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Resources, Volume 10, Issue 12 (December 2021) – 13 articles

Cover Story (view full-size image): The work evaluates the biomethane production increase after pretreatment of three lignocellulosic wastes (wheat straw (WS), barley straw (BS), and grape stem (GS)) with 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) ionic liquid. Crystallinity index, measured by X-ray diffraction (XRD) and lignocellulosic composition determined by TGA, before and after pretreatment were related to the methane yield of the solid fraction. Moreover, the methane potential of the liquid fraction was theoretically calculated in function of reducing fermentable sugar concentration. Methane production of solid plus liquid fraction obtained after [Emim][Ac] pre-treatment increased 1.61- and 1.34-fold compared with raw wheat straw and grape stem, respectively. View this paper
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24 pages, 3281 KiB  
Article
Portuguese Wood Pellets Market: Organization, Production and Consumption Analysis
by Leonel J. R. Nunes, Margarida Casau and Marta Ferreira Dias
Resources 2021, 10(12), 130; https://doi.org/10.3390/resources10120130 - 20 Dec 2021
Cited by 5 | Viewed by 4511
Abstract
Wood pellets are a form of energy that can be seen as an alternative to fossil fuels, thus contributing to the reduction of greenhouse gas emissions. In other words, wood pellets can be considered a solution contributing to the mitigation of climate change. [...] Read more.
Wood pellets are a form of energy that can be seen as an alternative to fossil fuels, thus contributing to the reduction of greenhouse gas emissions. In other words, wood pellets can be considered a solution contributing to the mitigation of climate change. The use of wood pellets has grown significantly in recent years, with different markets emerging, such as Portugal, both from production and consumption perspectives. The wood pellet industry in Portugal began its development about 15 years ago, with the companies installed in the country initially almost exclusively dedicated to the production of wood pellets for export to central and northern European markets. However, over the years, the domestic market, initially considered insignificant, began to develop; it recently reached a considerable consuming share of the national production. This study presents an analysis of the Portuguese wood pellet market using data collected on the sector, and specifically on producers and consumers. The information was gathered using surveys presented directly to consumers and producers and through interviews with other stakeholders in the sector. From the analysis of the information, it was possible to understand the market’s dynamics, its current evolution and its prospects for the upcoming years, since it can already be considered mature and consolidated. Full article
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13 pages, 518 KiB  
Article
Economic Indicators in Water and Wastewater Sector Contributing to a Circular Economy (CE)
by Marzena Smol and Renata Koneczna
Resources 2021, 10(12), 129; https://doi.org/10.3390/resources10120129 - 16 Dec 2021
Cited by 16 | Viewed by 4182
Abstract
Protection and sustainable management of water was indicated as one of the strategic tasks in the process of transformation towards a circular economy (CE) in the European Union (EU), therefore, the water and wastewater sector plays an important role in this process. At [...] Read more.
Protection and sustainable management of water was indicated as one of the strategic tasks in the process of transformation towards a circular economy (CE) in the European Union (EU), therefore, the water and wastewater sector plays an important role in this process. At the same time, the European Commission (EC) strongly underlined the importance of the possibility to assess the transformation process toward the CE, and developed a set of CE indicators that are available on the Eurostat website. However, these indicators have limited ability to assess the transformation progress in the water and wastewater sector. This paper presents a set of indicators for assessing the economic progress of transformation towards the CE in this sector. The proposed economic CE indicators were grouped into the following actions of the CE model in the water and wastewater sector: reduction, reclamation (removal), reuse, recycling, recovery and landfilling. The selection of specific indicators was based on a systematic review of the literature presenting economic indicators developed by international organisations and researchers (covering different thematic areas, scopes and potential applications). The selected economic CE indicators were assigned to three groups of the cash flow: income (revenues, expenses), costs, and investment financing. The proposed CE indicators can be used by water supply and sewage companies (i.e., supplying water to the public and wastewater treatment plants, and companies that use water in their production processes) to assess the level of the transformation toward the CE at a microeconomic level. An important aspect of future application and usage of the proposed set of CE economic indicators is the collection and processing of data needed for their reporting. The proposed set of CE economic indicators refers to information that are reported by the companies to prove its revenues, costs and investment outlays, and are collected by companies anyway. The proposed set of economic CE indicators is flexible, allowing the adaptation of indicators and areas of interest to maintain effectiveness throughout the transition period from linear to the CE model. Full article
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15 pages, 6103 KiB  
Article
Ensuring the Sustainability of Arctic Industrial Facilities under Conditions of Global Climate Change
by George Buslaev, Pavel Tsvetkov, Alexander Lavrik, Andrey Kunshin, Elizaveta Loseva and Dmitry Sidorov
Resources 2021, 10(12), 128; https://doi.org/10.3390/resources10120128 - 15 Dec 2021
Cited by 18 | Viewed by 3236
Abstract
Global climate change poses a challenge to the mineral development industry in the Arctic regions. Civil and industrial buildings designed and constructed without consideration of warming factors are beginning to collapse due to changes in the permafrost structure. St. Petersburg Mining University is [...] Read more.
Global climate change poses a challenge to the mineral development industry in the Arctic regions. Civil and industrial buildings designed and constructed without consideration of warming factors are beginning to collapse due to changes in the permafrost structure. St. Petersburg Mining University is developing technical and technological solutions for the construction of remote Arctic facilities and a methodology for their design based on physical and mathematical predictive modeling. The article presents the results of modeling the thermal regimes of permafrost soils in conditions of thermal influence of piles and proposes measures that allow a timely response to the loss of bearing capacity of piles. Designing pile foundations following the methodology proposed in the article to reduce the risks from global climate change will ensure the stability of remote Arctic facilities located in the zone of permafrost spreading. Full article
(This article belongs to the Special Issue Resource Provision of the Sustainable Development under Global Shocks)
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15 pages, 840 KiB  
Review
Electrocoagulation Sludge Valorization—A Review
by Kyösti Rajaniemi, Sari Tuomikoski and Ulla Lassi
Resources 2021, 10(12), 127; https://doi.org/10.3390/resources10120127 - 14 Dec 2021
Cited by 21 | Viewed by 5291
Abstract
In the field of electrocoagulation (EC), various studies on pollutant removal and on the use of different EC technologies have already been made. An EC process generates sludge, which is considered waste, resulting in increased operational costs that come from waste disposal. Sludge [...] Read more.
In the field of electrocoagulation (EC), various studies on pollutant removal and on the use of different EC technologies have already been made. An EC process generates sludge, which is considered waste, resulting in increased operational costs that come from waste disposal. Sludge contains valuable materials, such as the nutrients or metals removed during water purification, along with metals, such as aluminum or iron, which come from the electrodes used in an EC system. Based on the principles of circular economy or based on existing legislations, reducing the production of valuable wastes, and increasing the valorization rate of as many materials as possible are important endeavors. This study is mainly a review of the existing sludge valorization studies. This review highlights the valorization of sludge as a fertilizer (mainly as struvite), pigment, construction material (mainly as blocks), adsorbent, and catalyst. While it has already been found that EC sludge is valorizable, more studies on EC sludge valorization and on the quality of sludge produced from the effluent of EC processes are warranted. Full article
(This article belongs to the Special Issue Metal Recovery from the Secondary Resources)
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18 pages, 4614 KiB  
Article
The Assessment of Hydrogeosites in the Fann Mountains, Tajikistan as a Basis for Sustainable Tourism
by Katarzyna Pukowiec-Kurda, Oimahmad Rahmonov, Michał Sobala and Urszula Myga-Piątek
Resources 2021, 10(12), 126; https://doi.org/10.3390/resources10120126 - 13 Dec 2021
Cited by 2 | Viewed by 2351
Abstract
Despite the fact that the Fann Mountains are among the most popular tourist destinations in Tajikistan, they are still in the first stage of tourism development. This represents a great opportunity for the implementation of the principles of sustainable tourism, which will avoid [...] Read more.
Despite the fact that the Fann Mountains are among the most popular tourist destinations in Tajikistan, they are still in the first stage of tourism development. This represents a great opportunity for the implementation of the principles of sustainable tourism, which will avoid the mistakes associated with the uncontrolled tourism development currently observed in other mountain areas of the world. The aim of this article is to demonstrate, using the example of the Fann Mountains, how hydrogeosites in mountain areas can be valorised for the needs of cognitive tourism. The valorisation methods used in previous research to this point have focused on the evaluation of the objects themselves. This study additionally takes into account features of the surroundings of hydrogeostations, such as the visibility range, the vertical development of the view, and the diversity of the landscape. The conducted value assessments of the sites and their surroundings show that in both internal and external assessments the highest values were achieved by lakes and wetlands. This means that the evaluation of the surroundings has a strong influence on the results obtained and the choice of hydrogeotourism attractions. Full article
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15 pages, 4888 KiB  
Article
An Investigation into Current Sand Control Methodologies Taking into Account Geomechanical, Field and Laboratory Data Analysis
by Dmitry Tananykhin, Maxim Korolev, Ilya Stecyuk and Maxim Grigorev
Resources 2021, 10(12), 125; https://doi.org/10.3390/resources10120125 - 13 Dec 2021
Cited by 8 | Viewed by 3308
Abstract
Sand production is one of the major issues in the development of reservoirs in poorly cemented rocks. Geomechanical modeling gives us an opportunity to calculate the reservoir stress state, a major parameter that determines the stable pressure required in the bottomhole formation zone [...] Read more.
Sand production is one of the major issues in the development of reservoirs in poorly cemented rocks. Geomechanical modeling gives us an opportunity to calculate the reservoir stress state, a major parameter that determines the stable pressure required in the bottomhole formation zone to prevent sand production, decrease the likelihood of a well collapse and address other important challenges. Field data regarding the influence of water cut, bottomhole pressure and fluid flow rate on the amount of sand produced was compiled and analyzed. Geomechanical stress-state models and Llade’s criterion were constructed and applied to confirm the high likelihood of sanding in future wells using the Mohr–Coulomb and Mogi–Coulomb prototypes. In many applications, the destruction of the bottomhole zone cannot be solved using well mode operations. In such cases, it is necessary to perform sand retention or prepack tests in order to choose the most appropriate technology. The authors of this paper conducted a series of laboratory prepack tests and it was found that sanding is quite a dynamic process and that the most significant sand production occurs in the early stages of well operation. With time, the amount of produced sand decreases greatly—up to 20 times following the production of 6 pore volumes. Finally, the authors formulated a methodological approach to sand-free oil production. Full article
(This article belongs to the Special Issue Resource Provision of the Sustainable Development under Global Shocks)
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25 pages, 3113 KiB  
Article
Scenario Modeling of Sustainable Development of Energy Supply in the Arctic
by Yuriy Zhukovskiy, Pavel Tsvetkov, Aleksandra Buldysko, Yana Malkova, Antonina Stoianova and Anastasia Koshenkova
Resources 2021, 10(12), 124; https://doi.org/10.3390/resources10120124 - 07 Dec 2021
Cited by 41 | Viewed by 3944
Abstract
The 21st century is characterized not only by large-scale transformations but also by the speed with which they occur. Transformations—political, economic, social, technological, environmental, and legal-in synergy have always been a catalyst for reactions in society. The field of energy supply, like many [...] Read more.
The 21st century is characterized not only by large-scale transformations but also by the speed with which they occur. Transformations—political, economic, social, technological, environmental, and legal-in synergy have always been a catalyst for reactions in society. The field of energy supply, like many others, is extremely susceptible to the external influence of such factors. To a large extent, this applies to remote (especially from the position of energy supply) regions. The authors outline an approach to justifying the development of the Arctic energy infrastructure through an analysis of the demand for the amount of energy consumed and energy sources, taking into account global trends. The methodology is based on scenario modeling of technological demand. It is based on a study of the specific needs of consumers, available technologies, and identified risks. The paper proposes development scenarios and presents a model that takes them into account. Modeling results show that in all scenarios, up to 50% of the energy balance in 2035 will take gas, but the role of carbon-free energy sources will increase. The mathematical model allowed forecasting the demand for energy types by certain types of consumers, which makes it possible to determine the vector of development and stimulation of certain types of resources for energy production in the Arctic. The model enables considering not only the growth but also the decline in demand for certain types of consumers under different scenarios. In addition, authors’ forecasts, through further modernization of the energy sector in the Arctic region, can contribute to the creation of prerequisites that will be stimulating and profitable for the growth of investment in sustainable energy sources to supply consumers. The scientific significance of the work lies in the application of a consistent hybrid modeling approach to forecasting demand for energy resources in the Arctic region. The results of the study are useful in drafting a scenario of regional development, taking into account the Sustainable Development Goals, as well as identifying areas of technology and energy infrastructure stimulation. Full article
(This article belongs to the Special Issue Resource Provision of the Sustainable Development under Global Shocks)
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14 pages, 22196 KiB  
Article
The Role of Edible Insects in Rural Livelihoods, and Identified Challenges in Vhembe District, Limpopo, South Africa
by Zabentungwa T. Hlongwane, Rob Slotow and Thinandavha C. Munyai
Resources 2021, 10(12), 123; https://doi.org/10.3390/resources10120123 - 07 Dec 2021
Cited by 8 | Viewed by 4154
Abstract
Edible insects are an important natural commodity in rural areas that is used for household consumption and to generate income through trade. As a result, edible-insect trading is a profitable business that provides employment and improves the livelihoods of impoverished rural people. This [...] Read more.
Edible insects are an important natural commodity in rural areas that is used for household consumption and to generate income through trade. As a result, edible-insect trading is a profitable business that provides employment and improves the livelihoods of impoverished rural people. This study aimed at determining the socioeconomic benefits of and reasons for trading insects, and to assess if edible insects are included in economic development strategies in the Vhembe district of Limpopo province, South Africa. We conducted 72 questionnaire interviews targeting traders in 5 towns across the district. Five insect groups belonging to four insect orders are traded in informal markets of the district. Mopane worms (Gonimbrasia belina) were the most traded (42%) edible insects. Unemployment (45%) and the demand for edible insects (34%) were the major reasons for trading insects. Insect trading has numerous benefits; however, the provision of income (60%) and financial support (35%) were stated as the primary benefits. Despite several benefits associated with trading in insects, there are many challenges such as insect spoilage and a decline in the availability of edible insects in the wild. Edible insects play an important role in food security and the rural economy by generating employment opportunities for unemployed traders. Trading in insects is a traditional practice based on indigenous knowledge, which has persisted as an economic practice that improves rural livelihoods by reducing poverty and increases the human dignity of rural citizens. Only four governmental organisations in Limpopo included edible insects in economic development strategies. Trading insects is primarily an informal activity. The government could stimulate the activity and broaden and deepen the community benefits by providing infrastructure, access to harvest areas, financial support, and business training as part of a rural empowerment strategy to end hunger and poverty while creating employment opportunities in rural areas. Full article
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12 pages, 1315 KiB  
Article
Pellet Production from Residual Biomass of Greenery Maintenance in a Small-Scale Company to Improve Sustainability
by Alessio Ilari, Ester Foppa Pedretti, Carmine De Francesco and Daniele Duca
Resources 2021, 10(12), 122; https://doi.org/10.3390/resources10120122 - 03 Dec 2021
Cited by 17 | Viewed by 3547
Abstract
Replacing fossil energy sources with renewable energy sources is a key strategic action to limit environmental issues. To achieve this goal, substitution with biomass is beneficial due to its versatility in various fields. In terms of circular economy and sustainability, the possibility of [...] Read more.
Replacing fossil energy sources with renewable energy sources is a key strategic action to limit environmental issues. To achieve this goal, substitution with biomass is beneficial due to its versatility in various fields. In terms of circular economy and sustainability, the possibility of energy exploitation of residual biomass is particularly desirable in small-medium enterprises. The use of supply chain by-products can improve sustainability and create opportunities for companies. The purpose of this study is to evaluate the suitability of residual biomass of conifers and broad-leaved trees to produce quality pellets using an agri-pellet machine activated by the power take-off of a tractor. This system can be employed at the farm level. Wood biomass of four species was tested; poplar, stone pine, black locust, and oak. Wood chips samples were analyzed to determine their qualitative characteristics following the technical standard ISO 17225-4. Based on the results, different wood blends were created to produce pellets, subsequently characterized according to ISO 17225-2. The analyses carried out on wood chips and pellets were bulk density, moisture, ash content, calorific value, elemental composition, chlorine, sulfur, and heavy metals. In addition, particles size was measured only for wood chips, while the length, diameter, mechanical durability, and ash melting behaviors were determined only for pellets. Some of the analyzed mixtures show acceptable values according to the current ISO technical standards. The values related to the apparent pellet bulk density and the durability test highlight that not all the mixtures are suitable to produce quality pellets. Results also represent a good starting point for future studies. Full article
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19 pages, 4512 KiB  
Article
Bacterial Nanocellulose Derived from Banana Leaf Extract: Yield and Variation Factors
by Manuel Fiallos-Cárdenas, Angel D. Ramirez, Simón Pérez-Martínez, Hugo Romero Bonilla, Marco Ordoñez-Viñan, Omar Ruiz-Barzola and Miguel A. Reinoso
Resources 2021, 10(12), 121; https://doi.org/10.3390/resources10120121 - 27 Nov 2021
Cited by 10 | Viewed by 10714
Abstract
Bananas are one of the most important crops worldwide. However, a large amount of residual lignocellulosic biomass is generated during its production and is currently undervalued. These residues have the potential to be used as feedstock in bio-based processes with a biorefinery approach. [...] Read more.
Bananas are one of the most important crops worldwide. However, a large amount of residual lignocellulosic biomass is generated during its production and is currently undervalued. These residues have the potential to be used as feedstock in bio-based processes with a biorefinery approach. This work is based on the valorization of banana leaf and has the following objectives (i) to determine the effect of certain physical and environmental factors on the concentration of glucose present in banana leaf extract (BLE), using a statistical regression model; (ii) to obtain Bacterial Nanocellulose (BNC), using BLE (70% v/v) and kombucha tea as fermentation medium. In addition, the physicochemical properties of BNC were evaluated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The results indicate that storage time, location, leaf color, and petiole type are factors related to BLE concentration, which is reduced by approximately 28.82% and 64.32% during storage times of five days. Regarding BNC biosynthesis, the results indicate that the highest yield, 0.031 g/g, was obtained at 21 days. Furthermore, it was determined that the highest production rate was 0.11 gL1h1 at 11 days of fermentation. By FTIR, it was determined that the purification step with NaOH (3M) should be carried out for approximately two hours. This research supports the development of a circular bioeconomy around the banana value chain, as it presents a way of bioprocessing residual biomass that can be used to produce bioproducts. Full article
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34 pages, 8649 KiB  
Article
The Impact of Metal Mining on Global Water Stress and Regional Carrying Capacities—A GIS-Based Water Impact Assessment
by Simon Meißner
Resources 2021, 10(12), 120; https://doi.org/10.3390/resources10120120 - 26 Nov 2021
Cited by 29 | Viewed by 11156
Abstract
The consumption of freshwater in mining accounts for only a small proportion of the total water use at global and even national scales. However, at regional and local scales, mining may result in significant impacts on freshwater resources, particularly when water consumption surpasses [...] Read more.
The consumption of freshwater in mining accounts for only a small proportion of the total water use at global and even national scales. However, at regional and local scales, mining may result in significant impacts on freshwater resources, particularly when water consumption surpasses the carrying capacities defined by the amount of available water and also considering environmental water requirements. By applying a geographic information system (GIS), a comprehensive water footprint accounting and water scarcity assessment of bauxite, cobalt, copper, iron, lead, manganese, molybdenum, nickel, uranium and zinc as well as gold, palladium, platinum and silver was conducted to quantify the influence of mining and refining of metal production on regional water availability and water stress. The observation includes the water consumption and impacts on water stress of almost 2800 mining operations at different production stages, e.g., preprocessed ore, concentrate and refined metal. Based on a brief study of mining activities in 147 major river basins, it can be indicated that mining’s contribution to regional water stress varies significantly in each basin. While in most regions mining predominantly results in very low water stress, not surpassing 0.1% of the basins’ available water, there are also exceptional cases where the natural water availability is completely exceeded by the freshwater consumption of the mining sector during the entire year. Thus, this GIS-based approach provides precise information to deepen the understanding of the global mining industry’s influence on regional carrying capacities and water stress. Full article
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15 pages, 12013 KiB  
Article
Poaching of Encephalartos transvenosus, in the Limpopo Province, South Africa
by Tshianeo M. Ndou, Eduard M. Stam, Milingoni P. Tshisikhawe, Mercy A. Alabi and Adeyemi O. Adeeyo
Resources 2021, 10(12), 119; https://doi.org/10.3390/resources10120119 - 23 Nov 2021
Cited by 3 | Viewed by 2811
Abstract
There is an established link between deforestation and negative hydrological effects which may affect watersheds. The number of the cycads Encephalartos transvenosus Stapf & Burtt Davy in South Africa is drastically reducing, and they are nearly extinct. Additionally, poaching and reduction in the [...] Read more.
There is an established link between deforestation and negative hydrological effects which may affect watersheds. The number of the cycads Encephalartos transvenosus Stapf & Burtt Davy in South Africa is drastically reducing, and they are nearly extinct. Additionally, poaching and reduction in the population of cycads in reserves may impact negatively on watersheds in protected and buffer areas since the regeneration of this plant occurs over a long period. This research aimed to study the distributions of poached cycads, evaluate the factors responsible for poaching activity and suggest possible solutions towards conservation of E. transvenosus Stapf & Burtt Davy in some of the nature reserves in Limpopo province. Field observation was used to ascertain and collect locations of poached cycads. Data was obtained through the use of a questionnaire. Questionnaires were administered to rangers for the collection of data on causes of poaching, parts poached, measures taken and challenges of rangers in the nature reserves. Processing of the collected data was done by simple statistical analysis. The total population of rangers available in the reserves was used for the determination of the sample size of rangers by Slovin’s formula. Unemployment (46%) is the leading cause for poaching in Mphaphuli Nature Reserve, while trade is a leading factor in Modjadji and Lekgalameetse (37% and 60%) respectively. Debarked cycads amount to 14 (54%) while 12 of the total (26 poached cycads) were completely removed (46%). The most effective way of stopping the poaching of cycads as perceived by the rangers is by patrolling the nature reserves. The observed poaching of Encephalartos transvenosus is alarming since this plant has a low population size which is currently confined to the Limpopo Province in South Africa only. If poaching continues in the nature reserves, all cycads have the tendency of being removed. Therefore, there is a need to continually develop strategies for the conservation of cycads. The peculiar nature and challenges of each reserve have been established and unique solutions for these nature reserves in Limpopo Province have been proposed. Better conservation of cycad species can positively impact the hydrological process of the concerned area and better help the watersheds. Full article
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14 pages, 1349 KiB  
Article
Pretreatment of Lignocellulosic Biomass with 1-Ethyl-3-methylimidazolium Acetate for Its Eventual Valorization by Anaerobic Digestion
by Jose D. Marin-Batista, Angel F. Mohedano and Angeles de la Rubia
Resources 2021, 10(12), 118; https://doi.org/10.3390/resources10120118 - 23 Nov 2021
Cited by 6 | Viewed by 2286
Abstract
This study assessed the breakdown of lignocellulosic biomass (LB) with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) as a pretreatment to increase the methane yield. The pretreatment was conducted for wheat straw (WS), barley straw (BS), and grape stem (GS) at 120 °C [...] Read more.
This study assessed the breakdown of lignocellulosic biomass (LB) with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) as a pretreatment to increase the methane yield. The pretreatment was conducted for wheat straw (WS), barley straw (BS), and grape stem (GS) at 120 °C for 120 min, using several LB to [Emim][Ac] ratios (1:1, 1:3, and 1:5 w/w). Pretreatment significantly disrupted the lignocellulose matrix of each biomass into soluble sugars. GS showed the highest sugar yield, which was followed by WS, while BS was slightly hydrolyzed (175.3 ± 2.3, 158.2 ± 5.2, and 51.1 ± 3.1 mg glucose g–1 biomass, respectively). Likewise, the pretreatment significantly reduced the cellulose crystallinity index (CrI) of the resulting solid fractions of GS and WS by 15% and 9%, respectively, but slightly affected the CrI of BS (5%). Thus, BMP tests were only carried out for raw and hydrothermally and [Emim][Ac] (1:5) pretreated GS and WS. The untreated GS and WS showed similar methane yields to those achieved for the solid fraction obtained after pretreatment with an LB to [Emim][Ac] ratio of 1:5 (219 ± 10 and 368 ± 1 mL CH4 g–1 VS, respectively). The methane production of the solid plus liquid fraction obtained after IL pretreatment increased by 1.61- and 1.34-fold compared to the raw GS and WS, respectively. Full article
(This article belongs to the Special Issue Resource Recovery from Wastewater)
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