revealed the curing activation energy of about 70 kJ·mol−1.