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The scope of this work rests at the interface between food and energy sustainability. Thermochemical conversion of biomass is an attractive strategy for the production of low-cost biofuels, and bio-based insecticides are a more sustainable and often safer alternative for pest management in agricultural production. This work demonstrates a complimentary strategy to access both biofuels and a bio-based insecticide through a catalytic fast pyrolysis process. Technoeconomic modeling shows the bioinsecticidebio-based insecticide can be produced at a cost ≤1.7$ per kg while fully formulated bioinsecticidebio-based insecticides typically sell for ≥6$ per kg, which can significantly reduce the biofuel selling price. Supply chain analysis shows a 46–88% reduction in green-house gas emissions for this agrochemical can be achieved. By using insecticidal activity data from two well-known crop pests, spotted-wing drosophila (Drosophila suzukii, Matsumura) and oriental fruit moth (Grapholita molesta, Herbst), with an analytical analysis, which achieved ≥99% mass balance closure on the thermochemically derived distillate product, a structure–function relationship between phenol alkylation and insecticidal activity is proposed. An ecotoxicological assessment of the bio-based insecticide was performed using existing data and prediction tools across 18 metrics. It is estimated that a 2000 tonne per day biorefinery can supply 1–5% of the market, which is typical for other moderately scaled chemicals. The mixture of alkylated phenols, used as a bio-based insecticide, is an ideal coproduct that overcomes separation challenges associated with thermochemical streams, such as heterogeneity and reactivity, while providing a more sustainable source for agrochemicals. Synergistic strategies for energy and food production, such as coproduction of bio-based insecticides with biofuels, can be a viable approach to improve sustainability in both sectors.

The combustion of a viscous biofuel, liquefied wood (LW) produced via solvolysis of lignocellulosic biomass in acidified glycols, has been studied in a small gas turbine rig. The test rig includes a modified injection line which is compatible with acidic, viscous biofuels allowing fuel preheating and two pilot injectors, and a re-designed combustion chamber. The link between fuel properties and combustion performance of liquefied wood is investigated by burning the biofuel at different blending ratios with ethanol. Exhaust emissions have been compared to reference measurements with diesel fuel and ethanol. Combustion analysis is supported by the investigation of the engine operating parameters and the main emission species at different electrical loads. The experimental study reveals that it is possible to establish efficient operation of the micro gas turbine while utilizing liquefied wood-ethanol blends with high share of liquefied wood.

The reduction of greenhouse gases emissions from the aviation sector is focused on better engine efficiency or optimized flight pathways. However, the most relevant is probably the use of sustainable biofuels. In order to meet the strict jet fuelspecifications for commercial flights, these biofuels(drop-in fuels) must contain only paraffinic hydrocarbons, without heteroatoms. Several renewable aviation fuels have already been certified by ASTM, others are under examination. Anew promising route consists in the thermochemical conversion of lignin, the main co-product from 2nd generation ethanol. The EU FP7 BIOREFLY project will develop a first industrial pre-commercial lignin-to-jet fuel 2000 ty-1demonstration plant. The present work describes strategies, equipment and R&D lines of BIOREFLY, which aims at evaluating the properties of this bio-jet fuel and its blends in view of future ASTM certification. Injection features and the combustion properties of aviation engines will be investigated in an optical combustor rig. Combustion parameters, emissions and chemiluminescence provide fundamental data to understand the combustion behavior for different hydrocarbons species. Tests in micro-gas-turbines (i.e. power generation and APU-derivative units) will assess the effect of fuels in terms of emissions and evaluating their performances.

Introducing sustainable fuels in the different transport fields in the EU is a very challenging goal, but also a clear priority in the EU decarbonization strategy. In fact, the transport sector is extremely rigid and regulated, with consolidated norms and standards and well-defined economics. Adding more oxygenated components to the fuel mix is also limited by the so-called blend-wall: thus, the share of renewable drop-in hydrocarbons has been recently growing worldwide and in the European Union. However, as a large part of these relates to lipids, the supply of sustainable feedstock has become the major critical element of the value chain. Fast-growing demand from new sectors as Aviation also emerged, that together with Heavy Duty and Maritime represent the focus of the EC strategy, complementary to the electrification of the road transport, passenger cars and light duty vehicles. Introducing innovative processes at full commercial scale requires to overcome the Mountain of Death of processes, where the bankability of not yet demonstrated technologies is the core problem. This work addresses the impact of the EU policy scenario, depicting the status of the different process and technologies, both Bio-based and Recycled Carbon, on the Mountain of Death.

Increased public concerns and stricter regulatory frameworks promote the role of bioliquids (liquid fuel for energy purposes other than for transport, including electricity and heating and cooling, produced from biomass). This is a driving force for development and employment of micro-gas turbines (MGTs) due to their ability to combust bioliquids with less favorable properties in a decentralized manner. Gas turbines are characterized by relatively high combustion efficiency at relatively low concentrations of harmful emissions, relatively high effective efficiency and durability when utilizing a common portfolio of gas turbine approved fuels. It is thus desired to preserve these advantages of gas turbines also while burning bioliquids and further relying on their scalability that is crucial to efficient support of decentralized energy production at small scales. To support these objectives, MGT technology needs to allow for utilization of bioliquids with much wider spectrum of physical and chemical properties compared to common commercially available MGTs in a single MGT-based plant. In this view, the present study is providing the first thorough overview of challenges and solutions encountered by researchers across the wide area of bioliquids in MGTs.

Vegetable Oil (VO) is today the most used feedstock for transport biofuel production by transesterification to biodiesel. Other commercial technologies for renewable fuels production are mainly based either on Fischer-Tropsch (FT) synthesis from coal, natural gas and possibly biomass, or hydro treating of vegetable oil (Hydrotreated Vegetable Oil, HVO): this also includes Hydrotreated Renewable Jet fuel, HRJ, Used Cooking Oil (UCO) is a highly sustainable feedstock (based on EC-RED scheme): it is therefore considered as a possible alternative to VOs for greening of air transport and, under proper circumstances, for reducing the feedstock cost component. However, the use of UCO is not trivial in reactors, as catalysts are sensitive to impurities and contaminations, which are typical of waste oils. Moreover, the chemical composition of UCO is variable regionally as well as seasonally, because the type of base-vegetable oils vary with Country and period of the year. In the framework of the ITAKA EU FP7 project, (catalytic) thermochemical conversion of UCO has been considered to obtain an intermediate biofuel suitable for upgrading by hydrotreating. The catalytic conversion of UCO and Fatty Acids were investigated in a 1.5 kg/h pilot unit. UCO, properly filtered and conditioned, was characterized, and then converted in bio-oil by means of thermal and catalytic reactionsunder controlled conditions. The type of catalyst and the reaction conditions, including several parameters such as temperature, reactor geometry, heating rate and residence time, were evaluated, and selected combinations were tested. The bio-oil was characterized in terms of main constituents and hydrocarbons content, and GC-MS and GC-FID analyses were used to qualitatively and quantitatively assess the composition of the fuel.

After an introductory section about biofuels as a global change mitigation option, this chapter firstly introduces the reader to the methodology of environmental life cycle assessment (LCA). Afterward, the recently proposed life cycle sustainability assessment methodology capable of including further sustainability aspects is also briefly presented. The application of LCA methods to the production of biofuels has some important specific aspects to be considered that are discussed in the text followed by a discussion on indirect land-use change (iLUC) impacts. Then the most relevant LCA studies applied to biofuels are presented and the chapter ends with some concluding remarks.

Biochemical methods based on the metabolism of microbial populations are often used to convert organic substrates and biowastes into gaseous renewable biofuels, such as biogas and bioH2. The anaerobic digestion is a mature, well-established technology to produce biogas, while the biochemical methodologies used to produce bioH2 are still facing several challenges to be scaled-up, in some cases from lab units to pilot plants and in other cases from pilot to industrial plants. Biogas upgrading to bioCH4 and bioH2 purification can be performed to improve the economic added value of these gaseous biofuels, as they can be used in noble applications such as the injection in natural gas grids in the case of bioCH4, or in transportation sector in the case of both renewable fuels. A variety of technologies are available to perform the required purifications. In this chapter, the reader is invited to join a journey over the principles and technologies of anaerobic digestion, bioH2 production, and biogas upgrading and bioH2 purification. Also, the current state of the art on these technologies and future challenges are discussed.

Biodiesel production as well as consumption in the European nations is augmenting, taking into account the uncertainties connected with fossil fuel reserves and the related natural effects of their use. This biofuel can be generated from numerous oil-rich feedstocks and by using different processing technologies. Therefore, the techno-economic assessment for biodiesel production becomes of high relevance to make critical decisions under uncertainties that are essential for the successful implementation of the process on an industrial scale. The economic aspects of using different triglyceride- and nontriglyceride-based lipid biomasses as well as the processing technologies for biodiesel production are thoroughly discussed and compared in this chapter.

This chapter addresses the importance of biofuels and introduces the various production technologies that are further discussed in the following chapters. After the definition and classification of various biofuels, a general schematic of biorefineries for both energy-driven and product-driven categories is presented. A brief introduction to each chapter of this book is given to highlight the relevance and application of the topics covered.

Fast pyrolysis bio-oils are completely different from petroleum fuels and other bio-fuels available in the market, as regards both to their physical properties and chemical composition. When the unusual properties of these bio-oils are carefully taken into account in system and burner design, their combustion without a pilot flame or support fuel is possible on an industrial scale. The aim of the paper is to review the work done on combustion of fast pyrolysis bio-oils and highlight the latest and most important findings of its combustion from laboratory fundamentals to industrial scale. The main focus of the paper is on the bio-oil burner applications.In recent industrial scale bio-oil combustion tests, bio-oil has been found to be technically suitable for replacing heavy fuel oil in district heating. In addition, it has also been found out that limited possibilities for further lowering particulate emissions exist, since the majority of the particulates are typically incombustible matter. Curves for NO. x-emissions of fast pyrolysis bio-oil combustion for air-assisted atomization burners are presented in the paper.Current burner designs are quite sensitive to the changes in the quality of the bio-oil, which may cause problems in ignition, flame detection and flame stabilization. Therefore, in order to be able to create reliable bio-oil combustion systems that operate at high efficiency, bio-oil grades should be standardized for combustion applications. Careful quality control, combined with standards and specifications, all the way from feedstock harvesting through production to end-use is recommended in order to make sure that emission targets and limits in combustion applications are achieved. Also the cost-effectiveness of the total package is extremely important.

Alternative and Renewable Transport Fuels, grouping both Advanced Biofuels and Recycled Carbon fuels, are key routes for the decarbonisation of European Union (EU) and global transports: being sustainable transports a policy-driven area, the development and deployment of advanced biofuels and recycled carbon fuels will depend on well-designed regulatory frameworks. EU just ended the elaboration of the new Renewable Energy Directive (REDII), which includes specific provisions for sustainable fuels. In this context, air transport is among the most critical sectors to decarbonize, given the limited number of other options that can be adopted, such as optimization of flight routes, increase of jet engine energy efficiency, and few others. Overall, EU transports increased GreenHouse Gas (GHG) Emissions since 1990, while all other energy sectors succeeded in achieving a constant reduction over the same period. Aviation is steadily growing worldwide as well as in the EU, representing one of the most critical areas. This article investigates REDII and its implications on the different fuel production and utilisations sectors: opportunities and barriers from the new EU policy framework for these areas are identified and discussed. The large-scale deployment of these fuels will require large investments in new production facilities, to achieve considerable reductions in production costs (over the entire value chain, i.e. from feedstock production, collection and delivery, to conversion and supply). Moreover, in the specific case of Sustainable Aviation Fuels (SAF), significant investments in applying to and completing the ASTM certification for new jet fuels. In this respect, proper coordination between the REDII and the UN ICAO CORSIA programme will be essential to ensure large scale SAF market penetration.

Advanced Biofuels steadily developed during recent year, with several highly innovative processes and technologies explored at various scales: among these, lignocellulosic ethanol and CTO (Crude Tall Oil)-biofuel technologies already achieved early-commercial status, while hydrotreating of vegetable oils is today fully commercial, with almost 3.5 Mt/y installed capacity worldwide. In this context, microalgae grown in salt-water and arid areas represent a promising sustainable chain for advanced biofuel production but, at the same time, they also represent a considerable challenge. Processing microalgae in an economic way into a viable and sustainable liquid biofuel (a low-cost mass-product) is not trivial. So far, the most studied microalgae-based biofuel chain is composed by microorganism cultivation, lipid accumulation, oil extraction, co-product valorization, and algae oil conversion through conventional esterification into Fatty Acids Methyl Esters (FAME), i.e. Biodiesel, or Hydrotreated Esters and Fatty Acids (HEFA), the latter representing a very high quality drop-in biofuel (suitable either for road transport or for aviation). However, extracting the algae oil at low cost and industrial scale is not yet a mature process, and there is not yet industrial production of algae-biofuel from these two lipid-based chains. Another option can however be considered: processing the algae through dedicated thermochemical reactors into advanced biofuels, thus approaching the downstream processing of algae in a completely different way than separation. The present work examines the possible routes for thermochemical conversion of microalgae into liquid biofuels, distinguishing between dry-processes (namely Pyrolysis, PO) and wet-processes (near critical-water HydroThermal Liquefaction, HTL). A literature review on algae-HTL was carried out, distinguishing between batch and continuous experiments, and compared to original results from algae pyrolysis. In particular, pyrolysis was carried out on both starved (lipid-accumulated) and non-starved microalgae. Typical composition of major products is given for both PO and HTL, comparing the main characteristic of the products. Major engineering advantages and challenges in thermochemical conversion of algae into liquid biofuels were identified and discussed for both processes, in view of the production of a transport biofuel and the full exploitation of this renewable feedstock in energy and biorefinery complexes.

Advances in sustainable biofuel production and use. The XIX international symposium on alcohol fuels

Micro gas turbine units are reliable and versatile units for on-site combined heat and power production (CHP). Compared to internal combustion engines, CHP units based on micro gas turbines offer several advantages, among which the compactness, the high power-to-weight ratio, the lower pollutant emissions and maintenance costs. Depending on the specific type of gas turbine, also fuel flexibility could be better than diesel engines, as the fuel is continuously burnt in a hot environment and there is not possible mixing among fuel and lubricating oil. Within the framework of the EU-Russian Federation FP7 cooperative and specifically the Bioliquids-CHP project, a Garrett GTP 30–67 liquid fuel (diesel) micro gas turbine was characterised with diesel and then tested with different first generation biofuels, such as vegetable oil and biodiesel. An in-house test bench was designed, engineered, instrumented and built. In this research work, exhaust emissions from experimental campaign on the micro gas turbine run with diesel oil and biofuels are presented. Emissions were measured at various load. The experiments demonstrated that the MGT can be successfully operated with these biofuels, with emissions comparable to the standard diesel oil. The experiences gained on the operation of the micro gas turbine on first generation biofuels will serve as a basis for modifying the MGT to be operated with bio-oil from fast pyrolysis.

The European Union issued an ambitious target for the introduction of biofuels in the transport sector: 10% by 2020. 2nd generation biofuels (e.g. BTL, lignocellulosic ethanol, algae) are expected to play an important role in the medium term: among these, lignocellulosic ethanol is a key technology currently under industrialisation. In the present work, second generation ethanol modelled through a process simulation developed in the software Aspen Plus® environment. A literature-based comparative analysis of the conversion technologies in terms of yield, efficiency, feedstock and level of process integration is carried out. Crucial aspects of the process include high pretreatment performances, efficient hexose and pentose fermentation, enzyme strain development and solid co-product valorisation for process heat and power generation. The investigated plant size processes 240,000 t biomass/y, with a production capacity of about 40,000 t ethanol/y. Ethanol productivity ranges between 303 and 316 l/t dry biomass. Considering a total energy input (chemical energy contained in the biomass fed to the process) of 108 MW, 36 MW of ethanol are obtained, and additional 2.5 MW of power: the net process energy efficiency is calculated in the range from 35% to 37%. Modelling was aimed to better understand the production process from poplar as feedstock and could be used to support process development in design and optimisation. In particular the lignin-rich residue thermal/chemical valorisation is a key issue that needs further studies, in order to improve the environmental and economic performances of the process.

Nannochloropsis sp. F&M-M24 and Tetraselmis suecica F&M-M33 were cultivated outdoors in Green Wall Panels under nutrient deficiency to stimulate oil synthesis. Under nitrogen deprivation, Nannochloropsis attained average biomass and lipid productivities of 9.9 and 6.5 g m(-2) day(-1), respectively. Starved Tetraselmis cultures achieved a biomass productivity of about 7.6 g m(-2) day(-1) and a lipid productivity of 1.7 g m(-2) day(-1). Lipids represented 39.1% and 68.5% of non-starved and starved Nannochloropsis biomass, respectively. Starvation did not increase lipid content in Tetraselmis biomass. Important differences in lipid classes and in fatty acid composition were observed under the different cultivation conditions for both microalgae.

The aim of this research work is to investigate the use of straight vegetable sunflower oil (SFO), a liquid biofuel, in a Micro-Gas Turbine (MGT). Compared to conventional diesel engines, micro-gas turbines represent a very reliable, clean and performing small scale cogeneration technology. Commercial gas turbines have already been tested with unconventional fuels, such as biomass derived fuels; however, research work on using Straight Vegetable Oil (SVO) as fuel in MGTs are really scarce. The chemical and physical characteristics of SVO are different from fossil diesel oil and rather far from the common technical specifications for gas turbine liquid fuels, not only in terms of kinematic viscosity and Lower Heating Value, but also as regards other issues as contaminant levels and composition, fuel cold properties, ignition properties, etc. Therefore, particular attention has to be given to the atomization and evaporation phases, as these are the most critical steps to achieve stable and efficient long term operation. An analysis based on numerical correlations available from literature was initially adopted for the analysis of the atomization process, supported by CFD modeling to qualitatively investigate the flow pattern. Control parameters were revised and set so to produce a sunflower oil spray having evaporation time comparable to diesel, and minor adaptations to the fuel line were designed and installed on the MGT. Tests with blends and straight vegetable oil were carried out to assess the difference between the standard and the modified machine, fed by diesel, in terms of exhaust emissions, power output and performances, that were similar to the standard diesel-fed MGT. Measured exhaust emissions were as expected well below those typical of diesel engines of the same size fed with VO. The experimental campaign confirmed that it is possible to operate a MGT fed with SVO through the adoption of minor modifications and by adjusting control parameters.

Used Cooking Oil (UCO) and pure Fatty Acids (FAs) derived from food processing represent sustainable feedstocks for biofuel production. The catalytic and non-catalytic pyrolysis of these residual oils is a possible pathway to advanced biofuel production, alternative to catalytic hydrotreatment, already commercially deployed in large-scale installations. The present work first carried out a literature review of previous research works in the field, which provided the key information to the following implementation of a pilot-scale dedicated experimental work aimed at producing bio-hydrocarbons from residual vegetable oils, with a special focus on paraffinic fuels. Based on the literature survey, 4 different catalysts were selected for the experimental investigation. Catalytic and non-catalytic pyrolysis of UCO was initially carried out in 1.5 kg h −1 (max) feed pilot unit, operated at 500 °C, with the catalytic reactor working at 4 and 2.5 h −1 Weight Hourly Space Velocity (WHSV). Liquid yields and corresponding hydrocarbon fractions were investigated: these initial results suggested to extend the study to catalytic pyrolysis of pure FAs. At T = 500 °C and with activated carbons as catalyst, the total observed hydrocarbon yield mass fraction on UCO and FA increased from 23% (UWHSV = 4 h −1 ) to 35% (UCO, WHSV = 2.5 h −1 ) and finally to 40% (FA, WHSV = 2.5 h −1 ). A slight reduction in the overall liquid yield mass fraction was also observed in this last experiment with FAs (from 63% to ≈49%). Even if the current work on the pilot pyrolyser did not aim at investigating energy and process optimization, including yield maximization and catalyst lifetime, experimental results indicated that catalytic pyrolysis could be a promising way for industrial production of hydrocarbons from low quality lipid-based materials (as it is the case of UCOs) and without requiring hydrogen for catalytic hydrotreatment.

The current method of utilising biomass derived fast liquid (bio-crude oil or bio-oil) in a diesel engine requires three fuels and a complex start-up and shut down procedure. For more rapid and successful commercialisation of this renewable liquid fuel, a more convenient and cheaper method of utilisation is needed that provides a single fuel that is stable and readily ignites in a compression engine. This paper describes the production of emulsions from biomass fast pyrolysis liquid and diesel fuel for utilisation in diesel engines. The objective is to allow unmodified diesel engines to run on fast pyrolysis liquid derived from biomass without the cost and complexity of a dual fuel system. The immediate application is in stationary engines for power generation, but there are longer term opportunities for use as a transport fuel. This paper describes the production of the emulsions that have been tested in different diesel engines (tests in engines is reported in a separate paper).

Research in Advanced Biofuels steadily developed during recent years. A number of highly innovative technologies have been explored at various scale: among these, lignocellulosic ethanol and CTO (Crude Tall Oil)-biofuel technologies already achieved the early-commercial status, while hydrotreating of vegetable oils (HVO, or HEFA) can be considered today fully commercial. However, despite the level of innovation in each specific technological process under consideration, the feedstock maintains a central role in making a biofuel chain really sustainable. In this context, microalgae grown in salt-water and arid areas offers a considerable opportunity for advanced biofuel production: at the same time, however, they also represent a considerable challenge. Processing microalgae in an economic way into a viable and sustainable liquid biofuel (a low-cost mass-produced product) is not trivial. So far, the main attention has been given to cultivating the microorganism, accumulating lipids, extracting the oil, valorising co-products, and treating the algae oil into biodiesel (through esterification) or HEFA (Hydrotreated Esthers and Fatty Acids), this second one representing a very high quality biofuels, almost a drop-in fuel (suitable either for road transport or for aviation), which production exceed 2 Mt y-1 today. However, extracting the algae oil at low cost and at industrial scale is not yet a full industrial mature process, and the still limited market size of algae-to-biofuels makes difficult the development of industrial-scale systems. Nevertheless, another option can be considered, i.e. processing the whole algae into dedicated thermochemical reactors, thus approaching the downstream processing of algae in a completely different way from separation. The present work examines the possible routes for thermochemical conversion of microalgae, distinguishing between dry-processes (namely pyrolysis and gasification) and wet-processes (near critical water hydrothermal liquefaction and hydrothermal gasification). Typical expected elementary composition of major products is given. Main peculiarities of batch versus continuous processing are also discussed from an engineering point of view. Major engineering advantages and challenges in thermochemically conversion of algae are identified and discussed, in view of the production of a transport biofuel. Finally, future perspectives for each route are given in terms of current and expected technological readiness level.

Alternative fuels are expected to play a major role in EU in the coming years due European Directives on the promotion of renewable energies and reduction of greenhouse gas emissions in transports. However, while in road transports a variety of possible renewable fuels (mainly biofuels, but also electricity) can be considered, in aviation only high quality paraffinic biofuels can be adopted. This means that biomass must be converted through advanced processes into pure hydrocarbon fuels, fully compatible with the existing systems. The aviation sector is responsible for the 2% of the world anthropogenic CO2 emissions and the 10% of the fuel consumption: airlines’ costs for fuel reach 30% of operating costs. In addition, the aviation traffic is expected to double within 15 years from 2012, while fuel consumption and CO2 emissions should double in 25 years. Thus, more than 2 billion people and 40 Mt of good/cargo will have to be moved every year. In this context, the EU Flightpath set a target of 2 Mt per year for aviation alternative fuel by 2020 (i.e. 4% of annual fuel consumption). New processes towards bio-hydrocarbons are being developed, demonstrated and soon industrialized. The present work explores the possible routes from biomass feedstock to sustainable paraffinic fuels, either through bio or thermo-chemical processes, as well as discusses those more mature, focusing on industrial demonstration initiatives. In fact, while the number of possible options towards paraffinic biofuel production is very large, and covers both thermochemical and biochemical routes, as well as hybrid one, only two pathways are today ready for testing a significant large scale: these are FT and Hydrotreating. Major industrial activities and testing experiences are thus reported in the present work. In this context, the ITAKA group is developing a full value-chain in Europe to produce sustainable drop-in Synthetic Paraffinic Kerosene (SPK) – called HEFA – in an economically, socially and environmentally sound manner, at large scale enough to allow testing its use in existing logistic systems and in normal flight operations in Europe. The generated knowledge will aim to identify and address barriers to innovation. Within ITAKA, possible pre-processing of used (waste) cooking oil (UCO) to make it compatible with current downstream hydroprocessing techniques are being investigated: this can includes esterification of waste oils, as well as catalytic thermal processing, which will be carried out in a pilot unit available at RE-CORD/CREAR. First samples of feedstock oils were collected and characterized, for further investigation towards their conversion into biokerosene through hydrotreatment.

Vegetable oils became a very popular bioliquid for renewable power and transport applications. At local level, the short chain production of vegetable oils is currently important in terms of sustainability and use of rural area. This present work investigates the development of vegetable oils production chain in the Tuscany territory, focusing also to valorisation of the co-products (i.e., oil cake). The work is based on the study of the cultivation of rapeseed and sunflower, and the creation of an extraction plant based on cold-screw pressing technology, in order to obtain a raw vegetable oil suitable as biofuel. The German DIN 51623 standard was adopted to investigate the quality of vegetable oils obtained from different oil crops. Vegetable oils quality was evaluated by comparing the oil produced by a bench press at lab scale, comparing the results in terms of process yields and lipid fraction recovered. Due to the high phosphorous content of rapeseed oil, out of the DIN limits, an experimental procedure to remove P content and restore the oxidation stability of the oils was performed. The results showed a substantial P reduction by adding 2 wt% of P-removing additive. The oil cake properties were evaluated in view of its potential use for bioenergy production, in particular in terms of metals content. [Received: December 5, 2015; Accepted: September 20, 2016]

A large share of the vegetable oil market is today shifting from food to the energy sector. This trend led to discussions about the chance of confliction between these two chains and its possible social and environmental consequences. Moreover the increasing interest in pure vegetable oils for energy and biodiesel production are associated to a period of market volatilities and high prices. The economics of the biodiesel production is suffering the actual market situation. In this framework, the present work presents the results of the OVEST (ESTerified Vegetable Oils) project, which is supported by the Tuscany region. Aim of the project is the investigation of the use of waste oil streams and by-products from food industry to obtain an alternative feedstock for bioliquids and biofuels production. In the current food market, a number of secondary streams are available from the food industry: oleins and fatty acids, sludge oils and WCO (Waste Cooking Oils), represent several examples of these potential alternative feedstock. Most of these materials are characterized by high free fatty acid compositions. In the OVEST project, vegetable oil is obtained from waste materials by the re-esterification process, in order to obtain a new feedstock for biodiesel production and for power generation. A market analysis has been carried out in OVEST, to estimate the economic viability and the potential of each waste streams. Test on a modified Micro Gas Turbine (30 kWel) and in small scale co-generator (5 kWel) have been carried out. Performances and pollutant missions were monitored. The results of the experimentation confirmed the viability of these fuels for the energy production. From the environmental point of view, the use of these feedstock allows to meet the requirements of the European Directive EC/28/2009 (RED), that introduces minimum targets in terms of GHGs saving for bioliquids and biofuels. The present work showed that most of the input materials to the esterification process may be classified as wastes or residues, and that assuring an accurate traceability for each treatment and transport phase is a really complex issue. However the high GHG savings potential, as indicated in the RED for bioliquids from wastes, was confirmed by the work here carried out. Therefore OVEST project demonstrates the viability of the use of esterified oils as biodiesel feedstock or for direct energy generation, starting from a renewable source, non competing with food market and with a high GHG saving potential.

Advanced biofuels produced from lignocellulosic biomass offer an exciting opportunity to produce renewable liquid transportation fuels, biochemicals, and electricity from locally available agriculture and forest residues. The growing interest in biofuels from lignocellulosic feedstock in the United States (US) and the European Union (EU) can provide a path forward toward replacing petroleum-based fuels with sustainable biofuels which have the potential to lower greenhouse gas (GHG) emissions. The selection of biomass conversion technologies along with feedstock development plays a crucial role in the commercialization of next-generation biofuels. There has been synergy and, even with similar basic process routes, diversity in the conversion technologies chosen for commercialization in the EU and the US. The conversion technologies for lignocellulosic biomass to advanced biofuels can be broadly classified in three major categories: biochemical, thermochemical, and hybrid conversions. The objective of this review is to discuss the US and EU biofuel initiatives, feedstock availability, and the state-of-art conversion technologies that are potentially ready or are already being deployed for large-scale applications. The review covers and compares the developments in these areas in the EU and the USA and provides a comprehensive list of the most relevant ongoing development, demonstration, and commercialization activities in various companies, along with the different processing strategies adopted by these projects. © 2013 The Authors. Biofuels, Bioproducts, Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Biomass pretreatment aims at separating and providing easier access to the main biomass components (cellulose, hemicellulose and lignin), eventually removing lignin, preserving the hemicellulose, reducing the cellulose crystallinity and increasing the porosity of the material. Pretreatment is an essential step towards the development and industrialization of efficient 2nd generation lignocellulosic ethanol processes. The present work reviewed the main options available in pretreatment. Autohydrolysis and steam explosion were then selected for further investigation. Experimental work was carried out on batch scale reactors, using Miscanthus as biomass feedstock: the effects on sugar solubilization and degradation products generation have been examined for each of these two pretreatment systems. A new process using only water and steam as reacting media was then developed, experimentally tested, and results compared to those achieved by the autohydrolysis and steam explosion processes. Products obtained with the new pretreatment contained a lower amount of usual fermentation inhibitor compounds compared to that typically obtained in steam explosion. This result was achieved under operating conditions that at the same time allowed a good xylan yield, preventing degradation of hemicelluloses. The new pretreatment process was also able to act as an equalization step, as the solid material from the pretreatment phase had a similar composition even under different operating conditions. As regards the effect of pretreatment on enzymatic hydrolysis, the new process achieved yields similar to steam explosion on glucans: however, this was obtained reducing the formation of degradation products from sugars, mainly from C5 sugars. These results made the proposed pretreatment system suitable for further development and industrialization on pilot and industrial scale.

Biofuels is currently driving the interest in bioenergy sector. The recently issued Renewable Energy Directive (2009/28/EC) confirms the 10% target, set by the EC, for energy from renewable sources in transport. The European Union is the largest producer of biodiesel in the world and biodiesel is also the most important biofuel used in the EU. The aim of this paper is to investigate the biomass feedstock requirement, under different scenarios, with a focus on vegetable oils. The European production potential is compared with the amount of biomass required to meet the target on biofuels. Next generation biofuels and alternative feedstock for first generation pathways are considered as well as the share of biomass import. The scenario proposed allows to estimate the land required to meet the target at 2020 on biodiesel. Assuming different contribution of the next generation biofuels, from the 10% to the 30% is possible to estimate the contribution of first generation biodiesel. The results showed that, considering the total European arable land, this production will utilise 9–13%.

Biomass pretreatement is a key and energy-consuming step for lignocellulosic ethanol production; it is largely responsible for the energy efficiency and economic sustainability of the process. A new approach to biomass pretreatment for the lignocellulosic bioethanol chain could be mild torrefaction. Among other effects, biomass torrefaction improves the grindability of fibrous materials, thus reducing energy demand for grinding the feedstock before hydrolysis, and opens the biomass structure, making this more accessible to enzymes for hydrolysis. The aim of the preliminary experiments carried out was to achieve a first understanding of the possibility to combine torrefaction and hydrolysis for lignocellulosic bioethanol processes, and to evaluate it in terms of sugar and ethanol yields. In addition, the possibility of hydrolyzing the torrefied biomass has not yet been proven. Biomass from olive pruning has been torrefied at different conditions, namely 180–280°C for 60–120 min, grinded and then used as substrate in hydrolysis experiments. The bioconversion has been carried out at flask scale using a mixture of cellulosolytic, hemicellulosolitic, β-glucosidase enzymes, and a commercial strain of Saccharomyces cerevisiae. The experiments demonstrated that torrefied biomass can be enzymatically hydrolyzed and fermented into ethanol, with yields comparable with grinded untreated biomass and saving electrical energy. The comparison between the bioconversion yields achieved using only raw grinded biomass or torrefied and grinded biomass highlighted that: (1) mild torrefaction conditions limit sugar degradation to 5–10%; and (2) torrefied biomass does not lead to enzymatic and fermentation inhibition. Energy consumption for ethanol production has been preliminary estimated, and three different pretreatment steps, i.e., raw biomass grinding, biomass-torrefaction grinding, and steam explosion were compared. Based on preliminary results, steam explosion still has a significant advantage compared to the other two process chains.

Biomass fast-pyrolysis oil (PO) is a liquid biofuel derived from lignocellulosic biomass: it offers several advantages compared to the direct us of solid bio fuels, such as high energy density, storability and transportability typical of liquid fuels, possibility to use the fuel in engines and turbines, easier downscaling of plants (which is a very important aspect for decentralized energy generation schemes). In addition, PO is the lowest cost biofuel, thus offering the possibility to penetrate also the large scale power generation market. Biomass POs have been studied and applications tested for many years, either for heat generation in medium-scale boilers or power generation. The present works reviews and analyses the most relevant experiences carried out so far and published results in power production from biomass PO. Power generation systems (PGS) which are here examined are gas turbines, diesel engines, stirling engines, as well as co-firing applications in large scale power plants (coal or natural gas plants). The main techniques for upgrading this biofuel and their impact on technologies are also shortly introduced and considered. The current status of development for each PO-based power generation option is discussed. This review work showed that long term demonstration (either technical or economical) is however still needed, even for the most developed technologies (use of PO in modified gas turbines and cofiring in natural gas stations): projects are on going to achieve long term demonstration.Copyright © 2006 by ASME

Pure Vegetable Oil (PVO) is a 100% renewable fuel obtained from oil crops. PVO can be produced in a distributed manner in rural areas and commercial technologies almost exist for energy and transports, making possible to develop small scale chains, suitable for both industrialised as well as developing countries. The aim of the research work is to investigate over a three-year period the complete PVO chain under Italian conditions, i.e., crop selection, plantation and harvesting, seed drying and storage, oil extraction, cake (coproduct) valorisation and PVO use in small generators, cogenerators, micro gas turbines and greenhouse/school heating systems, supporting experimental work with environmental and socio-economic studies. The aim of the present paper is to present the results obtained at the end of the first year, as regards oil production in both cold decentralised systems and industrial systems, as well testing of the oil in a modified tractor. The PVO produced in the cold press met the current DIN...