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In recent years, attention to novel papermaking processes has increased significantly. The SEW fractionation process is one of the novel processes for producing a wide range of high value-added products such as pulp, paper, lignosulfonates, and biofuels in a biorefinery system. This study aimed to investigate the possibility of producing pulp and paper from Eldar pine (Pinus eldarica) using SEW fractionation and comparing it with the Kraft process followed by elemental chlorine free (ECF) bleaching. The results showed that the tensile, burst, and tear indexes are lower for SEW handsheets than for Kraft handsheets. The brightness before bleaching of SEW handsheets is higher than that of Kraft handsheets. The apparent density is higher for the SEW handsheets than the Kraft. Since there are some limitations in the use of SEW pulps such as high apparent density and lower strength properties than the Kraft pulps, however, these factors do not create industrial constraints for the use of these pulps. Low energy consumption of SEW pulps in the beating and high brightness before bleaching are among the obvious advantages of the SEW process. Therefore, it seems that in cellulose conversion industries, such as the production of nanocellulose, the use of SEW pulps has many advantages in terms of energy consumption, and the high brightness before bleaching eliminates long bleaching sequences in pulp mills. [ABSTRACT FROM AUTHOR]

Abstract: Black liquor gasification (BLG) has potential to replace a Tomlinson recovery boiler as an alternative technology to increase safety, flexibility and energy efficiency of pulp and paper mills. This paper presents an extensive literature review of the research and development of various BLG technologies over recent years based on low and high temperature gasification that include SCA-Billerud process, Manufacturing and Technology Conversion International (MTCI) process, direct alkali regeneration system (DARS), BLG with direct causticization, Chemrec BLG system, and catalytic hydrothermal BLG. A few technologies were tested on pilot scale but most of them were abandoned due to technical inferiority and very fewer are now at commercial stage. The drivers for the commercialization of BLG enabling bio-refinery operations at modern pulp mills, co-producing pulp and value added energy products, are discussed. In addition, the potential areas of research and development in BLG required to solve the critical issues and to fill research knowledge gaps are addressed and highlighted. [Copyright &y& Elsevier]

In this paper, a troubleshooting technique is developed to provide a sequence of necessary actions during deodorizer unit failure in a palm oil refinery. This paper introduces a fuzzy expert system that incorporates the knowledge of experienced plant workers in dealing with the complex problems of the palm oil deodorizer. The presented methodology uses both qualitative and quantitative data. Qualitative data are collected from several interview sessions with the technical staff in a palm oil refinery. Quantitative data are gathered from various sources, such as control and monitoring systems. The qualitative data are analyzed to discover the possible pattern of faults in the deodorizer failure. This tool can diagnose possible faults and provide a sequence of necessary actions when deodorizer failure occurs. The obtained results show the developed deodorizer troubleshooting tool is useful to guide plant workers/operators in diagnosing the possible faults and abnormalities during the troubleshooting process, as well as to provide field training for inexperienced staff. [ABSTRACT FROM AUTHOR]

The aim of this paper is to simulate a modular bio-refinery, which utilizes the thermochemical conversion process, to transform the Nigerian sawdust wood (Nesogordonia papaverifera) as feedstock to produce bio-oil, syngas, and bio-char. In this work, the thermochemical conversion process used is fast pyrolysis. For this work, the focus is on achieving an improved bio-oil, in both quality and quantity. The simulation software used is ASPEN Plus V11, using the fluid package Peng-Robinson with Boston-Mathias (PR-BM). The conventional components (N2, O2, H2O, H2, S, CO, CO2, and solid carbon) and non-conventional components (sawdust wood and ash) were adequately specified, and the reaction feeds were pyrolyzed at 300 °C at 5 bar, which generates the highest pyrolysis oil yield in comparison with other varied temperatures from 300 to 500 °C. In the process, the drying and decomposition were carried out using FORTRAN statements through calculator blocks. The result shows that the bulk of the bio-product is the bio-oil, with its component mixture being methanol, glyoxal, and glycol-01 taking up to about 70% yield. Sensitivity analysis shows that the yield of the bio-oil greatly reduces with a significant increase in temperature. Therefore, to ensure the optimal yield of the bio-oil for the Nigerian sawdust (Nesogordonia papaverifera) model used, the operating condition of the feed should be below 400 °C. [ABSTRACT FROM AUTHOR]

This paper describes an economic analysis of the GoBiGas plant, which is a first‐of‐its‐kind industrial installation for advanced biofuel production (ABP) via gasification, in which woody biomass is converted to biomethane. A previous technical evaluation of the demonstration unit confirmed that it is technically feasible to construct advanced biofuel production plants, using commercially available and widely used components. Thus, significant cost reductions for equipment cannot be expected as a consequence of learning effects. However, the equipment itself accounted for <20% of the total investment cost at GoBiGas and there exists the potential to reduce the production cost through learning how to assemble the process and reduce project‐specific costs. The analysis shows that a plant with capacity of 200 MW of biomethane is an attractive scale for future stand‐alone ABP plants with respect to limiting the production cost. For a 200‐MW ABP plant operated using forest residues as fuel, the production cost for biomethane is estimated at approximately 600 SEK/MWh, (60€/MWh, 75US$/MWh), which is equivalent to 5.4 SEK/liter gasoline [0.54 €/liter, or 2.5USD per gallon (9.9 SEK/€, 8 SEK/USD)], where the feedstock accounts for about 36% of the production cost. The most significant uncertainty factors pertaining to the estimated production costs are expected to relate to: trade conditions; the location of the installation; and the local price of feedstock. Thus, there is some potential for implementing cost‐competitive ABP systems of smaller capacity if low‐grade feedstocks (eg, waste‐derived woody biomass) can be utilized, and/or if the unit can be integrated with the already existing infrastructure. In this paper, we describe an economic analysis of the GoBiGas plant, which is a first‐of‐its‐kind industrial installation for advanced biofuel production (ABP) via gasification, in which woody biomass is converted to biomethane. [ABSTRACT FROM AUTHOR]

Studies on the effects of research and innovation in agriculture have been largely characterised by efforts to make a connection between expenditure and productivity. A number of issues have challenged the ability of productivity to measure the effects of research, namely, in recent years, increasing efforts towards improving the environmental performance of the farming sector. Besides environmental concerns, however, a number of recent concepts have emerged that are shaping the current research and policy agenda and which could result in a revision of the productivity concepts used to evaluate research impacts. The objective of this paper is to discuss these issues and their implications for studies on the impact of research and innovation. We address, in particular, the following issues: a) the development of the of bioeconomy and related concepts such as the circular economy, resource efficiency and bio-refinery; b) the connection with entrepreneurship and eco-innovation; c) changing tools in research assessment, in particular the widespread use of Life Cycle Assessment (LCA); and d) the evolving concepts of sustainability and ecosystem services. We argue that while the traditional notion of productivity, intended as output/input ratio, maintains (and may be strengthens) its role on the aggregate, a more analytical interpretation of the pathways towards research impacts is needed, as well as a broadened view of productivity and its determinants. [ABSTRACT FROM AUTHOR]

Levulinic acid (LA) has been ranked as one of the "Top 10" building blocks for future bio-refineries as proposed by the US Department of Energy. It is considered one of the most important platform molecules for the production of fine chemicals and fuels based on its compatibility with existing processes, market economics, and industrial ability to serve as a platform for the synthesis of important derivatives. Hydrogenation of LA to produce -valerolactone (GVL) is an active area of research due to the potential of GVL to be used as a biofuel in its own right and for its subsequent transformation into hydrocarbon fuels. This paper contains a new design for a simple, cost effective, and safe hydrogenation reactor for the transformation of levulinic acid to γ-valerolactone (GVL) by utilizing high boiling point organic fluid. The hydrogenation reactor is composed of a heating source--organic fluid (called "DOWTHERM A" or "thermex") and the catalytic reactor. The advantages of high boiling temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept more suitable and safer (water coming in contact with liquid metal is well understood in the metallurgical industry to be a steam explosion hazard) for heating the hydrogenation reactor. COMSOL multi-physics software version 4.3b was applied in this work and simultaneously solves the continuity, Navier-Stokes (fluid flow), energy (heat transfer), and diffusion with chemical reaction kinetics equations. It was shown that the heat flux supplied by the DOWTHERM A organic fluid could provide the necessary heat flux required for maintaining the hydrogenation process. It was found that the mass fractions of hydrogen and levulinic acid decreased along the reactor axis. The GVL mass fraction increased along the reactor axis. [ABSTRACT FROM AUTHOR]

• This paper summarizes the progress of EMF synthesis of biomass fuels in recent years, starting from the classification of different biomass feedstocks. • By summarizing and analyzing the different catalytic methods for various feedstocks, the limiting factors and key side reactions during the EMF synthesis reaction are presented. • Comprehensive analysis of the catalytic mechanism and theoretical calculations of EMF synthesis reactions in different studies is presented. The development of liquid fuel and fuel additive synthesis from abundant biomass substrates has obtained much attention in recent years. Among the proposed bio-fuels, 5-Ethoxymethylfurfural (5-EMF) is one of the most desirable gasoline alternatives because of its high stability, environment-friendly, and high energy density. More importantly, 5-EMF could be directly prepared from bio-based materials through etherification reactions in ethanol by straightforward synthetic methods from different biomass or bio-derived substrates, including 5-Hydroxymethylfurfural (5-HMF), fructose, glucose, and raw biomass. Given the apparent differences and crossover of catalytic approaches in the synthesis of 5-EMF from different feedstocks in the current publications. This paper reviews the research focus and catalyst characteristics in synthesizing 5-EMF using different feedstocks and compares the catalytic effect and mechanism of action of these catalysts in preparing 5-EMF. Hopefully, this review will facilitate and inspire future research on 5-EMF synthesis. [ABSTRACT FROM AUTHOR]

Abstract: The additional costs required for the pre‐treatment of lignocellulosic bio‐mass prior to enzymatic hydrolysis have limited the commercial implementation of lignocellulosic bio‐chemical production. The use of acidic mine drainage (AMD) water as an acid source for lignocellulosic pre‐treatment has recently been investigated. Large quantities of AMD in South Africa suggest that AMD can be obtained cheaply, thus reducing the cost and increasing the potential of lignocellulosic bio‐chemicals. Acidic mine drainage could undergo further remediation using sulfate‐reducing bacteria (SRB) so that the water is suitable for release. The feasibility of such a system could be greatly improved if this process were to be incorporated within a bio‐refinery, such that all fractions of the bio‐mass are used to produce multiple products. This paper investigates such a bio‐refinery system, and evaluates the different options based on the bio‐refinery complexity profile (BCP). Due to the abundance of grass in the regions where AMD is generated, this was found to be the most suitable feedstock. The most feasible bio‐refinery option was found to produce ethanol through fermentation of C6 sugars, although it is recommended that further investigation be conducted into additional high‐value bio‐chemicals from the C6 sugar platform. C5 sugars released in pre‐treatment could be used as a substrate by SRB for AMD remediation. Gasification and direct combustion of lignin had similar BCPs and thus further investigation is required to determine the preferred path. Similarly, further investigation is required for the best processing route for distillery silage. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

This paper reviews some of the most important aspects of microalgae as a potential source for biodiesel production. Microalgae are photosynthetic microorganisms that can grow rapidly in a variety of environments because of their unicellular or multicellular structure depending on the species. They have the advantage of self-reproduction using solar energy and converting it into chemical energy via photosynthesis. This process concludes a full cycle in a few days, obtaining higher lipid yields than terrestrial crops. This review shows several techniques and some methodologies used in the biodiesel production process from microalgae as well as the challenges that must be overcome for large-scale process and in bio-refineries. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A multistage process was employed to obtain value-added products from brewer's spent grain (BSG). This paper is focused on the production and characterisation of cellulose nano-fibres (CNF) as one of the products obtained during the complete process. In the first stage, protein-rich liquor was separated via the alkaline (NaOH) treatment of dried BSG and stored for further utilisation. In the second stage, bleaching treatments were conducted to separate cellulose, which was later converted to CNF by high-pressure homogenisation. The lignocellulosic product from each step was analysed for its chemical composition by means of alkaline hydrolysis combined with the HPEAC method. The thermal properties were measured using thermogravimetric analysis (TGA). The morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was done to observe changes in crystallinity. The nano-cellulose produced can be regarded as a value-added material from the bio-refinery of BSG along with numerous already-reported products. [ABSTRACT FROM AUTHOR]

• Glycerol-consuming Y. lipolytica can utilize glucose for efficient SA production. • First study for utilizing organic MSW in SA production by Y. lipolytica at low pH. • The highest SA yield of 0.61 g/g ever reported by yeast at low pH was achieved. • Fed-batch fermentation using waste hydrolysate at pH 2.8 resulted in 71.6 g/L SA. • Low pH SA production led to economic improvement and environmental sustainability. This paper presents an efficient, green and sustainable approach for succinic acid (SA) fermentation, in which glucose-rich hydrolysates from various waste streams were used as the substrate for SA production by Yarrowia lipolytica without pH control for the first time. First, Y. lipolytica PGC202 was found to be able to consume glucose-rich mixed food waste (MFW) hydrolysate for SA production with high efficiency. After medium optimization, a SA titer at 31.7 g/L with a yield of 0.52 g/g and productivity of 0.60 g/L/h was obtained from is FBB fermentation when using 60 g/L glucose-containing MFW hydrolysate as the carbon source supplemented with 3% tryptone. When glucose-rich hydrolysate from other waste streams was used, the highest SA yield of 0.61 g/g via yeast fermentation at low pH was achieved, which demonstrated the extensive substrate adaptability and great potential of Y. lipolytica. By feeding concentrated MFW hydrolysate, SA titer up to 71.6 g/L was achieved from fed-batch fermentation with pH decreased naturally to 2.8. Finally, with the revised recovery method, 68.3% of the total SA with purity between 89.5% and 91.0% was recovered from the acidic fermentation broth with only low input of acid for acidification, which demonstrated the great advantages of SA production at low pH over that under neutral conditions in terms of economic improvement and environmental sustainability. In general, this study overcomes one of the major economic drawbacks for future feasible large-scale fermentative SA production, and it also illustrates a promising prospective for bio-SA production. [ABSTRACT FROM AUTHOR]

The worldwide utilization of fossil energy, including its specific application as transportation fuel, significantly contributes to the continuous increase of the atmospheric CO 2 concentration. Several solutions have been promoted or scheduled to reduce CO 2 emissions. Among these solutions, the development of renewable energy resources, such as bio-fuels, offers important advantages as promoted by several countries and institutions who disclosed their plans to partly or totally use alternative renewable energy sources in the future. For the rapidly growing aviation sector, aviation fuel derived from fossil resources is still the major available energy source. The development of renewable aviation fuel is considered to be a promising future strategy to reduce related CO 2 emissions. The worldwide total aviation fuel consumption by commercial airlines increased from about 260 million m³/year in 2005 to over 340 million m³/year in 2018, and a further annual increase of about 5% is expected till 2050. Worldwide actions have hence been undertaken with respect to bio-aviation fuel production, distribution, and demonstration flying. As a relatively new topic, there are a lot of remaining challenges in technology development, fuel certification and distribution. The production technology, policy and environmental impact of bio-aviation fuel were comprehensively reviewed, including its production by the catalytic conversion of lipids, by the conversion of carbohydrates or lignocellulosic biomass, and by developing bio-refinery concepts for bio-aviation fuel production. The future reduction of CO 2 emissions in the aviation sector requires an improvement of the biomass to aviation fuel production technology through the correct integration of biology, chemical engineering, and energy crops. The paper illustrates this potential integration through reviewing the current research in the production of aviation fuels from biomass, including the complete industrial chain from airplane manufacturer, aviation fuel producer and provider, airline strategies, and ongoing R&D, bearing in mind that major efforts are required to foster the development of the cost-effective production of renewable aviation fuel. The different topics of the Table of contents will be subsequently dealt with. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• A critical review on the microalgae bio-refinery process synthesis via superstructure optimization. • The possible future research plans based on the research gaps were recommended. • Considering different feedstocks and products in superstructure is a good topic for future studies. • Development of the efficient exact or hybrid solution algorithms is a good subject for future studies. • Development of quantitative methods for analyzing the social aspects is a good topic for future studies. Microalgae have numerous potential advantages as feedstock in producing biofuels and other value-added end products. The variety in processing pathways for biofuel production is one of the main challenges in commercializing microalgae-based bio-refineries. The superstructure optimization method is a great solution to overcome this challenge and attracted much attention in the academic communities. In the present study, a systematic review of past studies has been carried out to determine the future perspective in the microalgae-based bio-refinery process synthesis area of study with an emphasis on the superstructure optimization approach. In this regard, the relevant papers published from 2011 to 2022 are taken from the literature and categorized based on different classifications such as their feedstocks and end products, mathematical model, model characteristics including uncertainty, objective function, sustainability, solution method, and economic and environmental analysis. Then, the existing research gaps in the literature have been described to specify future research directions. [ABSTRACT FROM AUTHOR]

Bioethanol is the most widely used alternative transportation fuel to petrol. Bioethanol is considered a clean, renewable, and environmentally friendly fuel that can contribute to climate change mitigation, decreased environmental pollution, and enhanced energy security. Commercial bioethanol production is based on traditional agricultural crops such as corn, sugarcane, and sugarbeet, primarily used as food and feed. In order to meet the growing demand for this fuel and decrease competition in the food and biofuel sectors for the same feedstock, other raw materials and process technologies have been intensively studied. Lignocellulosic biomass is one of the most abundant renewable resources, with it being rich in compounds that could be processed into energy, transportation fuels, various chemical compounds, and diverse materials. Bioethanol production from lignocellulosic biomass has received substantial attention in recent decades. This review gives an overview of bioethanol production steps from lignocellulosic biomass and challenges in the production process. The following aspects of bioethanol production are covered here, including pretreatment methods, process strategies, strain development, ethanol isolation and purification, and technical hurdles. [ABSTRACT FROM AUTHOR]

Scarcity and non-renewable nature of petroleum based liquid fuels have made them an un-reliable source of energy. Excessive greenhouse gas emissions and the associated effects on global warming have become noteworthy environmental, economic and social threats. In this milieu, the development of renewable, carbon-neutral and sustainable alternative energy sources has become inevitable. Biofuels have been found a promising alternative and a driving force for modern world. Different feed-stocks have been evaluated for biofuels production to date but microalgae have been found the most attractive due to their higher growth productivity, higher lipid contents, non-competitive nature with human food and their ability to grow on non-arable land using brackish or waste water. However, there are a number of technological barriers that are still questioning the economic feasibility and competitiveness of such biofuels. On the other hand, there are also a number of trade opportunities if we pay attention to the use of integrated system following the bio-refinery concept. Bio-refinery concept reflects the production of value added by-products along with the biofuels, contributing to an overall escalation of the economic feasibility of the whole system. These types of systems may help to progress the competitiveness of biodiesel production using microalgae as a potential feedstock. This paper reviews the most recent and relevant information on such integrated systems. Several aspects related to the treatment of municipal and animal wastewater with simultaneous recovery of microalgae and the potential of biodiesel production are discussed. Bio-refinery concept also presenting new opportunities for the cost-effective production of biodiesel coupled with valuable non-fuel by-products. [ABSTRACT FROM AUTHOR]

Abstract: Indonesia energy depends on fossil fuel which its availability get decrease; the price get higher day by day and the environment impact get worse on global warming. As tropical and agricultural country, Indonesia has plenty of bio- mass; therefore it was feasible to develop bio-fuel. In other, bio-fuel production must be wise because there were competition among food – feed – fuel. Jatropha curcas Linn (JCL) was one of non-edible bio-fuel resources, but there was mistake in development at Indonesia. This paper describe 8th study of gaseous bio-fuel from bio-methane with capsule husk as feedstocks, the waste of Crude Jatropha Oil (CJO). The study was conducted in Research Farm PT. Bumimas Ekapersada, Bekasi, West Java, from October until December 2011 to enhance the development of liquid bio-fuel – CJO/bio-diesel and gaseous bio-fuel – bio-methane in the concept of bio-refinery. Bio-methane was modern cooking fuel and the most efficient energetically. The utilization of industrial waste such as capsule husk will not compete with the food, but one of the problem was its low density, so the husk will float in the substrate. The problem can be solved by two stage digestion process, where hydrolysis reactor as process controlling. HDPE plastic drum with the volume of 160 liter was used as hydrolysis reactor. The reactors were arranged using Randomized Complete Design, three replications. The observed parameters were pH, temperature, substrate volume, volatile solid concentration, and acetic acid concentration This paper was focused on reporting of application technology modification on placement of ballast as oppressor substrate in hydrolysis reactor. 19kg of cement slabs is used to suppress 13kg dried husk (DH) + river water with the ratio 1: 8. The ballast was installed on 4, 7, 10 and 14 days of harvest retention time of hydrolysis substrate. The result showed ballast application can increase of hydrolysis substrate volume from 33.19% until 47.25% even no significantly different by statistical analysis. There was increasing in acetic acid concentration (93.27% - 128.51%) and statistical analysis showed significantly different on 4 days treatment. There was increasing on hydrolysis solution production on 4 days treatment (229.48%) and it was significantly different according statistical analysis. As the conclusion, the usage of 19kg ballast as oppressor can increase hydrolysis solution productivity on 160 liter HDPE hydrolysis reactor with concentration 1: 8 on 4 days harvest retention time. [Copyright &y& Elsevier]

Abstract: Black liquor gasification (BLG) for bio-fuel or electricity production at the modern pulp mills is a field in continuous evolution and the efforts are considerably driven by the climate change, fuel security, and renewable energy. This paper evaluates and compares two BLG systems for methanol production: (i) oxygen blown pressurized thermal BLG; and (ii) dry BLG with direct causticization, which have been regarded as the most potential technology candidates for the future deployment. A key objective is to assess integration possibilities of BLG technologies with the reference Kraft pulp mill producing 1000air dried tonnes (ADt) pulp/day replacing conventional recovery cycle. The study was performed to compare the systems’ performance in terms of potential methanol production, energy efficiency, and potential CO2 reductions. The results indicate larger potential of black liquor conversion to methanol from the pressurized BLG system (about 77million tonnes/year of methanol) than the dry BLG system (about 30million tonnes/year of methanol) utilizing identical amount of black liquor available worldwide (220million tDS/year). The potential CO2 emissions reduction from the transport sector is substantially higher in pressurized BLG system (117million tonnes/year CO2 reductions) as compared to dry BLG system (45million tonnes/year CO2 reductions). However, the dry BLG system with direct causticization shows better results when considering consequences of additional biomass import. In addition, comparison of methanol production via BLG with other bio-refinery products, e.g. hydrogen, dimethyl ether (DME) and bio-methane, has also been discussed. [Copyright &y& Elsevier]

South Africa has a wide range of mining activities making mineral resources important economic commodities. However, the industry is responsible for several environmental impacts; one of which is acid mine drainage (AMD). Despite several years of research, attempts to prevent AMD generation have proven to be difficult. Therefore, treatment of the resulting drainage has been common practice over the years. One of the recommended treatment methods is the use of second generation feedstocks (lignocellulosic biomass). This biomass is also acknowledged to be an important feedstock for bio-refineries as it is abundant, has a high carbon content and is available at minimal cost. It can also potentially be converted to fermentable sugars (e.g. glucose) through different treatment steps, which could further yield other valuable commodities (cellulase, poly-β-hydroxybutyric acid (PHB) and penicillin V). It is estimated by a generic flowsheet model that 7 tons of grass biomass can produce 1400 kg of glucose which can subsequently produce 205 kg, 438 kg and 270 kg of cellulase, PHB and Penicillin V, respectively. In this paper we investigate the feasibility of grass as feedstock for AMD treatment and the subsequent conversion of this acid pre-treated grass into valuable bio-products. [ABSTRACT FROM AUTHOR]

Although normally seen as a problem, current policies and strategic plans concur that if adequately managed, waste can be a source of the most interesting and valuable products, among which metals, oils and fats, lignin, cellulose and hemicelluloses, tannins, antioxidants, caffeine, polyphenols, pigments, flavonoids, through recycling, compound recovery or energy valorization, following the waste hierarchy. Besides contributing to more sustainable and circular economies, those products also have high commercial value when compared to the ones obtained by currently used waste treatment methods. In this paper, it is shown how the bio-refinery framework can be used to obtain high value products from organic waste. With spent coffee grounds as a case study, a sequential process is used to obtain first the most valuable, and then other products, allowing proper valorization of residues and increased sustainability of the whole process. Challenges facing full development and implementation of waste based bio-refineries are highlighted. [ABSTRACT FROM AUTHOR]

One of the consequences of the increase of large dairy concentrated feeding operations (CAFOs) is the abundance of dairy manure that needs to be disposed of or used in some way. CAFOs can become bio-refineries, harnessing the manure for heat, power, fuel, chemicals, fertilizers, fiber, wood composites, and biochar for production of multiple value-added co-products. The objective of this paper is to review options for using dairy manure fiber and its corresponding anaerobically digested (AD) fiber. Bedding for cows remains a common choice for employing the separated AD fiber. However, research has shown that AD fiber has potential for using it as a component of growth substrates used in container plant production systems, for producing composite materials, or as a feedstock for both chemical and thermochemical operations. Potential uses of AD fiber such as composite materials and liquid fuels are proposed based on experiences employing the manure and its fiber (both without a previous AD step and after AD). Thermochemical processing (e.g., liquefaction and pyrolysis) of AD fiber for fuels and chemicals has been conducted at laboratory level and still needs further study at larger scale. Gasification of AD fiber is a promising option since there is potential for integration of current methane production with methane produced from thermal gasification. [ABSTRACT FROM AUTHOR]

An efficient integrated bio-refinery process was established for mass production of silica, lignin, and nanocellulose from rice straw lignocellulose. A three-step process was used for achievement of three value-added products as: silica, lignin, and nanocellulose. At the first step of process, sodium hydroxide of 18% dosage was used as pulping agent to dissolve lignin, silica and other substances in rice straw to obtain cellulose pulp and black liquor. At the second step, silica powder and lignin are recovered by precipitation with sulfuric acid at suitable pH. Third step of process is nanocellulose fabrication from bleached cellulose pulp using a mixture of H2SO4 and H2O2. The suitable technical parameter for silica, lignin, and nanocellulose fabrication was established. At suitable condition, the silica, lignin, and nanocellulose yields were about 9.5%, 12.4%, and 28.7%, respectively, compared to the starting material in experimental scale. Moreover, this bio-refinery process was scaled-up for mass production of three products with relative high yields. The as-obtained products were characterized by SEM, IR, and XRD for determine the structure and morphology. [ABSTRACT FROM AUTHOR]

• Utilization of spent coffee grounds to biofuels and value-added products is presented. • Valorization of other coffee industry by-products to high-value refined products are suggested. • Potential of membrane technology for separation and purification of biofuels and value-added products is demonstrated. • Pathways towards SCG-integrated biorefinery scheme are proposed. Coffee is the second largest traded commodity after petroleum and the second most popular beverage after water. This big industry is believed to generate huge amount of waste with spent coffee grounds (SCGs) represents one of the main by-products. Recycling of such waste to fuels and value-added products through bio-refineries is a promising way to solve the problem of many countries that face daily challenges and heavy cost in waste disposal. This review aims to shadow the light on SCGs recycling potential in which over 230 published papers on SCGs recycling topic were gathered and discussed. Various opportunities to produce biofuels such as biodiesel, biogas, bioethanol, bio-oil and fuel pellets besides value-added products such as bioactive compounds, adsorbents, polymers, nanocomposites, and compost were discussed. Moreover, the potential of membrane technology related to various processes of biorefining, separation and purification in the proposed SCG-integrated biorefinery are presented. Based on the presented review, it is obvious that recycling of SCGs offers many worthwhile options to policymakers that can contribute towards huge financial saving on taxpayers of running and maintaining landfills besides saving the environment from harmful emissions. In conclusion, this review emphasizes that SCG-integrated biorefineries to produce different types of biofuels and value-added products are a very promising approach that shall be economically more scrutinized in the foreseen future. [ABSTRACT FROM AUTHOR]

Glycerol is a by-product of biodiesel, soap and fatty acid manufacturing plants, which are now facing sustainability threats and a reduction in prices in the market due to its oversupply as a result of the rapid expansion of biodiesel plants all over the world. The global production and consumption of glycerol, as well as demand and supply, are evaluated here. Glycerol offers a wide range of new opportunities based on its transformation in many applications due to its unique properties, renewability and availability in the current market. This paper is a comprehensive review of the utilization of glycerol as a value-added commodity, including in the synthesis of chemicals, in the production of hydrogen gas, as a fuel additive, as a fermentation substrate, in the co-pyrolysis and co-gasification of glycerol, in methanol production, in the development of fuel cells, in wastewater treatment and in many other applications. In the future, glycerol definitely will become a promising renewable feedstock in biorefineries to synthesize fuel, chemicals and power. [ABSTRACT FROM AUTHOR]

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Food chain-based waste is generated in tonnes globally and this has led to release of greenhouse gases, poor air quality, land and water pollution. Food wastes are generated in tremendous quantity globally from local producer to international consumers and traders. Authors have used systematic literature review to identify the research gaps, thematic areas, methodology, sustainable techniques and future directions of processing food supply chain waste. Research is focused towards utilization of food waste as source for recovery of value-added compounds through sustainable technologies. Food waste can be utilized to synthesis platform chemicals, nutraceuticals, sugars, bio-fuels, bio-gas and bio-char via thermo-chemical conversion, anaerobic digestion and fermentation processes. This paper summarizes and provides technical insights on achieving circular bio-economy via technological advances in food waste processing for enhanced recovery of value-added compounds and future industrial scale operations. The state of art perspectives of food waste valorization and market outlook of platform chemicals and other products provides profitable economy for the food waste generator. Food security requires holistic approaches for effective usage of resources with inter linked global policies. [ABSTRACT FROM AUTHOR]

Photosynthetic pigments, including chlorophyll, have an important role since they provide the oxygen and the source of energy for all living things. Plant and algae growth is affected by the photosynthesis speed which depends on the availability of carbon dioxide (CO 2 ). This paper reports on the pilot plant scale study of the impact of 20% to 50% CO 2 on biogas into the growing medium of microalgae which obtained bio-methane purification results as gaseous bio-fuels. Research material was produced from the Jatropha curcas Linn. husk biogas digester and a 0.15 m 3 HDPE drum was used as a purification. The purification tank was filled with Catfish ( Clarias gariepinus ) farm water which grew “wild” microalgae naturally. The water was fed from the top with continuous flow of (16 to 31) L· min –1 and the biogas was fed from the bottom at (18 to 29) L · min –1 . CO 2 level data of biogas was measured by orsat apparatus and processed with t test. The results achieved average efficiency reduction levels of CO 2 on 50% in two cycles (24% in the first and 26% in the second). [ABSTRACT FROM AUTHOR]