Energy and environmental assessment of hydrogen from biomass sources: Challenges and perspectives

Hydrogen is considered as one of the pillars of the European decarbonisation strategy, boosting a novel concept of the energy system in line with the EU's commitment to achieve clean energy transition and reach the European Green Deal carbon neutrality goals by 2050. Hydrogen from biomass sources can significantly contribute to integrate the renewable hydrogen supply through electrolysis at large-scale production. Specifically, it can cover the non-continuous production of green hydrogen coming from solar and wind energy, to offer an alternative solution to such industrial sectors necessitating of stable supply. Biomass-derived hydrogen can be produced either from thermochemical pathways (i.e., pyrolysis, liquefaction, and gasification) or from biological routes (i.e., direct or indirect-biophotolysis, biological water–gas shift reaction, photo- and dark-fermentation). The paper reviews several production pathways to produce hydrogen from biomass or biomass-derived sources (biogas, liquid bio-intermediates, sugars) and provides an exhaustive review of the most promising technologies towards commercialisation. While some pathways are still at low technology readiness level, others such as the steam bio-methane reforming and biomass gasification are ready for an immediate market uptake. The various production pathways are evaluated in terms of energy and environmental performances, highlighting the limits and barriers of the available LCA studies. The paper shows that hydrogen production technologies from biomass appears today to be an interesting option, almost ready to constitute a complementing option to electrolysis

Bio-Hydrocarbons through Catalytic Pyrolysis of Used Cooking Oils: towards sustainable jet and road fuels

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

Thermochemical conversion of microalgae: challenges and opportunities

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

Are algae ready to take off? GHG emission savings of algae-to-kerosene production

Aviation alternative fuels are perceived as an effective short-term mean to decarbonise our flights. Sustainable aviation fuels from algae have been recently approved for commercial flights, and here we present an assessment of their greenhouse gas (GHG) savings. Three case studies have been investigated with different plant designs and cultivation strategies. The Carbon Offsetting and Reduction Scheme for International Aviation's Life Cycle Assessment methodology is used as a guideline to assess the GHG saving potential of aviation fuels from algae. The approach here presented allows having a sound comparison with other alternative fuel production pathways. We show that the cultivation strategy based on oil maximisation does not necessarily provide significant advantages in terms of GHG savings. The assessed GHG savings fall in a wide range, being dependent on the inputs and cultivation strategy considered. In the best-case scenario, up to 68% of GHG savings can be achieved, therefore offering a substantial advantage over traditional fuels. When compared with the GHG saving of kerosene from other traditional bio-based feedstocks, like rapeseed, the results confirm algae as an interesting alternative, provided that certain conditions for their cultivation, such as high process optimisation, nutrient recycling and use of renewable energy to meet input demand, are met. The study also assessed the area potentially needed for an algae production plant able to supply large volumes of raw material to an existing commercial biorefinery. The findings confirm the potential of this feedstock to mitigate land abandonment on the coasts of the Mediterranean basin

Fuel rich ammonia-hydrogen injection for humidified gas turbines

The use of new fuels and operating strategies for gas turbine technologies plays a relevant component for carbon emissions reduction and the use of sustainable energy sources. Among non-carbon fuels, hydrogen-based fuels have been proposed as one of the main strategies for decarbonisation of the power sector. Ammonia is a good representative of these fuels as it is carbon-free and the second largest chemical commodity, having been produced worldwide for more than a century from various energy resources, i.e. fossil fuels, biomass or other renewable sources. However, the use of ammonia as a fuel in industrial gas turbines brings some practical challenges directly linked to the final efficiency of these systems, especially when the latter are compared to current Dry Low Nitrogen Oxides technologies. Thus, this work covers a series of analytical, numerical and experimental studies performed to determine the efficiency of using ammonia/hydrogen blends in combination with humidified methodologies to deliver competitive systems for the use of ammonia-hydrogen power generation. The study was conducted using CHEMKIN-PRO reaction networks employing novel reaction chemical kinetics, in combination with bespoke analytical codes to determine efficiencies of systems previously calibrated experimentally. Finally, experimental trials using steam injection were carried out to determine potential of these blends. The novel results demonstrate that the use of humidified ammonia-hydrogen injection provides similar efficiencies to both Dry Low Nitrogen Oxides and humidified methane-based technologies ∼30%, with flames that are stable and low polluting under swirling conditions, thus opening the opportunity for further progression on the topic

Bioliquids and their use in power generation - a technology review

The first EU Renewable Energy Directive (RED) served as an effective push for world-wide research efforts on biofuels and bioliquids, i.e. liquid fuels for energy purposes other than for transport, including electricity, heating, and cooling, which are produced from biomass. In December 2018 the new RED II was published in the Official Journal of the European Union. Therefore, it is now the right time to provide a comprehensive overview of achievements and practices that were developed within the current perspective. To comply with this objective, the present study focuses on a comprehensive and systematic technical evaluation of all key aspects of the different distributed energy generation pathways using bioliquids in reciprocating engines and micro gas turbines that were overseen by these EU actions. Methodologically, the study originates from the analyses of feedstock and fuel processing technologies, which decisively influence fuel properties. The study systematically and holistically highlights the utilisation of these bioliquids in terms of fuel property specific challenges, required engine adaptations, and equipment durability, culminating in analyses of engine performance and emissions. In addition, innovative proposals and future opportunities for further technical improvements in the whole production-consumption cycle are presented, thus serving as a guideline for upcoming research and development activities in the fast-growing area of bioliquids. Additionally, the paper systematically addresses opportunities for the utilisation of waste streams, emerging from the ever increasing circular use of materials and resources. With this, the present review provides the sorely needed link between past efforts, oriented towards the exploitation of bio-based resources for power generation, and the very recent zero-waste oriented society that will require a realistic exploitation plan for residuals originating from intensive material looping

Across-subject calibration of an instrumented glove to measure hand movement for clinical purposes

Motion capture of all degrees of freedom of the hand collected during performance of daily living activities remains challenging. Instrumented gloves are an attractive option because of their higher ease of use. However, subject-specific calibration of gloves is lengthy and has limitations for individuals with disabilities. Here, a calibration procedure is presented, consisting in the recording of just a simple hand position so as to allow capture of the kinematics of 16 hand joints during daily life activities even in case of severe injured hands. ‘across-subject gains’ were obtained by averaging the gains obtained from a detailed subject-specific calibration involving 44 registrations that was repeated three times on multiple days to 6 subjects. In additional 4 subjects, joint angles that resulted from applying the ‘across-subject calibration’ or the subject-specific calibration were compared. Global errors associated with the ‘across-subject calibration’ relative to the detailed, subject-specific protocol were small (bias: 0.49°; precision: 4.45°) and comparable to those that resulted from repeating the detailed protocol with the same subject on multiple days (0.36°; 3.50°). Furthermore, in one subject, performance of the ‘across-subject calibration’ was directly compared to another fast calibration method, expressed relative to a videogrammetric protocol as a gold-standard, yielding better results.This work was supported by the Ministerio de Economía y Competitividad [project number DPI2014-52095-P]; Universitat Jaume I [project number P1-1B2013-33], [project number P1-1B2014-10]; NIH [grant number NIH R01EB011615]. We thank Marta Mora, PhD, for her collaboration in coding for data glove acquisition, and the graduate student Sheyla Mestre Vicente for her collaboration in data collection. Authors thank also Union de Mutuas for their support in clinical guidanc

An automated microreactor for semi-continuous biosensor measurements.

Living bacteria or yeast cells are frequently used as bioreporters for the detection of specific chemical analytes or conditions of sample toxicity. In particular, bacteria or yeast equipped with synthetic gene circuitry that allows the production of a reliable non-cognate signal (e.g., fluorescent protein or bioluminescence) in response to a defined target make robust and flexible analytical platforms. We report here how bacterial cells expressing a fluorescence reporter ("bactosensors"), which are mostly used for batch sample analysis, can be deployed for automated semi-continuous target analysis in a single concise biochip. Escherichia coli-based bactosensor cells were continuously grown in a 13 or 50 nanoliter-volume reactor on a two-layered polydimethylsiloxane-on-glass microfluidic chip. Physiologically active cells were directed from the nl-reactor to a dedicated sample exposure area, where they were concentrated and reacted in 40 minutes with the target chemical by localized emission of the fluorescent reporter signal. We demonstrate the functioning of the bactosensor-chip by the automated detection of 50 μgarsenite-As l(-1) in water on consecutive days and after a one-week constant operation. Best induction of the bactosensors of 6-9-fold to 50 μg l(-1) was found at an apparent dilution rate of 0.12 h(-1) in the 50 nl microreactor. The bactosensor chip principle could be widely applicable to construct automated monitoring devices for a variety of targets in different environments

Phenotype Screening of an Azole-bisindole Chemical Library Identifies URB1483 as a New Antileishmanial Agent Devoid of Toxicity on Human Cells

We report the evaluation of a small library of azole-bisindoles for their antileishmanial potential, in terms of efficacy on Leishmania infantum promastigotes and intracellular amastigotes. Nine compounds showed good activity on L. infantum MHOM/TN/80/IPT1 promastigotes with IC50 values ranging from 4 to 10 μM. These active compounds were also tested on human (THP-1, HEPG2, HaCaT, and human primary fibroblasts) and canine (DH82) cell lines. URB1483 was selected as the best compound, with no quantifiable cytotoxicity in mammalian cells, to test the efficacy on intracellular amastigotes. URB1483 significantly reduced the infection index of both human and canine macrophages with an effect comparable to the clinically used drug pentamidine. URB1483 emerges as a new anti-infective agent with remarkable antileishmanial activity and no cytotoxic effects on human and canine cells

An IoT-Aware Smart System Exploiting the Electromagnetic Behavior of UHF-RFID Tags to Improve Worker Safety in Outdoor Environments

Recently, different solutions leveraging Internet of Things (IoT) technologies have been adopted to avoid accidents in agricultural working environments. As an example, heavy vehicles, e.g., tractors or excavators, have been upgraded with remote controls. Nonetheless, the community continues to encourage discussions on safety issues. In this framework, a localization system installed on remote-controlled farm machines (RCFM) can help in preventing fatal accidents and reduce collision risks. This paper presents an innovative system that exploits passive UHF-RFID technology supported by commercial BLE Beacons for monitoring and preventing accidents that may occur when ground-workers in RCFM collaborate in outdoor agricultural working areas. To this aim, a modular architecture is proposed to locate workers, obstacles and machines and guarantees the security of RCFM movements by using specific notifications for ground-workers prompt interventions. Its main characteristics are presented with its main positioning features based on passive UHF-RFID technology. An experimental campaign discusses its performance and determines the best configuration of the UHF-RFID tags installed on workers and obstacles. Finally, system validation demonstrates the reliability of the main components and the usefulness of the proposed architecture for worker safety