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Lab-scale experiments were carried out to investigate a new approach of preparing biochar-based catalyst for transesterification reaction. Black liquor (BL) from cotton pulping process was used as a precursor for preparing the catalyst via spray drying followed by fast carbonization in a fluidized bed reactor. Response surface methodology (RSM) was employed to statistically analyze and optimize the entire process of catalytic synthesis of biodiesel from a waste frying oil, consisted of the catalyst preparation and transesterification steps. Several major operation parameters of the biodiesel synthesis process, including alkaline loading in biochar, methanol to oil ratio, catalyst loading, and the carbonization temperature of catalyst, were studied for their effects on biodiesel conversion. The optimal condition for achieving the maximum biodiesel conversion (i.e. 91.5 %) was found to be: 27 wt% alkaline loading in biochar, 600 °C carbonization temperature, 7.7 methanol to oil ratio, and 6.5 wt% catalyst loading. Overall, the spry drying fluidized bed carbonization demonstrated its viability for significantly reducing duration of high temperature carbonization, opening up the prospects of manufacturing the catalyst in a much less energy consumption manor.

Lignin has an enormous valorization potential as a sustainable raw material. The most common source of industrial lignin is black liquor, a byproduct from the kraft process. However, the variabilit...

The alkaline pretreatment has the advantages of low energy input and atmospheric pressure to highly enhance the conversion of lignocellulose to ethanol. However, the black liquor from the process would pollute the environment, which hinders its industrial application. This study selected the potassium hydroxide (KOH) as the alkaline reagent for lignocellulosic pretreatment and investigated the feasibility of recycling the black liquor (BL) as molecular bio-activator for plant growth. After optimization of KOH pretreatment, the enzymatic saccharification efficiency of rice straw achieved to 86.6% under the optimum condition of 2% KOH, 15:1 of liquid–solid ratio, 70 °C for 1 h. The ethanol production and conversion ratio was 32.24 g/L and 53.0% respectively at 20% solid loading. The tobacco cultured in the nutrient solution with BL was more luxuriant than that without BL, of which the dry weight of plant increased 367% and the leaf area increment of tobacco was about 2∼4 times than the control after 30 days. Thus this study provided a promising way to accelerate the industrialization of alkaline pretreatment for cellulosic ethanol production.

Spent pulping chemicals along with liberated lignin called black liquor are a major liquid waste stream from wood digestion process. For wastewater quality improvement, lignin residue could be isolated via various techniques. According to difference in chemical pulping process (kraft and soda), variations of organic and inorganic substance were suspended in waste stream. This research aims to investigate the effects of the cooking chemical on organic waste (lignin) in black liquor. Organic waste in black liquor was isolated as soda lignin (SL) from soda black liquor (SBL) and kraft lignin (KL) from kraft black liquor (KBL) by acidic precipitation. In addition, lignin model compound (LMC) was used to establish base case measurement. The elemental analysis revealed the similarity of C, H, and O content of samples in range of 32-33%, 3-4%, and 35-38%, respectively. FTIR results showed that structures of lignin, functional group and guaiacyl to syringyl ratio were vary depended on type of chemical pulping with β-O-4 as the primary composition of the samples. Moreover, Py-GC/MS technique was applied for analyzing the degradation products in order to corroborate the result with the structure and thermal behavior analysis. The TGA results showed high stability of lignin up to around 400°C. Main degraded compounds of all samples were phenol, vanillin, catechol, and guaiacol. This finding suggested that not only lignin which caused high BOD and COD could potentially be isolated for value added product but also the discharge quality could be improved. In addition, different chemical processes effect residual lignin in black liquor and underscore the importance of lignin in black liquor as a potential material for renewable energy and chemical production.

In diverse fields, much attention has been concentrated on the preparation of lignin nanospheres with various structures. Here we report a facile self-assembly strategy for preparing super long-term stable hollow and solid nanospheres based on lignin fractionation. We found that different lignins obtained at different pHs during fractionation can form nanospheres with different particle sizes and structures. The self-assembled and formation mechanisms of the nanospheres were surveyed by dynamic light scattering (DLS), elemental analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The analysis results showed that the phenolic hydroxyl groups and the intermolecular π-π interaction play a decisive effect in the formation of nanospheres. This study can not only facilitate the advance of lignin-based nanotechnologies but also provide a broad prospect for the use of black liquor.

The fundamental reason for the environmental pollution caused by the papermaking industry is the inadequate treatment of the black liquor. How to dispose of the lignin macromolecules, which is the main pollutants in the black liquor, is the key to addressing the environmental pollution. At present, cross-flow membrane filtration is one of the effective ways to retain and recycle lignin macromolecules in black liquor. The paper proposes the adoption of a dynamic blade cross-flow membrane filtration equipment provided by German BOKELA company to treat papermaking black liquor. The experiment shows that when the black liquor is treated with dynamic blade rotation cross-flow, the membrane with a molecular weight cut-off of nanofiltration (NP010) delivers the best retaining effect, with 28 % more lignin in black liquor than that in untreated black liquor. Meanwhile, when the blade rotational speed reaches 300 rpm and the transmembrane pressure is 0.5 or 2 bar, the flux of black liquor through nanofiltration NP010 is relatively desirable.

Sulfide ions (S−2) derived from Na2S in black liquor, after the pulping process, is the source of production H2S during of black liquor recovery cycle in Kraft pulp and paper industries. Tow adsorbents (Cu-PAC, Cu-GAC) by loading Cu+2 on powder activated carbon (PAC) and granular activated carbon (GAC) were synthesized to created more adsorption sites and were improved their selectivity for removing S−2 from black liquor with 3 level of sulfidity (18, 20 and 22 %). The adsorbents were characterized by BET, FTIR, SEM, and EDX. Adsorption of S−2 for Cu-PAC and Cu-GAC were fitted well with Freundlich and Langmuir isotherm model respectively and both of the adsorbents followed pseudo-second-order kinetic. The results of thermodynamic parameters showed the endothermic process. The removal efficiency results showed Cu-PAC has better performance than Cu-GAC. This is due to the higher specific surface area of Cu-PAC, which has led to more adsorption sites for S−2. By considering appropriate temperature conditions and direct effect of the S−2 on the production of H2S during of black liquor recovery cycle, Cu-PAC will be able to prevent H2S production and odorous the black liquor recovery cycle by removing 79.89 % of the S−2.

This paper investigated the filtration of black liquor with blade cross-flow by membrane. The lignin content in black liquid filtered by the nanofiltration membrane (NP010) is high under the transmembrane pressure of 0.5 bar, 1 bar, 1.5 bar, and 2 bar at 300 rpm and 800 rpm. In this regard, the tangential velocity on the nanofiltration membrane surface and the pressure variation on the blade in the process of filtration are simulated and analyzed with Fluent software. The tangential flow velocity on the nanofiltration membrane surface and the dynamic pressure on the blade, as well as the law of change under different rotation speed and transmembrane pressure are obtained. The comparison between experimental and simulated results have validated the numerical model of the filtration of black liquid by the blade dynamic cross-flow. According to the experimental and simulated results, the optimized filtration conditions are obtained when the blade dynamic cross-flow uses 1 kDa nanofiltration membrane to filter black liquor.

Lignin is a by-product of the pulp and paper industry that can be precipitated by acidification from black liquor as a potential feedstock for valuable green materials. Precipitation and quantification of lignin from softwood black liquors have been documented and commercialized with well-established methods; however, applying those methods to the precipitation of lignin from hardwood black liquors has produced low lignin yields. A need to understand the main differences between hardwood and softwood lignin precipitation prompted the current investigation. Multiple black liquor samples from sweetgum and pine pulping were obtained at different times of standard kraft cooks. Two lignin fractions were precipitated from each of these black liquors, one at pH 9.5 and one at pH 2.5. Detailed lignin and carbohydrate material balances were performed around each of the sample sets, starting with the wood and ending with precipitated lignin fractions. For all conditions tested, the amount and purity of pine lignin precipitated were superior to sweetgum lignin. The maximum recovery for sweetgum lignin was 69.7%, while for pine lignin, it was 90.9%.

This article contains results of exergic analysis of kraft pulping flow chart. The results of exergic balances of main kraft pulping processes such as alkali recovery at recovery boilers, black liquor evaporation, chips cooking, lime decarbonation are considered in details in the article. The analysis of the process flow chart makes it possible to determine the bottlenecks in the use of heat energy and to substantiate principal lines for increasing energy efficiency of the processes under study. A main share of the exergy expended in the existing pulping process is due to alkali recovery in the recovery boiler and comprises 70% of the total exergy available in the system. A procedure of hydrothermal production of chemicals in the process of kraft pulping is studied. A schematic diagram and analysis of heat technique of the kraft pulping process which in fact consists of organic component removal from black liquor through its autoclave carbonation with flue gases releasing from lime kiln at the temperature 80-90 oC are given in the article. The removal of organic components under these conditions can reach 70 %. In the studied version the exergic efficiency ηe = 80 % is considerably higher than that of the flow chart existing for chemicals recovery which is equal to ηe = 48 %. This is the evidence of high energy efficiency of the method developed.

A new eco-friendly compound was prepared for the treatment of textile wastewater containing mixed dyes with various ranges of toxicity. Porous silica was extracted from a black liquor by-product using a simple method and characterized by porous morphology (the pore size ranged between 12 and 41 nm). The silica is the main corrosive agent present in the black liquor; thus, the extraction of silica from the black liquor was considered detoxification process. The extracted porous silica was used as a precursor material to prepare the hybrid material based on polyvinyl alcohol (PVA) as a binder polymer and functionalized by nicotinic acid. The multifunction prepared hybrid was characterized by FT-IR, TGA, DTGA, SEM, and EDX. The porous size of the prepared hybrid varied from 96 nm to 620 nm and presents a high thermal stability in comparison with its parent materials. The adsorption of cationic and anionic dyes was carried out. The adsorption kinetics parameters were fitted with pseudo-first-order and pseudo-second-order kinetic models for methyl orange (MO) and methylene blue (MB), respectively. The adsorption parameters indicated that the Langmuir model is better to describe the adsorption of dyes on the hybrid material. The maximum adsorption capacity was 484 and 771 mg/g for MO and MB, respectively.

This study was conducted to enhance the physical, mechanical and thermal properties of the short cycle coconut wood (SC-CTL) by impregnating with the kraft black liquor (BL) and black liquor/phenol formaldehyde (BL/PF) resin. The SC-CTL was impregnated with different kraft BL and BL/PF resin concentrations (i.e., 10, 15, 20 and 25% w/w) using the vacuum pressure method. Dimensional stability, mechanical and thermal properties of the impregnated SC-CTL were analyzed according to the standards. The results showed that the impregnation of BL/PF resin into SC-CTL have improved the coconut wood’s dimensional stability, mechanical and thermal properties. The morphology of coconut wood’s cells loaded with BL/PF resin clearly showed a full penetration. The results also suggested that the addition of 20% BL/PF resin was sufficient to enhance the dimensional stability, mechanical and thermal properties of SC-CTL. Thus, it is evident that the BL has the potentiality to be used as impregnant in SC-CTL through impregnation with vacuum-pressure method.

Paper production has been identified with industries that destroy forests (deforestation). Utilizing alternative wood substitute raw materials, such as pineapple leaves can be one solution to the problem. Pineapple plants can produce more than 70 leaves with cellulose content in the leaves which reaches 69.5-71.5%, so it has the potential to be used as raw material for paper. The organosolv process was chosen as a pulp manufacturing process because it produces high purity in the byproducts (lignin and hemicellulose), high pulp yield, easy recovery of black liquor and no sulfur element, making it safer for the environment. This study aims to determine the most influential factors in the organosolv pulping process with a factorial experimental design method 23. Variables used include solvent types (ethanol and acetic acid), pulp cooking time (60 minutes and 110 minutes) and types of leaf dryness (wet leaves) and dried leaves). From the results of the analysis, the most influential factor in the organosolv pulping process is the type of solvent (ethanol). Optimal operating conditions were obtained for solvent ethanol, cooking time of 60 minutes with wet leaves, where cellulose content was 96.31% and lignin content decreased by 17.80% in dry pulp.

The present study is aimed at optimizing the synthesis of Amphipilic lignin derivatives (A-LD) from the isolated lignin of A.mangium black liquor (BL), using the one and two step acid isolation method, and commercial lignin (LS) was used as comparison. The experimental design was conducted using Taguchi method, which consisted of four parameters and two level factors, with reference to the matrix orthogonal array, L8, including temperature, reaction time, amount of polyethylene glycol diglycidylethers (PEGDE) and Kraft lignin (KL). Furthermore, the kraft pulp of sweet sorghum bagasse (SSB) was used as substrate in the enzymatic hydrolysis (NREL method), with addition of A-LD, whose functional group and surface tension were then characterised using ATR-FTIR and surface tension equipment. Conversely, an improvement in the reducing sugar yield (RSY) compared to the control was observed after adding various A-LDs to the substrate during enzymatic hydrolysis. This product was more prospective for L2S than others products under milder circumstances, due to the fact that it possesses the lowest surface tension. Also, Taguchi analysis demonstrated the treatment at 60 °C for 1 h with 3.0 g and 1.0 g of PEDGE and lignin, respectively as the optimum condition, while the amount of lignin present was included as a factor with the propensity to significantly affect A-LD L1S and LS. Therefore, it was established that the A-LDs from A. mangium kraft lignin require milder synthesis conditions, compared to other existing methods and despite the differences in optimum experimental condition for L2S and LS, the functional groups in the IR spectra possessed very identical characteristics. ©2020. CBIORE-IJRED. All rights reserved

The weathering resistance properties of short cycle coconut trunk lumber (SC-CTL) were evaluated in response to impregnation using kraft black liquor (BL) and black liquor/phenol formaldehyde (BL/PF) resin. Concentrations of 10, 15, 20, and 25% w/w kraft BL and PF resin with BL were impregnated into SC-CTL using a vacuum-pressure method. Natural weathering tests lasting 6 and 12 months were performed according to ASTM D1435 (1999). After the prescribed testing period, samples were analyzed for their morphological changes via FT-IR and SEM. Mechanical tests were conducted to analyze changes caused by natural weathering in impregnated SC-CTL. The results showed that BL with PF resin impregnation into SC-CTL improved the resistance against natural weathering. The SEM study confirmed that fungi could not colonize the treated samples. The results also suggested that addition of 20% BL in PF resin was sufficient to inhibit weathering. Thus, it was concluded that impregnation of PF resin with BL is a good method to improve the mechanical properties of SC-CTL.

Blocky woodceramic electrode materials are prepared by Ni(NO3)2 catalysis and K2CO3 activation with waste poplar wood which is self-assembled with pulping black liquor lignin. The results show that the natural hierarchical pore structure of wood can be well preserved, and the activation, catalytic graphitisation, and Ni2+ doping are accomplished simultaneously in the sintering process. Meanwhile, some of the lignin which self-assembled onto the pore surface of wood and on the crystal surface of activator and catalyst is transformed into carbon nanosheet and multilayer graphene, and some present an orderly arrangement according to the original form of the crystal. Ni2+ doping not only builds the basic form of electrode but also reduces the stacks of carbon nanosheet and multilayer graphene. Meanwhile, activation can improve the pore structure, providing more channels for the storage and transmission of electrons and ions. At the current density of 0.25 A g−1, the specific capacitance of the sample can reach 150.8 F g−1.

Black liquor has caused a tremendous degree of pollution and waste. Exploring the utilization of lignin, which is the major component of black liquor, has become a key factor in dealing with the problem. In this study, lignin derived from black liquor was used as a raw material to prepare carbon materials through different activation methods including KOH, H3PO4, and steam activation. The structure and properties of obtained samples were characterized as well as electrochemical performance when applied on a lithium-oxygen battery. Results of N2 adsorption/desorption showed that all obtained samples possessed high surface area of over 1000 m2/g. XRD, Raman, and XPS also indicated that obtained samples possessed a large defect area and many functional groups. Electrochemical measurements illustrated that all obtained samples exhibited a high discharge capacity over 2.8 mAh/cm2 at 0.02 mA/cm2, while LKAC exhibited the highest discharge capacity of 7.2 mAh/cm2. Cycling tests of all obtained samples indicated a long cycle life of at least 300 cycles. LSAC maintained a 100% retention rate of capacity and stable terminal voltage even after 800th cycle, and its cycling performance was investigated further by XRD and EIS. This study demonstrated excellent performance for lignin-based carbon materials, and provided alternative materials for positive electrode of lithium-oxygen battery.

A highly functional, environmentally friendly carbonaceous adsorbent material using black liquor (a by-product from the pulp manufacturing) was produced and characterized. This study showed the effect of self-chemical activation driven by inherent alkali, originated from the unique composition of black liquor. A preparation of the micropore-dominant activated carbon was made in an easy and simple manner. The specific surface areas of samples were found to be 718–1591 m2/g variated upon heat treatment conditions. The sample activated at 850 °C (50 min as retention time) showed the maximum specific surface area of 1591 m2/g with 13.6% as a production yield. Considering the factors influencing pore structure of activated carbon materials in this study, it was confirmed that mesopore-related surface area increased gradually as the activation temperature and retention time increased. It is noteworthy to address that economically valuable micropore-dominant activated carbon can be produced by a simple heat treatment of the waste material, black liquor. The activated carbon sample derived from black liquor can be applied to various fields, such as environment and energy storage.

As the largest aromatic polymer of natural origin, lignin arouses the interest of researchers and industries worldwide. Its three-dimensional polymeric aromatic structure, besides being complex, varies depending on its botanical origin and extraction process, which makes its use as a raw material difficult. Currently, the main destination for lignin is burning for energy production. This study presents the characterization of lignin and lignin microparticles after processing by ultrasonic irradiation. Analyzes were performed to verify the dimensional, morphological and antioxidant characteristics of the particles as well as changes in their structure after sonication. A sample of eucalyptus wood lignin isolated from kraft black liquor was used and the modifications were analyzed by X-ray diffraction analysis, zeta potential, FTIR spectroscopy, particle size, scanning electron microscopy, TGA thermogravimetric analysis, phenolic compounds total by Folin–Ciocalteau and antioxidant analysis by DPPH. The results demonstrate that there was no change in the chemical structure of lignin with the application of ultrasonic radiation, but the reduction in particle size was able to reduce zeta potential with a lower probability of agglomeration between them, and consequent greater stabilization in solution. Also, the ultrasound treatment was able to increase the thermal stability of the lignin microparticle with a decrease of the mass loss rate with the time. The reduction in particle size was also able to expose a larger number of phenolic compounds and thereby increase the total phenolic content and lignin antioxidant activity making the lignin microparticle a promising material to study and application on food-active biodegradable polymers.

The present chemical converted graphene sheets are mostly dependent on the exfoliation of graphite with strong oxidants, which suffer from heavy burden of environmental pollution. Here, we report a simple, green and scalable method to synthesize graphene sheets by one-pot activation-synthesis method derived from black liquor, a biomass waste resource in pulping industry. The pulping black liquor consisting of alkali lignin as main components with phenyl skeletons and condensed aromatic segments was successively transferred from heterogeneous chemical states into micron-sized graphene sheets. The proposed conversion mechanism mainly consists of aromatic rebonding, refusion and deoxygenation reaction, in which alkaline species acting as situ-activation agent. The graphene sheets obtained from pulping black liquor (BL-G) show typical hexagonal honeycomb lattice in thickness of 1–3 atomic carbon layers with controllable lateral size ranging from 0.36 to 2.5 μm. After spin-coating single- or few-layer of BL-G sheets onto flexible substrate, it could produce transparent and conductive thin films (TCFs) with sheet resistance as low as 2.1 kΩ sq−1 and 85% transmittance for 550 nm light, suggesting its great potentials using as flexible electrode materials. This green synthesis route may pave a bright way in large-scale production of chemically converted graphene sheets.

To understand the effects and the mechanism of sodium carbonate (Na2CO3) addition on the bagasse alkaline black liquor (BABL) pyrolysis, the reaction variables such as temperature, heating rate, and amount of Na2CO3 addition into BABL-solids were investigated under N2 atmosphere from 50 °C to 1000 °C by thermogravimetic analysis (TGA). Scanning electron microscopy (SEM) and the Coats–Redfern method (CRM) were employed for surface microscopic morphology observations and kinetic analysis, respectively. The results showed that Na2CO3 plays an inhibiting and promoting role during devolatilization (200 °C to 650 °C) and the reduction stages (650 °C to 1000 °C), respectively. Adding Na2CO3 into BABL-solids tends to increase the thickness of the salt layer covering the BABL-solids surface, which increases the activation energy and reduces the weight loss ratio of BABL-solids pyrolysis within 200 °C to 650 °C. Adding Na2CO3 into the BABL-solids tends to increase the number of alkaline compounds or the active site of the reduction reaction, which reduces the activation energy and increases the weight loss ratio of BABL-solids pyrolysis within 650 °C to 1000 °C. The role of Na2CO3 as an additive could be well understood by studying the influence mechanism of Na2CO3 on BABL-solids pyrolysis.

Lignin-derived chemicals and fuel products have received much attention in the context of bio-refinery. In this study we prepared and characterized various lignin samples from black liquor (BL), a major byproduct from the pulp and paper manufacturing processes, and studied the pyrolysis behaviors of these isolated lignin samples at 600 °C under a N2 atmosphere. Three lignin samples were isolated from the Kraft pulping BL of Loblolly pine linerboard grade process (KL, obtained by direct evaporation; L10, obtained by precipitation at pH 10; L3, obtained by precipitation at pH 3), while another three were from the Kraft pulping BL of Loblolly pine bleach grade process (KB, B10, B3). The inorganic elements present in lignin samples were analyzed using an inductively coupled plasma (ICP) analyzer. The KL and KB samples contained a larger amount of inorganic elements, especially Na and S, than did the other lignin samples. Owing to large quantities of inorganic elements, the ash contents in KL and KB were highe...

Membrane fouling is the major factor limiting the wider applicability of the membrane-based technologies in water treatment and in separation and purification processes of biorefineries, pulp and paper industry, food industry and other sectors. Endeavors to prevent and minimize fouling requires a deep understanding on the fouling mechanisms and their relative effects. In this study, Brunauer-Emmett-Teller (BET) nitrogen adsorption/desorption technique was applied to get an insight into pore-level membrane fouling phenomena occurring in ultrafiltration of wood-based streams. The fouling of commercial polysulfone and polyethersulfone membranes by black liquor, thermomechanical pulping process water and pressurized hot-water extract was investigated with BET analysis, infrared spectroscopy, contact angle analysis and pure water permeability measurements. Particular emphasis was paid to the applicability of BET for membrane fouling characterization. The formation of a fouling layer was detected as an increase in cumulative pore volumes and pore areas in the meso-pores region. Pore blocking was seen as disappearance of meso-pores and micro-pores. The results indicate that the presented approach of using BET analysis combined with IR spectroscopy can provide complementary information revealing both the structure of fouling layer and the chemical nature of foulants.

A porous activated carbon (AC) was synthesized from cotton black liquor, and the synthesis process was optimized using response surface method (RSM). The AC prepared under the optimal condition was applied to the direct H2S catalytic oxidation. Complete parametrical computational fluid-dynamic (CFD) model, coupling stoichiometric reaction with variation of porosity as the user-defined scalars (UDS), was developed to simulate the removal process. Various experiments, including breakthrough, pressure drops, and H2S conversion at different experimental conditions, were carried out. The CFD model was validated by results from the experiments, as the experiment results were found to adequately match model predictions. Hence, the model developed in this study can be a useful tool for studying the fluid dynamics of H2S oxidation by AC catalyst at investigated experimental conditions.

Black liquor that contains various phenolic compounds from lignin solubilization has been the main byproduct of alkaline pretreatment of lignocellulosic biomass in the biorefinery. In this study, black liquor from alkaline pretreatment of corn stover was used as a sole carbon source for the cultivation of a marine protist, Thraustochytrium striatum. It was found that this strain can grow on black liquor and accumulate valuable products (e.g., fatty acids and carotenoids) simultaneously. Under optimal conditions (pH = 7 and NH4Cl = 2 g/L), the cell mass concentration reached 5.2 g/L with total aromatics decreased from 8.18 to 3.09 g/L within 7 day incubation. Fed-batch cultivation was adopted to increase the contents of total fatty acids and carotenoids to 13% and 0.24 mg/g dry cell mass, respectively. Although various compounds such as sugars and organic acids were detected in black liquor and consumed during microbial fermentation as carbon sources, lignin-derived compounds were identified as the major s...

As an environmentally unfriendly and low-cost by-product produced during the manufacturing of pulp and paper, ca.170 million tons of black liquor is generated per year in the world. Efforts to effectively convert black liquor into high-value products are very critical but remain challenging. Herein, we successfully prepare porous carbons using black liquor powders as precursors through a simple carbonization technique without any extra activators or templates. The black liquor-derived porous carbons (BL-PCs) exhibit a remarkable three-dimensional (3D) honeycomb-like morphology and a hierarchical porous structure. Additionally, the disordered degree of BL-PCs can be controlled by simply regulating carbonization temperature. A combination of 3D honeycomb-like morphology, hierarchical porous structure and decreased disordered degree not only contributes to the fast electrolyte ion transport, but also improves the rate performance and cycling stability when BL-PCs are used as anode materials for sodium-ion batteries. A typical BL-PC anode exhibits attractive electrochemical performances, including high rate capability and long-term cycling stability.

Hydrothermal liquefaction (HTL) and supercritical water gasification (SCWG), two effective thermochemical approaches converting biomass into biofuels, have received increasing attention due to their advantages of a fast reaction rate and the use of wet feedstocks without the need for an energy-intensive drying process. In this review, we first summarize the physical properties of the biocrude oil obtained from HTL and then examine the catalytic hydrotreatment of the biocrude oil with or without solvents. The experimental studies on the SCWG of sewage sludge, microalgae, black liquor, and food wastes are analyzed, and the corrosion and salt-deposition problems associated with the solutions are discussed. Finally, to fully comprehend the reaction mechanism of biomass components in hydrothermal media, the conversion of model compounds (cellulose, hemicellulose, lignin, lipid, protein, and their derivatives) is reviewed.

Black liquor (BL), a byproduct generated during the kraft pulping process, was used as a source of alkaline lignin (AL) to stabilize aqueous dispersions of carbon black (CB). Black liquor-treated carbon black (BL-CB) samples were prepared by varying the BL/CB/water ratio and characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) surface area. Improvement in dispersion of BL-CB with increased BL content was observed. The dope dyed viscose fibers were spun by addition of BL-CB to the viscose solution. These fibers exhibited deeper color strength than those obtained from conventional CB formulations at a comparable CB loading on the fiber.

International audience; A safe, cheap and straightforward on-demand hydrogen generation method has been developed using a polymethylhydrosiloxane (PMHS) emulsion as a hydride donor in a highly alkaline solution without the need of any other harmful catalyst. This system was used as a chemical blowing agent in the preparation of kraft black liquor foams.

The aim of this study was to investigate the properties of lignin obtained from black liquors of Scots pine (Pinus sylvestris L.) and European aspen (Populus tremula L.) woods cooked by Kraft method. In the study, the cooking process was carried out according to parameters such as: 1/4 of wood/liquor ratio, cooking temperature at (170±2) °C, and cooking time of 90 min. After the cooking process, the black liquor was taken to a beaker from the digester, and lignin was recovered in different ways from the black liquor with methyl alcohol (MeOH) and ethyl alcohol (EtOH). The material properties of the recovered lignin were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), and thermogravimetric analysis (TGA). Commercial lignin (cml-lignin) was used to compare the properties of lignin obtained from black liquor. SEM images showed that the particle sizes of lignin obtained with EtOH and MeOH were similar. In FT-IR, it was detected that the recovered lignin types have similar functional groups, while some differences were observed in intensities of the peaks. XRD results revealed that all lignin types were found to have a similar structure with the cml-lignin, and that alcohol types used during the recovery process of lignin do not have an important effect on the structural properties of lignin. The TGA results indicated that the thermal stability of recovered lignin has better thermal stability than cml-lignin. The results showed that the recovered lignin was similar to commercial lignin and that it can be recovered from the liquor leftover from Kraft pulping by the method described and used in industry., Cilj rada bio je istražiti svojstva lignina dobivenog od crnog luga drva bijelog bora (Pinus sylvestris L.) i jasike (Populus tremula L.), kuhanoga kraft metodom. Proces kuhanja u ovom je istraživanju proveden uz ove parametre: omjer drva i luga 1 : 4, temperatura kuhanja 170 ± 2 °C, vrijeme kuhanja 90 min. Nakon procesa kuhanja crni je lug premješten iz digestora u čašu te je lignin metilnim alkoholom (MeOH) i etilnim alkoholom (EtOH) na različite načine izdvojen iz crnog luga. Svojstva izdvojenog lignina analizirana su skenirajućim elektronskim mikroskopom (SEM), infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR), difrakcijom X-zraka (XRD) i termogravimetrijskom analizom (TGA). Za usporedbu svojstava lignina dobivenog iz crnog luga poslužio je komercijalni lignin (cml-lignin). SEM slike pokazale su da su veličine čestica lignina dobivenog uz pomoć EtOH i MeOH bile slične. FT-IR analizom utvrđeno je da izdvojeni tipovi lignina imaju slične funkcionalne grupe te da su se pojavile neke razlike u intenzitetu pikova. Rezultati XRD-a otkrili su da svi tipovi lignina imaju sličnu strukturu kao i cml-lignin i da vrsta alkohola upotrijebljenog tijekom procesa izdvajanja lignina nema bitan učinak na strukturna svojstva lignina. Rezultati TGA analize pokazali su da je toplinska stabilnost izdvojenog lignina bolja od toplinske stabilnosti cml-lignina. Prema rezultatima istraživanja može se zaključiti da je izdvojeni lignin sličan komercijalnom ligninu, da može biti izdvojen iz tekućine koja je preostala od proizvodnje celuloze opisanom kraft metodom te da se može rabiti u industriji.

Producción Científica, Different lignins from different sources (hardwoods, softwoods and crop residues) and obtained as by-products of different processes such pulping or biorefining were depolymerized in alkaline supercritical water (SCW: 386 °C and 260 bar) in an intensified continuous process to produce high value-added compounds with low-molecular-weight in only 300 ms of reaction time. The products obtained were analysed to determine the yield, selectivity to monomers, chemical structure and molecular weight distribution. The char formation was low in most cases, but the proportion of heavy and light oils were variable upon the starting material used. The monoaromatics yield depends mostly on the type of lignin utilized being the non-wood biorefinery lignins less suitable for monomers production than the technical wood ones (13-8%). The monomer distribution depends on the biomass of origin and the pulping method. This technology is equally effective when directly treating a black liquor and better results are obtained if compared to the corresponding isolated lignin., Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (grants CTQ2016-79777-R and PID2019-105975 GB-I00), Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (grants VA277P18 and CLU-2019-04)

In the last decade, lignin has received much attention as a feedstock to produce bio-based products. This study investigates the potential benefits of using lignin to mitigate the environmental impact of the road construction sector. An environmental life cycle assessment (LCA) of various top-layer bio-based asphalts using kraft lignin was conducted. From a cradle-to-grave perspective, lignin-based asphalts were compared with conventional asphalts. The results of the LCA revealed that the climate change impact of lignin-based asphalts could be 30–75% lower than conventional asphalts. For the other ten impact categories, trade-offs were observed. Overall, two key factors to make the environmental impact of lignin-based asphalts lower than conventional asphalts are 1) increasing the amount of bitumen-substituted and 2) using low-grade biomass fuels for process steam in the pulp mill. The substitution of weak filler with lignin was beneficial only for climate change and could lead to a worse overall environmental performance than conventional asphalts. Similarly, higher environmental impacts for lignin-based asphalts could be obtained if the pulp mill consumed natural gas to complete the energy balance to replace the part of the black liquor from which lignin is extracted. This study also includes an in-depth discussion on methodological choices such as the allocation methods for lignin, functional units, and asphalt layers considered. We believe that such a methodological discussion could be helpful to support future Product Category Rules for asphalt mixtures.

This study aimed to synthesize a composite material composed of bio-based, porous carbon matrix and Cu nanoparticles through a simple, low-cost, and environmentally friendly method. Concentrated Kraft black liquor was used as a carbon precursor, and Cu nanoparticles were homogeneously deposited on the carbon matrix using electrochemical deposition. The textural properties determined using N2 isotherms indicated increased surface area of a carbon matrix with a micro-mesoporous structure. Voltammetric tests demonstrated that the composite exhibited catalytic properties for electrochemical CO2 reduction. Compared to the bio-based, porous carbon sample (C matrix), the bio-based carbon electrode electrochemically decorated with Cu nanoparticles (C–Cu composite) exhibited increased current values of approximately 2.4 times, a potential shift of approximately 90 mV, and an onset potential of −1.02 V, under CO2 saturation.

Made available in DSpace on 2022-04-28T19:42:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This study reports an alternative method for black liquor treatment with potential for energy and process savings in the paper and pulp industry. Gasification of black liquor was carried out under sub- and supercritical conditions, varying the black liquor feed composition (0.10, 2.55 and 5.00 wb%) and temperature (350, 425 and 500 °C). Liquid products were identified by high resolution mass spectrometry (FT-Orbitrap MS) and compounds belonging to classes O3 and O4 were found to be the most representative in the products of reactions performed at 500 °C. The mass spectra results also revealed the overall selectivity of reactions, where decarboxylation and demethoxylation reactions were favored under subcritical and supercritical conditions, respectively. Among the gaseous products, hydrogen and methane were produced with maximum of 69.04 and 28.75 mol%, respectively, at 2.55 wb% and 425 °C. The proposed thermodynamic modelling of the reaction system satisfactorily predicted the gas phase behavior of the system. In the economic analysis, the simulated conditions indicated that the main energy requirements for a scaled-up black liquor gasification process are related to the necessary heat exchangers and pressurizing of the black liquor solution. Furthermore, the cost of the black liquor gasification is around 0.06 US$ per kg of feed stream. Liquid and gaseous products from gasification could be obtained at a cost of 56.64 US$ and 3.35 US$ per tonne of stream, respectively. Therefore, black liquor gasification is an interesting route for obtaining combustible gases and value-added bioproducts. Department of Chemical Engineering State University of Maringá (UEM) Petroleum and Energy from Biomass Research Group (PEB) Chemistry Department Federal University of Sergipe (UFS) Department of Chemical Engineering Federal University of Maranhão (UFMA) School of Chemical Engineering State University of Campinas (UNICAMP) Department of Energy Engineering São Paulo State University (UNESP) Department of Chemical Engineering Technological Federal University of Paraná (UTFPR) School of Engineering & Water: Effective Technologies and Tools (WETT) Research Centre RMIT University Department of Agronomy State University of Maringá (UEM) Department of Energy Engineering São Paulo State University (UNESP) CAPES: 180/2019–00 CNPq: 202519/2020–1 CAPES: 88887.338

In this work, the conventional scenario of the black liquor (BL) concentration and combustion is compared with the BL upgrading gasification process for ammonia production. The chemical processes synthesis, modeling and simulation are performed by using Aspen Plus® software. The determination of the heat recovery and the solution of the energy integration problem is handled by a mixed integer linear programming model. An incremental financial analysis incorporates the uncertainty related to the acquisition and selling costs of the feedstock and fuels produced and carbon taxation by using the Monte Carlo method. As a result, the incremental financial analysis found that only the integrated pulp and ammonia production route with partial electricity import may economically outperform the conventional kraft pulp mill for moderate carbon taxations (40-90 EUR/tCO2), depending on the interest rate adopted. In this regard, middle-to-high carbon taxations may render ammonia co-production attractive in the Brazilian context of a highly renewable electricity mix.

Reusing and establishing new purposes for the effluents generated during a given technological process is one of the biggest challenges that industries face to achieve the environmentally friendly status. Lignocellulosic biomass is one of the least used bioresources in the world, consisting chiefly of lignin, cellulose, and hemicelluloses, and could be obtained from several sources, among which are the residues from agricultural and industrial lignocellulosic crops. The cellulose extracted from these residues can be depolymerized giving rise to nanocellulose (NC), a multipurpose nanometer-scale bio-based material. Abundance, biodegradability, renewability, and low-cost, coupled with excellent mechanical properties appoint NC as one of the most promising nanometric biomaterials. Behind the polysaccharides present in the fiber, lignin is a heterogeneous natural aromatic biomacromolecule, and one of the most abundant biopolymers in nature. With proper and selective depolymerization, lignin has the potential to be converted into a broad spectrum of oxygen-containing aromatics. To extract cellulose from lignocellulosic biomass, it is essential to apply a combination of pre treatments and bleaching steps to the fibers. These procedures will help to surpass the recalcitrance presented by the lignocellulosic biomass and thus to isolate the cellulose from the remaining components. The employment of an alkaline chemical pre-treatment to remove lignin and hemicellulose constituents and other extractable materials from the biomass, generates a very dark liquor by-product (black liquor). The sequential bleaching step produces a yellowish liquor by-product. Despite the fact that black liquor is frequently used for heat and power generation, the separation and upgrading of the lignin present in the liquors can significantly enrich the process economics. Consequently, extracting lignin from these by-products can be considered a key issue in the successful development of biorefineries. Therefore, in these study, different biomasses were tested (hemp, castor bean and giant reed) for the lignocellulosic fractionation. The fiber content of these crops and their different composition, affects the composition of the residual liquors. The resultant liquors, before and after lignin precipitation and removal, were then characterized. Tests are being made to evaluate the effects of the application of the different liquors on the germination and production of crambe seeds (with high potential to be used by the oleochemical industry). Preliminary tests indicate that its application to produce biomass is valid and that the loop (Biomass production . biomass fractionation . by-products recovery . biomass production), can be closed, this way contributing to the circular economy and to a resource efficient economy., Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 406-410

Declining oil production in Indonesia lately has been much discussed by industrial practitioners, especially from the petroleum industry. The decrease is due to the age of old drilling wells with high water cut (> 90%), so it is necessary to pursue a production method that can increase the production of these old wells. The EOR (Enhanced Oil Recovery) method is one way of extracting oil from oil wells that cannot be further retrieved by injecting materials that are not in the reservoir. One ingredient that can be injected is Sodium Ligno Sulfonate (SLS) surfactant derived from lignin. Lignin was obtained from the lignin isolation process from Black Liquor, which in this study came from the pulp and paper mill waste of PT. Indah Kiat, Pekanbaru, Sumatra, Indonesia. This study aims to determine the effect of variations in H2SO4 concentrations (concentrations of 15%, 20%, 25%, 30% w/w) on the yield of lignin isolation results, and to compare the functional groups between dirty lignin, clean lignin, and pure lignin using FT-IR. Based on the research results, it was found that the best lignin is lignin with an H2SO4 concentration of 20%, with the highest yield and the color of lignin produced tends to be similar to pure lignin. In addition, it was found that the peak of the net lignin group had more similarity with commercial lignin compared to crude lignin. Keywords: Lignin, Black Liquor, Enhanced Oil Recovery (EOR), FTIR

During the wood delignification a multicomponent spent liquor (black liquor) is formed. Depending on the type of wood, black liquor is enriched with valuable extractives. The isolation of extractives from processing liquors and their conversion into biologically active substances, tall products is according to development trend of pulp and paper industry. It includes the introduction of scientific based technologies in manufacturing processes with reference to modern environmental protection requirements. Now the extraction efficiency of sulphate soap does not exceed 75–80% whereby the quality of obtained soap is low. Sulphate soap, especially extracted after hardwood cooking, contains a large amount of impurities. This complicates the process of soap treatment into valuable biologically active substances (beta-sitosterol, etc.). In the present work the addition of demulsifying and coagulating substances into the black liquor is proposed to intensify the hardwood sulphate soap extraction. The chemical colloidal characteristics of the obtained sulphate soap were investigated. Two critical micelle concentration (CMC) were found on the surface tension isotherms. The second critical micelle concentration (CMC2) in the concentration range of 0.9–1.0% CMC2 indicates the restructuring of micelles into a spherocylindrical shape. A comparative qualitative and quantitative analysis of the composition of sulfate soap obtained in industrial conditions and in the presence of selected additives in laboratory was carried out. Surfactants promote the extraction of phytosterol from black liquor obtained from hardwood species cooking. The influence of surfactant addition on the main physical and colloidal chemical characteristics of black liquor before and after isolation of sulphate soap is investigated. A decrease in viscosity and a de foaming of a black liquor solution is observed as a result of the addition of surfactant additives., При делигнификации древесины образуется черный щелок – отработанный раствор многокомпонентного состава, обогащенный ценными экстрактивными веществами, количество которых варьируется в зависимости от вида древесины. Извлечение этих веществ из производственных растворов и переработка их в биологически активные вещества, таловые продукты соответствует тенденции развития целлюлозно-бумажных предприятий – внедрению технологий, основанных на научных разработках с возможностью их технического применения, с сочетанием современных требований охраны окружающей среды. На современных предприятиях эффективность извлечения сульфатного мыла не превышает 75‒80%, при этом получают продукт невысокого качества с большим количеством посторонних примесей, особенно при выделении из отработанных щелоков после варки лиственных пород древесины. Это усложняет процесс переработки мыла, в том числе в ценные биологически активные вещества (бета-ситостерин и др.). В работе для интенсификации выделения лиственного сульфатного мыла предлагается введение деэмульгирующих и коагулирующих добавок в черный щелок. Исследованы коллоидно-химические характеристики полученного лиственного сульфатного мыла. На изотермах поверхностного натяжения обнаружены две критические концентрации мицеллообразования (ККМ). Появление ККМ2 (в области концентраций 0.9–1.0%) свидетельствует о перестроении мицелл в сфероцилиндрическую форму. Проведен сравнительный качественный и количественный анализ состава производственного сульфатного мыла и полученного в лаборатории в присутствии выбранных добавок. Введенные вещества способствуют извлечению фитостерина из черного щелока лиственных пород древесины. Рассмотрено влияние добавок ПАВ на основные физико- и коллоидно-химические характеристики черного щелока до и после отделения сульфатного мыла. В результате введения добавок ПАВ наблюдается снижение вязкости и уменьшение пенообразования раствора черного щелока.

In this work, a novel delignification process was proposed for the fractionation of invasive species such as Acacia dealbata wood. Organosolv process catalyzed with an acidic ionic liquid, 1-butyl-3-methylimidazolium hydrosulfate was evaluated to obtain cellulose-enriched solids and liquid fractions rich in hemicelluloses derived compounds and lignin. Under selected operating conditions (190 °C, 60% ethanol, 60 min of reaction time and 0.6 g 1-butyl-3-methylimidazolium hydrosulfate/g wood), high solubilization of lignin and hemicelluloses and cellulose recovery (87.5%, 88.7% and 88.3%, respectively), with a pulp yield of 43.1% were achieved. Moreover, 62.6 % of lignin was recovered by precipitation from the black liquor (composed mainly by 4.43 g xylose/L, 7.66 g furfural/L and 3.59 g acetic acid/L). In addition, enzymatic digestibility of delignified wood was also assayed. Overall, this work presents an alternative biorefinery scheme based in the use of environmentally friendly solvent and catalyst for selective fractionation of A. dealbata wood., The authors acknowledge the financial support received from the Spanish “Ministry of Economy and Competitiveness” (Project CTQ2017-82962-R) and from “Xunta de Galicia” (GRC ED431C 2018/47 and Centro Singular de Investigación Biomédica “CINBIO”). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). A. Romaní thanks BioTecNorte operation (NORTE-01–0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte., info:eu-repo/semantics/publishedVersion