Sustainable Processing Of Biomass Research Articles

Solar and open sun drying of untreated and pretreated banana stalk chips biomass: a sustainable processing of biomass using renewable solar energy

The stalk of banana is an abundant biomass that can be sustainably converted into bioenergy, biofuels, biosorbents, animal feeds and fibers. The moisture content of freshly harvested banana stalk is high, so drying is essential before its storage and prior to some of the conversion processes. Hence, solar and open sun drying characteristics of banana stalk chips were investigated. Untreated (5, 10 and 15 mm thick) and pretreated (hot water, salt water and sulphite) banana stalk chips were dehydrated in a solar dryer and directly in sunlight. The data were fitted to twelve drying models. The moisture diffusivities were also evaluated. Banana stalk dried mainly in the falling-rate phase and the rate of drying increased with decreasing chip thickness. However, the chips dried slower in direct sunlight compared to the solar dryer. The pretreatments significantly (P < 0.05) enhanced the rate of dehydration of the chips in the solar dryer. Diffusivities for the solar and direct sunlight drying of banana stalk chips were 1.28 × 10–9–5.32 × 10–9 m2 s−1 and 1.08 × 10–9–3.65 × 10–9 m2 s−1, respectively. The Weibull model aptly described the solar drying of the chips while the Midilli-Kucuk and Weibull models most properly depicted the open sun dehydration of untreated and pretreated chips, respectively. Solar energy may be more efficiently utilized for drying banana stalk chips biomass by using a solar dryer as well as a very thin layer of chips and by pretreating the biomass prior to the drying operation. The effective use of solar energy for drying banana stalk biomass can reduce its processing cost and enhance the sustainability of biomass utilization.

Development of life cycle inventory and greenhouse gas emissions from damaged paddy grain as fermentation feedstock: A case study in Malaysia

Glucose is an intermediate substance of various bio-based products in a biorefinery concept. A sustainable processing of biomass into glucose could provide alternative for managing waste of the paddy industry. A detailed model of glucose production life cycle inventory from the waste of the paddy industry, and evaluation of potential greenhouse gas was conducted from a cradle-to-gate approach in Malaysia. The foreground data for cultivation and milling of EPFG was based on real production data, while glucose production was based on laboratory study. The inventory highlighted the areas where the processing system would have the largest impact on raw materials, energy consumption, and emissions. This life cycle GHG quantifies the main hotspot for glucose production from paddy waste with agriculture at 74.6% and purification process at 5.3%, thus indicating a significant impact on the systems. The overall GHG impact of glucose production in mass allocation procedure produces 1.2 t CO2eq/t glucose. Finally, based on the comparison analysis results, converting paddy processing waste into glucose may be considered as an alternative for managing waste from paddy supply chain as the total emissions are within the second-generation feedstock biorefinery.

MICROALGAE AS A PROMISING ALTERNATIVE FOR DEVELOPMENT OF BIOREFINERIES: MAIN TECHNOLOGICAL AND ECONOMICAL CHALLENGES

Biorefining is sustainable biomass processing to obtain energy, biofuels and high value products through different technologies and processes for biomass transformation. On the other hand, microalgae have been received great interest as a biofuel feedstock in response to the uprising energy crisis, climate change and depletion of natural sources. However, the development of microalgal biofuels does not satisfy the economic feasibility to reach commercial status. Due to this, different high-value co-products have been produced through the extraction of microalgae fractions to improve the economical profile of this technology, generating in this way the microalgae biorefineries. Examples of these high-value products are pigments, proteins, lipids, carbohydrates, vitamins, and antioxidants, with applications in cosmetics, nutritional and pharmaceuticals industries. To promote the sustainability of this process, an innovative microalgae biorefinery structure is implemented through the generation of multiple products, usually in form of biofuel and other high valueproducts. This review presents the current challenges in the extraction of high value products from microalgae and its integration in the biorefinery. It describes the general characteristics of microalgae, and their potential to be used as a raw material in the biorefinery process.&#x0D; Keywords: microalgae, bioenergy, bioproducts, biorefineries.

Sugarcane biorefineries: potential opportunities towards shifting from wastes to products

Biorefining involves the sustainable processing of biomass into a spectrum of marketable food and feed ingredients, bio-based products (chemicals and materials), and bioenergy (biofuels, power, and/or heat). The processing of sugarcane is a successful example of renewable bioenergy being produced on a large industrial scale. As the world largest crop by production quantity, around 1907 millions of tons of sugarcane were globally produced last year. Currently, most of the sugarcane mills produce first generation (1 G) ethanol, sugar, and energy from the burning of bagasse. However, the use of part of the sugarcane bagasse to produce second generation (2 G) ethanol is beginning to move towards an industrial reality. The 2 G ethanol process itself also generates several side-streams, which could be further used to obtain high added-value products. Integrated 1 G-2 G biorefineries, where the whole sugarcane biomass is converted to bioenergy and a suite of bio-based products, can be an attractive investment option for a future scenario of a low-carbon economy. The purpose of this review is to gather together the most recent technologies that have been developed to enable the whole use of feedstocks, byproducts, and side-streams within the sugarcane biorefinery. Possible ways to improve the efficiency of biomass processing are discussed, such as the use of low-cost additives, together with the economic and environmental aspects related to the implementation of a sugarcane biorefinery. Potential applications of sugarcane bagasse and straw to obtain valuable products including enzymes, biofertilizers, nanocellulose and lignin-derived commodities are presented as opportunities to improve the attractiveness of this business model.

Quantitative recovery and regeneration of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate via industrial strategy for sustainable biomass processing

Quantitative recovery is necessary for scale-up application of acidic ionic liquids (AILs). Ultrafiltration and bipolar membrane electrodialysis (BMED) was employed for the recovery and regeneration of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate (Bmim[HSO4]) after biomass pretreatment. Ultrafiltration was designed for the purification of BMED feed solution. During BMED treatment, Bmim+ retention with OH− generation occurred in mixing section and SO42− immigration with H+ generation occurred in aciding section. Resulting aqueous Bmim[OH] in mixing section and H2SO4 in aciding section could be utilized for quantitative synthesis of Bmim[HSO4]. Influence of BMED operating mode and major parameters including BMED feed concentration and current density of BMED module were studied in detail. The highest recovery ratio for Bmim+ and SO42− reached 96.2% and 96.0%. And the lowest energy consumption of specific Bmim[HSO4] recovery approached 9.0 kw∙h/kg. Insight gained from this study suggested a sustainable biomass processing methodology using AILs.

Biorefinery Approach for Aerogels.

According to the International Energy Agency, biorefinery is “the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (fuels, power, heat)”. In this review, we survey how the biorefinery approach can be applied to highly porous and nanostructured materials, namely aerogels. Historically, aerogels were first developed using inorganic matter. Subsequently, synthetic polymers were also employed. At the beginning of the 21st century, new aerogels were created based on biomass. Which sources of biomass can be used to make aerogels and how? This review answers these questions, paying special attention to bio-aerogels’ environmental and biomedical applications. The article is a result of fruitful exchanges in the frame of the European project COST Action “CA 18125 AERoGELS: Advanced Engineering and Research of aeroGels for Environment and Life Sciences”.

Optimization of enzymatic hydrolysis of bamboo biomass for enhanced saccharification of cellulose through Taguchi orthogonal design

Conversion of raw lignocellulosic biomass is a challenge when the processes have to be carried out on a larger scale in industrial units for bioethanol production. Hence, sustainable biomass processing technologies are essential to attain higher productivity at reduced operational costs. For this purpose, optimization of process parameters of enzymatic hydrolysis of Bambusa bambos was carried out using commercially available cellulase. The effect of different physicochemical parameters such as pH, temperature, enzyme/substrate ratio, mixing speed, and feed particle size was investigated. To analyze their effect on enzymatic hydrolysis and to find optimum values of these parameters, the Taguchi method of optimization was utilized. Five factors pH (4–7), temperature (32−56 °C), enzyme/substrate ratio (5–20 %), mixing speed (0−180 rpm) and particle size (60−240μM) with four levels produced L16 orthogonal Taguchi experimental design. Experiments were performed as per design and responses were analyzed in terms of glucose production. The optimum response (132.67 mg/dl of glucose) was found at pH 5, temperature 48 °C, enzyme/substrate ratio of 20 %, zero mixing speed, and 60 μM particle size. Enzyme/substrate ratio and pH exhibited more contribution to optimum response than mixing speed and particle size. Thus, we recommend that operate the enzymatic hydrolysis at lower mixing speed and particle size to economize the process while handling higher solid loadings.

Lignocellulosic biomass: Hurdles and challenges in its valorization.

Lignocellulosic biomass (LCB) is globally available and sustainable feedstock containing sugar-rich platform that can be converted to biofuels and specialty products through appropriate processing. This review focuses on the efforts required for the development of sustainable and economically viable lignocellulosic biorefinery to produce carbon neutral biofuels along with the specialty chemicals. Sustainable biomass processing is a global challenge that requires the fulfillment of fundamental demands concerning economic efficiency, environmental compatibility, and social responsibility. The key technical challenges in continuous biomass supply and the biological routes for its saccharification with high yields of sugar sources have not been addressed in research programs dealing with biomass processing. Though many R&D endeavors have directed towards biomass valorization over several decades, the integrated production of biofuels and chemicals still needs optimization from both technical and economical perspectives. None of the current pretreatment methods has advantages over others since their outcomes depend on the type of feedstock, downstream process configuration, and many other factors. Consolidated bio-processing (CBP) involves the use of single or consortium of microbes to deconstruct biomass without pretreatment. The use of new genetic engineering tools for natively cellulolytic microbes would make the CBP process low cost and ecologically friendly. Issues arising with chemical characteristics and rigidity of the biomass structure can be a setback for its viability for biofuel conversion. Integration of functional genomics and system biology with synthetic biology and metabolic engineering undoubtedly led to generation of efficient microbial systems, albeit with limited commercial potential. These efficient microbial systems with new metabolic routes can be exploited for production of commodity chemicals from all the three components of biomass. This paper provides an overview of the challenges that are faced by the processes converting LCB to commodity chemicals with special reference to biofuels.

Chemical Transformations of Biomass-Derived C6-Furanic Platform Chemicals for Sustainable Energy Research, Materials Science, and Synthetic Building Blocks

Recent advances in the area of biomass-derived C6-furanic platform chemicals for sustainable biomass processing are analyzed focusing on chemical reactions important for development of practical applications and materials science. Among the chemical processes currently being studied, tuning the amount of oxygen-containing functional groups remains the most active research direction. Production of efficient fuels requires the removal of oxygen atoms (reduction reactions), whereas utilization of biomass-derived furanic derivatives in material science points out the importance of oxidation in order to form dicarboxylic derivatives. Stimulated by this driving force, oxidation and reduction of 5-(hydroxymethyl)furfural (HMF) are nowadays massively studied. Moreover, these fundamental transformations are often used as model reactions to test new catalysts, and HMF transformations guide the development of new catalytic systems. From the viewpoint of organic synthesis, highly diverse chemical reactivity is explor...

Separation technology–Making a difference in biorefineries

In the quest for a sustainable bio-based economy, biorefineries play a central role as they involve the sustainable processing of biomass into marketable products and energy. This paper aims to provide a perspective on applications of separations that can make a great difference in biorefineries, by significantly reducing the costs and thus making the processes competitive without subsidies. A parallel is drawn between bio-refinery and petro-refinery, to highlight the specific separation challenges encountered in biorefineries and point out the impact of separations on the total costs. Existing and foreseen separations in biorefineries are reviewed, and the upcoming challenges in the bio-domain (additional to current fossil) are identified. Relevant industrial examples are provided to illustrate the tremendous eco-efficiency benefits of well-designed separation processes based on process intensification principles (e.g. reactive separations, dividing-wall column, affinity and trigger-enhanced separations). These examples also illustrate the low sustainability of several bio-separations currently practiced, in terms of high relative energy requirements, large amounts of gypsum co-production and/or excess use of caustic.

Strategy and design of Innovation Policy Road Mapping for a waste biorefinery

Looming energy crisis, climate change concerns coupled with decreasing fossil fuel resources has garnered significant global attention toward development of alternative, renewable, carbon-neutral and eco-friendly fuels to fulfil burgeoning energy demands. Waste utilization and its management are being pursued with renewed interest due to the gamut of biobased products it can offer apart from providing enough energy to meet a major fraction of the world’s energy demand. Biorefining is the sustainable processing of biomass into a spectrum of marketable products and energy. Integrating all components of waste treatment culminating into biobased products and energy recovery in a single integrated waste biorefinery is self sufficient, highly sustainable and is very beneficial. Designing systematic innovation policies are essential for development and commercialization of new technologies in this important futuristic research area. This communication explores Innovation Policy Road Mapping (IPRM) methodology available in the literature and applies it to design integrated waste biorefinery.

Biohydrogen, biomethane and bioelectricity as crucial components of biorefinery of organic wastes: a review.

Biohydrogen is a sustainable form of energy as it can be produced from organic waste through fermentation processes involving dark fermentation and photofermentation. Very often biohydrogen is included as a part of biorefinery approaches, which reclaim organic wastes that are abundant sources of renewable and low cost substrate that can be efficiently fermented by microorganisms. The aim of this work was to critically assess selected bioenergy alternatives from organic solid waste, such as biohydrogen and bioelectricity, to evaluate their relative advantages and disadvantages in the context of biorefineries, and finally to indicate the trends for future research and development. Biorefining is the sustainable processing of biomass into a spectrum of marketable products, which means: energy, materials, chemicals, food and feed. Dark fermentation of organic wastes could be the beach-head of complete biorefineries that generate biohydrogen as a first step and could significantly influence the future of solid waste management. Series systems show a better efficiency than one-stage process regarding substrate conversion to hydrogen and bioenergy. The dark fermentation also produces fermented by-products (fatty acids and solvents), so there is an opportunity for further combining with other processes that yield more bioenergy. Photoheterotrophic fermentation is one of them: photosynthetic heterotrophs, such as non-sulfur purple bacteria, can thrive on the simple organic substances produced in dark fermentation and light, to give more H2. Effluents from photoheterotrophic fermentation and digestates can be processed in microbial fuel cells for bioelectricity production and methanogenic digestion for methane generation, thus integrating a diverse block of bioenergies. Several digestates from bioenergies could be used for bioproducts generation, such as cellulolytic enzymes and saccharification processes, leading to ethanol fermentation (another bioenergy), thus completing the inverse cascade. Finally, biohydrogen, biomethane and bioelectricity could contribute to significant improvements for solid organic waste management in agricultural regions, as well as in urban areas.

Microalgae based biorefinery: Issues to consider

Biorefining is sustainable biomass processing to obtain energy, biofuels and high value products through processes and equipment for biomass transformation. The biorefinery concept has been identified as the most promising way to create a biomass-based industry. Microalgae are classified as promising candidates in biorefinery processes because they are particularly important for obtaining multiple products. This review article describes the biorefinery concept taking into account its different interpretations and comparing it with the traditional biomass transformation processes. It describes the general characteristics of microalgae, and their potential to be used as a raw material in the biorefinery process. The review focuses on the state of the art of products obtained from microalgae for the biofuel industry, mainly for biodiesel production, and the different methods to extract oil for biodiesel production as well as other products. Based on this information, several aspects are suggested to be taken into account for the development of a topology for a microalgae-based biorefinery.

Life cycle analyses and resource assessments.

Prof. Ulgiati stresses that we should always use an ecosystem view when transforming energy from one form to another. Sustainable growth and development of both environmental and human-dominated systems require optimum use of available resources for maximum power output. We have to adapt to the laws of nature because nature has to take care of all the waste products we produce. The presentation addresses a much needed shift away from linear production and consumption pattern, toward reorganization of economies and lifestyle that takes complexity--of resources, of the environment and of the economy--into proper account. The best way to reach maximum yield from the different kinds of biomass is to use biorefineries. Biorefinery is defined as the sustainable processing of biomass into a spectrum of marketable products like heat, power, fuels, chemicals, food, feed, and materials. However, biomass from agricultural land must be used for the production of food and not fuel. Prof. Voss focuses on the sustainability of energy supply chains and energy systems. Life cycle analyses (LCA) provides the conceptual framework for a comprehensive comparative evaluation of energy supply options with regard to their resource requirements as well as the health and environmental impact. Full scope LCA considers not only the emissions from plant operation, construction, and decommissioning but also the environmental burdens and resource requirements associated with the entire lifetime of all relevant upstream and downstream processes within the energy chain. This article describes the results of LCA analyses for state-of-the-art heating and electricity systems as well as of advanced future systems. Total costs are used as a measure for the overall resource consumption.

Methane-free biogas for direct feeding of solid oxide fuel cells

This paper deals with the experimental analysis of the performance and degradation issues of a Ni-based anode-supported solid oxide fuel cell fed by a methane-free biogas from dark-anaerobic digestion of wastes by pastry and fruit shops. The biogas is produced by means of an innovative process where the biomass is fermented with a pre-treated bacteria inoculum (Clostridia) able to completely inhibit the methanization step during the fermentation process and to produce a H 2/CO 2 mixture instead of conventional CH 4/CO 2 anaerobic digested gas (bio-methane). The proposed biogas production route leads to a biogas composition which avoids the need of introducing a reformer agent into or before the SOFC anode in order to reformate it. In order to analyse the complete behaviour of a SOFC with the bio-hydrogen fuel, an experimental session with several H 2/CO 2 synthetic mixtures was performed on an anode-supported solid oxide fuel cell with a Ni-based anode. It was found that side reactions occur with such mixtures in the typical thermodynamic conditions of SOFCs (650–800 °C), which have an effect especially at high currents, due to the shift to a mixture consisting of hydrogen, carbon monoxide, carbon dioxide and water. However, cells operated with acceptable performance and carbon deposits (typical of a traditional hydrocarbon-containing biogas) were avoided after 50 h of cell operation even at 650 °C. Experiments were also performed with traditional bio-methane from anaerobic digestion with 60/40 vol% of composition. It was found that the cell performance dropped after few hours of operation due to the formation of carbon deposits. A short-term test with the real as-produced biogas was also successfully performed. The cell showed an acceptable power output (at 800 °C, 0.35 W cm −2 with biogas, versus 0.55 W cm −2 with H 2) although a huge quantity of sulphur was present in the feeding fuel (hydrogen sulphide at 103 ppm and mercaptans up to 10 ppm). Therefore, it was demonstrated the interest relying on a sustainable biomass processing which produces a biogas which can be directly fed to SOFC using traditional anode materials and avoiding the reformer component since the methane-free mixture is already safe for carbon deposition.

The development of biocommodities and the role of North West European ports in biomass chains

AbstractBiomass‐derived commodities will compete with commodities derived from fossil fuels in 20 years' time. This perspective will explore the economic conditions that will govern the development of, and the trade in these biocommodities. Markets for biocommodities will open up new revenues for both the agricultural and the chemical sector. We shall explore the importance of the biorefinery concept for the establishment of these new markets.Biorefinery is the sustainable processing of biomass into a spectrum of marketable products and energy. Trade in biobased substances will be greatly enhance if standard ‘commodities’ are defined and produced in several places in the world.Now we turn to the second question of this perspective: where will biocommodities be produced and where will they be used? The choice of where to process the biomass will depend on the type of biomass, transport distances, bulk density, decay rate, ease of handling, the type of process(ses), the presence of markets, the cost of labor, and logistical conditions.Ports, both on the exporting side and on the importing side, will have a major influence on the formation of biomass chains. In export ports, crude or partially pre‐treated biomass will be collected and processed/ transformed into a biocommodity. Existing industries, such as feed production, can be combined with the production of biocommodities, The role of port areas and chemical industries in several biomass chains are shown. The combination of a major port and major application markets for biomass, such as feed industry, chemical industry, biofuels industry and power generation, will allow for the formation of a biomass hub.The formation of a biomass hub will be a step‐by‐step process in which services and exchange markets are added to existing logistical and industrial structures. The port of Rotterdam has an excellent starting point to become a hub in international biomass trade and processing. In the near future, 5–15 years from now, international biomass trade will become standardized and biocommodities will be defined, partly on the basis of technologies still in development. © 2009 Society of Chemical Industry and John Wiley &amp; Sons, Ltd