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[en] A great fraction of worldwide energy carriers and material products come from fossil fuel refinery. Because of the on-going price increase of fossil resources, their uncertain availability, and their environmental concerns, the feasibility of oil exploitation is predicted to decrease in the near future. Therefore, alternative solutions able to mitigate climate change and reduce the consumption of fossil fuels should be promoted. The replacement of oil with biomass as raw material for fuel and chemical production is an interesting option and is the driving force for the development of biorefinery complexes. In biorefinery, almost all the types of biomass feedstocks can be converted to different classes of biofuels and biochemicals through jointly applied conversion technologies. This paper provides a description of the emerging biorefinery concept, in comparison with the current oil refinery. The focus is on the state of the art in biofuel and biochemical production, as well as discussion of the most important biomass feedstocks, conversion technologies and final products. Through the integration of green chemistry into biorefineries, and the use of low environmental impact technologies, future sustainable production chains of biofuels and high value chemicals from biomass can be established. The aim of this bio-industry is to be competitive in the market and lead to the progressive replacement of oil refinery products. (author)
[en] Biomass fast pyrolysis liquefaction has aroused great attention and interests both at home and abroad extensively in recent years. This paper reviews the physicochemical properties and discusses the characteristics of the components and compositions of biomass pyrolysis oil. Furthermore, the problems and focuses were summarized with some suggestions presented on upgrading and applications of bio-oil in the decades
[en] Highlights: • MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus. • Treatment condition had obvious effect on yield of furfural and glucose conversion. • Optimum condition was obtained (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). • MIBK/H2O pretreatment was effective for production of clean energy and biochemical. - Abstract: Forest wood biomass can be a sustainable and cost-effective feedstock for the biorefinery industries, but the rigid and compact structure of plant cell is a major barrier for production of clean energy and biochemical. In this case, the MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus and then systematically evaluated pretreatment conditions (e.g., MIBK/H2O ratio, reaction temperature and time, NaCl concentration, and HCl dosage) on the effect of furfural yield. The resulting solid fraction obtained from the optimum pretreatment condition for furfural yield was to produce fermentable glucose by enzymatic hydrolysis. Study on enzymatic hydrolysis of the raw material and resulting solid fraction obtained by single aqueous system was also contrastively investigated. The furfural yield was 65.9% and the recovery of residue was 46.9% under an optimal reaction condition (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). Meanwhile, the yield of glucose of cellulose was improved after the pretreatments with different systems and a maximum value was up to 60.2% by the MIBK/H2O pretreatment. The effective fermentable glucose production was mainly affected by the significant removal of hemicelluloses, change of CrI, and destruction of surface morphology of Eucalyptus. The MIBK/H2O pretreatment can be considered as a potential approach for efficient conversion of Eucalyptus to clean energy and biochemicals.
[en] Highlights: ► Simplified model for biomass combustion was developed. ► Porous zone conditions are used in the bed. ► Model is fully integrated in a commercial CFD code to simulate a small scale pellet boiler. ► Pollutant emissions are well predicted. ► Simulation provides extensive information about the behaviour of the boiler. - Abstract: This paper presents a computational fluid dynamic simulation of a domestic pellet boiler. Combustion of the solid fuel in the burner is an important issue when discussing the simulation of this type of system. A simplified method based on a thermal balance was developed in this work to introduce the effects provoked by pellet combustion in the boiler simulation. The model predictions were compared with the experimental measurements, and a good agreement was found. The results of the boiler analysis show that the position of the water tubes, the distribution of the air inlets and the air infiltrations are the key factors leading to the high emission levels present in this type of system.
[en] Highlights: ► Method to determine the optimal location and size of biomass power plants. ► The proposed approach is a hybrid of PSO algorithm and optimal power flow. ► Comparison among the proposed algorithm and other methods. ► Computational costs are enough lower than that required for exhaustive search. - Abstract: This paper addresses generation of electricity in the specific aspect of finding the best location and sizing of biomass fueled gas micro-turbine power plants, taking into account the variables involved in the problem, such as the local distribution of biomass resources, biomass transportation and extraction costs, operation and maintenance costs, power losses costs, network operation costs, and technical constraints. In this paper a hybrid method is introduced employing discrete particle swarm optimization and optimal power flow. The approach can be applied to search the best sites and capacities to connect biomass fueled gas micro-turbine power systems in a distribution network among a large number of potential combinations and considering the technical constraints of the network. A fair comparison among the proposed algorithm and other methods is performed.
[en] A study is presented in which an optimisation model is built to determine the economic viability of three small biofuel fired CHP plants. The model formulated to describe heat and electricity production with CHP plants is based on simulation data for three existing plants. The modeled system extends from the production facilities to the district heating substations of the consumers, thus combining operational and design planning. We find that, compared to the long term average situation in the Nordic countries, higher electricity prices or lower investment costs are needed to make CHP plants attractive in small district heating networks. The results are relatively sensitive to the original economic parameters, and this uncertainty over future cash flows may further reduce investments in small CHP plants
[en] The present work deals with evaluation of the adaptation and biomass production of various switchgrass cultivars (upland and lowland type) in Southern Italy. A field trial was established in 1998 with 15 switchgrass varieties in ENEA Trisaia (Matera). The experiment was conducted for four years (1998-2001). During each growing period, a series of measurements were taken. At the end of each growing season, a final harvest was made in order to estimate the fresh and dry matter yields of the different varieties. The mean dry matter yield was recorded at a maximum (12.36 t/ha) in the third year, and it fluctuated from 5.63 (9005439) to 26.08 (SL 93-3) t/ha. The crop yields tend to stabilize from the fourth year of its cultivation. In fact, the yield recorded for this year was reduced to 10.27 t/ha, averaged over all the varieties
[en] Highlights: • Microalgal biomass from wastewater treatment can be used for biochar production. • MPBR is applicable in microalgae cultivation and wastewater treatment. • Pyrolysis can be a suitable process in biochar production. • Optimization process in conversion of microalgal biomass to biochar is suggested. - Abstract: Microalgae have received increasing attentions due to its capacity of carbon fixation and serving as feedstock for producing biofuels and other value-added products. Microalgae can be used to remediate wastewater for simultaneously nutrient removal and biomass production, thereby significantly lowering the costs of microalgal feedstock. Recently, converting microalgal biomass biochar is of particular interest since biochar has numerous opportunities in application. In this review, innovative methods developed for microalgae-based wastewater treatment are described. Conventional and novel technologies used for producing biochar from microalgal biomass, such as pyrolysis and hydrothermal approaches, are presented. Future challenges and potential applications of the biochar derived from microalgal biomass collected from wastewater treatment system (e.g., soil amendment or adsorbent) are also discussed.
[en] Biogas, the end product of anaerobic digestion of cattle dung, can successfully supplement the cooking fuels in the countryside areas of India, where the raw material needed for its production is plentifully available. Because of the lack of awareness regarding selection of a suitable model and size of biogas plant, the full potential of the biogas producing material is not harnessed, and the economic viability of biogas technology is rendered doubtful. To facilitate this decision making, the economics of family size biogas plants, i.e. with capacity from 1 to 6 m3, was studied, and three prevalent models, viz. KVIC, Janta and Deenbandu, were compared. Calculations for installation cost and annual operational cost were made for the state of Punjab, India, where the hydraulic retention time is 40 days, and current market prices were taken into account. Comparison of the economics revealed that the cost of installation and annual operational cost of each capacity were higher for the KVIC model, followed by the Janta and then the Deenbandhu model. Irrespective of the model, as the capacity of the biogas plant increases, the installation, as well as the annual operational cost increase proportionately. With increase in capacity, the payback period decreased exponentially with the exponential character being highest for the KVIC model, followed by the Janta and then the Deenbandhu model. However, on the basis of comparative economics, the Deenbandhu model was found to be the cheapest and most viable model of biogas plant
[en] Highlights: • An energy resource data for oil palm biomass is generated. • The data encompasses crucial fuel and physicochemical characteristics. • These characteristics guide on biomass behaviors and technology selection. • Oil palm biomass is advantageous in today’s energy competitive markets. • Overall, it is a green alternative for biorefinery establishment. - Abstract: The scarcity of conventional energy such as fossil fuels (which will lead to eventual depletion) and the ever-increasing demand for new energy sources have resulted in the world moving into an era of renewable energy (RE) and energy efficiency. The Malaysian oil palm industry has been one of the largest contributor of lignocellulosic biomass, with more than 90% of the country’s total biomass deriving from 5.4 million ha of oil palms. Recent concerns on accelerating replanting activity, improving oil extraction rate, expanding mill capacity, etc. are expected to further increase the total oil palm biomass availability in Malaysia. This situation has presented a huge opportunity for the utilization of oil palm biomass in various applications including RE. This paper characterizes the various forms of oil palm biomass for their important fuel and other physicochemical properties, and assesses this resource data in totality – concerning energy potential, the related biomass conversion technologies and possible combustion-related problems. Overall, oil palm biomass possesses huge potential as one of the largest alternative energy sources for commercial exploitation.