Synthesis of Bio-aromatics from Black Liquors Using Catalytic Pyrolysis

Abstract

Bio-aromatics (benzene, toluene, xylenes, BTX) were prepared by the catalytic pyrolysis of six different black liquors using both in situ and ex situ approaches. A wide range of catalysts was screened and conditions were optimized in microscale reactors. Up to 7 wt % of BTX, based on the organic fraction of the black liquors, was obtained for both the in situ and ex situ pyrolysis (T = 500–600 °C) using a Ga-modified H-ZSM-5 catalyst. The in situ catalytic pyrolysis of black liquors from hardwood paper mills afforded slightly higher yields of aromatics/BTX than softwood black liquors, a trend that could be confirmed by the results obtained in the ex situ catalytic pyrolysis. An almost full deoxygenation of the lignin and carbohydrate fraction was achieved and both organic fractions were converted to a broad range of (substituted) aromatics. The zeolite catalyst used was remarkably stable and even after 100 experiments in batch mode with intermittent oxidative catalyst regeneration, the yields and selectivity toward BTX remained similar. The ex situ pyrolysis of black liquor has potential for large-scale implementation in a paper mill without disturbing the paper production process.

Catalytic Conversion of Free Fatty Acids to Bio-Based Aromatics: A Model Investigation Using Oleic Acid and an H-ZSM-5/Al2O3 Catalyst

“…Significant achievements have also been realized in the catalytic upgrading of liquid biomass sources 11 , 12 like bioderived ethanol, 13 pyrolysis oils, 14 and model compounds ( e.g ., furanics 15 ) to BTX over various catalysts ( e.g ., ZSM-5 zeolite 16 ). Liquid industrial waste streams, such as black liquor 17 (from the pulp and paper industry) and crude glycerol 18 (from the biodiesel industry), have also been applied for bio-BTX synthesis. A continuous pilot plant for the conversion of crude glycerol using an acidic catalyst is currently in operation.…”

Molecular Composition of Size-Fractionated Fulvic Acid-Like Substances Extracted from Spent Cooking Liquor and Its Relationship with Biological Activity

“…58 The reuse of the organic matter in spent cooking liquor to produce fulvic acid-like fertilizer or plant growth synergist through an extraction and ultrafiltration procedure has been implemented in Shandong Tranlin Group (Liaocheng, Shandong, China), thereby generating additional revenue from this spent cooking liquor. The innovative technology treatment of spent cooking liquor to produce fertilizer or plant growth synergist has less energy consumption and operational cost when compared with the reuse of spent cooking liquor to synthesis bioaromatics 59 or produce biofuel 5 as all procedures were carried under common temperature and pressure and the materials are reusable.…”

Regeneration of pristine HZSM-5 extrudates during the production of deeply deoxygenated bio-oil fromex situcatalytic fast pyrolysis of biomass in a bench-scale fluidised-bed reactor

“…The majority of the work has been performed on microreactors, known as pyrolysis-GC/MS systems, where a very small amount of biomass (milli-or micrograms) was pyrolysed in the presence of catalysts and the evolved products are analysed using GC/MS. [1][2][3][4][5][6] This technique is very useful for catalyst screening or comparison with different process parameters, but it may not be representative of a fullscale production as no real bio-oil or liquid is produced. A comprehensive review on catalytic pyrolysis of biomass by Yildiz et al 2016 (ref.…”

“…This has been investigated in a variety of scales including micro-scale using pyrolysis-GC/MS systems, 4,[9][10][11] a few grams scale using fixed-bed reactors 1,12,13 and bench or lab scale using continuous biomass feeding systems such as bubbling or circulating fluidised-bed reactors, 8,14-22 conical spouted-bed reactors, 23 a mechanically agitated bed reactor, 24,25 an ablative reactor 26,27 and fixed-bed reactors, [28][29][30][31] where real liquid bio-oil could be produced and analysed. Some important previous studies related to the regeneration of ZSM-5-based catalysts applying other types of raw materials rather than biomass or its pyrolysis vapour include crude glycerol, 32 carinata oil, 33 black liquor, 6 kraft lignin, 30 oil sludge, 34 plastic mixtures, 35 waste tire 36 and model compounds such as furan 37 and ethylene. 20 In addition, the regeneration of ZSM-5 was studied using bio-oil 38 and CaO-catalysed bio-oil 39 in fixed-bed flow reactors.…”