• Journal of the Korean Wood Science and Technology
• /
• v.15 no.1
• /
• pp.1-11
• /
• 1987

A kraft black liquor obtained from pulping of pine (Pinus densiflora Sieb et Zucc) was used for producing three kinds of adhesive such as black liquor-phenol formaldehyde resin, methyloeated kraft lignin-phenol formaldehyde resin, and lignin cake-phenol resin. In case of producing black liquor-phenol formaldehyde resin, about 60 percent of the phenolic resin could be replaced by black liquor. Also the optimal press condition appeared to be $160^{\circ}C$ for 7 min. (l5.77Kg/$cm^2$ in dry test, 8.54Kg/$cm^2$ in 4 hr. boil test). Phenol could be substituted up to 80-90 percent by methylolated kraft lignin. The suitable conditions of factors affecting bond quality were pH to 2.6, methanol as solvent and 0.2ml formaldehyde per 1g of the adhesives, respectively. The optimal press condition was $150^{\circ}C$ for 4 min. (188.54Kg/$cm^2$ in dry test, 10.08Kg/$cm^2$ in 4 hr. boil test). In preparing lignin cake-phenol resin, a suitable mixing ratio of phenol to powered kraft lignin was one to one by weight. The optimal press condition was $150^{\circ}C$ for 4 min.(18.46Kg/$cm^2$ in dry test, 12.31Kg/$cm^2$ in 4 hr. hoil test).

• Korean Chemical Engineering Research
• /
• v.54 no.6
• /
• pp.753-761
• /
• 2016

Liquid-liquid extraction (LLE) can be used for the recovery of acetic acid from black liquor prior to bioethanol fermentation. Recovery of value-added chemicals such as acetic-, formic- and lactic acid using LLE from Kraft black liquor was studied. Acetic acid and formic acid have been reported to be strong inhibitors in fermentation. The study elucidates the effect of three reaction parameters: pH (0.5~3.5), temperature ($25{\sim}65^{\circ}C$), and reaction time (24~48 min). Extraction performance using tri-n-octylphosphine oxide as the extractant was evaluated. The maximum acetic acid concentration achieved from hydrolyzates was 69.87% at $25^{\circ}C$, pH= 0.5, and 36 min. Factorial design was used to study the effects of pH, temperature, and reaction time on the maximum inhibitor extraction yield after LLE. The maximum potential extraction yield of acetic acid was 70.4% at $25.8^{\circ}C$, pH=0.6 and 37.2 min residence time.

• Journal of the Korean Wood Science and Technology
• /
• v.51 no.1
• /
• pp.38-48
• /
• 2023

Two important steps in utilizing technical kraft lignin (KL) from black liquor to synthesize lignin-phenol-formaldehyde (LPF) resin are its extraction via precipitation and fractionation. However, the effects of precipitation pH and acetone fractionation on the characteristics of hardwood KL have not been studied for LPF resins. Therefore, this paper reports the effects of the precipitation pH of black liquor and acetone fractionation on the characteristics of KL from mixed hardwood species for LPF resins. The precipitation was conducted at various pH levels from 3 to 9 of black liquor to obtain crude KL (C-KL), which was used in acetone fractionation to produce acetone-soluble KL (AS-KL) and acetone-insoluble KL (AI-KL). Precipitation at pH 3 and 9 produced the highest and lowest yields of C-KL, respectively. As expected, the C-KL infrared spectra were similar regardless of the precipitation pH levels. As the pH increased, the molecular weight of C-KL increased. However, the molecular weight of AS-KL and AI-KL after acetone fractionation increased to a maximum of 4,170 and 47,190 g/mol at pH 7, then decreased to 3,210 and 19,970 g/mol at pH 9, respectively. The smallest molecular weights of AS-KL and AI-KL were 3,210 and 15,480 g/mol and were found at pH 9 and 3, respectively. These results suggest that both AS-KL at pH 9 and AI-KL at pH 3 have good potential as starting lignins for synthesizing LPF resins that require cross-linking for polymerization.

• Carbon letters
• /
• v.22
• /
• pp.81-88
• /
• 2017

In the present study, biomass-based lignin was extracted from industrial waste black liquor and the extracted lignin was characterized by means of attenuated total reflectance-Fourier transform infrared spectroscopy and $^1H-nuclear$ magnetic resonance spectroscopy. The extracted lignin was carbonized at different temperatures and then activated with steam at $850^{\circ}C$. The extracted lignin in powder state was transformed into a bulky carbonized lignin due to possible fusion between the lignin particles occurring upon carbonization. The carbonized and then pulverized lignin exhibits brittle surfaces, the increased thermal stability, and the carbon assay with increasing the carbonization temperature. The scanning electron microscopic images and the Brunauer-Emmett-Teller result indicate that the steam-activated carbon has the specific surface area of $1718m^2/g$, which is markedly greater than the carbonized lignin. This study reveals that biomass-based activated carbon with highly porous structure can be produced from costless black liquor via steam-activation process.

• Journal of Energy Engineering
• /
• v.5 no.2
• /
• pp.176-182
• /
• 1996

The effects of some additives (black liquor, NaOH, water and wood) on the conversion of coal and product were investigated in the lab-scale, high pressure reacting system around 375$^{\circ}C$. The addition of black liquor enhances the coal conversion yield about 38.6%, which is mainly due to NaOH in black liquor. Also, sulfur of the black liquor in coal liquefaction process evolved hydrogen sulfide, which causes the odor problem. Addition of water in coal liquefaction increased CO$_2$content in the gas phase, and low boiling range components in liquid products. Coprocessing of wood and coal at 400$^{\circ}C$ increased yield of liquid product about 8%, but higher temperature above 400$^{\circ}C$ reduced liquid product due to increase of gas products.

• Korean Chemical Engineering Research
• /
• v.60 no.1
• /
• pp.25-33
• /
• 2022

This study developed the black liquor evaporation process models using the multiple-effect-evaporator according to the number of effects to predict steam consumption. The developed models were divided into the black liquor preheating and evaporation processes, and a virtual reboiler was added to predict steam consumption. In simulation results, the steam consumption in the double-effect-evaporator was decreased by 48.9 %, and as the number of effects increased, the steam consumption was decreased. Finally, the steam consumption in the octuple-effect-evaporator was decreased by 61.2 %. Also, this study suggests a strategy for deriving the optimal number of effects in the process by analyzing the latent heat recovered from the saturated vapor produced in the multiple-effect-evaporator and the amount of saturated vapor produced by each effect.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.295-303
• /
• 2006

The pulp yield was improved by about 4.5-5% when polysulfide (PS) and anthraquinone (AQ) were added to the kraft cooking liquor (white liquor). The exchange of the black liquor with fresh white liquor further increased the yield. The highest pulp yield was obtained when the PS cooking liquor containing 70% of total active alkali (AA) and 100% of AQ was used from the beginning of the reaction and the black liquor was exchanged with fresh white liquor containing the residual 30% of AA just after temperature reached $135^{\circ}C$. There was a good correlation between kraft pulp yields of a hardwood species and the ratios of the amount of xylose to glucose (X/G ratio), liberated by an acid hydrolysis of the pulps. However, the correlation was dependent on raw material wood species. Therefore, it is required in advance to establish a correlation between the yields and X/G ratios for raw material wood species of a target pulp in order to estimate pulp yield using X/G ratio. The X/G ratios of relatively high yield pulps showed higher values than those expected from the correlation. In a mill trial, the superiority of the PS-AQ isothermal cooking (ITC) process over the kraft ITC process was confirmed by examining X/G ratio of pulps obtained. The pulp yield in the PS-AQ ITC process was estimated at about 57.0%. This yield is very high, which indicates that reaction conditions of the PS-AQ ITC process are optimal.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2008.10a
• /
• pp.13-14
• /
• 2008

In black dyeing of PET fabric, high concentrations of disperse dyes of three primary color are generally used, which leads low exhaustion level of dye and discharge of a large amount of unfixed dye into dyehouse effluent. In this study, the effect of combination ratio of dye concentration, liquor ratio, and dyeing pH on dyeing and color property of black dyed PET fabric was investigated.

• Solar Energy
• /
• v.18 no.3
• /
• pp.161-167
• /
• 1998

The effects of some additives(black liquor, wood and lignin) on the conversion of coal and product were investigated in the lab-scale, high pressure reacting system around $375^{\circ}C$. The addition of lignin to coal during liquefaction significantly increased the depolymerization of coal and enhanced the quality of the liquid products. Coprocessing of wood and coal at $400^{\circ}C$ increased yield of liquid product about 8%, but higher temperature above $400^{\circ}C$ reduced liquid product due to increase of gas products. The addition of black liquor resulted in an enhancement in coal conversion yields, however, the observed increase is lower than that obtained in the presence of NaOH because lignin present in black liquor is not very effective due to the $OH^-$ presence.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.758-767
• /
• 2014

In this study, we selected an Escherichia coli strain (E. coli MG 1655) metabolizing arabinose derived from acid hydrolyzed black liquor as a carbon source and investigated effect of organic acids (acetic acid, formic acid, and lactic acid) presented in black liquor on growth of the E. coli MG 1655. We measured growth of E. coli MG 1655 under various concentration of each and combined three kinds of organic acids. The E. coli MG 1655 shows tolerance to acetic acid, lactic acid and formic acid at these concentrations ($1.0g/{\ell}$ acetic acid, $1.2g/{\ell}$ lactic acid and $0.8g/{\ell}$ formic acid, respectively), but displays some growth retardation over $1.5g/{\ell}$ acetic acid, lactic acid $2.0g/{\ell}$, and formic acid $1.2g/{\ell}$, respectively. In addition, formic acid was shown to be a critical factor affecting growth of the E. coli MG 1655 in the presence of three kinds of organic acids. These results indicate that the inhibitors should be removed at least $1.0g/{\ell}$ of acetic acid, $1.2g/{\ell}$ of lactic acid, $0.8g/{\ell}$ of formic acid for normal cell growth required for high yield fermentation. In addition, there is a need to construct recombinant strains that may be resistant to the same or higher organic acids concentration (> $1.2g/{\ell}$) in the growth.