High-yield bio-oil production from macroalgae (<i>Saccharina japonica</i>) in supercritical ethanol and its combustion behavior

Zeb, Hassan,Park, Jongkeun,Riaz, Asim,Ryu, Changkook,Kim, Jaehoon Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.327 No.-

<P><B>Abstract</B></P> <P>The effect of reaction parameters (temperature, time and biomass-to-solvent (BS) ratio) on properties (higher heating value (HHV) and O/C and H/C ratios) and yields of bio-oil produced from macroalgae (<I>Saccharina japonica</I>) liquefaction using supercritical ethanol (scEtOH) as a solvent was investigated. At 400°C using a BS ratio of 1/10 and reaction time of 45min, a high yield of bio-oil (88wt%) with a HHV of 35.0MJkg<SUP>−1</SUP>, O/C ratio of 0.14, and H/C ratio of 1.62 was obtained. Compared with water-based liquefaction, (subcritical water at 300°C, bio-oil yield of 43wt%, HHV of 20.7MJkg<SUP>−1</SUP>, O/C ratio of 0.48, and H/C ratio of 2.01; supercritical water at 400°C, bio-oil yield of 37wt%, HHV of 29.0MJkg<SUP>−1</SUP>, O/C ratio of 0.18, and H/C ratio of 1.76), the yield and energy content of the bio-oil produced using scEtOH were significantly higher. This enhancement was attributed to the reactivity of scEtOH with the intermediates generated from macroalgae. The utility of the generated bio-oil was demonstrated by application in a commercial 100 MW<SUB>e</SUB> generation plant. The thermal efficiency of the bio-oil (86.0%) was quite similar to that of heavy fuel oil (HFO) (87.1%), suggesting that the HFO could be fully replaced by the bio-oil.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Almost complete conversion of macroalgae in supercritical ethanol (scEtOH). </LI> <LI> High-yield (88wt%) and high-energy-content (35MJkg<SUP>−1</SUP>) bio-oil produced in scEtOH. </LI> <LI> ScEtOH produced higher-yield and better-quality bio-oil than water-based reaction. </LI> <LI> Bio-oil can be used as a combustion fuel for green electricity generation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effective conversion of the carbohydrate-rich macroalgae (<i>Saccharina japonica</i>) into bio-oil using low-temperature supercritical methanol

Zeb, Hassan,Riaz, Asim,Kim, Jaehoon Elsevier 2017 Energy conversion and management Vol.151 No.-

<P><B>Abstract</B></P> <P>The use of supercritical methanol (scMeOH) for the liquefaction of the carbohydrate-rich macroalgae <I>Saccharina japonica</I> was investigated at low temperature (250–300°C). At 300°C, almost complete conversion (98.1wt%) and a high bio-oil yield (66.0wt%) were achieved. These values are higher than those achieved with supercritical ethanol (scEtOH, 87.8wt% conversion, 60.5wt% bio-oil yield) and subcritical water (subH<SUB>2</SUB>O, 91.9wt% conversion, 40.3wt% bio-oil yield) under identical reaction conditions. The superior liquefaction in scMeOH is attributed to the beneficial physical properties of scMeOH, including its higher polarity, superior reactivity, and higher acidity. The superior reactivity of scMeOH was evident from the larger amount of esters (54.6 area%) produced in scMeOH as compared to that in scEtOH (47.2 area%), and the larger amount of methyl/methoxy-containing compounds (78.6 area%) produced in scMeOH than that of ethyl/ethoxy-containing compounds (58.2 area%) produced in scEtOH. The higher bio-oil yield combined with its higher calorific value (29.2MJkg<SUP>−1</SUP>) resulted in a higher energy recovery of 135% for scMeOH as compared to those of scEtOH (118%) and subH<SUB>2</SUB>O (96%). When considering the amount of alcohol consumed during the liquefactions and the production of light bio-oil fractions that evaporate during bio-oil recovery, the higher methanol consumption (5.3wt%) than that of ethanol (2.3wt%) leads to similar bio-oil yields (∼51wt%).</P> <P><B>Highlights</B></P> <P> <UL> <LI> 98.1% carbohydrate-rich macroalgae was converted in scMeOH at 300°C. </LI> <LI> The conversion in scMeOH was higher than those of scEtOH (87.8%) and subH<SUB>2</SUB>O (91.9%). </LI> <LI> Higher energy recovery values of scMeOH than those of scEtOH and subH<SUB>2</SUB>O. </LI> <LI> High reactivity of scMeOH can be the reason for high conversion. </LI> <LI> Higher consumption of methanol than ethanol verified the high reactivity of scMeOH. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A new role of supercritical ethanol in macroalgae liquefaction (<i>Saccharina japonica</i>): Understanding ethanol participation, yield, and energy efficiency

Zeb, Hassan,Choi, Jaeyeon,Kim, Yunje,Kim, Jaehoon Elsevier 2017 ENERGY Vol.118 No.-

<P><B>Abstract</B></P> <P>Liquefaction of macroalgae was performed in a stirred autoclave reactor using supercritical ethanol (scEtOH) as a solvent. There was a sharp transition in ethanol consumption during macroalgae liquefaction in scEtOH when the temperature was increased from 350 to 400 °C. At 350 °C, a small amount of ethanol (6 wt%) reacted with intermediates, while at 400 °C, 18 wt% of the ethanol was consumed. Taking into account this increased consumption of ethanol at 400 °C, the bio-oil yield decreased from 79.2 to 53.9 wt%, energy recovery from 202.5% to 72.2%, and energy efficiency from 111.6% to 62.7%. The produced bio-oil had a molecular weight of 398 g mol<SUP>−1</SUP>, a HHV of 36.49 MJ kg<SUP>−1</SUP>, an O/C ratio of 0.12, and a H/C ratio of 1.58. To confirm the unique role of scEtOH in biomass liquefaction, subcritical water (subH<SUB>2</SUB>O) and supercritical water (scH<SUB>2</SUB>O)-based liquefactions were carried out and the results compared with those obtained for scEtOH-based liquefaction. GC-MS results from the bio-oil produced with scH<SUB>2</SUB>O revealed the percentage area of compounds containing an ethoxy group to be as low as 20%, while this value reached 62% when using scEtOH.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Supercritical ethanol not only acts as a solvent but also as a reagent. </LI> <LI> Ethanol consumption during reaction was calculated by GC-MS ethanol calibration. </LI> <LI> Bio-oil yield, ER and EE were re-calculated considering consumed amount of ethanol. </LI> <LI> Decrease in bio-oil yield, ER and EE when consumed ethanol was taken into account. </LI> </UL> </P>

Upgrading low-boiling-fraction fast pyrolysis bio-oil using supercritical alcohol: Understanding alcohol participation, chemical composition, and energy efficiency

Jo, Heuntae,Prajitno, Hermawan,Zeb, Hassan,Kim, Jaehoon Elsevier 2017 Energy conversion and management Vol.148 No.-

<P><B>Abstract</B></P> <P>Herein, a supercritical methanol (scMeOH) route for efficient upgrading of the low-boiling fraction of fast pyrolysis bio-oil containing a large amount of low-molecular-weight acids and water was investigated. The effects of various reaction parameters, including the temperature, concentration, and time, were explored. The yield of bio-oil and the energy efficiency of the scMeOH upgrading process were determined based on the amount of methanol that participated in the reaction during upgrading and fractionation of the upgraded heavy-fraction bio-oils (UHBOs) and upgraded light-fraction bio-oils (ULBOs). Upgrading at 400°C with 9.1wt% bio-oil for 30min generated a high bio-oil yield of 78.4wt% with a low total acid number (TAN) of 4.0mg-KOH/g-oil and a higher heating value of 29.9MJkg<SUP>−1</SUP>. The energy recovery (ER) was 94–131% and the energy efficiency (EE) was in the range of 79–109% depending on the calorific values of the ULBOs. Compared with upgrading in supercritical ethanol and supercritical isopropanol, less alcohol participation, a lower TAN, and higher ER and EE were achieved with scMeOH upgrading. Plausible pathways for bio-oil upgrading in supercritical alcohols based on detailed compositional analysis of the UHBO, ULBO, and gaseous products were discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Non-catalytic and non-hydrogen based bio-oil upgrading was conducted using scMeOH. </LI> <LI> 16–40wt% alcohols were consumed during the upgrading. </LI> <LI> High bio-oil yield of 78.4wt% and low TAN of 4.0mg KOH/g were achieved. </LI> <LI> Effect of supercritical alcohols, reaction times, temperature and bio-oil concentration was conducted. </LI> <LI> scMeOH upgrading has good energy recovery (ER) and energy efficiency (EE) compared with scEtOH and scIPA. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Solvothermal liquefaction of alkali lignin to obtain a high yield of aromatic monomers while suppressing solvent consumption

Riaz, Asim,Verma, Deepak,Zeb, Hassan,Lee, Jeong Hyeon,Kim, Jin Chul,Kwak, Sang Kyu,Kim, Jaehoon The Royal Society of Chemistry 2018 GREEN CHEMISTRY Vol.20 No.21

<P>The unique physicochemical properties and high solubility of a wide range of biomass-derived feedstocks make sub- and supercritical alcohols promising media for thermochemical conversion to liquid fuels and value-added chemicals. Short-chain alcohols (C1-C3) not only hydrogenolyse a variety of recalcitrant feedstocks by donating <I>in situ</I> hydrogen, but also suppress the char formation by capping reactive intermediates. However, the beneficial features of supercritical alcohols also bring some demerits, such as their excessive decomposition and high consumption, which has been given cursory attention to date. Consequently, the aim of this study was to elucidate the role of sub- and supercritical alcohols as a hydrogen donor, their self-reactivity, their reactivity with the feedstock, the extent of their conversion under catalytic and non-catalytic conditions, and the detailed pathways to byproduct formation. Based on the solvent reactivity, the optimum conditions were investigated for the solvothermal liquefaction of recalcitrant alkali lignin to give a high yield of aromatic monomers with careful emphasis on the solvent consumption. The addition of formic acid instead of the more commonly used hydrodeoxygenation catalysts (<I>e.g.</I>, CoMo/Al2O3, Ru/Al2O3) can not only suppress ethanol consumption significantly (from 42.3-46.8 wt% to 7 wt%), but can also result in complete lignin conversion by providing an excess amount of active hydrogen. The reaction at 350 °C for a short duration of 60 min led to the complete decomposition of alkali lignin and afforded a high yield of aromatic derivatives (36.7 wt%), while at the same time, suppressing ethanol consumption (11.8 wt%) and the formation of ethanol-derived liquid products. The alkylation of lignin-derived phenolic intermediates at the expense of the solvent is a time-dependent reaction, instead of the primary stabilization reaction. Molecular dynamics simulations using dilignol molecules revealed that the ethanol-formic acid mixture reduced the activation and thermal energies required for the dissociation of C-C and C-O bonds in the lignin structure.</P>

Kinetic and thermodynamic evaluation of pyrolysis of jeans waste via coatsredfern method

Rumaisa Tariq,Abrar Inayat,Muhammad Shahbaz,Hassan Zeb,Chaouki Ghenai,Tareq Al-Ansari,김재훈 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.1

Used textiles, such as jeans wastes, exhibit a high potential for generating renewable and sustainable energy. However, limited research has been devoted toward investigating the kinetic and thermodynamic parameters of textile wastes during pyrolysis and applying these wastes as feedstock for fuels such as biogas. Therefore, this study investigated the kinetic and thermodynamic aspects of the thermal decomposition of jeans waste to evaluate its potential for sustainable energy production. Jeans waste was heat treated at 50–850 °C under different heating rates of 10–40 °C min−1. Active pyrolysis for the decomposition of jeans waste occurred at temperatures ranging from 250 to 550 °C. Specific Coats-Redfern-type reaction mechanisms were applied to determine the kinetic and thermodynamic variables in the active temperature zone. The thermodynamic parameters (ΔH and ΔG) and activation energies increased when the heating rate was increased from 10 to 30 °C min−1. When the heating rate was further increased to 40 °C min−1, ΔH, ΔG, and the activation energies decreased. For heating rates of 10, 20, 30, and 40 °C min−1, the pre-exponential factors varied in the ranges of 7.4×103 to 1.4×104, 1.8×104 to 5.1×1010, 2.8×104 to 5.3×1010, and 3.6×104 to 3.1×1010 min−1, respectively. In each reaction mechanism model, the entropy changed negatively for all the heating rates examined in this study. This work and its results could serve as a guide for implementing such pyrolysis processes for textile wastes at a practical scale for bioenergy applications.

An efficient hydration of nitriles with ruthenium-supported heterogeneous catalyst in water under moderate conditions

Muhammad Asif Hussain,최은주,Adnan Maqbool,Muhammad Atif,Hassan Zeb,여재구,유정아,조영훈,Moses Noh,김정원 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.99 No.-

A facile eco-friendly heterogeneous catalytic system has been developed for amide synthesis that furtherutilized in pharmaceutical and organic chemistry. The Ru/MnO2 catalyst has shown outstanding andunprecedented activity for a wide range of aliphatic and benzylic nitriles in green solvent water at 60 C. The system has also exhibited a remarkable tolerance for selective hydration of heteroatom (e.g. nitrogen,oxygen and sulphur atoms) containing nitriles. Pharmaceutically important nicotinamides andpyrazinamide has been synthesized by hydration of the heteroatomic nitriles with appreciable yieldsand selectivities. Moreover, the Ru/MnO2 catalyst has employed water as a benign solvent, with morethan 30,000 TONs and reusabilityfive times after isolation from the reaction mixture by centrifugationand easy workup that established a path for green environmental and technologically acceptableprotocol.

Effect of pyrolysis temperature on the physiochemical properties of biochars produced from raw and fermented rice husks

Hafiza Sana,Riaz Asim,Arshad Zubaria,Zahra Syeda Tahsin,Akhtar Javaid,Kanwal Sumaira,Zeb Hassan,Kim Jaehoon 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.8

This study investigated the slow pyrolysis behavior of raw rice husk (RRH) and fermented rice husk (FRH) in a fixed-bed reactor at temperatures in the range of 200–600 °C. The effects of pyrolysis temperature on the biochar yield, composition, and physiochemical properties were examined to evaluate the energy potential of biochars produced from RRH and FRH. The FRH-derived biochar produced at 600 °C was found to be more suitable than the RRH-derived biochar because of its higher carbon content (68.9% vs 42.1%), GCV (31.6 vs 24.1 MJ kg−1), and true density (1.94 vs 1.54 g cm −3). The slow pyrolysis in the high-temperature regime facilitated the formation of lignin-rich and aromatically condensed biochar, making it particularly useful for producing carbon-rich materials. Thus, slow pyrolysis can be a technically viable approach for producing high-energy-density solid fuels that can replace medium-ranking coals in co-firing.