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Biorefinery: Current Status, Challenges, and New Strategies

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A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Applied Biosciences and Bioengineering".

Deadline for manuscript submissions: closed (31 October 2020) | Viewed by 54638

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Special Issue Editors

Dr. Kwang Ho Kim

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Guest Editor

Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea
Interests: lignocellulosic biomass; lignin chemistry; thermochemical conversion process; renewable materials

Prof. Dr. Chang Geun Yoo

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Guest Editor

Department of Chemical Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
Interests: biological/thermochemical conversion of biomass to fuels and chemicals; bio-based material application; elucidation of biomass and bio-product properties; development of lignocellulosic biorefinery
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Special Issue Information

Dear Colleagues,

Renewable fuels and chemicals derived from lignocellulosic biomass offer unprecedented opportunities for replacing fossil fuel derivatives, reducing our overdependence on imported oil and mitigating current climate change trends. Despite technical developments and considerable efforts, breakthrough technologies are still required to overcome hurdles in developing sustainable biorefineries. In recent years, new biorefinery concepts including a lignin-first approach and a closed-loop biorefinery have been introduced to tackle technoeconomic challenges. Furthermore, researchers have advanced the development of new technologies which enable the utilization of biomass components for sustainable materials.

It is now apparent that advanced processes are essential for ensuring the success of future biorefineries. In this Special Issue, we invite submissions that explore the process for biomass fractionation, lignin valorization, and sugar conversion or introduce new bioproducts (chemicals and materials) from renewable resources, addressing the current status, technical/technoeconomic challenges, and new strategies. This Special Issue will provide a more comprehensive view on developing future biorefinery.

Dr. Kwang Ho Kim
Dr. Chang Geun Yoo
Guest Editors

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Keywords

Biorefinery
Lignocellulosic biomass
Biomass fractionation
Lignin valorization
Sugar conversion
Reenwable materials

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Published Papers (11 papers)

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Editorial

Jump to: Research, Review

3 pages, 159 KiB

Open AccessEditorial

Editorial on Special Issue “Biorefinery: Current Status, Challenges, and New Strategies”

by Kwang Ho Kim and Chang Geun Yoo

Appl. Sci. 2021, 11(10), 4674; https://doi.org/10.3390/app11104674 - 20 May 2021

Viewed by 1424

Abstract

The overdependence on fossil fuels has raised concerns about global warming and the energy crisis, which has warranted significant research to find alternatives [...] Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

Research

Jump to: Editorial, Review

12 pages, 1767 KiB

Open AccessArticle

A Simultaneous Conversion and Extraction of Furfural from Pentose in Dilute Acid Hydrolysate of Quercus mongolica Using an Aqueous Biphasic System

by Jong-Hwa Kim, Seong-Min Cho, June-Ho Choi, Hanseob Jeong, Soo Min Lee, Bonwook Koo and In-Gyu Choi

Appl. Sci. 2021, 11(1), 163; https://doi.org/10.3390/app11010163 - 26 Dec 2020

Cited by 12 | Viewed by 2997

Abstract

This study optimizes furfural production from pentose released in the liquid hydrolysate of hardwood using an aqueous biphasic system. Dilute acid pretreatment with 4% sulfuric acid was conducted to extract pentose from liquid Quercus mongolica hydrolysate. To produce furfural from xylose, a xylose standard solution with the same acid concentration of the liquid hydrolysate and extracting solvent (tetrahydrofuran) were applied to the aqueous biphasic system. A response surface methodology was adopted to optimize furfural production in the aqueous biphasic system. A maximum furfural yield of 72.39% was achieved at optimal conditions as per the RSM; a reaction temperature of 170 °C, reaction time of 120 min, and a xylose concentration of 10 g/L. Tetrahydrofuran, toluene, and dimethyl sulfoxide were evaluated to understand the effects of the solvent on furfural production. Tetrahydrofuran generated the highest furfural yield, while DMSO gave the lowest yield. A furfural yield of 68.20% from pentose was achieved in the liquid hydrolysate of Quercus mongolica under optimal conditions using tetrahydrofuran as the extracting solvent. The aqueous and tetrahydrofuran fractions were separated from the aqueous biphasic solvent by salting out using sodium chloride, and 94.63% of the furfural produced was drawn out through two extractions using tetrahydrofuran. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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12 pages, 2065 KiB

Open AccessArticle

Environmentally Friendly Approach for the Production of Glucose and High-Purity Xylooligosaccharides from Edible Biomass Byproducts

by Soo-Kyeong Jang, Chan-Duck Jung, Ju-Hyun Yu and Hoyong Kim

Appl. Sci. 2020, 10(22), 8119; https://doi.org/10.3390/app10228119 - 16 Nov 2020

Cited by 7 | Viewed by 1963

Abstract

Xylooligosaccharides (XOS) production from sweet sorghum bagasse (SSB) has been barely studied using other edible biomasses. Therefore, we evaluated the XOS content as well as its purity by comparing the content of total sugars from SSB. An environmentally friendly approach involving autohydrolysis was employed, and the reaction temperature and time had variations in order to search for the conditions that would yield high-purity XOS. After autohydrolysis, the remaining solid residues, the glucan-rich fraction, were used as substrates to be enzymatically hydrolyzed for glucose conversion. The highest XOS was observed for total sugars (68.7%) at 190 °C for 5 min among the autohydrolysis conditions. However, we also suggested two alternative conditions, 180 °C for 20 min and 190 °C for 15 min, because the former condition might have the XOS at a low degree of polymerization with a high XOS ratio (67.6%), while the latter condition presented a high glucose to total sugar ratio (91.4%) with a moderate level XOS ratio (64.4%). Although it was challenging to conclude on the autohydrolysis conditions required to obtain the best result of XOS content and purity and glucose yield, this study presented approaches that could maximize the desired product from SSB, and additional processes to reduce these differences in conditions may warrant further research. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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9 pages, 1772 KiB

Open AccessArticle

Catalytic Conversion of α-Pinene to High-Density Fuel Candidates Over Stannic Chloride Molten Salt Hydrates

by Seong-Min Cho, June-Ho Choi, Jong-Hwa Kim, Bonwook Koo and In-Gyu Choi

Appl. Sci. 2020, 10(21), 7517; https://doi.org/10.3390/app10217517 - 26 Oct 2020

Cited by 3 | Viewed by 2136

Abstract

The synthesis of dimeric products from monoterpene hydrocarbons has been studied for the development of renewable high-density fuel. In this regard, the conversion of α-pinene in turpentine over stannic chloride molten salt hydrates (SnCl₄·5H₂O) as a catalyst was investigated, and the reaction products were analyzed with gas chromatography/flame ionization detector/mass spectrometer (GC/FID/MS). Overall, the content of α-pinene in a reaction mixture decreased precipitously with an increasing reaction temperature. Almost 100% of the conversion was shown after 1 h of reaction above 90 °C. From α-pinene, dimeric products (hydrocarbons and alcohols/ethers) were mostly formed and their yield showed a steady increase of up to 61 wt% based on the reaction mixture along with the reaction temperature. This conversion was thought to be promoted by Brønsted acid activity of the catalyst, which resulted from a Lewis acid-base interaction between the stannic (Sn^(IV)) center and the coordinated water ligands. As for the unexpected heteroatom-containing products, oxygen and chlorine atoms were originated from the coordinated water and chloride ligands of the catalyst. Based on the results, we constructed not only a plausible catalytic cycle of SnCl₄·5H₂O but also the mechanism of catalyst decomposition. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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17 pages, 1944 KiB

Open AccessArticle

Techno-Economic Evaluation of Hand Sanitiser Production Using Oil Palm Empty Fruit Bunch-Based Bioethanol by Simultaneous Saccharification and Fermentation (SSF) Process

by Andre Fahriz Perdana Harahap, Jabosar Ronggur Hamonangan Panjaitan, Catia Angli Curie, Muhammad Yusuf Arya Ramadhan, Penjit Srinophakun and Misri Gozan

Appl. Sci. 2020, 10(17), 5987; https://doi.org/10.3390/app10175987 - 29 Aug 2020

Cited by 12 | Viewed by 5023

Abstract

Oil palm empty fruit bunch (OPEFB) is a potential raw material abundantly available for bioethanol production. However, the second-generation bioethanol is still not yet economically feasible. The COVID-19 pandemic increases the demand for ethanol as the primary ingredient of hand sanitisers. This study evaluates the techno-economic feasibility of hand sanitiser production using OPEFB-based bioethanol. OPEFB was alkaline-pretreated, and simultaneous saccharification and fermentation (SSF) was then performed by adding Saccharomyces cerevisiae and cellulose enzyme. The cellulose content of the OPEFB increased from 39.30% to 63.97% after pretreatment. The kinetic parameters of the OPEFB SSF at 35 °C, which included a µ max, ks, and kd of 0.018 h⁻¹, 0.025 g/dm³, and 0.213 h⁻¹, respectively, were used as input in SuperPro Designer^® v9.0. The total capital investment (TCI) and annual operating costs (AOC) of the plant were $645,000 and $305,000, respectively, at the capacity of 2000 kg OPEFB per batch. The batch time of the modelled plant was 219 h, with a total annual production of 32,506.16 kg hand sanitiser. The minimum hand sanitiser selling price was found to be $10/L, achieving a positive net present value (NPV) of $108,000, showing that the plant is economically feasible. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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12 pages, 979 KiB

Open AccessArticle

Drying Effect on Enzymatic Hydrolysis of Cellulose Associated with Porosity and Crystallinity

by Bonwook Koo, Jaemin Jo and Seong-Min Cho

Appl. Sci. 2020, 10(16), 5545; https://doi.org/10.3390/app10165545 - 11 Aug 2020

Cited by 12 | Viewed by 2530

Abstract

The effect of drying on the enzymatic hydrolysis of cellulose was determined by analysis of porosity and crystallinity. Fiber hornification induced by drying produced an irreversible reduction in pore volume due to shrinkage and pore collapse, and the decrease in porosity inhibited enzymatic hydrolysis. The drying effect index (DEI) was defined as the difference in enzymatic digestibility between oven- and never-dried pulp, and it was determined that more enzymes caused a higher DEI at the initial stage of enzymatic hydrolysis and the highest DEI was also observed at the earlier stages with higher enzyme dosage. However, there was no significant difference in the DEI with less enzymes because cellulose conversion to sugars during hydrolysis did not enhance enzymatic hydrolysis due to the decrease in enzyme activity. The water retention value (WRV) and Simons’ staining were used to measure pore volume and to investigate the cause of the decrease in enzymatic hydrolysis. A decrease in enzyme accessibility induced by the collapse of enzymes’ accessible larger pores was determined and this decreased the enzymatic hydrolysis. However, drying once did not cause any irreversible change in the crystalline structure, thus it seems there is no correlation between enzymatic digestibility and crystalline structure. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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13 pages, 769 KiB

Open AccessFeature PaperArticle

Observation of Potential Contaminants in Processed Biomass Using Fourier Transform Infrared Spectroscopy

by Jingshun Zhuang, Mi Li, Yunqiao Pu, Arthur Jonas Ragauskas and Chang Geun Yoo

Appl. Sci. 2020, 10(12), 4345; https://doi.org/10.3390/app10124345 - 24 Jun 2020

Cited by 288 | Viewed by 10326

Abstract

With rapidly increased interests in biomass, diverse chemical and biological processes have been applied for biomass utilization. Fourier transform infrared (FTIR) analysis has been used for characterizing different types of biomass and their products, including natural and processed biomass. During biomass treatments, some solvents and/or catalysts can be retained and contaminate biomass. In addition, contaminants can be generated by the decomposition of biomass components. Herein, we report FTIR analyses of a series of contaminants, such as various solvents, chemicals, enzymes, and possibly formed degradation by-products in the biomass conversion process along with poplar biomass. This information helps to prevent misunderstanding the FTIR analysis results of the processed biomass. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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11 pages, 4486 KiB

Open AccessArticle

Effects of Gamma-Valerolactone Assisted Fractionation of Ball-Milled Pine Wood on Lignin Extraction and Its Characterization as Well as Its Corresponding Cellulose Digestion

by Muhammad Ajaz Ahmed, Jae Hoon Lee, Arsalan A. Raja and Joon Weon Choi

Appl. Sci. 2020, 10(5), 1599; https://doi.org/10.3390/app10051599 - 28 Feb 2020

Cited by 18 | Viewed by 3204

Abstract

Gamma-valerolactone (GVL) was found to be an effective, sustainable alternative in the lignocellulose defragmentation for carbohydrate isolation and, more specifically, for lignin dissolution. In this study, it was adapted as a green pretreatment reagent for milled pinewood biomass. The pretreatment evaluation was performed for temperature (140–180 °C) and reaction time (2–4 h) using 80% aqueous GVL to obtain the highest enzymatic digestibility of 92% and highest lignin yield of 33%. Moreover, the results revealed a positive correlation (R² = 0.82) between the lignin removal rate and the crystallinity index of the treated biomass. Moreover, under the aforementioned conditions, lignin with varying molecular weights (150–300) was obtained by derivatization followed by reductive cleavage (DFRC). 2D heteronuclear single quantum coherence nuclear magnetic resonance (2D-HSQC-NMR) spectrum analysis and gel permeation chromatography (GPC) also revealed versatile lignin properties with relatively high β-O-4 linkages (23.8%–31.1%) as well as average molecular weights of 2847–4164 with a corresponding polydispersity of 2.54–2.96, indicating this lignin to be a heterogeneous feedstock for value-added applications of biomass. All this suggested that this gamma-valerolactone based pretreatment method, which is distinctively advantageous in terms of its effectiveness and sustainability, can indeed be a competitive option for lignocellulosic biorefineries. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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11 pages, 1526 KiB

Open AccessFeature PaperArticle

Fractionation of Cellulose-Rich Products from an Empty Fruit Bunch (EFB) by Means of Steam Explosion Followed by Organosolv Treatment

by Jae Hoon Lee, Muhammad Ajaz Ahmed, In-Gyu Choi and Joon Weon Choi

Appl. Sci. 2020, 10(3), 835; https://doi.org/10.3390/app10030835 - 24 Jan 2020

Cited by 9 | Viewed by 3691

Abstract

In this study an empty fruit bunch (EFB) was subjected to a two-step pretreatment to defragment cellulose-rich fractions as well as lignin polymers from its cell walls. First pretreatment: acid-catalyzed steam explosion (ACSE) pretreatment of EFB was conducted under the temperature range of 180–220 °C and residence time of 5–20 min. The ACSE-treated EFB was further placed into the reactor containing 50% aq. ethanol and NaOH as a catalyst and heated at a temperature of 160 °C for 120 min for the second pretreatment: alkali-catalyzed organosolv treatment (ACO). The mass balance and properties of treated EFB were affected by the residence time. The lowest yield of a solid fraction was obtained when the residence time was kept at 15 min. Xylose drastically decreased, especially under the ACSE pretreatment. However, the crystallinity of cellulose increased by increasing the severity factor of the pretreatment and was 47.8% and 57% udner the most severe conditions. The organosolv lignin fractions also showed the presence of 14 major peaks via their pyrolysis-GC analysis. From here, it can be suggested that this kind of pretreatment can indeed be one potential option for lignocellulosic pretreatment. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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Review

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18 pages, 491 KiB

Open AccessReview

Biorefinery: The Production of Isobutanol from Biomass Feedstocks

by Yide Su, Weiwei Zhang, Aili Zhang and Wenju Shao

Appl. Sci. 2020, 10(22), 8222; https://doi.org/10.3390/app10228222 - 20 Nov 2020

Cited by 19 | Viewed by 4435

Abstract

Environmental issues have prompted the vigorous development of biorefineries that use agricultural waste and other biomass feedstock as raw materials. However, most current biorefinery products are cellulosic ethanol. There is an urgent need for biorefineries to expand into new bioproducts. Isobutanol is an important bulk chemical with properties that are close to gasoline, making it a very promising biofuel. The use of microorganisms to produce isobutanol has been extensively studied, but there is still a considerable gap to achieving the industrial production of isobutanol from biomass. This review summarizes current metabolic engineering strategies that have been applied to biomass isobutanol production and recent advances in the production of isobutanol from different biomass feedstocks. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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16 pages, 3164 KiB

Open AccessFeature PaperReview

Lignin to Materials: A Focused Review on Recent Novel Lignin Applications

by Osbert Yu and Kwang Ho Kim

Appl. Sci. 2020, 10(13), 4626; https://doi.org/10.3390/app10134626 - 3 Jul 2020

Cited by 143 | Viewed by 15153

Abstract

In recent decades, advancements in lignin application include the synthesis of polymers, dyes, adhesives and fertilizers. There has recently been a shift from perceiving lignin as a waste product to viewing lignin as a potential raw material for valuable products. More recently, considerable attention has been placed in sectors, like the medical, electrochemical, and polymer sectors, where lignin can be significantly valorized. Despite some technical challenges in lignin recovery and depolymerization, lignin is viewed as a promising material due to it being biocompatible, cheap, and abundant in nature. In the medical sector, lignins can be used as wound dressings, pharmaceuticals, and drug delivery materials. They can also be used for electrochemical energy materials and 3D printing lignin–plastic composite materials. This review covers the recent research progress in lignin valorization, specifically focusing on medical, electrochemical, and 3D printing applications. The technoeconomic assessment of lignin application is also discussed. Full article

(This article belongs to the Special Issue Biorefinery: Current Status, Challenges, and New Strategies)

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