High-silica faujasite zeolite-tailored metal encapsulation for the low-temperature production of pentanoic biofuels

Zeolite-encapsulated metal nanoclusters are at the heart of bifunctional catalysts,which hold great potential for petrochemical conversion and the emerging sustainable biorefineries.Nevertheless,efficient encapsulation of metal nanoclusters into a high-silica zeolite Y in particular with good structural integrity still remains a significant challenge.Herein,we have constructed Ru nanoclusters(~1 nm)encapsulated inside a high-silica zeolite Y(SY)with a SiO_(2)/Al_(2)O_(3) ratio(SAR)of 10 via a cooperative strategy for direct zeolite synthesis and a consecutive impregnation for metal encapsulation.Compared with the benchmark Ru/H-USY and other analogues,the as-prepared Ru/H-SY markedly boosts the yields of pentanoic biofuels and stability in the direct hydrodeoxygenation of biomass-derived levulinate even at a mild temperature of 180℃,which are attributed to the notable stabilization of transition states by the enhanced acid accessibility and properly sized constraints of zeolite cavities owing to the good structural integrity.

Past, Present and Future: A Role for Liquid Biofuels in Transitioning to Net Zero?

Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in biofuels production infrastructure. Concerns over the environmental impacts of large-scale biofuels production combined with tariff barriers have greatly restricted the global trade in biofuels. First-generation biofuels produced either by fermentation of sugars from maize or sugarcane (ethanol) or transesterification of triglycerides (biodiesel) presently contribute less than 4% of terrestrial transportation fuel demand and techno-economic modelling foresees this only slowly increasing by 2035. With internal combustion and diesel engines widely anticipated as being phased out in favour of electric power for motor vehicles, a much-reduced market demand for biofuels is likely if global demand for all liquid fuels declines by 2050. However, second-generation, thermochemically produced and biomass-derived fuels (renewable diesel, marine oils and sustainable aviation fuel) have much higher blend limits;combined with policies to decarbonise the aviation and marine industries, major new markets for these products in terrestrial, marine and aviation sectors may emerge in the second half of the 21st century.

Tuning the selectivity of natural oils and fatty acids/esters deoxygenation to biofuels and fatty alcohols:A review

The chemical transformation of natural oils provides alternatives to limited fossil fuels and produces compounds with added value for the chemical industries.The selective deoxygenation of natural oils to diesel-ranged hydrocarbons,bio-jet fuels,or fatty alcohols with controllable selectivity is especially attractive in natural oil feedstock biorefineries.This review presents recent progress in catalytic deoxygenation of natural oils or related model compounds(e.g.,fatty acids)to renewable liquid fuels(green diesel and bio-jet fuels)and valuable fatty alcohols(unsaturated and saturated fatty alcohols).Besides,it discusses and compares the existing and potential strategies to control the product selectivity over heterogeneous catalysts.Most research conducted and reviewed has only addressed the production of one category;therefore,a new integrative vision exploring how to direct the process toward fuel and/or chemicals is urgently needed.Thus,work conducted to date addressing the development of new catalysts and studying the influence of the reaction parameters(e.g.,temperature,time and hydrogen pressure)is summarized and critically discussed from a green and sustainable perspective using efficiency indicators(e.g.,yields,selectivity,turnover frequencies and catalysts lifetime).Special attention has been given to the chemical transformations occurring to identify key descriptors to tune the selectivity toward target products by manipulating the reaction conditions and the structures of the catalysts.Finally,the challenges and future research goals to develop novel and holistic natural oil biorefineries are proposed.As a result,this critical review provides the readership with appropriate information to selectively control the transformation of natural oils into either biofuels and/or value-added chemicals.This new flexible vision can help pave the wave to suit the present and future market needs.

Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels

Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.

Highly Efficient Synthesis of Clean Biofuels from Biomass Using FeCuZnAIK Catalyst

Highly efficient synthesis of clean biofuels using the bio-syngas obtained from biomass gasi- fication was performed over Fel.5CulZnlAllK0.117 catalyst. The maximum biofuel yield from the bio-syngas reaches about 1.59 kg biofuels/（kgcat·rh） with a contribution of 0.57 kg alcohols/（kgcat·rh） and 1.02 kg liquid hydrocarbons/（kgcat·rh）. The alcohol products in the resulting biofuels were dominated by the C2＋ alcohols （mainly C2-C6 alcohols） with a content of 73.55%-89.98%. The selectivity .of the liquid hydrocarbons （C5＋） in the hydrocarbon products ranges from 60.37% to 70.94%. The synthesis biofuels also possess a higher heat value of 40.53-41.49 MJ/kg. The effects of the synthesis conditions, including temperature, pressure, and gas hourly space velocity, on the biofuel synthesis were investigated in detail. The catalyst features were characterized by inductively coupled plasma and atomic emission spectroscopy, X-ray diffraction, temperature programmed reduction, and the N2 adsorption-desorption isotherms measurements. The present biofuel synthesis with a higher biofuel yield and a higher selectivity of liquid hydrocarbons and C2＋ alcohols may be a potentially useful route to produce clean biofuels and chemicals from biomass.

Optimization of Biofuel Formulation by Mixture Design

With the full growth of energy needs in the world, several studies are now focused on finding renewable sources. The aim of this work is to optimise biofuel formulation from a mixture design by studying physical properties, such as specific gravity and kinematic viscosity of various formulated mixtures. Optimization from the mixture plan revealed that in the chosen experimental domain, the optimal conditions are: 40% for used frying oil (UFO), 50% for bioethanol and 10% for diesel. These experimental conditions lead to a biofuel with a density of 0.84 and a kinematic viscosity of 2.97 cSt. These parameters are compliant with the diesel quality certificate in tropical areas. These density and viscosity values were determined according to respective desirability values of 0.68 and 0.75.

Study of the Viscosity and Specific Gravity of the Ternary Used Frying Oil (UFO)-Bioethanol-Diesel System

Fossil fuels cover around 80% of global energy consumption. However, the problems linked to their use justify the choice of using biofuel. In order to reduce as much as possible, diesel rate, an increase in the number of additives may be considered. Thus, in this work, the study of the used frying oil (UFO), bioethanol and diesel ternary system was undertaken. It emerges from this study that the addition of bioethanol reduces the viscosity and the density of the ternary system and permits a 90% substitution rate for diesel between the UFO and bioethanol. Finally, the percentage of oil becomes 40% after adding alcohol compared to the binary diesel crude vegetable oil mixture where this rate is 30%.

Current Situation and Perspective of Second Generation Solid Biofuels Production： Case Study——CMR （Campinas Metropolitan Region）, Sao Paulo, Brazil

This proposal aims to assess the market introduction of advanced technologies for the production of 2nd generation solid biofuels, specifically technologies for the production of briquettes and pellets from agro-industrial wastes. The development of this project will evaluate the socio-environmental and techno-economical feasibility and use of 2nd generation solid biofuels in the CMR （Campinas Metropolitan Region）. The successful introduction of second generation briquettes and pellets to market depends, mainly, on two aspects： logistics in supply chains which generate waste, and the efficiency of production technologies. The study of logistics （supply chain） is based on survey data of the main productive supply chains, analysis, and modeling to optimize the facility location in the network for each case. The evaluation of the efficiency of production technology is provided by testing specially designed waste compacting devices, and comparing these results with the resulting power consumption during the production, in demonstration-scale, of a round of briquettes. The costs and consumption during the demonstration-scale production of briquettes are used for validation and correction of an optimization model. This project was approved in late 2012 with a period of two years for its implementation. Later in 2013, it was decided also to extend its implementation to the Metropolitan Region of Manaus, Amazon. Due to its recent beginning, the results shown here are only preliminary.

A review of the current state of biofuels production from lignocellulosic biomass using thermochemical conversion routes

The rapid increase in energy demand,the extensive use of fossil fuels and the urgent need to reduce the carbon dioxide emissions have raised concerns in the transportation sector.Alternate renewable and sustainable sources have become the ultimate solution to overcome the expected depletion of fossil fuels.The conversion of lignocellulosic biomass to liquid(BtL)transportation fuels seems to be a promising path and presents advantages over first generation biofuels and fossil fuels.Therefore,development of BtL systems is critical to increase the potential of this resource in a sustainable and economic way.Conversion of lignocellulosic BtL transportation fuels,such as,gasoline,diesel and jet fuel can be accomplished through various thermochemical processes and processing routes.The major steps for the production of BtL fuels involve feedstock selection,physical pretreatment,production of bio-oil,upgrading of bio-oil to transportation fuels and recovery of value-added products.The present work is aiming to give a comprehensive review of the current process technologies following these major steps and the current scenarios of biomass to liquid facilities for the production of biofuels.

Facile biphasic catalytic process for conversion of monoterpenoids to tricyclic hydrocarbon biofuels

Terpenoids have drawn much attention to scientists in synthesizing high-performance bio-jet fuels due to their ring structures,which feature potential high densities.Here,a facile biphasic catalytic process has been developed for the production of high-density tricyclic hydrocarbon biofuels from a monoterpenoid,1,8-cineole,using sulfuric acid(H2SO4)as the homogeneous catalyst.A^100%conversion of 1,8-cineole and a>40%carbon yield of cyclic dimers were achieved at 100℃within two hours.The mechanism for the acid-catalyzed conversion of 1,8-cineole to cyclic hydrocarbon dimers were explored.In particular,the formation of the diene intermediates and the following dimerization of dienes was essential to synthesize tricyclic terpene dimers.The biphasic catalytic process accelerated the deoxygenation rate and enabled the dimerization with the aid of organic solvent while controlling the reaction rates to avoid the formation of solid residues.Moreover,this process also facilitated the product separation by organic solvent extraction while enabling easy recycle of the homogenous catalysts.

A durable Ni/La-Y catalyst for efficient hydrogenation of γ-valerolactone into pentanoic biofuels

Zeolite-supported metal catalysts containing hydrogenation centers and acid sites are promising in the chemoselective hydrogenation of biomass platform molecules into value-added chemicals and fuels.The primary challenge of employing such bifunctional catalysts for biomass conversion lies in catalyst stability in the liquid phase under harsh conditions. Herein, we have prepared a Ni/La-Y nanocatalyst via an improved wet impregnation method. Compared with Ni nanoparticles on H-Y, La addition shows a significantly enhanced stability and performance in the continuous liquid-phase hydrogenation of γ-valerolactone(GVL) into ethyl pentanoate(EP) at 200 ℃ for 1000 h. Complementary characterization studies reveal that La addition in the metal/zeolite catalyst not only efficiently modulates the acid property of the zeolite to alleviate coke formation, but also suppresses zeolite dealumination and metal agglomeration and leaching upon catalysis over a 1000 h period. These findings provide an efficient approach for improving the stability of zeolite-supported bifunctional catalysts, leading to potential application in hydrogen-assisted biomass valorization under the liquid-phase conditions.

Assessment of Feedstock Options for Biofuels Production in Ghana

In the wake of climate change and increasing fossil fuel prices, biofuels are becoming attractive to agricultural dependent economies in sub-Saharan Africa and other regions of the world. This study evaluates the energy production potential of biomass resources grown on the available arable agricultural land under two principal scenarios: using 2.5% and 5% of the available arable land for energy crop expansion. Using conservative biofuel yields from crops in the sub-region, a 2.5% of uncultivated arable land dedicated to four traditional crops grown in Ghana namely maize, cassava, sweet sorghum and oil palm could potentially replace 9.3% and 7.2% of transportation fuels by 2020 and 2030 respectively. Using 5% of the uncultivated arable land to cultivate the above four crops and jatropha could potentially produce biofuel to replace 17.3% of transport fuels by 2020 and 13.3% by 2030. In order to enrol such a scheme, government is encouraged to put in place appropriate structures to ensure that, the industry meet international sustainability standards.

Synthesis and catalytic performance of bimetallic NiMo-and NiW-ZSM-5/MCM-41 composites for production of liquid biofuels

This work presents a synthesis of bimetallic NiMo and NiW modified ZSM-5/MCM-41 composites and their heterogeneous catalytic conversion of crude palm oil( CPO) to biofuels. The ZSM-5/MCM-41 composites were synthesized through a self-assembly of cetyltrimethylammonium bromide( CTAB) surfactant with silica-alumina from ZSM-5 zeolite,prepared from natural kaolin by the hydrothermal technique. Subsequently,the synthesized composites were deposited with bimetallic NiMo and NiW by impregnation method. The obtained catalysts presented a micro-mesoporous structure,confirmed by XRD,SEM,TEM,EDX,NH_3-TPD,XRF and N_2 adsorption-desorption measurements. The results of CPO conversion demonstrate that the catalytic activity of the synthesized catalysts decreases in the series of NiMo-ZSM-5/MCM-41 > NiW-ZSM-5/MCM-41 > Ni-ZSM-5/MCM-41 > Mo-ZSM-5/MCM-41 > W-ZSM-5/MCM-41 > NiMo-ZSM-5 > NiW-ZSM-5 > ZSM-5/MCM-41 > ZSM-5 > MCM-41. It was found that the bimetallic NiMo-and NiW-ZSM-5/MCM-41 catalysts give higher yields of liquid hydrocarbons than other catalysts at a given conversion. Types of hydrocarbon in liquid products,identified by simulated distillation gas chromatography-flame ionization detector( SimDis GC-FID),are gasoline( 150-200 ℃; C5-12),kerosene( 250-300 ℃; C5-20) and diesel( 350 ℃; C7-20).Moreover,the conversion of CPO to biofuel products using the NiMo-and NiW-ZSM-5/MCM-41 catalysts offers no statistically significant difference( P> 0.05) at 95% confidence level,evaluated by SPSS analysis.

An Arthrobacter strain isolated from desert soils in the region of Shule River (China) can convert cellulose to potential biofuels

In this study, an Arthrobacter strain from desert soils in the Shule River Valley was isolated, China, which has a strong ability to convert cellulose to potential biofuel. In total, from five soil sample sites, six strains were isolated that grew well on CMC-Agar medium, with colony diameters ranging from 3~4 mm, among them, one strain had a strong ability to produce biofuels. Based on morphological and phylogenetic analyses, the isolate was identified as Arthrobacter nitroguajacolicus strain SLP1. The chemical properties of the biofuel extracted from the fermentation broth of strain SLP1 were analysed by gas chromatography and mass spectrometry. A total of 41 kinds of carbon compounds were identified, of those,five were detected at peak concentration and the carbon numbers ranged from C16–C22, which can be classified as alkanes,alkenes, and alcohols. Furthermore, biofuel-producing ability of strain SLP1 was enhanced using NTG mutagen. In a total of 94 mutant strains, four show the most enhanced biofuel production relative to the original strain. Biofuel production conditions were optimized by growing the four mutant strains on LB-Agar and SS-Agar medium.

The impacts of biofuels on food security and supply in China

Biofuels are the current promising alternative to fossil fuels. However, the fluctuating food prices caused by oil price led to critics to biofuels. The paper surveyed biofuels production and grain production and consumption demand, and come to the conclusion that there was a little impact of corn ethanol on international food price, and there was no impact on China’s food prices. China has launched non-food biofuels development strategy to use marginal lands for growing hard crops, such as sweet sorghum, tuber crops, and switchgrass etc. to produce biofuels without any impact on food security in the future.

Genetic Bioengineering in the Achievement of Algae Biofuels and High-Value Bio-products

The dependence to fossil fuels has increased the amount of greenhouse gases in the atmosphere.That is why,the production of renewable and sustainable biofuels has gained a long-term importance for both scientific and political necessities.In this context,algae are promising in terms of alternative biofuels resources.For this reason,intensive scientific researches have been carried out in recent years on providing optimum efficiency in this regard.Bioengineering is a discipline that applies engineering principles of design and analysis to biological systems and biomedical technologies.Examples of bioengineering research include bacteria or microalgae engineered to produce valuable bioactive chemicals.Microalgae by target gene modification may serve as a promising source for the production of biofuels and bio-based chemicals.A lot of research has been carried out by applying microalgae genomic editing technique with the aim to produce numerous biotechnological products.Some successful previously reported research and production activities are still underway in this area.However,in order to produce the desired products efficiently with manipulated microalgae biorefinery,there is a need to overcome the problem of low biomass production despite high production costs.The aim of this work is to give special attention to the rich potential content of microalgae and to provide information on algal genetic manipulations to increase products by bioengineering methods.

Towards Biorefinery Production of Microalgal Biofuels and Bioproducts: Production of Acetic Acid from the Fermentation of <i>Chlorella</i>sp. and <i>Tetraselmis suecica</i>Hydrolysates

Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzymatic saccharification of microalgal biomass (Chlorella sp. and T. suecica) as fermentation feedstock to produce industrially important chemicals, in particular acetic acid and butyric acid. By using hydrolysate with low sugar content as substrate for the anaerobic fermentation (1.5 - 2.4 g/L), we were able to prevent the bacterium C. saccharoperbutylacetonicum from activating its solventogenesis pathway. As a result, the fermentation process generated a product stream that was dominated by organic acids (acetic acid and butyric acid) rather than solvents (butanol, ethanol and acetone). Acetic acid constituted up to 92 wt% of Chlorella’s fermentation products and 80 wt% of T. suecica’s fermentation products. For T. suecica, the fermentation consumed almost all of the sugar available in the hydrolysate (up to 92% of initial sugar) and produced a reasonable yield of fermentation products (0.08 g fermentation products/g sugar). The Gompertz equation was successfully used to predict the formation kinetics of acetic acid and other fermentation products across both species. The results in the study demonstrate the production of industrially important chemicals, such as acetic acid and butyric acid, from the fermentation of microalgal sugar. The process described in the study can potentially be used as a value-adding step to generate biochemicals from cell debris in an integrated microalgal biorefinery system.

Sustainability and Entrepreneurship in the Biofuels Supply Chain： A Proposal for a Survey

Investments in bio-energies require deep and accurate analysis to evaluate their economical feasibility both by the investors＇ and the policy makers＇ perspectives. The chance to attain locally organized supply chains is presumably higher where there is a higher concentration of human, natural and financial capitals. After a literature review about social capital and energy supply chain （prg. 1）, we investigate the instruments for public direct financial incentive （prg. 2） and the development of the public intervention plans in the agro-energy sector within the Local Development Plans （LDP） by Local Action Groups （LAG）. Then, we present the case study of the Apulia Region （prg. 3） based upon a unique dataset, specifically built that collects LDP data relative to social capital. We finally propose a new methodological approach that makes use of social network analysis investigating the net of relationships underneath the territorial organization of the LAGs and the local supply chains. Results seem to show that site specificities affect the sustainability of biofuels supply chains, and that effect seems to be reciprocally bounded, thus calling for the inclusion of such measures when planning new policies, and for analytical approaches encompassing historical perspectives. Finally, we draw the conclusions.

The Production of Biofuels in South Africa： Policy and Availability of Energy Crops

Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy sources; and by dealing with environmental issues. One such environmental issue is the unsustainable use of agricultural land. There is a need in South Africa there to convert to sustainable and renewable energy resources, such as biofuels, but the production of biofuels will ultimately place pressure on the limited and fragile agricultural resources of the country. This paper sets out firstly to investigate national agricultural policies which could impact on the production of biofuels. It points out that national agricultural policies are hampering the domestic production of biofuels in that the focus is on land reform and increasing the volume of agricultural exports, whereas the provision of food and energy to meet domestic needs features only as a secondary aim. The second objective of this paper is to investigate the possibility of utilising energy crops for biofuel production in South Africa. Annual agricultural production, surplus import and export figures, provide an indication of the capacity of South African farmers to produce crops for biofuel production.

Food Commodity Prices Volatility: The Role of Biofuels

Food commodity prices have recently increased sharply and become more volatile, highlighting greater uncertainty in markets and threatening global food security. High fuel prices combined with legislative mandates have increased biofuel production raising the average cost of food on the global market and particularly in developing countries and established a link between crude oil and agricultural prices. We investigate the role of biofuels in explaining increased volatility in food commodities. Multivariate GARCH models and volatility decompositions are estimated on grains and crude oil daily prices over a twelve-year sample from 2000-2011. We find increases in correlations and co-movements between grains and crude oils prices after 2006 and particularly in 2008 when crude oil prices were high. Increased volatility in grains during the 2008-09 spike was largely due to shocks transmitted from crude oil to grains especially corn, wheat and soybean prices.