Studies on the Lignin of Eucalyptus regnans I. Thiolignin

1948 ◽  
Vol 1 (1) ◽  
pp. 112
Author(s):  
FN Lahey ◽  
JWT Merewether
Keyword(s):  
Acetic Anhydride ◽  
Pure State ◽  
Dimethyl Sulphate ◽  
Black Liquor ◽  
Eucalyptus Regnans ◽  
Kraft Process

By pulping Eucalyptus regnans by the kraft process, acidifying the black liquor, and fractionating the product, a thiolignin has been prepared in a pure state. Thiolignin reacts with diazomethane to yield a trimethyl derivative, and with dimethyl sulphate to yield a hexamethyl derivative. Thiolignin, trimethylthiolignin, and hexamethylthiolignin react with acetic anhydride in pyridine to yield respectively hepta-, tetra-, and mono-acetyl derivatives. The data obtained are consistent with the formula C52H35O10.(OCH3)9.C(CH3)OH.(CHOH)3.CH = C(OH).OH.SH.

Studies on the Lignin of Eucalyptus regnans. III. The Isolation of an Alkali Lignin from Sulphate Pulping

1949 ◽  
Vol 2 (1) ◽  
pp. 117
Author(s):  
JWT Merewether
Keyword(s):  
Acetic Anhydride ◽  
Alkaline Hydrolysis ◽  
Empirical Formula ◽  
Benzoyl Chloride ◽  
Dimethyl Sulphate ◽  
Hydroxyl Groups ◽  
Equivalent Weight ◽  
Eucalyptus Regnans ◽  
Alkali Lignin ◽  
Hydrolysis Of

An alkali lignin containing no sulphur has been obtained as a by-product from the sulphate pulping of Eucalyptus regnans. Like other alkali lignins it contains hydroxyl groups, both acidic and alcoholic, as well as methoxyl groups. Acetic anhydride in pyridine yields an octoacetyl derivative which is readily hydrolysed by boiling water to a heptacetyl derivative. In pyridine, benzoyl chloride yields an octobenzoyl derivative while in aqueous alkali it yields a hexabenzoyl compound. Dimethyl sulphate yields a heptamethyl alkali lignin, diazomethane a hexamethyl derivative, while cold alkaline hydrolysis of the latter gives a pentamethyl derivative, and hot alkaline hydrolysis yields an anhydrotrimethyl alkali lignin. One of the methoxyl groups formed by methylation is unstable to acetylation by acetic anhydride in pyridine, heptamethyl alkali lignin yielding a hexamethyldiacetyl derivative, hexamethyl alkali lignin a pentamethyltriacetyl derivative, pentamethyl alkali lignin a tetramethyltetracetyl derivative, and anhydrotrimethyl alkali lignin the corresponding anhydrodimethyltetracetyl alkali lignin. Triphenylchloromethane in pyridine yields a monotrityl derivative.p-Nitrophenylhydrazine gives a di-p-nitrophenylhydrazone and phenylhydrazine a phenylhydrazone-osazone. Potentiometric titration shows two points of inflection and an equivalent weight of 863. The data are consistent with the empirical formula C92Hl04O34(1754) or C73H54O9,(OCH3)14,(OH)3,C(OH),CO-CH20H,C0,COOH

Brownstock washing: A review of the literature

TAPPI Journal ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 9-19 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART
Keyword(s):  
High Efficiency ◽  
Black Liquor ◽  
Material Balance ◽  
Kraft Pulping ◽  
Wash Water ◽  
Pulp Fibers ◽  
Kraft Process ◽  
Cooking Process ◽  
Materials Used ◽  
Entrapped Air

Brownstock washing is a complex, dynamic process in which dirty wash water or weak black liquor (dissolved organic and inorganic material obtained from the pulp cooking process) is separated from pulp fibers. The use of material balance techniques is of great importance to identify potential problems and determine how well the system is operating. The kraft pulping industry was the first known to combine pulp washing with the recovery of materials used and produced in the wood cooking process. The motivation behind materials recovery is economic, and more recently, environmentally driven. The chemicals used in the kraft process are expensive as compared to those used in the sulfite process. For the kraft process to be economically viable, it is imperative that a very high percentage of the cooking chemicals be recovered. To reach such high efficiency, a variety of washing systems and monitoring parameters have been developed. Antifoam additives and processing aids have also played an important role in increasing washing effectiveness. Antifoam materials help attain washing effectiveness by preventing entrapped air from forming in the system, which allows for an easier, unimpeded flow of filtrate through the screens and washers.

Investigation of acid hydrolysis for carbohydrate analysis in kraft black liquor

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Silvia Maitz ◽  
Marlene Kienberger
Keyword(s):  
Acid Hydrolysis ◽  
High Performance ◽  
Degradation Products ◽  
Black Liquor ◽  
Amperometric Detection ◽  
Kraft Process ◽  
Kraft Black Liquor ◽  
Carbohydrate Degradation ◽  
Reliable Detection ◽  
Hydrolysis Of

Abstract Black liquor (BL) from the kraft process is considered a promising feedstock for several biorefinery scenarios. Besides lignin and carboxylic acids, this liquor also contains hemicelluloses and their degradation products. A simple and reliable detection of those is of importance for further processing of the liquor. The present paper presents a thorough investigation of quantitative analysis of carbohydrates, by performing acid hydrolysis experiments with a concentrated BL sample of 44% total dry solids. The hydrolysates were then analysed for the four monosaccharides arabinose, xylose, galactose and glucose, by high performance ion chromatography (HPIC) with pulsed amperometric detection. The amount of sulphuric acid needed for complete hydrolysis of the carbohydrates was determined in the range of 3.5–5 mol kg−1 of BL. A lower acid concentration led to insufficient liberation of galactose and glucose, while higher acid concentrations led to degradation of arabinose and xylose. The carbohydrate degradation was also investigated over time for different dilutions and hydrolysis temperatures. These experiments confirmed that the hexoses require considerably harsher conditions for complete liberation compared to xylose and arabinose. The use of internal recovery standards (RSs) was tested; the highest recoveries were obtained by direct spiking of the samples with the RS prior to hydrolysis.

Studies on the Lignin of Eucalyptus regnans. IV. Alkali Lignin

1949 ◽  
Vol 2 (4) ◽  
pp. 600
Author(s):  
JWT Merewether
Keyword(s):  
Empirical Formula ◽  
Black Liquor ◽  
Hydroxyl Groups ◽  
Eucalyptus Regnans ◽  
Alkali Lignin ◽  
Active Methylene ◽  
Methylene Group ◽  
Alcoholic Hydroxyl ◽  
Soluble Alkali

By pulping Eucalyptus regnans using the soda process and acidifying the black liquor a crude alkali lignin has been isolated. This has been separated into two fractions, dioxan-ether insoluble alkali lignin-A and dioxan-ether soluble alkali lignin-B. A series of derivatives has been made from each. The data for alkali lignin-A are consistent with the empirical formula C68H78O27, containing nine methoxyl. groups, three acidic, and four alcoholic hydroxyl groups, one of which is tertiary, one carbonyl, and one active methylene group. Alkali lignin-B has been found to be identical with the alkali lignin previously isolated from sulphate black liquor.

Integrative Chemistry toward Biosourced SiC Macrocellular Foams Bearing Unprecented Heat Transport Properties

2014 ◽  
Vol 1621 ◽  
pp. 209-214
Author(s):  
Simona Ungureanu ◽  
Marc Birot ◽  
Gérard Vignoles ◽  
Christophe Lorette ◽  
Gilles Sigaud ◽  
...  
Keyword(s):  
Transport Properties ◽  
Heat Transport ◽  
Lignin Content ◽  
Black Liquor ◽  
Paper Mill ◽  
Low Grade ◽  
Kraft Process ◽  
Composite Foams ◽  
Heat Transport Properties ◽  
First Time

ABSTRACTBlack liquor is a by-product of the paper mill Kraft process that deserves more valorization than its present use as low-grade fuel. In this work, SiC/C composite foams were prepared for the first time from concentrated emulsions by carbothermal reduction of bio-sourced precursors combining sodium silicate by lignin at 1400°C. The composition of the materials was determined by XRD, FTIR and Raman analyses. Their porous structure was characterized by SEM, mercury intrusion porosimetry, and nitrogen sorption, while their thermal properties were measured by TGA and dynamic DSC. Concerning their heat transport properties, we found out that when the starting lignin content was increased, the final C/Si ratio, the specific surface area and the heat diffusivity increased as well. Its high values were attributed to a cooperative effect between radiative heat transfer and the presence of partially graphitized carbon.

Studies on the Lignin of Eucalyptus regnans F. Muell. V. Ethanol Lignin

1953 ◽  
Vol 6 (1) ◽  
pp. 44
Author(s):  
JWT Merewether
Keyword(s):  
Molecular Weight ◽  
Acetic Anhydride ◽  
Hydrogen Chloride ◽  
Benzoyl Chloride ◽  
Aqueous Alkali ◽  
Carbonyl Groups ◽  
Equivalent Weight ◽  
Eucalyptus Regnans

Lignin has been isolated from Eucalyptus regnans F. Muell. by refluxing with ethanolic hydrogen chloride, and the product separated into an ether-insoluble ethanol lignin-A and an ether-soluble ethanol lignin-B. Ethanol lignin-A has an equivalent weight of 1400 and, on the assumption that the molecular weight is of this order, contains two ethoxyl and nine methoxyl groups. Acetic anhydride and benzoyl chloride in pyridine yield respectively a hepta-acetate and heptabenzoate, while benzoyl chloride in aqueous alkali yields a pentabenzoate. Diazomethane yields a dimethyl derivative which gives a penta-acetate on acetylation. Schotten-Baumann benzoylation of this dimethyl derivative yields a dibenzoate. Two carbonyl groups are present, as shorn by the formation of a bisphenylhydrazone and a bis-p-nitrophenylhydrazone. The data are consistent with the formula C59H38O10(OC2H5)2(OCH3)9(OH)7.

Stabilization, degradation, and dissolution behavior of Scots pine polysaccharides during polysulfide (K-PS) and polysulfide anthraquinone (K-PSAQ) pulping

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1049-1058 ◽  
Author(s):  
Markus Paananen ◽  
Stella Rovio ◽  
Tiina Liitiä ◽  
Herbert Sixta
Keyword(s):  
Scots Pine ◽  
Black Liquor ◽  
Kraft Pulping ◽  
Cooking Time ◽  
Dissolution Behavior ◽  
Pulp Yield ◽  
Yield Increase ◽  
Ion Concentrations ◽  
Kraft Process ◽  
Diffusion Phenomena

Abstract The behavior of Scots pine (Pinus sylvestris L.) polysaccharides was studied during modified kraft pulping processes of wood meal by polysulfide (K-PS) and polysulfide anthraquinone (K-PSAQ) at the hydroxide ion concentrations of 0.50 and 1.55 M [OH-] with a high liquor-to-wood (L/W) ratio of 200. The high L/W ratio was selected for avoiding diffusion phenomena and to be able to focus on the chemistry of polysaccharides. A comparison with the kraft process reference at 160°C revealed a substantial increase in pulp yield (6–7% in K-PS pulping and 7.5–10.5% in K-PSAQ pulping) mainly attributed to galactoglucomannan (GGM) stabilization. Due to the rapid delignification rate at 1.55 M [OH-] concentration, the temperature could be lowered from 160°C to 130°C without a notable prolongation of cooking time. In K-PS pulping at 130°C, no additional GGM stability was observed compared to 160°C, whereas cellulose and arabinoxylan preservation was improved. In K-PSAQ pulping, GGM preservation was also significantly improved. At 130°C, pulp yield increase of approximately 8% in PS pulping and more than 11% in PSAQ pulping was observed. The amount of dissolved softwood hemicelluloses in black liquor was significantly increased at the higher [OH-] level and even further in the presence of PS and AQ. Simultaneously, the formation of hydroxy acids was decreased, indicating a significant stabilization of the dissolved polysaccharide fraction parallel to the pulp polysaccharides.

Black Liquor Gasifier/Gas Turbine Cogeneration

1998 ◽  
Vol 120 (3) ◽  
pp. 442-449 ◽  
Author(s):  
S. Consonni ◽  
E. D. Larson ◽  
T. G. Kreutz ◽  
N. Berglin
Keyword(s):  
North America ◽  
Gas Turbine ◽  
Performance Modeling ◽  
Black Liquor ◽  
Environmental Safety ◽  
Pulp And Paper ◽  
Generation Rate ◽  
Paper Production ◽  
Cost Benefits ◽  
Kraft Process

The kraft process dominates pulp and paper production worldwide. Black liquor, a mixture of lignin and inorganic chemicals, is generated in this process as fiber is extracted from wood. At most kraft mills today, black liquor is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MWfuel (or 0.5 million tonnes of dry solids per day), with nearly 50 percent of this in North America. The majority of presently installed Tomlinson boilers will reach the end of their useful lives during the next 5 to 20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifier/gas turbine cogeneration promises higher electrical efficiency, with prospective environmental, safety, and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modeling of gasifier/gas turbine cogeneration systems using different black liquor gasifiers modeled on proposed commercial designs.

scholarly journals Black Liquor-Gasifier/Gas Turbine Cogeneration

1997 ◽  
Author(s):  
Stefano Consonni ◽  
Eric D. Larson ◽  
Niklas Berglin
Keyword(s):  
North America ◽  
Gas Turbine ◽  
Performance Modeling ◽  
Black Liquor ◽  
Environmental Safety ◽  
Pulp And Paper ◽  
Generation Rate ◽  
Paper Production ◽  
Cost Benefits ◽  
Kraft Process

The kraft process dominates pulp and paper production worldwide. Black liquor, a mixture of lignin and inorganic chemicals, is generated in this process as fiber is extracted from wood. At most kraft mills today, black liquor is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MWfuel (or 0.5 million tonnes of dry solids per day), with nearly 50% of this in North America. The majority of presently-installed Tomlinson boilers will reach the end of their useful lives during the next 15 to 20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifier/gas turbine cogeneration promises higher electrical efficiency, with prospective environmental, safety, and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modeling of gasifier/gas turbine cogeneration systems using different black liquor gasifiers modeled on proposed commercial designs.

Effect of Ash Addiction on the Rheological and Thermal Behavior of the Black Liquor Resulting from CENIBRA's Kraft Process

2015 ◽  
Vol 7 (6) ◽  
pp. 1921-1934
Author(s):  
Euler Túlio dos Santos ◽  
Humberto L. dos Santos ◽  
Luana D. L. Guerra ◽  
José Márcio Q. Moreira ◽  
Nariella Diniz ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Black Liquor ◽  
Kraft Process
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