Search

Paper and pulp mills generate substantial quantities of cellulose-rich sludge materials that are disposed in landfills at a large scale. For sustainability purposes, sludge materials can be bioprocessed to produce renewable fuels and useful chemicals. The enzymatic hydrolysis of cellulose is the process bottleneck that affects the conversion economics directly by using zero-cost raw materials. In order to study and optimize the process, the characteristics of the sludge raw materials should be first evaluated. In this work, sludge samples were obtained from paper mills located at different locations in Wisconsin and Minnesota. Part of the sludge samples was washed (de-ashed) with hydrochloric acid while the other part remained unwashed. The samples were subjected to multiple spectroscopic analyses techniques to evaluate the morphological properties of cellulose fibers and to estimate the total structural carbohydrate content. The results showed that the de-ashing process changed some fiber characteristics and cellulose crystallinity structure in all sludge samples. Sludge sample A (obtained from Kraft pulp and recycled paper mill region) showed a high percentage of fiber, with crystalline cellulose, compared to the other two sludge samples suggesting that sludge A is a valuable source to make value-added products. Aspen Plus mass and energy calculations performed in view of the 'zero' cost and the reliable supply of sludge raw materials producing 2 mol H 2 /mol glucose. Moreover, the results showed that extracting crystalline cellulose from these sludge samples is more profitable than crystalline cellulose made from the other lignocellulosic feedstocks. The results reported here showed that the utilization of these sludge materials would be an economically attractive and promising alternative for the production of hydrogen. Image 1 • A new method for paper mill sludge (PMS) characterization as renewable feedstock. • The deashing step has a major effect on the bioconversion of the PMS. • Studying the crystalline cellulose of the PMS. • A relation between the characterization and potential sugar yield was established. [ABSTRACT FROM AUTHOR]

Highlights: [•] Paper grade pulp was upgraded to dissolving pulp by two stages of treatment. [•] EG-rich industrial cellulase was used for enzymatic treatment. [•] α-Cellulose content and viscosity can be adjusted by alkali peroxide treatment. [•] Reducing sugar in spent liquor can be recovered to generate value-added products. [Copyright &y& Elsevier]

Abstract: This paper evaluates system aspects of biorefineries based on biomass gasification integrated with pulp and paper production. As a case the Billerud Karlsborg mill is used. Two biomass gasification concepts are considered: BIGDME (biomass integrated gasification dimethyl ether production) and BIGCC (biomass integrated gasification combined cycle). The systems analysis is made with respect to economic performance, global CO2 emissions and primary energy use. As reference cases, BIGDME and BIGCC integrated with district heating are considered. Biomass gasification is shown to be potentially profitable for the mill. The results are highly dependent on assumed energy market parameters, particularly policy support. With strong policies promoting biofuels or renewable electricity, the calculated opportunity to invest in a gasification-based biorefinery exceeds investment cost estimates from the literature. When integrated with district heating the BIGDME case performs better than the BIGCC case, which shows high sensitivity to heat price and annual operating time. The BIGCC cases show potential to contribute to decreased global CO2 emissions and energy use, which the BIGDME cases do not, mainly due to high biomass demand. As biomass is a limited resource, increased biomass use due to investments in gasification plants will lead to increased use of fossil fuels elsewhere in the system. [Copyright &y& Elsevier]

Sustainable power generation for portable electronic devices is of high interest due to increasing energy demands. Miniaturized biofuel cells are well-reported for this purpose where ubiquitous fluids, like glucose or lactate, can be leveraged. However, such biofuel cells need enzymes to complete the catalysis, leading to many prevalent issues like the longevity of enzymes, complicated immobilization, additional mediators etc. Therefore, non-enzymatic glucose biofuel cells (NEGBFCs) are gaining interest due to their cost-effectiveness, high repeatability and excellent stability. However, based on our best knowledge such glucose biofuel cells are not reported in microfluidic environment, and therefore their potential is not exploited. Realization of the functionality of such NEGBFCs in a microscale is crucial to replace them with their enzymatic counterparts. In this work, for the first time, a microfluidic non-enzymatic glucose biofuel cell (μNEGBFC) is developed on a paper-based platform using metallic catalysts. The catalysts for electrocatalytic energy generation is fabricated using electrodeposition method and their detailed physicochemical characterizations are done. The μNEGBFC is capable of producing a power density of 12.5 μW/cm2 with a stable potential of 410 mV. This green power output can be used to operate low-power micro-devices and lab-on-chip sensors in a more continual and viable manner. [Display omitted] • A simple, cost-effective electrodeposition technique was used for electrode fabrication. • Gold deposited anode and copper deposited cathode were used as electrodes. • A paper-based Microfluidic Non-Enzymatic Biofuel Cell (μNGBFC) was constructed. • The developed μNGBFC generated a power density of 12.5 μW/cm2. • The μNGBFC was capable of retaining 56% of the initial power after 72 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ex-situ catalytic pyrolysis of paper sludge was demonstrated in a pilot plant. • >99 wt% of minerals in the paper sludge are recovered. • The bio-oil with HHV of 40.9 MJ kg−1 is produced with a carbon yield of 21%. • The bio-based chemicals mainly contain paraffins, olefins, and aromatics. Paper sludge is a solid waste by-product abundantly produced in the paper industry and contains fine minerals and lignocellulosic biomass. In this contribution, the ex-situ catalytic fast pyrolysis of paper sludge with a high mineral content of ca. 71 wt% is reported for the first time and demonstrated in a pilot-scale unit (feeding rate of 11.3 kg h−1) using a granular Na 2 CO 3 /γ-Al 2 O 3 catalyst (loading of 650 g) to produce a high-grade bio-oil at a fast pyrolysis temperature of 475 ± 5 °C (pre-screened using a pyroprobe) and a catalytic upgrading temperature of 500 °C. Besides, > 99 wt% minerals in the paper sludge could be recovered, including paper fillers such as CaCO 3 (major) and talc. The bio-oil obtained at a carbon yield of 21 C.% has a low oxygen content of 3.2 wt%, a low total acidity number of 5.2 mg KOH g−1, low H 2 O content of 0.7 wt%, and a high higher heating value of 40.9 MJ kg−1. It consists of value-added bio-based chemicals such as paraffins, olefins, and low molecular weight aromatics. The results demonstrate that the use of paper sludge to recover minerals and to obtain fuels and chemicals using ex-situ catalytic pyrolysis is technically feasible at a pilot plant scale, which will be of importance for the development of future bio-based economy. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae is one of the prominent strains in the brewing and bioethanol industries and has been used for many industrial purposes for ages. Though the organism is an outstanding ethanol producer, the major limiting factor is the stress the organism undergoes during fermentation. One of the significant stresses is the ethanol stress, created by ethanol accumulation in the medium. The ethanol starts to interact with the yeast cell membrane; further, as ethanol concentration increases, it affects a lot of cell organelles. Thereby, cellular activities get disrupted, causing cell death and hence reducing ethanol production. The organism has developed many strategies to overcome this stress by activating the stress response pathway, which regulates many genes involved in modifying the cell membrane cell wall, renaturation of proteins, and altering the metabolism. However, with higher ethanol concentrations, the yeast cells will be unable to tolerate, leading to cell death. Hence, to minimize cell death at higher ethanol concentrations, there is a need to understand the effect of ethanol and its response by the organism; this helps improve the ethanol tolerance of the organism and, thereby, ethanol production. Although many research works are carried out to understand the vital aspect of the tolerance and are reported, very few review papers cover all these points. Hence, this review is designed to include information on all the elements of ethanol tolerance, i.e., ethanol tolerance of different strains of S. cerevisiae , the effect of ethanol on the yeast cells, the mechanism used to tolerate the ethanol, and various techniques developed to improve the ethanol tolerance of the yeast cells. [Display omitted] • Saccharomyces cerevisiae: key in brewing, bioethanol; historic importance; widespread applications. • Detailed exploration of ethanol's harmful effects on yeast, disrupting cellular activities and reducing ethanol production. • Explore ethanol stress adaptations, emphasizing stress response pathway's role in cell component modification. • Addressing the challenge of ethanol tolerance, emphasizing the importance of minimizing cell death for enhanced production. [ABSTRACT FROM AUTHOR]

• Hemicelluloses-rich aqueous byproducts from WTCPs are often disposed of as waste. • Valorization of hemicelluloses-derived products into fuels, chemicals, and bioproducts. • Circular bioeconomy and use of all biomass processing byproducts from WTCPs. • Challenges to integrate and scale up aqueous byproduct processing in biorefineries. Thermochemical pretreatments are employed prior to energy, chemicals, and fuels production from biomass. Wet thermochemical processes (WTCP) are treatments used to modify biomass properties in water as the primary solvent, with or without added reactants/catalysts. WTCP includes hot water extraction, steam explosion, hydrothermal liquefaction, hydrothermal carbonization (HTC), and supercritical water gasification. WTCP also includes processes that add chemicals to reduce reaction time and improve efficiency, i.e., organosolv, alkali, and low acid pretreatment. Operational parameters in WTCP are usually selected to optimize the yields of sugars after enzymatic hydrolysis of the resulting solids and biogas from the pretreated solids, or to ensure that hydrochar (e.g., from HTC) performs adequately in environmental applications. However, a key byproduct from WTCPs is an aqueous fraction (rich in nutrients, hemicellulose-derived sugars, and chemicals) often disposed of as waste. The necessity of resource conservation and proper management and the need to make WTCP-based biorefineries economically and environmentally sound require using all the byproducts of biomass processing. Options for downstream conversion of the WTCPs' aqueous byproducts are dispersed in the literature. Thus, this paper aims to put together works that report the parameters of WTCPs that allowed removing hemicellulose-derived fractions and nutrients from biomass (either partially or almost entirely), the yields and properties of this aqueous byproduct, methods of characterization, current and expected uses, and the challenges for scaling up WTCPs and using the aqueous stream. The paper focuses on expected and existing methods that allow the valorization of the aqueous fraction and reduce wastes within a circular bioeconomy framework. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of spray characterization of MD-NH (a blend of methyl decanoate and n-heptane in a molar ratio of 1:1 to characterize biodiesel) in an in-cylinder environment of diesel engines to provide a reference for the experimental study of engines in advanced combustion mode. Based on the Peng-Robinson state equation, the thermodynamic model of real fluid was established, and the influence law of ambient temperature and pressure on the diffusion characteristics of fuel flow was analyzed. Based on the constant volume combustion bomb experiments, the variations of spray penetration distance, spray cone angle, spray projection area, spray air entrainment mass, and spray fragmentation forms in different critical environment conditions were studied. The results show that the transport properties of the fuel change abruptly within the critical point neighborhood of the fuel. As the ambient temperature increases, near the critical temperature, the thermal conductivity of biodiesel decreases and then increases; density and kinematic viscosity decrease at an accelerated rate; and surface tension increases to a maximum and then disappears sharply. The diffusion coefficient decreases sharply when the ambient pressure reaches the critical pressure. The spray characteristics of biodiesel in sub/supercritical conditions were different. Compared with the subcritical environment, the biodiesel spray penetration distance decreases, the spray cone angle increases, the spray projection area decreases, and the air entrainment mass increases in the supercritical atmosphere, which induces a gas-liquid interface mixing layer and promotes the mixing of biodiesel with the atmosphere gas. The experimental data in this paper fill the gap in the study of biodiesel spray characteristics in supercritical environments and provide a basis for high-fidelity numerical simulation of the spray model. • This paper used MD-NH (a blend of 1 mol of methyl decanoate and 1 mol of n-heptane) as the characterization fuel for biodiesel. • The influence laws of temperature and pressure on the thermophysical properties of MD-NH fuel were investigated. • The spray characteristics of MD-NH in real engine environmental conditions were quantitatively analyzed using the schlieren method. • The spray fragmentation form of MD-NH fuel in different environments was analyzed multivariable. [ABSTRACT FROM AUTHOR]

[Display omitted] • The specific catalytic properties of oxygen vacancy were systematically explored. • The defect of metal oxide improved the utilization efficiency of microwave energy. • Syngas concentration in the bio-gas could reach 61.5 mol% with Fe 3 O 4 as a catalyst. • The lower heating value of light bio-oil was up to 30.45–31.21 MJ/kg. • Iron oxide provided reactive sites for CO 2 reduction to CO in microwave pyrolysis. This paper proposed to use ferric oxide (Fe 2 O 3) and ferroferric oxide (Fe 3 O 4) as catalysts with both microwave absorption and catalytic properties. Carbon dioxide (CO 2) was introduced as the reaction atmosphere to further improve the quality of biofuel produced by microwave pyrolysis of food waste (FW). The results showed the bio-gas yield and the syngas concentration (H 2 + CO) increased to 70.34 wt% and 61.50 mol%, respectively, using Fe 3 O 4 as the catalyst. The content of aliphatic hydrocarbons in bio-oil produced with the catalyst Fe 2 O 3 increased to 67.48% and the heating value reached 30.45 MJ/kg. Compared with Fe 2 O 3 catalyst, Fe 3 O 4 exhibited better microwave absorption properties and catalytic properties. Transmission electron microscopy (TEM) and Electron paramagnetic resonance (EPR) characterizations confirmed that the crystal surface of Fe 3 O 4 formed more oxygen vacancy defects and unpaired electrons. Additionally, according to the X-ray photoelectron spectroscopy (XPS) analysis, the content of lattice oxygen in Fe 3 O 4 was 14.11%, a value that was much lower than Fe 2 O 3 (38.54%). The oxygen vacancy defects not only improved the efficient utilization of microwave energy but also provided the reactive sites for the reaction between the volatile organic compounds (VOCs) and CO 2 to generate CO. This paper provides a new perspective for selecting catalysts that have both microwave absorption and catalytic properties during the microwave pyrolysis of biomass. [ABSTRACT FROM AUTHOR]

Production of γ-valerolactone (GVL) from biomass-derived platform levulinic acid (LA) via catalytic transfer hydrogenation (CTH) over renewable lignosulfonate-derived catalyst is reported herein. Lignosulfonate-derived catalysts were prepared by assembled Zr-metals with sodium lignosulfonate (LigS) derived from the industry paper waste. The resulting Zr-LigS catalyst exhibited excellent catalytic performance in 92.5% GVL yield under mild conditions. With the combination of detail catalyst characterizations, catalytic performance of the Zr-LigS catalyst, in-situ ATR-FTIR and poisoning experiments, the hydrothermal treatment of Zr4+ and LigS resulted in the formation of basic sites, which contributed significantly to the CTH reaction. Kinetic experiments demonstrated that the activation energy was as low as 41.9 kJ/mol. Furthermore, isotopic labeling experiments suggested that the β -H in isopropanol is transferred to the C O bond of LA by the formation of six-membered intermediates on the basic sites, which is the rate-determining step. [Display omitted] • Renewable Zr-LigS catalyst is prepared by hydrothermal method. • Zr-LigS catalyzes CTH with more than 90%γ-valerolactone yield under mild condition. • In-situ liquid phase FTIR was employed to study the mechanism. [ABSTRACT FROM AUTHOR]

Literature shows that the crude oil market has a vital link with subcomponents products, i.e., gasoline and diesel, and alternative energy markets, i.e., natural gas and biofuels. The biofuel industry is a promising solution for many problems such as global warming and high oil prices. Therefore, our paper explores the effect of structural crude oil market shocks on the real price of biofuel. We use structural vector autoregression (SVAR) model as proposed by Kilian (2009) over the period from March 1995 to June 2019. Our main finding reveals that long-run fluctuations in the real prices of biofuel are attributed mainly to global demand shocks and oil-market specific shocks, whereas oil supply shocks have an insignificant role. Our results also indicate that the three shocks combined can justify 68 percent of the variation in the real prices of biofuel, whereas the aggregate demand shocks are the most significant contributor because it justifies 35 percent, and oil-specific demand shocks explain 28 percent. The policy implication of our paper is that the stability of the biofuel market comes from the demand side, not the supply side. Thus, energy demand management is a critical tool to stabilize the biofuel market. [ABSTRACT FROM AUTHOR]

Abstract: We calculated carbon and energy balances and costs of 14 different Fischer–Tropsch (FT) fuel production plants in 17 complete well-to-wheel (WTW) chains. The FT plants can use natural gas, coal, biomass or mixtures as feedstock. Technical data, and technological and economic assumptions for developments for 2020 were derived from the literature, recalculating to 2005 euros for (capital) costs. Our best-guess WTW estimates indicate BTL production costs break even when oil prices rise above $75/bbl, CTL above $60/bbl and GTL at $36/bbl. CTL, and GTL without carbon capture and storage (CCS), will emit more CO2 than diesel from conventional oil. Driving on fuel from GTL with CCS may reduce GHG emissions to around 123gCO2/km. Driving on BTL may cause emissions of 32–63gCO2/km and these can be made negative by application of CCS. It is possible to have net climate neutral driving by combining fuels produced from fossil resources with around 50% BTL with CCS, if biomass gasification and CCS can be made to work on an industrial scale and the feedstock is obtained in a climate-neutral manner. However, the uncertainties in these numbers are in the order of tens of percents, due to uncertainty in the data for component costs, variability in prices of feedstocks and by-products, and the GHG impact of producing biomass. [Copyright &y& Elsevier]

Conventional fuels used for supplying internal combustion piston engines include petrols and diesel oils produced from petroleum. These are a non-renewable energy source. The environmental policy of the European Union is geared towards increasing the share of renewable fuels in the overall energy consumption. An alternative fuel originating from a renewable source, which could be used for feeding self-ignition internal combustion engines are the fatty acid methyl esters (FAME) of plant oils. The paper reports selected results of testing a 1.3 MULTIJET SDE 90 PS self-ignition engine with the Common Rail reservoir feed system supplied with mixtures of diesel oil and rape oil fatty acid methyl esters (FAME). Tests were carried out on an engine test bed equipped with an eddy-current brake. The purpose of the tests was to determine the economic–energy and ecological indices of engine operation. The concentrations of exhaust gas gaseous components were measured using a MEXA-1600DEGR analyzer, while the particulate concentrations, with a MEXA-1230PM analyzer. In addition, the variations of working medium pressures in the engine chamber and of fuel pressure upstream the injector were recorded as a function of crankshaft rotation angle using the AVL IndiSmart 612 indication system for this purpose. The physicochemical properties of fuels used in the tests were determined using a fuel analyzer. The obtained testing results made it possible to determine and assess the operation indices of the engine fed with mixtures of diesel oil and rape oil fatty acid methyl esters (FAME) with slightly higher ester contents than the requirements of the currently applicable diesel oil standard. • The investigations a modern internal combustion engine powered by blends of diesel oil and rapeseed oil methyl esters. • Physico-chemical properties of the fuels of concern and the engine performance indicators were examined and analysed. • Engine fuelling with B20 and B30 led to an increase in hourly fuel consumption and specific fuel consumption. • Concentrations of PM, CO and HC in the exhaust gas were reduced. Smoke opacity was lower. NO x in the exhaust increased. • Engine fuelled with B20 and B30 blends produced higher values of the maximum total relative amount of combustion heat. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biofuel synthesis from spent tea waste can be a sustainable waste management option. • Biochar, activated carbon, and nanoparticles synthesis from tea wastes are highlighted. • Utilization of tea waste as adsorbent for pollutants abatement is discussed. • Hierarchical porous supercapacitor development from tea waste is summarized. • Development of carbon dots from tea waste for environmental application is promising. In many industrialized and developing countries, the copious amount of solid waste and byproducts produced by tea processing and production enterprises today pose a distressing and pervasive problem. Consequently, finding a sustainable way to repurpose tea waste (TW) in various applications has become the primary focus of the global research community. The current study highlights the advantageous use of TW biomass in agricultural compost and other uses, as well as the sustainable reutilization of tea industry waste. Additionally, to gain a better understanding of their potential application in environmental fields, this paper also aims to draw attention to recent solid-state fermentation applications in the feed industry, as well as highlight valorization technologies and their effectiveness in converting TW using important thermo-chemical processes, such as pyrolysis, hydrothermal carbonization, gasification, and combustion. In order to increase the competitiveness and societal acceptance of biorefineries, the present paper also examines the latest developments in environmental biotechnology. However, these biomaterials hold great promise for use in developing nanoparticles and composite biomaterials. The conclusions of this review study are crucial for the environment friendly and sustainable growth of the world. This review envisions resource management in the context of a circular bioeconomy and zero waste. [ABSTRACT FROM AUTHOR]

• Fine particles were sampled and size-separated in the reheater section at the 800 MW th Avedøre Power Station Unit 2 (AVV2) as well as at the 900 MW th Studstrup Power Station Unit 3 (SSV3), both using wood pellets as fuel. Coal fly ash (CFA) was applied in both power stations to act as an alkali capturing additive. In addition, experiments in a pilot-scale pulverized-fuel biomass combustion test-rig were conducted, using the same fuel and CFA-additive, in order to compare the impact of the CFA-addition. A comparison of particle concentrations revealed a higher quantity of submicron particles (PM 1) at AVV2, compared to SSV3, while the PM 1 values at the pilot-scale combustion unit were substantially higher, compared to fine particle concentrations at the full-scale CHPs. • Further, ash deposition during firing of wood pellets with CFA-addition was quantified by an advanced deposit probe at SSV3. The results showed that with a probe surface temperature of 550 °C, and 2 % or 3 % CFA-addition, no significant deposit was formed. When increasing the probe surface temperature to 650 °C, at 3 % CFA-addition, some deposit was formed on the upstream side of the probe. No Cl was detected in the deposit samples, indicating that Cl-related corrosion can be effectively handled by 2.0 % or 3.0 % coal fly ash addition. • Finally, deposit formation when firing different biomasses (wheat straw, wood, bark and leaves), with and without K-capturing additives, was also investigated in an entrained flow reactor (EFR). In terms of deposit formation, the K- and Cl-rich Danish wheat straw proved to be the most problematic fuel, while milled wood pellets, HTC leaves and bark, had significantly lower deposition propensities. Kaolin and two types of CFA, rich in Al and Si, were applied as additives, the results showed that the deposition propensity of wheat straw decreased significantly when applying a molar ratio of fuel-K/additive-Al of 1.0. • This paper contains an outline of the experiments conducted, the results obtained, as well as implications and impact of the data gained on future applications of biomass for heat and power production units. Fine particles were sampled at the 800 MW th Avedøre Power Station Unit 2 (AVV2) as well as at the 900 MW th Studstrup Power Station Unit 3 (SSV3), both utilizing wood pellets together with coal fly ash (CFA), for alkali capturing. In parallel, fine particle formation was quantified in the BoCTeR pilot-scale pulverized-fuel biomass combustion test-rig, at the Technical University of Munich, using the same wood pellets and CFA-additive as was applied in full-scale, to compare the impact of the CFA-addition. A comparison between fine particle formation and concentration in the BoCTeR and in full-scale, revealed a higher quantity of submicron particles (PM 1) at AVV2, compared to SSV3, i.e. differences between the two full-scale boilers, while the PM 1 -values at BoCTeR was found to be substantially higher than what was measured in full-scale, mainly due to differences in temperature–time history between these two combustor scales. Ash deposition during wood pellets firing with CFA-addition, was quantified by an advanced deposit probe at SSV3. The results showed that with a probe surface temperature of 550 °C, and 2 %wt or 3 %wt CFA-addition, no significant amount of deposit was formed. When increasing the probe surface temperature to 650 °C, at 3 %wt CFA-addition, deposit was formed on the upstream side of the probe. No Cl was detected in the deposit samples, indicating that Cl-related corrosion can be effectively suppressed by 2 %wt or 3 %wt coal fly ash addition. Finally, deposit formation when firing different pre-treated biomasses; K- and Cl-rich wheat straw, milled wood pellets, hydrothermally carbonized (HTC)-leaves and steam exploded (SE)-bark, with and without a K-capturing additives, was also investigated in the entrained flow reactor at Technical University of Denmark (DTU-EFR). In terms of deposit formation, the K- and Cl-rich wheat straw proved to be the most problematic fuel, while milled wood pellets, HTC-leaves and SE-bark, had significantly lower deposition propensities. When applying kaolin and two types of CFA (both rich in Al and Si), as K-capturing additive, the deposition propensity of wheat straw decreased significantly, when applying a molar ratio of fuel-K/additive-Al of 1.0. This paper was originally presented at the recent 28th International Conference on Impacts of Fuel Quality on Power Production, the, Aare, Sweden, September 19–23, 2022. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effects of the production of ethanol, a renewable biofuel, oil prices, population, and exchange rate on corn prices in the US (1985:m1-2020:m7) using a nonlinear smooth transition model. According to the findings, (i) ethanol production (β 1 = 0.072, p < 0.01) has an increasing effect on corn prices. (ii) Oil prices (β 2 = 0.064, p < 0.05) and population (β 3 = 0.851, p < 0.01) put a pressure on corn prices. (iii) The increase in the real exchange rate (β 4 = −2.142, p < 0.01) has a decreasing effect on corn prices. The estimation results provide several critical policy implications for ethanol-food competition within the framework of sustainable development policies. First, ethanol production puts pressure on corn prices. Second, policy-oriented research on the biofuel-food competition can provide guidance to ensure sustainability. Finally, in the transformation process of the ethanol industry, technological innovations (use of second or third-generation biofuels) can moderate the food-fuel nexus. [ABSTRACT FROM AUTHOR]

Despite early promises, Furfural failed to become a major chemical intermediate as it could not compete with cheap and abundant petrochemicals. But recent societal pressures to replace fossil resources with renewable ones, combined with recent technology developments may give it a second chance today. This paper presents recent developments in furfural manufacture and valorization that I have been personally involved in. Specifically, it will first discuss advanced furfural manufacture that integrate biomass fractionation with xylose dehydration. Attention will then be devoted to furfural upgrading to aviation fuels and to chemical intermediates such as BDO/THF and FDCA. Furfural, a bio-based intermediate that has been sleeping for 50 years, may awaken thanks to recent progress made in its manufacture and its valorization to fuels and chemicals. [Display omitted] • Integrate Furfural production with fractionation to improve biomass utilization. • Produce Furfural at high yield with biphasic dehydration or extraction/dehydration processes. • Upgrade Furfural to kerosene and diesel for aviation and heavy-duty transport. • Upgrade Furfural to a variety of chemical intermediates. [ABSTRACT FROM AUTHOR]

• Innovative integration of slow and fast pyrolysis within drop-in biofuel production. • Biochar co-production leads to carbon sequestration and high GHG emission savings. • Tuning biomass flows, significant reductions of fossil-based inputs are achieved. • Improved scenarios at higher RES share to further reduce GHG emissions are proposed. • The proposed methodology establishes a foundation for innovative BECCS solutions. Biochar has an enormous potential to store carbon in the long-term. Differently than BioEnergy Carbon Capture and Storage (BECCS) technologies, biochar incorporates biogenic carbon in a solid form that offers multiple benefits as carbon sink, soil improver or for advanced materials production. The present study proposes an innovative approach, where carbon sequestration through biochar is obtained through the integration of slow pyrolysis with fast pyrolysis in decentralised biorefining systems, and then converted producing drop-in fuels from pyrolysis oil hydrotreating or gasification and Fischer-Tropsch (FT) synthesis. The scope is either to achieve negative GHG emissions assigned to advanced biofuels, or to export the generated carbon credit for the carbon markets (i.e. outside the biofuels carbon intensity). The innovative concept entails process integration and optimisation for the different stages of biomass drying, conversion and upgrading into biofuels in a way to reduce fossil-based inputs, applying a full value chain approach. Methodological choices for the assumptions on life cycle emissions calculation are discussed, evaluating the environmental performances by comparing the new concept to traditional biofuels value chains. Using a tailored lifecycle accounting methodology, this paper demonstrates that high GHG emissions savings can be achieved. The improved scenario shows how the carbon sequestration with biochar further reduces the carbon intensity up to –4.2 gCO 2 e MJ−1 for pyrolysis oil-based fuels, and to −20.2 gCO 2 e MJ−1 for FT-based fuels: this demonstrated that carbon negative sustainable biofuels can be obtained. The study demonstrates that an integrated biorefinery of 100 MW capacity can deliver additional 13.3 and 6.8 ktons of CO 2 e of GHG savings of per year, from drop-in fuels made of hydrotreated pyrolysis oil and FT synthesis, respectively. [ABSTRACT FROM AUTHOR]

The aim of the paper is to present renewable energy market development with particular regard paid to biofuels in the EU. The analysis included data on the share of renewables in Gross Island energy consumption, changes of renewable energy in the years 2004–2016 and the amount of liquid biofuels. The authors of the paper used descriptive and statistical methods to describe the changes in bioenergy development in the European Union (EU). The biggest share of biofuels and renewable waste can be seen in Latvia (31.2%), Finland (26.7%) and Sweden (24.8%). The highest percentage of wind energy in 2015 was found in: Denmark (7.2%), Portugal (4.3%), Ireland (4.0%) and Spain (3.5%). The highest share of solar energy in 2015 was found in Cyprus (3.5%), Spain (2.6%) and Greece (2.2%). The highest contribution of geothermal energy was found in 2015 in Italy (3.5%), Portugal (0.8%) and Slovenia (0,7%). Hydropower was the biggest in 2015 in Sweden (14.2%), Austria (9.6%) and Slovenia (5.0%). The highest coefficients of variation of the share of electricity from renewable energy sources were found in the years 2004–2017 in Malta (140.3%), Cyprus (101.1%) and United Kingdom (71.9%). In addition, the highest coefficients of variation of share of renewable energy sources in heating and cooling in the years 2004–2017 were found in Malta (72.4%), United Kingdom (69.81%) and Hungary (44.91%). Moreover, the highest coefficients of variation of share of renewable energy sources in transport in the years 2004–2017 were found in Finland (113.78%), Malta (115.52%) and Belgium (96.53%). The biggest producers of ethanol and biodiesel in EU were Germany, France and Poland. Cluster analysis data show that Germany and France are of key importance in the production of biodiesel and ethanol. The biodiesel production increased in the years 2003–2017 from 719,32 million liters to 13323 million liters (increase 1852.2%). However, in the years 2014–2017 a stagnation in biofuel production was observed from 13673 million liters to 13323 million liters (−2,56%). The situation on the market and the increasing demand for green energy suggest that the production of ethanol and esters of vegetable oils will increase by 2030, which will contribute to the development of this sector. [ABSTRACT FROM AUTHOR]

Graphical abstract Lignosulfonate, a waste by-product from the paper industry, was simply assembled with ZrCl 4 to construct sustainable catalysts (Zr LS) for highly efficient hydrogen transfer of biomass-derived oxygenates under mild conditions. Highlights • Renewable, cost-effective and robust zirconium–lignosulfonate hybrid is prepared. • Zr LS catalyzes MPV reduction with 90–100% yields at as low as 80 °C. • Acid-base sites of Zr LS exhibit synergism. • Kinetics and reaction mechanism were investigated. • Both performances and structures of Zr LS are stable during reuse. Abstract Both value-added utilization of low-rank renewable feedstocks to prepare catalytic materials and selective transformation of bioderived aldehydes are very attractive topics. Herein, lignosulfonate, a waste by-product from the paper industry, was simply assembled with ZrCl 4 under non-toxic hydrothermal conditions for scalable preparation of Zr-containing polyphenolic biopolymer catalysts (Zr LS). Systematic characterizations indicated that the strong coordination between Zr4+ and phenolic hydroxyl groups in lignosulfonate led to the formation of strong Lewis acid-base couple sites (Zr4+−O2−) and porous inorganic-organic framework structure (mesopores centered at 6.1 nm), while the inherent sulfonic groups in lignosulphonate could serve as Brønsted acidic sites. The cooperative role of these versatile acid−base sites in Zr LS afforded excellent catalytic performance for Meerwein-Ponndorf-Verley (MPV) reaction of a broad range of bioderived platform chemicals under mild conditions (80 °C), especially of furfural (FF) to furfuryl alcohol (FA), in quantitative yields (96%) with high FA formation rate of 9600 μmol g−1 h−1 and TOF of 4.37 h−1. Kinetic studies revealed that the activation energy of the MPV reduction of FF was as low as 52.25 kJ/mol, accounting for the high reaction rate. Isotopic labelling experiments demonstrated direct hydrogen transfer from the α-C of 2-PrOH to the α-C of FF on acid-base sites was the rate-determining step. Moreover, Zr LS showed good recyclability for at least seven reaction cycles. [ABSTRACT FROM AUTHOR]

Abstract This paper is an Editorial for the special issue (SI) of Renewable and Sustainable Energy Reviews (RSER) devoted to the 12th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), held from the 4th to 8th October 2017 in Dubrovnik, Croatia. The key focus of RSER is to publish critical thinking across the wide field of renewable and sustainable energy. The journal publishes either pure review papers or research papers with a precise review element. Overall, the guest editors invited 36 papers presented on 12th SDEWES conference, of which 17 were accepted after rigorous peer review process. The SDEWES conferences present a continuous effort in gathering high level scientists and research papers across the field of sustainability and by now the amount of accumulated knowledge, through conference papers and special journal issues, is significant. Each SDEWES journal editorial presents a wider overview of special issue journal papers in order to maintain the continuation of knowledge generation on the main sustainability topics. The main topics covered in this RSER editorial include renewable energies with special focus on integration, markets and roadmaps, energy efficiency in buildings, industrial process and transport, bio based economy focused on bio based chemicals and biofuels, energy storage focused on batteries, thermal and geological storages and various sustainability assessments in several sectors and technologies. All were considered in light of the Circular Economy. [ABSTRACT FROM AUTHOR]

Abstract The present work investigates solid biofuel, derived from household food waste (food residue biofuel, FRB) as a potential bioenergy source in cement manufacturing. Up-to-date investigations of household food waste as a solid fuel focused on composition and heating value, yet no results are available regarding impact on plant efficiency and emissions upon utilization. A multidimensional model based on fundamental principles (mass and enthalpy balances) is used together with actual data from fossil fuel operation to identify and quantitatively asses the impacts on plant performance, product quality and atmospheric emissions. Τhe energy needed to prepare low moisture FRBs is determined and suitable processes are singled out. Key issues of cement plant operation are identified and quantitatively assessed via simulation in an actual dry-process plant, when FRBs substitute 20% of thermal energy (provided by petcoke). The facility utilizes 1.65 × 105 tpa of fossil fuels to produce 1.5 × 106 tpa clinker. It is found that energy efficiency falls and clinker production diminishes by about 0.5 t clinker/t FRB. Refractory thermal rating and main blower capacity constraints remain satisfied. Non-biogenic green-house-gas emissions are reduced by ~60 kg/t clinker. Emitted concentrations slightly increase for several pollutants, mainly nitrogen oxides (NO x) hydrogen chloride (HCl) and metals; they decrease for sulphur dioxide (SO 2) and particulates. Maximum emission limits are observed for all regulated pollutants but NO x. Incombustible chlorine and inclusions of alkalis in cement increase by ~9%. To reap the bioenergy benefits and mitigate impacts, blends of FRB (~80%wt) with paper residues (~20%wt) are investigated. Conforming to plant operational constraints and product specifications, the blends ensure production level, environmental compliance and reduced emission rates. The results direct towards customer-tailored FRB blends with lignocellulosic residues, that best suit the design, specific quarry raw materials, operating conditions and individual parameters of the cement plant towards more sustainable cement manufacturing. Highlights • Food waste can be valorized to biochemicals and biofuels, including solid fuels. • Drying to ≤ 15% moisture gives stable, nonhazardous food residue biofuels (FRBs). • Substitution of petcoke by FRBs in cement kilns decreases clinker level. • Lower CO 2 , SO 2 and mercury but higher chlorines and NO x emissions result. • Superior blends of FRB with paper residues improve clinker production and emissions. [ABSTRACT FROM AUTHOR]

Abstract In this research, we aim at exploring the influence of renewables on industrial production (Ip) in the US by following continuous wavelet coherence and partial continuous wavelet coherence analyses. To this end, we observed the co-movements between, biofuels and Ip, solar and Ip, wind and Ip, geothermal and Ip, wood and Ip, and, waste and Ip in the US for the monthly period from January 1989 to November 2016. The primary motivations behind this research are twofold. Firstly, it attempts to reach the co-movements, if exists, between renewables' consumption and industrial production by following time domain and frequency domain analyses. Secondly, it aims at observing the potential co-movements between renewable energy sources (geothermal, solar, wind, biofuels, wood, and, waste) and Ip by adding some control variables (fossil fuels, total biomass etc.) into the wavelet models to understand clearly the responses of the industrial production to the impulses in renewables in both short term and long term periods. The paper hence eventually reveals significant effects of geothermal, wind, solar, biofuels, wood, and, waste on US industrial production in short term cycles and long term cycles. Thereby, following this paper's results of continuous wavelet analyses which depict the impact of renewables on US economy at 1–3-year frequency and 3–8-year frequency for the time period from January 1989 to November 2016, one might provide policy makers with relevant current and future efficient renewables' energy policy for the US and other countries which have similar structures with the US. Highlights • Explores the influence of renewables on industrial production (Ip) in the US. • Employs continuous wavelet coherence and partial continuous wavelet coherence analyses. • Observes the co-movements between, biofuels-Ip, solar-Ip, wind-Ip, geothermal-Ip, wood-Ip, and, waste-Ip pairs. • Reaches strong co-movements between renewables and Ip both in short run and in the long run. • Can claim that renewable energy sources can influence positively the US industrial production. [ABSTRACT FROM AUTHOR]

Abstract Greater production of agricultural biomass for energy generation means a greater overlap between the energy and agricultural value chains. The production of biofuels from food crops was previously criticised as conflicting with food production. Use of so-called 'marginal land' is proposed to overcome previous controversies. Using interviews and document analysis, this paper explores the meaning of 'marginal land' for non-food energy crop production in Denmark and conflicts that arose over its proposed use. In Denmark there was a different conception of marginal land – environmentally sensitive land where intensive cultivation causes impacts. Policies were put in place to promote the use of this 'environmentally marginal land'. However, competing environmental objectives for this land – for different types of biodiversity, ecosystems services and aesthetic preferences meant these policies were repealed. The paper shows how discussions of biomass production on agricultural land, and particularly marginal land, reflect the nuances of competing land uses in agriculturally intensive countries like Denmark. It is not only a matter of trade-offs between different types of agricultural production, such as food and fuel, or between environmental benefits and production, but over the optimal environmental use of the land to achieve multifunctional benefits. As well as questions of equity, access and practicality, the marginal land debate in agriculturally intensive countries needs to include questions of appropriate and desired environmental outcomes and means of stakeholder engagement to establish these. Highlights • Growing biomass on marginal land is seen to overcome 'food versus fuel' debates. • Danish stakeholders identified marginal land as environmentally sensitive land. • Growing biomass on 'environmentally marginal' land creates environmental benefits. • Use of this land for biomass was resisted due to landscape and biodiversity change. • 'Marginal land' debates should include symbolic and aesthetic land use dimensions. [ABSTRACT FROM AUTHOR]

Highlights • A 1-D model was proposed to predict fuel's spray combustion characteristics. • N -pentanol causes multiple effects on the evaporation and ignition processes of both fuels. • Physical ignition delay of biodiesel blends occupied less proportion than that of diesel blends. • The effects of the parameters of the Arrhenius-typed correlation were discussed. • New correlations focused on the liquid length and ignition delay were proposed. Abstract Spray mixing and combustion processes are regarded as the major factors that determine the energy conversion efficiency and emission level of internal combustion engines. However, the related researches mainly rely on 3D flow simulation or optical engine experiments, which are highly expensive and time-consuming. In order to provide a more convenient solution, this paper developed a one-dimensional semi-phenomenological model to achieve accurate and efficient predictions on spray combustion characteristics. The model was constructed by a dimensionless spray theoretical model and limited experimental data of macroscopic spray characteristics. Inside the proposed model, a physical module was used to physical module spray air-fuel mixing conditions like fuel distribution and evaporation. Besides, an improved Arrhenius-typed correlation concerning injection parameters and environment variables was introduced to describe the chemical ignition characteristic of spray combustion. The optical experiment results showed that this method is simple and effective, and the forecasting is satisfactory. Based on the new model, the influences of blending n -pentanol on the spray combustion characteristics of diesel and biodiesel were investigated. On the physical aspect, the critical fuel concentration at liquid length position decreases with n -pentanol is blended into both fuels in the most cases, but witnessed a significant leap in 1200 K condition, especially for diesel blends; the physical ignition delay times of both diesel and biodiesel blends decreases first and go up later. On the chemical aspect, the join of n -pentanol caused the gap between the physical delay time and the chemical delay time much narrower, but the ignition patterns were different in diesel blends and biodiesel blends. Moreover, this paper proposed a series of correlations focused on the liquid length and ignition delay of n -pentanol blends sprays. These correlations covered wide conditions and showed better prediction accuracy than traditional ones. [ABSTRACT FROM AUTHOR]

Abstract In Sub-Saharan Africa, now dubbed the 'Green OPEC' of the global bioenergy economy, biofuels have been hailed as a 'new profitability frontier' that will provide 'win-win' outcomes and deliver development to poor communities. Yet, in an era of economic recession and soaring food prices, their 'sustainability' has been at the centre of controversy. This paper focuses on the case of Sierra Leone, where in 2008, a Swiss bioenergy company ushered in the largest foreign direct investment since the end of the country's civil war. Although recently set back by the catastrophic impacts of the Ebola crisis, there continues to be much support for the government's strategy to secure foreign direct investment in biofuels production in agriculturally rich regions of the country. Bioenergy proponents believe that such investments will transform rural areas, in light of the fact that Sierra Leone has over the last decade been consistently ranked as one of the poorest in the world, facing food insecurity, high unemployment and entrenched poverty. But land access and control remain central to debates around biofuels and development, particularly for poor rural people living in project areas. This paper explores the perceptions of a wide range of project stakeholders, many of whom have differing interpretations of what biofuel sustainability entails. The paper concludes by reflecting on the implications this may have for the present post-Ebola environment, where evolving policy discussions on land investment and 'green' development continue to assume a key part of the government's recovery trajectory. [ABSTRACT FROM AUTHOR]

The paper presents a techno-economic comparison among five alternative process configurations for bio-methanol production from the gasification of residual forestry biomass. Process design and simulations are performed in Aspen Plus for mass and energy balance calculation, followed by preliminary sizing and economic analysis. Process schemes include a gasification island (state-of-the-art low-pressure gasification compared against a high-pressure gasifier) with syngas conditioning and compression, heat recovery, syngas composition adjustment (by CO 2 capture or addition of hydrogen produced by electrolysis), methanol synthesis and purification and a heat recovery cycle for power generation. CO 2 capture is performed with conventional chemical absorption in the benchmark cases, while low-temperature partial condensation of CO 2 is modeled in the advanced scenario. Methanol output is 14–15 kt/y in the CO 2 capture cases and 36 kt/y in the H 2 addition option. Configurations with a pressurized gasifier and phase-change-based CO 2 separation are the most efficient ones, with a primary energy efficiency of 50 % and a Levelized Cost of Methanol (LCOM) of 700 €/t MeOH. In comparison, LCOM increases to 730 €/t MeOH in the case with conventional capture or between 792 €/t MeOH and 831 €/t MeOH (depending on the CCS technology) if the gasification pressure is conservatively reduced to 2.5 bar. In the H 2 addition scenario, LCOM increases to 821 €/t MeOH due to the significant impact of the electricity consumption for H 2 production, (only partly compensated by the increased methanol production). Scenarios with CO 2 capture feature negative CO 2 emissions, in the range −1.64 to −1.84 t CO2eq /t MeOH , as a result of the capture and storage of biogenic CO 2 (BECCS approach). • Study of 5 bio-methanol configurations with CO 2 Capture and Storage or H 2 addition. • Process design and simulation of high- and low-P biomass gasification to methanol. • Partial liquefaction CO 2 capture and benchmarking against chemical absorption. • Minimum Levelized Cost of MeOH (700 €/t) for high-P gasifier and low-T CO 2 removal. • Negative net fossil CO 2 emissions of biomass-to-MeOH process due to BECCS. [ABSTRACT FROM AUTHOR]

Sugarcane ethanol is an alternative to fossil fuels that can mitigate greenhouse gas emissions and offer socioeconomic benefits, but at the same time have a series of negative impacts. Brazil is the second largest producer of fuel ethanol globally, with this production predicted to almost double over the next 15 years. However sugarcane ethanol production in the country has been shown to interact with a range of ecosystem services. It is only when such interactions are understood that we can fully determine the potential trade-offs, synergies and sustainability outcomes of biofuel production in the country. This paper explores the local perceptions about the impacts of sugarcane production on ecosystem services in two municipalities in the state of Sao Paulo with significant sugarcane production: Capivari and Rancharia. Impact perceptions have been elicited through interviews with local residents, with the results showing that perceptions vary between the two study sites and are affected considerably by the different local experiences with sugarcane production. For example, although sugarcane farming has been traditionally performed in Capivari, it has been Rancharia that has experienced more recently a rapid sugarcane expansion that has caused considerable changes in land use and farming patterns. Interview results also suggest that the negative effects of sugarcane farming can be reduced through the adoption of good agricultural practices and the enforcement of existing laws, as many respondents cited considerable improvements in ecosystem health from such actions. Assessing the perception of local communities such as the one reported in this paper can be crucial in designing policies and planning land uses that enhance the sustainability of biofuel production. [ABSTRACT FROM AUTHOR]

Given the expected rise in the importance and rate of decisions being made in the biofuel sector and the complexity of the system, this paper is focused on an analysis that, although well-established in economic and environmental evaluation theory, has not been widely used yet to assess biodiesel production. The aim of this study, in particular, is to analyze, from a quantitative point of view, the water footprint resulting from the use of various types of crops for the production of Italian biodiesel, combining it with the import costs of these crops, based on the current trade partners, and the crop energy conversion efficiency. The problem from the importing country's point of view is to minimize the total cost related to the import of crop products and, at the same time, to minimize the overall water footprint, ensuring a quantity of biodiesel produced at least equal to the pre-defined target set by the European Union for 2020. The paper provides a first glance at addressing optimal resource allocation and the design of biodiesel imports in the EU regulation context, contributing to reducing the water footprint, without ignoring the economic aspects. The study represents an original contribution for the identification of potential environmental policy drivers in the context of an economic sector characterized by potential growth, serving as a guide for the resolution of the trade-offs between biodiesel demand, import costs of feedstocks and water impact. [ABSTRACT FROM AUTHOR]

The demand for biofuels is rising with the growing population and decreasing reserves of petroleum. Indeed the rising population and increasing level of greenhouse gases not only contribute for global warming, but also imparts serious effects on humans and the environment. There is a constant urge to find other alternatives to the petroleum-based products. Of the three generations of biofuel feed stocks i.e. food crops, non-food crops and microalgae-derived biofuels; it is discussed that microalgae can be the best source of feed stock in terms of food security and for reducing the harmful impact on the environment. This paper serves as base to discuss the benefits of using microalgae as a source of biomass for biofuels and the methods that can be used to enhance the microalgal biology in order to improve their production. It reviews how the use of optimized nutrient concentration and culture conditions increase the yield, cell density and lipid productivity. It further reviews the role of bacteria in enhancing/inhibiting the microbial biomass and lipid productivity in microalgal-bacterial biological associations. The final part of the paper lays emphasis on the importance of improving microalgal biology by the use of genetic engineering and metabolic engineering in order to obtain desired results. Overall stress is placed upon unfolding and unraveling the gaps present in producing microalgal biomass, such as inefficient and reduced production, poor penetration of light in dense cultures, low oil content and higher harvesting costs. Overcoming of these major bottlenecks by ecologically engineering species specific valuable microalgal-bacterial mini consortium might lead to specific and noteworthy breakthrough in the production of clean, green, renewable, sustainable and high yielding microalgal biofuel. [ABSTRACT FROM AUTHOR]

Investigation of the high-pressure thermophysical properties of biofuels, e.g., bulk modulus, surface tension, and viscosity is of paramount importance in fuel injection systems in diesel engines. Another crucial and dangerous phenomenon that may occur in biofuels at high pressures is phase transition (solidification), which can drastically increase the viscosity of the biofuel. This effect may hamper proper operation of the engine, especially under cold-start conditions. Unfortunately, the availability of high-pressure thermophysical properties of biofuels is still limited. The goal of this paper is to investigate the impact of high pressures on thermophysical properties of biofuels on the example of rapeseed fatty acid methyl esters (RME) in a wide range of pressures ( 0.1 t o 250 M P a ) and temperatures ( 5 t o 20 ° C ). To this end we employed innovative ultrasonic techniques, i.e., the Bleustein-Gulyaev surface acoustic waves for measuring RME viscosity, and ultrasonic bulk compressional waves for measuring sound velocity in RME and consequently evaluating RME thermophysical parameters, e.g., bulk modulus and surface tension. The viscosity of the measured RME displayed an abrupt increase at pressures: 260 MPa ( t = 20 ° C ), 230 MPa ( t = 15 ° C ), 190 MPa ( t = 10 ° C ), and 130 MPa ( t = 5 ° C ). Evidently it was a signature of the phase transition (solidification) occurring in the RME. The discovered high viscosity high-pressure phase in RME can be very detrimental for operation of modern common rail Diesel engines. Therefore, the results of research presented in this paper should be interesting for engineers and designers working with modern common rail Diesel engines using biofuels. [ABSTRACT FROM AUTHOR]

As lifecycle emissions accounting becomes more widely used in policy, it is important to understand how it has been applied. This paper analyses policy-making for two U.S. fuel regulations—the federal Renewable Fuel Standard (RFS) and the California Low Carbon Fuel Standard (LCFS)—that were pioneering not only in using life cycle assessment (LCA) in performance-based environmental regulations, but especially for including emissions from indirect land use change (ILUC). The case studies in this paper focus, in particular, on the decision to include ILUC in lifecycle emissions accounting. Tracing the development of these policies shows the key role of environmental policy entrepreneurs in advocating for ILUC emissions accounting during policy formulation. Moreover, it highlights a paradox in the use of science: although ILUC policy proponents were motivated by best available research, they were also politically enabled by scientific uncertainty and lack of understanding. Understanding this political dimension of decision-making is valuable for scholars as well as practitioners facing similar decisions. [ABSTRACT FROM AUTHOR]

Due to their potential role in addressing the challenges of energy and environment, biofuels have been receiving significant attention from scientists in various disciplines and countries. Over the past few decades, the biofuel science has undergone major changes with regard to its rate of development, focus, and the contributing countries. We put the evolution the biofuel science into context by analyzing 49,000 relevant papers (comprising 0.26% of all publications across physical and life sciences) published between 1990 and 2014. We first determine the scientific contributions of different countries to the science on biofuels, and then analyze how the R&D expenditure and biomass availability is associated with their outputs. Subsequently, the structure of biofuel science in terms of the links between biomass feedstocks and final products are quantitatively discussed. We find that 28%, 16%, and 15% of all papers considered are published by researchers from the EU, China, and USA, respectively. Denmark, Sweden, and Finland have the highest number of biofuel-related publications per capita (i.e. 133, 113, and 103 papers per million capita and annum, respectively). The percentage share of studies on edible, lignocellulosic, and algal biomass are 46%, 40%, and 14%, respectively. Fermentation, hydrolysis, and esterification are the most widely studied conversion pathways, while liquefaction and life cycle assessment are the most cited subfields. Finally, using United States’ statistics, it is shown that upon accounting for the time delay between the nominal budget release year and the calendar year in which corresponding papers would ultimately appear in print, the publication trend was closely correlated to the R&D expenditure (r=0.98). [ABSTRACT FROM AUTHOR]

Due to shortages of fossil fuels, and the worldwide concern approximately climate change and global warming, biofuels have become an important source of sustainable energy. Several species can be used to produce biofuels such as soybeans ( Glycine max ), oil palm ( Elaeis guineensis ), and Jatropha ( Jatropha curcas L.). Therefore, the objective of this paper was to integrate the information available in the literature and report the most promising strategies for genetic and biotechnological progress in Jatropha. Jatropha has become a potential crop to produce biofuel due to the high oil content found in the seeds, which can be transformed into biofuel. Jatropha has an average seed oil content of 35%, and the oil extracted from the seeds has 24.6% crude protein and 47.2% crude fat. Moreover, Jatropha has several agronomic morphological traits that make it a useful crop for biofuel production and animal feed, such as drought tolerance, rapid growth, and ease of propagation. It can be grown at almost any altitude, and plants can produce for more than 50 years. Additionally, Jatropha oil has good stability to oxidation, low viscosity, a low pour-point, which makes Jatropha oil better than soybean or palm oil. This paper presented an innovative and comprehensive literature review on all agronomic aspects of Jatropha, and the strategies that have been used to select superior genotypes for Jatropha breeding. Several important traits of Jatropha are affected by the environment and new strategies to select superior genotypes are required by breeders. Therefore, genomic wide selection associated with recurrent selection can be an appropriate strategy for Jatropha breeding. [ABSTRACT FROM AUTHOR]

In response to resource depletion and tightening carbon emissions policies, the product oil is gradually being substituted by biofuels and faced with falling demand. A large number of studies have been done on the optimization of the biofuel supply chain, but few of them have considered the existing petroleum pipelines for policy reasons. Market-based reforms in the oil and gas industry have provided the possibility of pipeline sharing, whereby pipeline owners can use the remaining delivery capacity to transport other liquid fuels that are allowed into the pipeline, such as biofuels, thereby increasing pipeline benefits and reducing biofuel logistics costs. This paper develops a logistics optimization model considering multi-product pipeline scheduling from the perspective of biofuel suppliers and proposes a pipe-rail transportation mode to assess the optimization potential of logistics costs. Finally, this paper verifies the feasibility of the proposed approach using a logistics system in a region of China as a practical case study and conducts a sensitivity analysis on whether changes in the demand for product oil and biofuels affect the choice of pipeline opening location, concluding that there is no effect within a 4-fold increase in biofuel production and a 0.78-fold decrease in product oil demand. • Propose a method to evaluate the sharing capacity of single-source pipelines. • Develop a logistics optimization model considering pipeline scheduling. • Propose a pipe-rail transportation mode. • Reduce biofuel logistics costs by 8.64% or 8.41%. • Pipeline sharing program will not be affected until biofuels increase 4 times. [ABSTRACT FROM AUTHOR]

Abstract: Black liquor gasification (BLG) is currently being developed as an alternative technology for energy and chemical recovery at chemical pulp mills. This study examines how different assumptions regarding systems surrounding the pulp mill affect the CO2 emission balances for different BLG concepts. The syngas from the gasification process can be used for different applications; this study considers production of renewable motor fuels and electricity generation. Both a market pulp mill and an integrated pulp and paper mill are considered as host mill for the BLG plant. Furthermore, the consequences of limited availability of biomass are shown, i.e., increasing the use of biomass in a mill is not necessarily CO2-neutral. The results show that the potential to reduce CO2 emissions by introducing BLG is generally much higher for a market pulp mill than for an integrated pulp and paper mill. Electricity generation from the syngas is favoured when assuming high grid electricity CO2 emissions where as motor fuel production is favoured when assuming low grid electricity CO2 emissions. When considering the consequences of limited availability of biomass, the CO2 emission balances are strongly affected, in some cases changing the results from a decrease to an increase of the CO2 emissions. [Copyright &y& Elsevier]

Efficient upgrading of low value bio-derived heavy naphtha to high added value products (isomers and olefins) in a biorefinery context. [Display omitted] • Successful upgrading of BtL-naphtha to fuels and chemicals in pilot scale. • Good agreement between bench and pilot scale tests in hydroisomerization and FCC. • Isomerization over 0.1 wt% Pt/ZSM-5 leads to efficient production of isoparrafins. • Fluid catalytic cracking of BtL-naphtha requires high temperatures (600–650 °C). • Chemicals yield of ∼27 wt% can be attained with naphtha fluid catalytic cracking. The development of efficient processes for the upgrading of low value bio-derived liquid intermediates to high added value products in biorefineries is critical for the establishment of a robust and competitive bio-based economy. We show in this paper that low quality surrogate heavy naphtha, representative of biofuels from thermochemical biomass conversion processes, can be efficiently converted to high quality fuel and chemicals (olefins) via hydroisomerization and catalytic cracking, respectively. Hydroisomerization over a low loading 0.1 wt% Pt/ZSM-5 catalyst leads to the conversion of normal paraffins to C 5 -C 8 isoparaffins with limited cracking, and produces a fuel with higher octane and lower cetane number, suitable for use in future powertrains such as HCCI engines. Catalytic cracking of the naphtha on a commercial ZSM-5 based FCC catalyst results in the production of a significant amount of olefins at 600 °C, primarily propylene followed by ethylene, n-butene, pentene and i-butene. Both processes are validated on pilot scale. Some differences observed between bench and pilot scale results are due to scalability phenomena and different reaction conditions. Still, excellent agreement with regards to the composition of the products at similar conversion level exists, demonstrating the scalability and applicability of these upgrading processes in thermochemical biorefineries. [ABSTRACT FROM AUTHOR]

Lignin stands the most abundantly available source of renewable aromatic compounds which is generated as a useless waste by-product in numerous industrial processes, e.g., in pulp and paper manufacturing as well as during second-generation ethanol production. The present work aims to investigate the effect of reaction conditions (particularly the reaction atmosphere type) on the composition of the volatiles that evolved during the pyrolysis of lignin. The pyrolytic studies were carried out using coupled microscale techniques, i.e., Py-GC-MS, and Py-FT-IR. The pyrolysis is usually carried out under an inert atmosphere. Herein, there was additionally studied comprehensively the effect of oxidizing (CO 2 and air) and reducing atmosphere (H 2). There was found a profound impact of the processing temperature on the composition changes of volatiles. A minor effect was noted for the pyrolysis atmosphere on the qualitative composition of the volatiles, but certain quantitative differences between their concentration were observed. Their composition confirmed the complex molecular structure of lignin. Among the identified compounds, there were found phenol derivatives as primary products of cleavage of lignin structures as well as aliphatic oxygen compounds and aromatic hydrocarbons as the products of the secondary decomposition and deoxygenation thereof. • Pyrolysis of wheat straw lignin via Py-FTIR and Py-GC-MS within 300–800 °C was done. • The effect of inert, CO 2 , H 2 and air reaction atmospheres in pyrolysis was studied. • A minor effect of pyrolysis atmosphere on the volatiles qualitative composition. • Impact of pyrolysis reaction atmosphere on quantitative composition of volatiles. • Py-FT-IR and Py-GC-MS as complementary techniques for fast pyrolysis investigation. [ABSTRACT FROM AUTHOR]

Despite a substantial literature using life cycle assessment (LCA) approach, the extent to which second and third generation biofuels are more sustainable than the first generation remains a subject of debate. Although the existence of limitations due to LCA variability and uncertainty, this paper intends to determine global tendencies based on a statistic and critical interpretation of previously published study results, reviewing 61 recent papers addressing an environmental evaluation of microalgae biofuels. Such information is compared to the same impact indicators for fossil fuels and for ethanol and biodiesel from terrestrial crops in Europe and Brazil. For each case, the system boundaries and the methodological choices were precisely described. The sustainability potential of all biofuels was evaluated by the Global Warming Potential (GWP), the Energy Ratio (ER) and the Land Use (LU), allowing a broad estimation of the biofuels’ contribution to climate change mitigation, their net energy efficiency and their competiveness with food production chain. The results highlight that algae-derived biodiesel is, by far, the most efficient alternative in terms of land use compared to other biofuels, avoiding competition with food crops. Some biodiesel pathways can also satisfactorily perform in terms of greenhouse gases emissions reduction, but some others can be even worst than fossil diesel. Nevertheless, in terms of energy efficiency, algae biofuels cannot compete with other biofuels or fossil fuels. They present very low performances, even demanding more energy for its production then the energy they can deliver. Moreover, no pathway can be conclusively selected as preferable between the two main technologies available for microalgae biodiesel due to high uncertainties. However, open raceway pounds technology seems to be preferable as it looks less GHG intensive, requiring lower energy input and land use. Energetic and GWP performances can be improved if production pathways are carefully chosen and optimized. [ABSTRACT FROM AUTHOR]

Lignin is a complex phenylpropanoid biopolymer conferring mechanical strength to plant cell walls. Biorefineries, along with pulp and paper industry, generate large quantities of lignin. Lignin valorization is an essential process for an advanced, sustainable, and economical biomass-based industry. However, converting lignin into value-added products remains a challenge due to its heterogeneity and irregular structure. Many wild microorganisms have evolved complex metabolic and enzyme systems for lignin degradation and conversion. Great efforts have been made to explore their potentials for lignin valorization. This paper reviews the recent development in biological conversion of lignin into value-added products. It also covers potential catabolic pathways, exploration of new lignin degradation systems, and lignin consolidated bioprocessing (Lignin CBP). [ABSTRACT FROM AUTHOR]

This paper reviews path-creation processes in road transport systems in the Nordic countries: e-mobility in Denmark, hydrogen and fuel-cell electrical vehicles in Norway, and advanced biofuels in Finland and Sweden. The study builds on the path creation literature, which seeks to explain the emergence of new technological pathways. Drawing on recent insights concerning the differences between design- and manufacturing-intensive technologies, the paper analyses the influence of technological characteristics on path creation processes. The case comparison indicates that technological characteristics seem to have greater influence on the content of activities in the later phase rather than the early phase of path creation processes. The analysis also emphasises that barriers to path creation processes differ depending on technological characteristics. This highlights the importance of considering technological characteristics in energy and transport policies. [ABSTRACT FROM AUTHOR]

Dedicated annual sorghum crops, such as sweet sorghum or energy sorghum, may provide an option for farmers to supply cellulosic feedstocks for biofuel production and help the industry meet government mandates. Kansas farmers are poised to be major producers of sweet sorghum for biofuels due to favorable agro-ecological conditions. The purpose of this paper is to assess Kansas farmers' willingness to grow sweet sorghum under contract as a feedstock for biofuel production. The paper examines farmers' willingness-to-pay for contract attributes and the impact of socio-economic factors on their willingness-to-pay for these attributes. A stated choice survey was administered to Kansas farmers to assess their willingness to grow sweet sorghum for biofuels under various contracting scenarios. Results show that farmers may be willing to grow biomass for bioenergy under contract, but may have varying preferences for the importance of contract attributes such as net returns, contract length, insurance availability, government incentives, and potential for biorefinery harvest options based on socio-economic characteristics of growers. [ABSTRACT FROM AUTHOR]

The authors discuss in this paper the potential of a micro gas turbine (MGT) combustor when operated under unconventional conditions, in terms of variation in the fuel supplied. The authors’ expertise in the field of micro-combustor has addressed, in recent years, some topics of current interest, as the fuelling with gaseous and liquid biofuels and the NOx reduction through the optimization of the combustor. While the previous authors’ works were mainly referring to a tubular combustor of a 100kW MGT, the present proposal deals with an annular, reverse flow combustor of a 30kW MGT. In this case the particular location of both the injectors and of the secondary and diluting holes allows the combustor process to develop under nearly RQL conditions. This is of special interest when supplying the combustion chamber with low LHV fuels. In addition, recent authors’ papers have demonstrated that the integration of the MGT with a solar field leads the combustor to require a decreased fuel/air equivalence ratio because of the higher air entry temperature. Under these aspects, the existence of a Rich region within the combustor may be helpful for the early phases of the oxidation process. The pollutant formation rates should be effectively controlled by the secondary (Quick-mix) and diluting (Lean) air flows. The authors’ methodology relies on an advanced CFD approach that makes use of a reaction scheme coupled with an accurate study of the turbulent interaction of the reacting species. Extended kinetic mechanisms are also included in the combustion model. A preliminary set-up of the model will be based on the combustion analysis with boundary conditions provided by thermodynamic analysis of the micro-turbine. Several computational examples are discussed, namely: - The analysis of the combustor response with reduced equivalence ratios or changes in the inlet air conditions; - The comparison of combustion efficiency and pollutant production with different fuels. [ABSTRACT FROM AUTHOR]

The development of an environmentally sustainable and financially viable replacement for fossil fuels continues to elude industry investors even though the benefits of replacing them is undisputed. Biofuels are among the promising replacements for fossil fuels. However, the development and production process for bio-based fuels creates uncertainty for industry investors. In order to increase process profitability, financial tools can be implemented with current technology. This paper proposes the use of forward contracts to mitigate risk, and it also considers the impact of carbon tax constraints and price uncertainty. Specifically, a stochastic optimization approach is implemented to develop strategies, which increases the net present value (NPV) of a production facility through determination of an optimal production schedule, as well as the creation of a portfolio of forward contracts to reduce product price risk. Results of numerical case studies show that if the policymaker is risk averse, production is higher in the early planning period rather than the later period. This paper also investigates the ability to maintain inventory in order to create additional financial benefit. [ABSTRACT FROM AUTHOR]

Cellulose is a very abundant polymer that is found in nature. Cellulose has been used as a raw material for production of biofuels for many years. However, there are multiple processing steps that are required so that cellulose can be used as a raw material for biofuel production. One of the most important steps is the breakdown of cellulose into intermediate sugars which can then be a viable substrate for biofuel production. Cellulases are enzymes which play a role in the catalysis of the breakdown of cellulose into glucose. Nanomaterials and micromaterials have been gaining a lot of attention over the past few years for its potential in immobilizing enzymes for industrial procedures. Immobilization of enzymes on these nanomaterials has been observed to be of great value due to the improvement in thermal stability, pH stability, regenerative capacity, increase in activity and the reusability of enzymes. Similarly, there have been multiple reports of cellulase enzymes being immobilized on various nanoparticles. The immobilization of these cellulase enzymes have resulted in very efficient processing and provide a great and economic solution for the processing of cellulose for biofuel production. Hence in this paper, we review and discuss the various advantages and disadvantages of enzymes on various available nanomaterials. • Immobilization of cellulase onto MNPs makes the recovery process easier. • Cellulase immobilized on composite materials has high loading capacity and great reusability. • CNTs are suitable for enzyme immobilization especially for the purpose of biofuel production. • Immobilization on MOF was observed to be an excellent strategy for the improvement in enzyme activity. [ABSTRACT FROM AUTHOR]

• An historical event analysis of the Australian biofuel innovation system is undertaken. • The system is characterised by R&D and industry development mechanisms, but policy layering has been inadequate. • Each dynamic has emerged multiple times. • Legitimacy for biofuels has been limited, restricting effective industry development and market formation initiatives. Like many countries, since the 1980s, Australia has introduced a range of government policies to support the development of a biofuels industry. Despite growth in the use of biofuels over this period industry development has not progressed to the extent seen in many of these other countries. This paper uses the technological innovation systems perspective to guide an historical event analysis of the biofuels innovation system within Australia over a period of almost 40 years. Results suggest two main system dynamics have been present: a series of science and technology cycles that aimed to progress biofuel technologies toward commercial competitiveness with incumbent petroleum industries; and several short lived industry development cycles that were weakened by limited market formation mechanisms and insufficient socio-political legitimation. It is concluded that the introduction of biofuel quotas in the absence of sufficient industrialisation of biofuels, while promoting some growth, undermined their effectiveness. The results are discussed in terms of the need for policy layering to support effective system development. [ABSTRACT FROM AUTHOR]

Under the dual pressures of oil depletion and low carbon transition, biofuels are considered effective alternatives for fuel oil due to their renewable nature and environmental friendliness. However, oil demand remains high, which indicates that biofuels and fuel oil will coexist for a long time to come. While pipelines offer an efficient means of transporting liquid fuels, the initial investment required is substantial. Therefore, this paper proposes a comprehensive framework that focuses on sharing already existing multi-product pipelines with biofuels, thus evaluating the pipeline remaining potential to transport biofuels. The core component of this framework is the evaluation method for determining the multi-product pipeline remaining capacity. We coupled fuel oil consignment contracts into the remaining capacity evaluation method and developed a model for evaluating the multi-product pipeline transport biofuels potential, aiming to maximize biofuels pipeline transport volume. The objective of this model is to optimize the transportation volume of biofuels through pipelines. Various constraints are taken into account, such as product batch movement, prohibited sequences, operational constraints, delivery time frames, and inventory levels. Moreover, this study evaluates and discusses the benefits of biofuels transportation capacity using eight real-world multi-product pipeline systems without impacting fuel oil consignment contracts. The findings indicate that pipelines are capable of transporting 49,849 m 3 of biofuels per week, increasing revenue by 1.78 million C N Y. Simultaneously, the low energy consumption for pipeline transportation can lead to a weekly reduction of 34.6 tons in carbon emissions. The evaluation model anticipatively provides the ability to respond to future market developments. • Propose multi-product pipelines with biofuel sharing mode. • Develop an evaluation model that accounts for time and facility factors. • Increase pipeline operators' revenue by 1.78 million C N Y per week. • Reduce biofuel transportation carbon emissions by 34.6 tons per week. • Validate the necessity of factor consideration with different scenarios. [ABSTRACT FROM AUTHOR]

• Recent progress in the catalytic thermochemical conversion processes are reviewed. • Potential of biomass as a biofuel for renewable energy applications is addressed. • Use of catalyst in gasification can reduce reaction time and increase gas yield. • Activity and stability of the catalyst should be overcome for bio-oil production. • Optimization of process and reactor design needs to be also considered. This review paper introduces various biomasses (e.g., agricultural, woody biomass waste) used in thermochemical conversion processes, including gasification, pyrolysis, and hydrothermal liquefaction. The recent advances and progress in catalytic thermochemical conversion technologies are analyzed. In particular, the role of catalysts in different reactors on the major products (bio-oil and syngas) is discussed with respect to the product yield and property. Various catalytic reaction mechanisms during the thermochemical conversion reaction are discussed to explain the conditions to enhance the desired pyrolysis product quality. Furthermore, different types of reactors for each thermochemical process are reviewed. Further processing technologies using biomass pyrolytic bio-oil products are also introduced. Finally, this review paper presents the related challenges and opportunities encountered in thermochemical conversion processes to understand better the future of thermochemical conversion processes in biorefineries. [ABSTRACT FROM AUTHOR]