Biomass

12 pages, 1768 KiB

Open AccessReview

The Role of Lignin Structure on Cellulase Adsorption and Enzymatic Hydrolysis

by Wenjuan Wu, Penghui Li, Lijing Huang, Yumeng Wei, Jiaquan Li, Lu Zhang and Yongcan Jin

Biomass 2023, 3(1), 96-107; https://doi.org/10.3390/biomass3010007 - 1 Mar 2023

Cited by 21 | Viewed by 6823

Lignin is one of the important components of lignocellulosic cell walls, which endows plant cell walls with rigidity and strength and protects them from microbial invasion. The presence of lignin is thought to hinder the conversion of biomass to bioenergy, so understanding enzyme-lignin [...] Read more.

Lignin is one of the important components of lignocellulosic cell walls, which endows plant cell walls with rigidity and strength and protects them from microbial invasion. The presence of lignin is thought to hinder the conversion of biomass to bioenergy, so understanding enzyme-lignin interactions is very important in order to reduce the inhibition of lignin and improve the hydrolysis yields. Conversion of lignocellulosic raw materials into bioethanol is divided into pretreatment, enzymatic hydrolysis, and fermentation. In this paper, both pretreatment and enzymatic hydrolysis of lignocellulose are described in detail. Finally, the reasons why lignin hinders enzymatic hydrolysis efficiency, mainly from forming spatial barriers and interacting with cellulase, are discussed, and the influencing factors and mechanisms of action of cellulase hydrolysis are explored with a view to targeted regulation of lignin structure to improve lignocellulosic saccharification. Full article

(This article belongs to the Special Issue Pretreatment, Enzymatic Hydrolysis, and Fermentation Applied to Ethanol from Lignocellulosic Biomasses)

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18 pages, 6286 KiB

Open AccessArticle

Seaweed Pellets as a Renewable Fuel Feedstock

by Mohiodin Nazemi, Runar Unnthorsson and Christiaan Richter

Biomass 2023, 3(1), 78-95; https://doi.org/10.3390/biomass3010006 - 20 Feb 2023

Cited by 2 | Viewed by 6101

Abstract

Seaweed can be a desirable source of renewable energy or fuel after it has been processed by combustion, thermochemical conversion by gasification, pyrolysis, or hydrothermal liquefaction (HTL) or biochemical conversion routes like anaerobic digestion (AD). This work explores how well the measured properties [...] Read more.

Seaweed can be a desirable source of renewable energy or fuel after it has been processed by combustion, thermochemical conversion by gasification, pyrolysis, or hydrothermal liquefaction (HTL) or biochemical conversion routes like anaerobic digestion (AD). This work explores how well the measured properties of seaweed pellets match the specifications for the various fuel and energy conversion options listed. Blends of hay, wood chips, sawdust, and seaweed were pelletized. Eight pellet blends with dominant seaweed content and minimum acceptable mechanical strength and stability were produced and their physical and chemical properties were reported. The seaweed pellets had an energy content of around 14 MJ/kg, and each pellet could withstand almost 200 N of compression force. Their water content was around 5% or less and their ash content was around 20–34%. According to the results, a higher wood content increased the energy content of the pellets. Among those properties measured in this project, none of them contradicted the typical specifications of combustion, HTL, and AD. However, the low water content and low strength of some pellet types were unable to meet the specifications for certain types of gasification and pyrolysis. Full article

(This article belongs to the Special Issue Biomass Conversion and Processing Technologies of Carbon-Based Materials for Environmental and Energy Application Development)

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12 pages, 3134 KiB

Open AccessFeature PaperArticle

Combined Effects of Deep Eutectic Solvents and Pulsed Electric Field Improve Polyphenol-Rich Extracts from Apricot Kernel Biomass

by Ioannis Makrygiannis, Vassilis Athanasiadis, Eleni Bozinou, Theodoros Chatzimitakos, Dimitris P. Makris and Stavros I. Lalas

Biomass 2023, 3(1), 66-77; https://doi.org/10.3390/biomass3010005 - 1 Feb 2023

Cited by 8 | Viewed by 2578

Abstract

Apricots are one of the most important fruits in the Mediterranean region for both their nutritional and economic value. They are widely cultivated and consumed fresh or dried or are used in the food industry for the production of jams, juices, etc. In [...] Read more.

Apricots are one of the most important fruits in the Mediterranean region for both their nutritional and economic value. They are widely cultivated and consumed fresh or dried or are used in the food industry for the production of jams, juices, etc. In any case, the seeds they contain constitute waste. The kernels are very rich in bioactive compounds such as polyphenols, a fact that makes them very appealing in cosmetology. However, the extraction of the bioactive compounds of apricot kernels is poorly examined. In this study, the preparation of polyphenol-rich extracts from apricot kernel biomass is discussed. To this end, a common extraction procedure with water as a solvent was employed. To enhance the extraction yield, the use of a deep eutectic solvent (DES) was examined. In addition, the use of pulsed electric field (PEF) either as a standalone extraction method or as a complementary step was also examined. According to the results, it was evident that when PEF was applied before the extraction procedure, an increase of 88% in the total polyphenol content (TPC) was recorded. Likewise, the use of a glycerol:choline chloride (2:1, w/w) DES increased the TPC by ~70%. When the two approaches were combined, a 173% increase was recorded. According to the above, it can be concluded that apricot kernel biomass is a very good source of polyphenols, especially using the proposed extraction procedure. Full article

(This article belongs to the Special Issue Valorization of Agri-Food Waste Biomass for the Extraction of Bioactive Compounds)

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2 pages, 232 KiB

Open AccessEditorial

Acknowledgment to the Reviewers of Biomass in 2022

by Biomass Editorial Office

Biomass 2023, 3(1), 64-65; https://doi.org/10.3390/biomass3010004 - 16 Jan 2023

Viewed by 1208

Abstract

High-quality academic publishing is built on rigorous peer review [...] Full article

33 pages, 3641 KiB

Open AccessReview

Selecting Catalysts for Pyrolysis of Lignocellulosic Biomass

by Maria do Carmo Rangel, Francieli Martins Mayer, Mateus da Silva Carvalho, Giovanni Saboia and Arthur Motta de Andrade

Biomass 2023, 3(1), 31-63; https://doi.org/10.3390/biomass3010003 - 10 Jan 2023

Cited by 22 | Viewed by 6837

Abstract

The pyrolysis of lignocellulosic biomass is a promising technology for obtaining renewable chemicals and fuels to replace fossil-based products. However, due to the complexity of the lignin, cellulose and hemicellulose molecules, a large variety of compounds are often formed, making commercial implementation difficult. [...] Read more.

The pyrolysis of lignocellulosic biomass is a promising technology for obtaining renewable chemicals and fuels to replace fossil-based products. However, due to the complexity of the lignin, cellulose and hemicellulose molecules, a large variety of compounds are often formed, making commercial implementation difficult. The use of a catalyst during reactions has been recognized as one of the major improvements in pyrolysis, allowing the production of selected compounds. Moreover, the large number of available catalysts opens up a wide range of possibilities for controlling the reaction network. Zeolites, hierarchical zeolites, alkali and alkaline earth oxides, transition metals and carbonaceous materials, among others, have been investigated in the pyrolysis of a variety of biomasses. In addition, bifunctional catalysts play a role in pyrolysis, as well as the addition of plastics as hydrogen donors. This review aims to present and discuss in detail state-of-the-art catalytic pyrolysis, focusing on the relationships between the properties of the catalysts and the obtained products. A guideline for selecting catalysts for lignocellulosic biomass is also provided. Full article

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13 pages, 1517 KiB

Open AccessArticle

Development of Anaerobic Biodigester for the Production of Biogas Used in Semi-Continuous System Bioprocesses: An Efficient Alternative for Co-Digestion of Low Biodegradability Biomass

by Claudinei de Souza Guimarães and David Rodrigues da Silva Maia

Biomass 2023, 3(1), 18-30; https://doi.org/10.3390/biomass3010002 - 3 Jan 2023

Viewed by 5011

Abstract

The objective of this work was to develop an automated anaerobic biodigester capable of operating in a semi-continuous or batch system for biogas production. Low biodegradability biomass has little efficiency in the production of biogas by anaerobic digestion processes and an efficient alternative [...] Read more.

The objective of this work was to develop an automated anaerobic biodigester capable of operating in a semi-continuous or batch system for biogas production. Low biodegradability biomass has little efficiency in the production of biogas by anaerobic digestion processes and an efficient alternative is the use of bioprocesses in semi-continuous system. Two experiments were carried out in the same proportions but in different processes, and all control and automation parameters were tested and evaluated. For testing, mixtures of organic waste, anaerobic sludge (inoculum) and raw sewage without any treatment from the sewage treatment plant, in mesophilic phase (37 °C), were used during the 60 days of experiment. The semi-continuous system showed the greatest reduction in organic matter, expressed by the removal of 80.7% Total Solids Volatile (TVS) and the greatest volume (68.5 L) and methane percentage (78.5%). Finally, with these and other results found, it is possible to conclude that the biodigester developed for semi-continuous system, with the automation and control system, was satisfactory for the reduction in organic matter and biogas production. In addition, all operating system worked properly and with the use of current, low-cost technologies, the application and development on a larger scale becomes viable in the future. Full article

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17 pages, 814 KiB

Open AccessReview

Strategies to Ensure Fuel Security in Brazil Considering a Forecast of Ethanol Production

by Felipe de Oliveira Gonçalves, Rafael Firmani Perna, Emília Savioli Lopes, Laura Plazas Tovar, Rubens Maciel Filho and Melina Savioli Lopes

Biomass 2023, 3(1), 1-17; https://doi.org/10.3390/biomass3010001 - 3 Jan 2023

Cited by 8 | Viewed by 3138

Abstract

Ethanol production in Brazil started in the early 1930s due to laws created by the Brazilian government. However, ethanol production only increased significantly with the National Program of Ethanol implementation in 1975. This program was another action taken by the Brazilian government aiming [...] Read more.

Ethanol production in Brazil started in the early 1930s due to laws created by the Brazilian government. However, ethanol production only increased significantly with the National Program of Ethanol implementation in 1975. This program was another action taken by the Brazilian government aiming to provide conditions for the development of the ethanol industry in the country. With the program, it was possible to achieve significant progress; however, it finished in the mid-1980s. Currently, ethanol is produced on a large scale by more than 300 sugarcane mills all over the country. In 2016, the Brazilian government provided another incentive for ethanol production by creating the RenovaBio Program, which aimed to reduce greenhouse gas emissions. Besides the environmental aspect, Brazil’s ethanol industry needs to develop to supply future biofuel demand. According to the forecast provided in this paper, and considering technical, economic, and environmental aspects regarding the Brazilian ethanol industry, the current and only feedstock used is likely to be insufficient. Thus, the ethanol produced from corn would be an attractive secondary feedstock to complement sugarcane ethanol as the primary feedstock. Full article

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Biomass, Volume 3, Issue 1 (March 2023) – 7 articles

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