Use Of Black Liquor Research Articles

Sustainability and circularity assessment of the potential of a biofuel produced from black liquor as a substitute for conventional fuels

The European Bioeconomy Strategy aims to accelerate the deployment of a sustainable European bioeconomy to maximize its contribution to the 2030 Agenda and its Sustainable Development Goals (SDGs), as well as to the Paris Agreement on climate change. In this context, transport is considered as a key sector, with aviation and shipping playing an important role due to the need to meet its huge demand. In order to reduce potential emissions from the transport sector, the use of biofuels could be considered as a solution. However, with the aim of using biofuels to replace conventional fuels, it is important to assess their cost-effectiveness and feasibility, and in this aspect the valorization of waste streams for their production could help to meet this challenge. This is the framework of this research report, which is based on the use of black liquor (BL) from pulp and paper production to produce biofuel through a hydrothermal liquefaction (HTL) unit. Three technological designs and production capacities were considered: full extraction of the oil phase and its upgrading by catalytic hydrothermal deoxygenation (Scenario 1, S1), partial extraction of the oil phase (Scenario 2, S2) and full extraction but without upgrading (Scenario 3, S3). Low (100 t/d), medium (300 t/d) and high (600 t/d) production capacities were regarded.From the modelling data, a life cycle perspective was adopted, taking into account both the environmental analysis (LCA) and the life cycle costs (LCC), as well as the circular potential using different performance, resource-flow circularity and economic indicators. In addition, a composite indicator, CILCA-LCC-CA, has been proposed to obtain a single score taking into account the three assessments: environmental, cost and circularity. The results obtained show that S3, with a production of 300 t/d, has the lowest environmental impact and the highest profitability corresponds to a capacity of 600 t/d. In terms of circularity, S3 also shows the best performance, mainly due to its higher resource productivity and lower energy intensity. These results are in line with those obtained for the composite indicator, and also show that higher production capacities and a simple but efficient process technology, such as S3, is the alternative with the highest potential for both sustainability and circularity.

Exergoeconomic assessment of a cogeneration pulp and paper plant under bi-operating modes

In the current study, the exergoeconomic analysis of a cogeneration pulp and paper plant under bi-operating modes at different environment temperatures of 290, 295, 305, 310, and 320 K was investigated. Two operating modes of the cogeneration system, i.e., a hybrid operating mode using a power boiler and a recovery boiler and a singular operating mode using a power boiler only, were considered. Natural gas was utilized as the main fuel in the power boiler, while black liquor with heavy fuel oil was employed in the recovery boiler. The total capital investment, total operating, exergy, unit exergy, and exergy destruction costs for each operating mode were evaluated. The results indicated that the total capital investment cost was 3420.27 $/h, and the total capital investment and the operation and maintenance costs in the hybrid and singular modes were 5853.27 and 6226.67 $/h, respectively. As well, the unit exergy cost and the exergy cost of steam introduced by the power boiler were 39.31 $/MWh and 2503.69 $/h, respectively. Where these values for the recovery boiler were 34.69 $/MWh and 554.30 $/h, respectively. Furthermore, the exergy destruction costs at an environment temperature of 320 K for the power and recovery boilers were 1436.6 and 213.63 $/h, respectively. In the hybrid mode, the soda at a 10% concentration was recovered, with a rate of 32 t per hour desired for the cooking process in the pulp mill. In addition, the use of black liquor as a bio-fuel in the recovery boiler saved 14% of the consumption of natural gas.

Characteristics of liquid waste from biopulping of oil palm empty fruit bunches using black liquor

Biopulping is a process that is carried out before fiber ripening using chemicals in the pulp ripening process. The use of black liquor in the biopulping process can reduce pollution due to chemicals. This study aims to determine the effect of black liquor on the characteristics of liquid waste biopulping oil palm empty fruit bunches (OPEFB). Observations made include BOD5, COD, TSS, and pH. This study used a completely randomized research design with three replications. The research data were analyzed using the F test. If different, it was continued with Duncan’s test at 5%. The results showed that black liquor in the OPEFB biopulping process significantly affected BOD5, COD, and pH but had no significant impact on TSS. The resulting waste still needs to be processed because it exceeds the maximum waste generated from the pulp mill based on the Decree of the State Minister of the Environment (KEP 51-/MENLH/10/1995).

Pretreatment of sugarcane bagasse with dilute citric acid and enzymatic hydrolysis: Use of black liquor and solid fraction for biogas production

This study evaluated the pretreatment of sugarcane bagasse (SCB) with dilute citric acid solution for biogas production. The black liquor (BL) from pretreatment and residual solid fraction (RSF) obtained after enzymatic hydrolysis were used as substrates for the biogas production. After saccharifications of the pretreated solid fractions performed with Cellic® CTec 3 cocktail, the highest concentration of total reducing sugars (TRS) was in the range of 10.7–184.8 g L−1 and the sugar yields were in the range of 3.5–88.8%. For BL, the contents of glucose, xylose, and arabinose were in the range of 1.9–8.9 g L−1, 4.0–24.7 g L−1, and 0.2–5.4 g L−1, respectively. Biogas production from BL and RSF resulted, respectively, in maximum values of 563.6 and 57.8 NmL gCOD−1, indicating the feasibility of using dilute citric acid pretreatment coupled to biogas production in biorefineries. Brief energy and economic assessment were carried out considering the energy balance (thermal energy generated by burning biogas - thermal energy spent in the pretreatment), as well as revenue from a possible sale of electricity generated in a combined heat and power system.

Flexible polyurethane foams produced from industrial residues and castor oil

This study presents the development and characterization of polyurethane foams synthesized with biopolyols obtained using an industrial residue, the black liquor (BL), and glycerol (GL), in two grades of purity: high purity (P.A.), and crude (blond) from biodiesel production. For the biopolyol synthesis, GL with different purity grades and BL (0 and 15 wt.%) were reacted with castor oil. The glycerolysis with BL was performed without the use of catalyst due to the high basicity of black liquor, which was used without prior purification, reducing the use of chemical inputs. The biopolyols produced were characterized and applied to obtain polyurethane foams (PUFs) using water as a chemical blowing agent. The foams were evaluated by Fourier transform infrared spectroscopy, scanning electron microscope, apparent density, insoluble fraction, thermogravimetric analysis and mechanical resistance. The results showed that the biopolyol source and amount of blowing agent influenced the morphology of the foam, and therefore, the mechanical behavior of the polymeric material. The biopolyol produced with the black liquor and glycerol P.A. (BP-1) presented the highest hydroxyl index (593 mg KOH/g) and the foams obtained showed apparent densities in the range of 14.6–75.9 kg/m³. Thereby, this work has shown that it is possible to prepare biopolyols that can be used in the production of polyurethane foams from the use of black liquor and other renewable materials.

Potential use of black liquor as lignin source for synthesis of polyurethane foam

This study was conducted to recover lignin from black liquor for synthesis of lignin-based polyurethane foam (LPUF). To do so, lignin was precipitated from black liquor through acid precipitation at different pH values. The precipitated lignin samples were characterized by mid-infrared spectroscopy (MIR), thermogravimetric analysis (TGA), proton nuclear magnetic resonance (1H-NMR), and ultraviolet–visible (UV–Vis) spectroscopy (UV–Vis) techniques. After that, lignin sample with higher purification and lower molecular weight was selected for preparation of lignin polyol. Then, microwave-assisted liquefaction was employed to liquefy lignin sample. The obtained lignin polyol was used successfully to synthesize LPUF samples in different 4, 4′-diphenylmethane diisocyanate (MDI) indexes. The effect of MDI index on properties of LPUF samples was investigated through MIR, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and compressive strength tests. The results demonstrated that MDI content could change morphology of the prepared LPUF samples and caused reduction of cell size and more regularity of cellular structure. Also, thermal and mechanical properties of LPUF samples were found to be influenced by MDI index.

WITHDRAWN: Use of Black Liquor from paper mill waste outperforms Alkali Solution for Enhanced Oil Recovery in core samples from the Upper Assam Basin

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Size-Controlled and Super Long-Term Stable Lignin Nanospheres through a Facile Self-Assembly Strategy from Kraft Lignin.

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.

A heat- and mass-integrated design of hydrothermal liquefaction process co-located with a Kraft pulp mill

This paper aims to establish a new standard process for heat and mass integration of hydrothermal liquefaction, co-located with an existing Kraft pulp mill, to produce bio-crude. Hydrothermal liquefaction is an energy-intensive process that operates at high temperature and pressure and produces a biocrude similar to conventional crude oil. The key advantages of installing hydrothermal liquefaction in proximity with a Kraft Mills enables the use of black liquor as a feed to hydrothermal liquefaction, asset repurposing and optimisation, as well as supply chain and logistics integration. This work follows a design process to increase the energy efficiency of the hydrothermal liquefaction process by using an iterative mass and heat integration procedure to optimise mass and energy flows and assets of the hydrothermal liquefaction process. The method uses process simulation tools, Pinch Analysis, heat exchanger network design tool, and the understanding of the process constraints to develop a heat exchanger network for the hydrothermal liquefaction process with maximum energy recovery, minimum number of units and enhanced mass integration. The number of heat exchangers in the network reduced from 14 to 7 when the proposed method was applied. Substituting bio-crude from the new integration hydrothermal liquefaction process for conventional fuels has the potential to decarbonise transport fuels by 11.3 kg CO2-e/GJ of fuel.

Building a Bridge from Papermaking to Solar Fuels.

Black liquor, an industrial waste product of papermaking, is primarily used as a low-grade combustible energy source. Despite its high lignin content, the potential utility of black liquor as a feedstock in products manufacturing, remains to be exploited. Demonstrated here in is the use of black liquor as a primary feed-stock for synthesizing graphene quantum dots that exhibit both up-conversion and photoluminescence when excited using visible/near-infrared radiation, thereby enabling the photosensitization of ultraviolet-absorbing TiO2 nanosheets. In addition, these graphene quantum dots can trap photo-generated electrons to realize the effective separation of electron-hole pairs. Together, these two processes facilitate the solar-powered generation of H2 from H2 O, and CO from H2 O-CO2 , using broadband solar radiation.

Building a Bridge from Papermaking to Solar Fuels

AbstractBlack liquor, an industrial waste product of papermaking, is primarily used as a low‐grade combustible energy source. Despite its high lignin content, the potential utility of black liquor as a feedstock in products manufacturing, remains to be exploited. Demonstrated here in is the use of black liquor as a primary feed‐stock for synthesizing graphene quantum dots that exhibit both up‐conversion and photoluminescence when excited using visible/near‐infrared radiation, thereby enabling the photosensitization of ultraviolet‐absorbing TiO2 nanosheets. In addition, these graphene quantum dots can trap photo‐generated electrons to realize the effective separation of electron‐hole pairs. Together, these two processes facilitate the solar‐powered generation of H2 from H2O, and CO from H2O–CO2, using broadband solar radiation.

Micellar-polymer for enhanced oil recovery for Upper Assam Basin

One of the major enhanced oil recovery (EOR) processes is chemical flooding especially for the depleted reservoirs. Chemical flooding involvesinjection of various chemicals like surfactant, alkali, polymer etc. to the aqueous media. Bhogpara and Nahorkatiya are two depleted reservoirs ofupper Assam basin where chemical flooding can be done to recover the trapped oil that cannot be recovered by conventional flooding process.Micellar-polymer (MP) flooding involves injection of micelle and polymer to the aqueous phase to reduce interfacial tension and polymer is addedto control the mobility of the solution, which helps in increasing both displacement and volumetric sweep efficiency and thereby leads to enhancedoil recovery. This work represents the use of black liquor as micelle or surfactant that is a waste product of Nowgong Paper Mills, Jagiroad, Assam,which is more efficient than the synthetic surfactants. The present study examines the effect of MP flooding through the porous media of twodepleted oil fields of upper Assam basin i.e. Bhogpara and Nahorkatiya for MP EOR. This work also compares the present MP flood with the earlierwork done on surfactant (S) flooding. It was experimentally determined that the MP flood is more efficient EOR process for Bhogpara andNahorkatiya reservoirs. The study will pertain to the comprehensive interfacial tension (IFT) study and the displacement mechanism inconventional core samples.

Adsorption and separation of black liquor-derived phenol derivatives using anion exchange resins

Abstract Kraft black liquor is the major waste stream of the paper pulping industry. This stream is usually directly incinerated in such facilities for energy production and recycling of the inorganic chemicals involved. However, lignin and other low molecular organic fragments dissolved in black liquor give rise to a large variety of aromatic fine chemicals. Energetic use of black liquor and its components prevents the removal of these valuable compounds from the waste stream. We present an easy protocol for adsorption and selective desorption of low molecular phenol derivatives from black liquor depending on the composition of the desorption system. Furthermore, adsorption experiments in model systems provide a rationale for the selectivity of the desorption process. The described process represents a powerful technique for combination of adsorption of low molecular phenols derivatives from alkaline waste streams and online separation of the desired products with respect to their molecular structure.

Micellar-polymer for enhanced oil recovery for Upper Assam Basin

Abstract One of the major enhanced oil recovery (EOR) processes is chemical flooding especially for the depleted reservoirs. Chemical flooding involves injection of various chemicals like surfactant, alkali, polymer etc. to the aqueous media. Bhogpara and Nahorkatiya are two depleted reservoirs of upper Assam basin where chemical flooding can be done to recover the trapped oil that cannot be recovered by conventional flooding process. Micellar-polymer (MP) flooding involves injection of micelle and polymer to the aqueous phase to reduce interfacial tension and polymer is added to control the mobility of the solution, which helps in increasing both displacement and volumetric sweep efficiency and thereby leads to enhanced oil recovery. This work represents the use of black liquor as micelle or surfactant that is a waste product of Nowgong Paper Mills, Jagiroad, Assam, which is more efficient than the synthetic surfactants. The present study examines the effect of MP flooding through the porous media of two depleted oil fields of upper Assam basin i.e. Bhogpara and Nahorkatiya for MP EOR. This work also compares the present MP flood with the earlier work done on surfactant (S) flooding. It was experimentally determined that the MP flood is more efficient EOR process for Bhogpara and Nahorkatiya reservoirs. The study will pertain to the comprehensive interfacial tension (IFT) study and the displacement mechanism in conventional core samples.

Using Black Liquor from the Soda Pulping Process for Protein Production by Candida utilis

Black liquor produced from pulping with a high value of chemical oxygen demand (COD) and biological oxygen demand (BOD) is highly harmful if discharged into the environment directly. One possible way to decrease the damage to the soil and water is to reuse the organic substances contained in it to cultivate yeasts for producing single-cell proteins (SCP) while reducing the COD. With this in mind, this study is devoted to treatment technology and the comprehensive utilization of black liquor. Various parameters were evaluated, and the COD of black liquor, initial pH, and nitrogen sources had significant influences on biomass and crude protein production. The research resulted in the maximum values of COD removal rate and crude protein production with 78.78 ±3.21% and 1.18 ±0.02 g/L achieved, respectively, under the optimized condition of black liquor concentration (60%), the recruitment of urea (0.5 g/L), initial pH (6.0), temperature (34 °C), shaking speed (180 rpm), and incubation time (36 h). Furthermore, this study provided a potential viable treatment of black liquor and revealed a feasible way to make full use of black liquor for the economical production of SCP.

Charge Storage Capacity of Renewable Biopolymer/Conjugated Polymer Interpenetrating Networks Enhanced by Electroactive Dopants

Renewable materials are requested for large scale electrical storage, a coming necessity with the growth of intermittent solar and wind renewable electricity generation. Biopolymers are a source of inexpensive materials, in particular through the use of black liquor from paper production, a waste product. Interpenetrating networks of the biopolymer lignosulfonate (Lig) and conjugated polymer polypyrrole (Ppy) are synthesized by galvanostatic polymerization from pyrrole/lignosulfonate mixture in acidic aqueous electrolyte. Methoxy and phenolic functional group present in the non‐conducting lignosulfonate are converted to quinone groups. The redox chemistry of quinones is used for charge storage, along with charge storage in polypyrrole. A large variation of the electrochemical activity between lignosulfonates obtained from different sources is observed. The charge storage capacities are significantly enhanced by also including another electroactive dopant, anthraquinone sulfonate (AQS). AQS redox peaks act as an internal reference (standard) to probe the redox electrochemistry of Lig. The synthesized Ppy(Lig) and Ppy(Lig‐AQS) electrodes are characterized by cyclic voltammetry, galvanostatic charge‐discharge cycling, electrochemical quartz crystal microbalance, and atomic force microscopy.

Paper and Paperboard Demand and Associated Carbon Dioxide Emissions in Asia Through 2050

SummaryThis study estimated paper and paperboard demand, pulpwood demand, and carbon dioxide (CO2) emissions from production of paper and paperboard through 2050 in ten Asian countries. Under scenarios of varying population, gross domestic product (GDP), and per capita paper and paperboard demand, we analyzed the relationship between economic growth and consumption of paper and paperboard. We also evaluated options to reduce CO2 emissions through increased use of black liquor, waste paper pulping, and wood chemical pulping, as well as improvements in pulp, paper, and paperboard production technology. The quadratic curve model (inverted U) for per capita consumption of paper and paperboard against per capita GDP resulted in significant regression coefficients and higher adjusted R2 values than linear and logarithmic curve models for all uses of paper and paperboard. The estimated paper and paperboard demand in the ten countries in 2050 ranged from 112% (328%) to 156% (454%) of total 2005 consumption for the world (for the ten Asian countries). Of this estimated paper and paperboard demand, China accounted for about 50% and India 20%. The estimated pulpwood demand in these ten countries in 2050 ranged from 13% (48%) to 21% (84%) of global (ten country) 2005 wood supply potential. The introduction or increase of the use of black liquor, waste paper pulping, the combination of wood chemical pulping and black liquor, and technological improvements produced CO2 reductions of 24%, 5%, 32%, and 25%, respectively, compared to 2050 emission levels in the no‐measure (unadjusted) option, assuming sustainable forest management.

Thermal Degradation of Alkaline Black Liquor from Wheat Straw. 2. Fixed-Bed Reactor Studies

The usual problems experienced with common recovery boilers are aggravated in processes involving alkaline black liquor derived from straw. The consequent need to develop alternative processes for the use of black liquor for energy purposes, such as pyrolysis or gasification, requires a good understanding of the thermochemical behavior of this substance. There is, however, little information available. Part 1 of this work (Gea, G.; Murillo, M. B.; Arauzo, J. Ind. Eng. Chem. Res. 2002, 41, 4714), therefore, studied the thermal degradation of alkaline black liquor from straw in a thermogravimetric system. The present work also focuses on its pyrolysis. In particular, the influence has been analyzed of the final pyrolysis temperature (250−900 °C) and the heating rate (5−30 °C/min) on the product yields, gas composition, and specific surface area of the resulting char in a fixed-bed reactor. The results obtained show that both the energy recovery and the specific surface area of the char increase with a rise ...