Technical cost modelling for a generic 45-m wind turbine blade producedby vacuum infusion (VI)

A detailed technical cost analysis has been conducted on a generic 45-m wind turbine blade manufactured using the vacuum infusion (VI) process, in order to isolate areas of significant cost savings. The analysis has focused on a high labour cost environment such as the UK and investigates the influence of varying labour costs, programme life, component area, deposition time, cure time and reinforcement price with respect to production volume. A split of the cost centres showed the dominance of material and labour costs at approximately 51% and 41%, respectively. Due to the dominance of materials, it was shown that fluctuations in reinforcement costs can easily increase or decrease the cost of a turbine blade by up to 14%. Similarly, improving material deposition time by 2 h can save approximately 5% on the total blade cost. However, saving 4 h on the cure cycle only has the potential to provide a 2% cost saving.     

Lactic acid recovery from fermentation broth of kitchen garbage by esterification and hydrolysis method

Kitchen garbage was utilized to produce lactic acid (LA) to reduce the corresponding cost. The whole process for pure LA production involved fermentation, esterification and hydrolysis. Kitchen garbage could produce 47.9 g L^?1 LA with pH adjusted with ammonia to 6–7. Then the fermentation broth was concentrated by water evaporation, the ammonium lactate inside was esterified with the butanol to produce butyl lactate. Proper catalyst was studied to improve esterification rate, a cation-exchange resin modified by FeCl₃ as a catalyst was proved to be effective. The esterification yield of ammonium lactate (NH₄LA) could reach 96%. Pure LA was hydrolyzed from the obtained butyl lactate in presence of a cation-exchange resin in the H⁺ form as a catalyst. The catalyst for hydrolysis could be regenerated and reused to save the cost. LA production from the kitchen garbage could not only save cost, but also solve the pollution problems of kitchen garbage.     

Effect of carbon fillers on properties of polymer composite bipolar plates of fuel cells

Bipolar plates are major components of fuel cell (FC) stacks and they make up a large portion of the stack volume and cost. In order to reduce their weight and fabrication cost, polymer composite materials with various carbon conducting fillers are tested for use as composite bipolar plates for FCs. The composite materials are prepared by using graphite with a small vol.% of carbon black (CB), multi-walled carbon nanotubes (MWNTs) or carbon fibres (CF) in an epoxy resin. The electrical conductivity and flexural properties of the composites are measured as a function of the carbon conductive filler content. The highest electrical conductivity is observed at a total conducting filler content of 75 vol.%. The addition of a small amount of hybrid conducting filler enhances the electrical conductivity up to certain threshold, viz. 5 vol.% of CB, 2 vol.% of MWNTs, and 7 vol.% of CF. Above these thresholds, the electric conductivity decreases with increasing filler content, due to the lack of sufficient resin to bind the fillers tightly. The hybrid filler system has better properties than the single filler system. The experimental results indicate that there is an optimum composition range with respect to electrical conductivity and mechanical properties.     

Multi-objective optimization of diesel engine performance,vibration and emission parameters employing blends of biodiesel,hydrogen and cerium oxide nanoparticles with the aid of response surface methodology approach

Recent surges in crude oil prices have motivated researchers to find an alternative sustainable fuel called biodiesel from various inedible oils with lower carbo impact on the environment. The research is performed in diesel engine fuelled with blends of biodiesel coupled with cerium oxide nanoparticles and hydrogen content so as to optimize various factors which are responsible for performance, vibration and emission characteristics. Multi-objective optimization is achieved by employing RSM which also examines prime input parameters (engine load, nanoparticle concentration, compression ratio, hydrogen blend percentage and ignition pressure) responsible in varying engine characteristics. Henceforth, blends of Water Hyacinth can be successfully applied in diesel engine with lower environmental impact and enhanced cost effectiveness. Experimentation is performed on the central composite rotating design (CCRD) matrix with 5-level factor. Engine load was applied between 0 and 100%, NPC varied between 0 and 80 ppm, CR ranges between 17 and 19, hydrogen blend percentage varies between 0 and 40% and at a maximum injection pressure of 240 bar. Pareto-optimal conditions achieved for input conditions of 28.68% biofuel blend, 87.88 engine load, 80 ppm NPC, compression ratio of 19 and 194.54 bar infusion pressure were BTE, BSEC, NOx, UBHC and vibration reduction are 33.57%, 0.2550, 461.3002 ppm vol., and 28.08 ppm vol. And 22.21%, respectively.     

Performance analysis and exergoeconomic assessment of a proton exchange membrane compressor for electrochemical hydrogen storage

Electrochemical hydrogen compression (EHC) is a promising alternative to conventional compressors for hydrogen storage at high pressure, because it has a simple structure, low cost of hydrogen delivery, and high efficiency. In this study, the performance of an EHC is evaluated using a three-dimensional numerical model and finite volume method. The results of numerical analysis for a single cell of EHC are extended to a full stack of EHC. In addition, exergy and exergoeconomic analyses are carried out based on the numerical data. The effects of operating temperature, pressure, and gas diffusion layer (GDL) thickness on the energy and exergy efficiencies and the exergy cost of hydrogen are examined. The motivation of this study is to examine the performance of the EHC at different working conditions and also to determine the exergy cost of hydrogen. The results reveal that the energy and exergy efficiency of EHC stack improve by almost 3.1% when operating temperature increases from 363 K to 393 K and the exergy cost of hydrogen decreases by 0.5% at current density of 5000 A m⁻². It is concluded that energy and exergy efficiency of EHC stack decrease by 25% and 5.4% when the cathode pressure increases from 1 bar to 30 bar, respectively. Moreover, it is realized that the GDL thickness has a considerable effect on the EHC performance. The exergy cost of hydrogen decreases by 53% when the GDL thickness decreases from 0.5 mm to 0.2 mm at current density of 5000 A m⁻².     

Preparation and properties of thin epoxy/compressed expanded graphite composite bipolar plates for proton exchange membrane fuel cells

Although the composite bipolar plates prepared by the method of the vacuum resin impregnation in compressed expanded graphite (CEG) sheets have been applied in the KW-class stacks, there have been few investigations of the preparation and properties of them so far. In this research, the influences of the microstructure on the physical properties of the thin epoxy/CEG composites (the thickness is 1 mm) are investigated for the first time and the optimum preparation conditions are obtained. Results demonstrated that the mechanical property and the impermeability of the composites increases evidently with the resin content changing from 4% to 30%, while the electrical properties keep nearly constant. It can be attributed to the continuous expanded graphite (EG) conductive network of the raw CEG sheet. The epoxy (30 wt.%)/CEG composite is shown to be the optimum composite, displaying in-plane conductivity of 119.8 S cm⁻¹, through-plane resistance of 17.13 mΩ cm², density of 1.95 g cm⁻³, gas permeability of 1.94 × 10⁻⁶ cm³ cm⁻² s⁻¹ and flexural strength of 45.8 MPa. The alcohol scrubbing is the optimum method of surface post-processing. The performance of a single cell with the optimum composite bipolar plates is tested and demonstrated to be outstanding. Above all, the composite prepared by resin vacuum impregnation in the CEG sheet is a promising candidate for bipolar plate materials in PEMFCs.     

Performance analysis and economic competiveness of 3 different PV technologies for hydrogen production under the impact of arid climatic conditions of Morocco

For green hydrogen production, the choice of the appropriate renewable energy source to drive the water electrolysis process is crucial. Currently, solar Photovoltaic (PV) energy is one of the most popular and cheapest renewable energy sources; however, the performance of this technology is highly affected by the weather condition especially after the exposition to harsh climate conditions for long periods. Accordingly, the aim of this study is to assess the appropriate PV technology for hydrogen production under the impact of arid climatic conditions. For this reason, we evaluated the hydrogen production from 3 PV technologies, namely: monocrystalline (m-Si), polycrystalline (p-Si) and amorphous (a-Si) technologies exposed outdoors for a period of 3 years under the arid climatic conditions of Errachidia, Morocco. In addition, the degradation rate of each technology has been calculated and its impact on hydrogen production and its cost has been investigated.The results show that, the technology with the higher yearly hydrogen yield is the p-Si with 37.07 kg/kWp, followed by the m-Si with 36.84 kg/kWp and finally the a-Si with 36.68 kg/kWp. As for the cost of hydrogen production, the lowest cost was found in the case of the p-Si technology as well with 4.89 $/kg, whereas for the m-Si and a-Si technologies it was found equal to 5.48 $/kg and 6.28 $/kg respectively. However, the evaluation the impact of the PV modules degradation reveals that p-Si is technology affect the most with an annual degradation rate of 0.92%, followed by the a-Si with 0.72% and m-Si technologies with 0.45%. Nonetheless, when taken in consideration the impact of the degradation on the cost of hydrogen production, the p-Si remain the most cost effective technology even though the cost has increase to 5.32 $/kg, 5.78 $/kg and 6.67 $/kg for the p-Si, m-Si and a-Si technologies respectively.     

A dual photoelectrode-based double-chambered microbial fuel cell applied for simultaneous COD and Cr (VI) reduction in wastewater

Cerium oxide (CeO₂) and cuprous oxide (Cu₂O) were used for the first time as photoanode and photocathode, respectively, in a microbial fuel cell (MFC) for simultaneous reduction of chemical oxygen demand (COD) and Cr(VI) in wastewater. The photoelectrodes, viz. Photoanode and photocathode were separately prepared by impregnating activated carbon fiber (ACF) with the respective metal oxide nanoparticles, followed by growing carbon nanofibers (CNFs) on the ACF substrate using catalytic chemical vapor deposition. The MFC, operated under visible light irradiation, showed reduction in COD and Cr(VI) by approximately 94 and 97%, respectively. The MFC also generated high bioelectricity with a current density of ~6918 mA/m² and a power density of ~1107 mW/m². The enhanced performance of the MFC developed in this study was attributed to the combined effects of the metal oxide photocatalysts, the graphitic CNFs, and the microporous ACF substrate. The MFC based on the inexpensive transition metal oxides-based photoelectrodes developed in this study has a potential to be used at a large scale for treating the industrial aqueous effluents co-contaminated with organics and toxic Cr(VI).     

Catalytic combustion and system performance assessment of MCFC-MGT hybrid system

The catalytic combustor is applied as an off-gas and startup combustor for a molten carbonate fuel cell-micro-gas turbine (MCFC-MGT) hybrid system (HS) so as to utilize the waste energy of fuel cell off-gas. Three types of catalysts are prepared over a cordieritic honeycomb support. One is Pt catalyst which is not cost effective and less high temperature stability. CeZrO₂ and LaMnO₃ have been selected as an additive for another two Pt catalysts to improve the performance. Tests have been completed in realistic conditions and reaction feed close to the MCFC-MGT hybrid system. Simulations are carried out with a fluid mechanical code that incorporates detailed transport and heat loss mechanisms. The simulation results are compared with the Pt catalyst test results. The agreement confirms the accuracy of simulation. The model can be used to develop an MCFC-MGT hybrid system with an off-the-shelf gas turbine and assess the performances during part-load operation. From the experimental results, the reaction starts at 620 K for 1 vol.% CH₄ using Pt catalyst, while the temperature is above 800 K for the addition of additive. For the 50% CH₄ conversion, the preheated temperature of the three catalysts is 713 K, 870 K and 950 K respectively. While all of the catalysts exhibit good performance when using the MCFC off-gas as fuel. The results of performance analysis for part-load conditions show that the cell operation temperature and turbine inlet temperature (TIT) should be maintained as close as possible to the design value to prevent the performance degradation.     

Catalyst layer optimization by surface tension control during ink formulation of membrane electrode assemblies in proton exchange membrane fuel cell

A cost effective production of the membrane electrode assemblies (MEA) is a crucial issue for the generation of electricity by proton exchange membrane fuel cells (PEMFC). The deposition of the exact catalyst content on the electrodes in a single printing step is desirable to save processing time and enable cost reduction. In this study, an innovative MEA production process by screen print is developed to produce high performance catalyst layers. The control of the surface tension of the catalyst ink is fundamental to allow the catalyst layer deposition in a single printing step. The electrodes prepared in this way show higher performance than those prepared in several steps. The optimal ink developed shows a viscosity of 2.75 Pa s, a total solid content of 33.76 wt.%, a density of 1.294 g cm⁻³, and tack value of 92 U.T.     

Micro fluidic structure selection of metal mesh combinations in proton exchange membrane fuel cells for air supply enhancement

One of the most significant factors affecting the performance of a proton exchange membrane fuel cell is the flow path for the passage of air and water, which is responsible for oxygen dispersion. A three-dimensional fine mesh, with optimized flow paths, exhibits the best performance in commercialized fuel cell electric vehicles, but the manufacturing cost is significantly high. To achieve high performance at a lower cost, the possibility of using a combination of commercially available screen meshes was investigated. The overlapped screen meshes should provide improved mass transport similar to a 3-D fine mesh. By using an optimized combination of screen meshes (200 and 100 mesh) and gasket thickness (150 μm thinner than the mesh flow field), an improvement in oxygen mass transport was achieved. The suggested combination shows a lower oxygen gain (0.030 V) than a single mesh (0.050 V) and a conventional single serpentine flow field (0.150 V).     

Process integration and economic analysis of bio-oil platform for the production of methanol and combined heat and power

Process to process material and heat integration strategies for bio-oil integrated gasification and methanol synthesis (BOIG-MeOH) systems were developed to assess their technological and economic feasibility. Distributed bio-oil generations and centralised processing enhance resource flexibility and technological feasibility. Economic performance depends on the integration of centralised BOIG-MeOH processes, investigated for cryogenic air separation unit (ASU) and water electrolyser configurations. Design and operating variables of gasification, heat recovery from gases, water and carbon dioxide removal units, water-gas shift and methanol synthesis reactors and CHP network were analysed to improve the overall efficiency and economics. The efficiency of BOIG-MeOH system using bio-oil from various feedstocks was investigated. The system efficiency primarily attributed by the moisture content of the raw material decreases from oilseed rape through miscanthus to poplar wood. Increasing capacity and recycle enhances feasibility, e.g.1350 MW BOIG-MeOH with ASU and 90% recycle configuration achieves an efficiency of 61.5% (methanol, low grade heat and electricity contributions by 89%, 7.9% and 3% respectively) based on poplar wood and the cost of production (COP) of methanol of 318.1 Euro/t for the prices of bio-oil of 75 Euro/t and electricity of 80.12 Euro/MWh, respectively. An additional transportation cost of 4.28-8.89 Euro/t based on 100 km distance between distributed and centralised plants reduces the netback of bio-oil to 40.9-36.3 Euro/t.     

A novel electrode-bipolar plate assembly for vanadium redox flow battery applications

A novel electrode-bipolar plate assembly has been developed and evaluated for application in the vanadium redox flow battery (VRB). It is composed of three parts: a graphite felt (electrode), an adhesive conducting layer (ACL) and a flexible graphite plate (bipolar plate). The ACL connects the electrode with the bipolar plate to an assembly. By the evaluations of cost, resistivity, surface morphology, electrolyte permeation and single cell performance, this novel assembly demonstrates its applicability in VRB as evident in the following outcomes: (1) lowers the cost and area resistivity to about 10% and 40% of the conventional setups, respectively; (2) improves electrical conductivity to 4.97 mΩ cm as compared to over 100 mΩ cm of the carbon-plastic composite bipolar plate; (3) attains zero electrolyte permeation; and (4) achieves a higher energy efficiency of 81% at a charge/discharge current density of 40 mA cm⁻² when employed in a VRB single cell, which is 73% for the conventional setup. All these indicate that the novel electrode-bipolar plate assembly is a promising candidate for VRB applications.     

Microbial fuel cells for bioelectricity generation through reduction of hexavalent chromium in wastewater: A review

The study proposes the use of microbial fuel cell (MFC) technology to reduce toxic Cr(VI) present in industrial wastewater to less toxic trivalent chromium [Cr(III)], while generating electricity through a bioelectrochemical oxidation-reduction process. Factors influencing the treatment process and electricity generation include the concentration of Cr(VI) in wastewater, substrate types used for anodes, types of microorganisms involved, types of cathode and anode, surface area of the cathode and anode, and pH and temperature of cathodic and anodic solutions. While other heavy metals in wastewater may be removed by MFC technology, Cr(VI) removal is more efficient in terms of electricity generation. Previous research indicated that the maximum electrical power generated by Cr(VI) removal through the use of MFCs is 1600 mW/m², which is expected to increase as the factors affecting this process are optimized. Based on current data, MFC-based electricity generation along with Cr(VI) removal is a potential future source of sustainable energy. However, research priorities need to focus on reducing the cost of MFC technology by using economical and effective materials and increasing electricity production.     

Polymerization of α-pinene using Lewis acidic ionic liquid as catalyst for production of terpene resin

The polymerization of α-pinene was investigated in the presence of Lewis acidic ionic liquids (ILs). The results indicated that ILs 1-(1-ethyl acetate-yl)-3-methylimidazolium chloroaluminates ([EtOCOCH₂-mim]Cl-AlCl₃), especially molar fraction of AlCl₃ x = 0.67, had excellent catalytic performance for the polymerization of α-pinene. The yield and softening point of solid resin reached to 52.0% and 115 °C, respectively, when the polymerization was carried out at −5 °C for 4 h. IL was reused for five times without a decrease in the catalytic performance. Compared with the traditional catalyst AlCl₃, IL exhibited some advantages such as simplicity and efficiency of the product isolation, higher yield and softening point of the product, and excellent reusability.     

Realistic simulation of fuel economy and life cycle metrics for hydrogen fuel cell vehicles

The present work contributes an engineered life cycle assessment (LCA) of hydrogen fuel cell passenger vehicles based on a real‐world driving cycle for semi‐urban driving conditions. A new customized LCA tool is developed for the comparison of conventional gasoline and hydrogen fuel cell vehicles (FCVs), which utilizes a dynamic vehicle simulation approach to calculate realistic, fundamental science based fuel economy data from actual drive cycles, vehicle specifications, road grade, engine performance, fuel cell degradation effects, and regenerative braking. The total greenhouse gas (GHG) emission and life cycle cost of the vehicles are compared for the case of hydrogen production by electrolysis in British Columbia, Canada. A 72% reduction in total GHG emission is obtained for switching from gasoline vehicles to FCVs. While fuel cell performance degradation causes 7% and 3% increases in lifetime fuel consumption and GHG emission, respectively, regenerative braking improves the fuel economy by 23% and reduces the total GHG emission by 10%. The cost assessment results indicate that the current FCV technology is approximately $2,100 more costly than the equivalent gasoline vehicle based on the total lifetime cost including purchase and fuel cost. However, prospective enhancements in fuel cell durability could potentially reduce the FCV lifetime cost below that of gasoline vehicles. Overall, the present results indicate that fuel cell vehicles are becoming both technologically and economically viable compared with incumbent vehicles, and provide a realistic option for deep reductions in emissions from transportation. Copyright © 2016 John Wiley & Sons, Ltd.     

Rapid fabrication of microfluidic polymer electrolyte membrane fuel cell in PDMS by surface patterning of perfluorinated ion-exchange resin

In this paper we demonstrate a simple and rapid fabrication method for a microfluidic polymer electrolyte membrane (PEM) fuel cell using polydimethylsiloxane (PDMS), which has become the de facto standard material in BioMEMS. Instead of integrating a Nafion sheet film between two layers of a PDMS device in a traditional “sandwich format,” we pattern a perfluorinated ion-exchange resin such as a Nafion resin on a glass substrate using a reversibly bonded PDMS microchannel to generate an ion-selective membrane between the fuel-cell electrodes. After this patterning step, the assembly of the microfluidic fuel cell is accomplished by simple oxygen plasma bonding between the PDMS chip and the glass substrate. In an example implementation, the planar PEM microfluidic fuel cell generates an open circuit voltage of 600–800 mV and delivers a maximum current output of nearly 4 μA. To enhance the power output of the fuel cell we utilize self-assembled colloidal arrays as a support matrix for the Nafion resin. Such arrays allow us to increase the thickness of the ion-selective membrane to 20 μm and increase the current output by 166%. Our novel fabrication method enables rapid prototyping of microfluidic fuel cells to study various ion-exchange resins for the polymer electrolyte membrane. Our work will facilitate the development of miniature, implantable, on-chip power sources for biomedical applications.     

Charge–discharge properties of surface-modified carbon by resin coating in Li-ion battery

The effect of an epoxy resin coating on the electrochemical performance of Li-ion batteries is investigated. Mesocarbon microbeads (MCMB), which constitute a promising carbon anode material for rechargeable Li-ion batteries is used as a starting carbon material. The surface coating of the MCMB is carried out by refluxing in a dilute H₂SO₄ solution and mixing in the epoxy resin-dissolved tetrahydrofuran (THF) solution. After heat treatment at 1000–1300 °C, the resin coating layer on the MCMB is converted to an amorphous phase which is identified by means of a high resolution transmission electron microscope (HRTEM) and a electron energy loss spectroscopy (EELS) analyses. The Brunauer–Emmett–Teller (BET) surface area of MCMB is increased by the formation of the amorphous epoxy resin coating layer. The electrochemical performance of the MCMB, such as the charge–discharge capacity and cycleability, is enhanced by the surface modification through epoxy resin coating. The reasons for the improvement of electrochemical performance are discussed in terms of the results from HRTEM observation, EELS analysis, and cyclicvoltammetry     

A novel fabrication of yttria-stabilized-zirconia dense electrolyte for solid oxide fuel cells by 3D printing technique

Three-dimensional (3D) printing technique represents a revolutionary advancement in the manufacturing sector due to its unique capabilities to process the shape complexity. This work is focusing on dense 8 mol.% yttria-stabilized-zirconia (8YSZ) electrolyte fabrication via digital light processing (DLP)-stereolithography-based 3D printing technique. Multiple 8YSZ electrolyte green bodies are printed simultaneously in a batch using ceramic-resin suspension made of 30 vol% 8YSZ powder loading in a photo-curable resin. Together with an optimized debinding and sintering procedure, the 8YSZ green body changes into a dense electrolyte, and the density of the sintered electrolyte was measured as 99.96% by Archimedes' water displacement method. The symmetric cell fabricated of silver-Ce_0.8Gd_0.2O_1.9 (Ag-GDC) as cathode/anode and dense 8YSZ electrolyte printed by DLP-stereolithography delivers a high open circuit voltage of approximately 1.04 V and a peak power density up to 176 mW·cm⁻² at 850 °C by using hydrogen as the fuel and air as the oxidant. The electrochemical performance of the symmetric cell Ag-GDC|YSZ|Ag-GDC with 8YSZ electrolyte fabricated via DLP-stereolithography is comparable to that of the same cell with 8YSZ electrolyte fabricated by conventional dry pressing method. This 3D printing technique provides a novel method to prepare dense electrolytes for solid oxide fuel cell (SOFC) with good performance, suggesting a potential application for one-step fabrication of complex structure SOFC stack.     

Impact of powertrain hybridization on the performance and costs of a fuel cell electric vehicle

Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs) have gained attention due to the growing concern about air quality in large urban centers. Barriers such as high purchase price and the lack of a supply infrastructure delay the mass adoption of these vehicles. The current work uses the Advanced Vehicle Simulator (ADVISOR) to analyze the influence of the degree of hybridization (DOH) on the performance and total cost of an FCEV (Hyundai Nexo 2019 model). The costs and fuel economy results of the different configurations (different DOH) are compared to those of the original vehicle. The configuration with the highest degree of hybridization (DOH = 61.2%) showed an 8.3% increase in fuel economy and a total cost reduction of 13.2% compared to the original vehicle. In addition, the best vehicle configuration results are compared to a same-segment gasoline-internal combustion engine vehicle and the original Hyundai Nexo in different cost scenarios.