Hydrocracking of organocell lignin for phenol production

Meier, Dietrich; Berns, J.; Faix, O.; Balfanz, U.; Baldauf, W.

doi:10.1016/0961-9534(95)92632-i

Cited by 49 publications

(36 citation statements)

References 2 publications

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“…Commonly studied hydrogenation catalysts typically are composed of cobalt, tungsten, palladium, or nickel [37]. Cobalt-and nickel-promoted molybdenum catalysts have been the most studied ones among them [66,68,103,104]. Oasmaa and Johansson [77] have reported high yields of lignin oils on hydrotreatment of kraft lignin in the presence of a water-soluble molybdenum catalyst.…”

Section: Catalysts In Lignin Conversionmentioning

confidence: 98%

Lignin Depolymerization and Conversion: A Review of Thermochemical Methods

2010

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The structure of lignin suggests that it can be a valuable source of chemicals, particularly phenolics. However, lignin depolymerization with selective bond cleavage is the major challenge for converting it into value-added chemicals. Pyrolysis (thermolysis), gasification, hydrogenolysis, chemical oxidation, and hydrolysis under supercritical conditions are the major thermochemical methods studied with regard to lignin depolymerization. Pyrolytic oil and syngases are the primary products obtained from pyrolysis and gasification. A significant amount of char is also produced during pyrolysis. Thermal treatment in a hydrogen environment seems very promising for converting lignin to liquid fuel and chemicals like phenols, while oxidation can produce phenolic aldehydes. Reaction severity, solvents, and catalysts are the factors of prime importance that control yield and composition of the product. IntroductionThe depleting stocks of fossil fuels and the growing concern over the excessive emission of greenhouse gases have forced researchers to investigate renewable, abundant and comparably cleaner alternatives to liquid fuels and chemicals produced from petroleum [1][2][3]. Biomass appears to be a promising alternative and a renewable source for fuels and chemicals. Significant achievements have already been made in the production of ethanol fuel from biomass, primarily starch and sugarrich components. However, research on second-generation bioethanol is focused on a more abundant [4,5] and often relatively cheap [6][7][8] biomass feedstock known as lignocellulosic biomass. Lignocellulosic biomass consists of three basic components: cellulose, hemicellulose, and lignin. Cellulose is a linear polymer of glucose consisting of parts with crystalline structure and parts with amorphous structure [9], while hemicellulose is an amorphous, heterogeneously branched polymer of pentoses and hexoses, mainly xylose, arabinose, mannose, galactose, and glucose. Lignin is an amorphous and highly branched polymer of phenylpropane units, which can account for up to 40 % of the dry biomass weight [10]. The concept of a biorefinery that integrates processes and technologies for biomass conversion demands efficient utilization of all three components [11]. Most of the biorefinery schemes, however, are focused on utilizing easily convertible fractions while lignin remains relatively underutilized to its potential [11]. The lignocellulosics-to-ethanol process makes use of the cellulose and hemicelluloses, leaving lignin as waste. In addition, pulp and paper refineries also generate huge amounts of lignin. Presently, lignin is being utilized as a low-grade boiler fuel to provide heat and power to the process [3]. However, the chemical structure of lignin suggests that it may be a good source of valuable chemicals if it could be broken into smaller molecular units [7].Several studies have been done to convert lignin to more value-added products. These include attempts to convert lignin to liquid fuel additives and commercially important chem...

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Section: Catalysts In Lignin Conversionmentioning

confidence: 98%

Lignin Depolymerization and Conversion: A Review of Thermochemical Methods

2010

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“…Desired reactions include hydrodeoxygenation, the removal of oxygen in the form of water and depolymerisation. Typically, high pressures (100-200 bar) and temperatures (300-450°C) are required to convert lignin into low molecular weight compounds in good yield [63,64].…”

Section: Lignin Pyrolysis For Phenolicsmentioning

confidence: 99%

Biomass pyrolysis for chemicals

Wild¹

2011

Biofuels

145

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“…Presence of Cu in a reducing medium (H 2 ) causes complete reduction of these groups and production of benzene and toluene. Also, partial reduction of carbonyl produces phenol, cresols, alkyl phenols and xylenols [25,26]. Cellulose undergoes a depolymerization at around 200 C in presence of water.…”

Section: Mechanism Descriptionmentioning

confidence: 99%