Development of large-scale hydrogen liquefaction processes from 1898 to 2009

This paper presents a review of the development of large-scale hydrogen liquefaction processes throughout the world from 1898 to 2009. First, there is a concise literature review including numerous past, present, and future designs given such as the first hydrogen liquefaction device, long time ago simple theoretical processes, today's actual plants with efficiencies 20–30%, a list of the capacity and location of every hydrogen liquefaction plant in the world, and some modern more efficient proposed conceptual plants with efficiencies 40–50%. After that, further information about the development and improvement potential of future large-scale liquid hydrogen liquefaction plants is given. It is found that every current plant is based on the pre-cooled Claude system, which is still the same as was 50 years ago with little improvement. Methods to resolve the challenges of the future plants include proposing completely new configurations and efficient systems coupled with improved efficiencies of the main system components such as compressors, expanders, and heat exchangers. Finally, a summary and comparison of the process efficiencies are described, including a newly proposed Multi-component Refrigerant (MR) system being developed by NTNU and SINTEF Energy Research AS.     

Insitu upgradation of biocrude vapor generated from non-edible oil cake's hydrothermal conversion over aluminated mesoporous catalysts

In this work, biocrude vapors generated from hydrothermal conversion of Pongammia pinnata cake using high pressure reactor at 400 °C and 25 kg/cm² were upgraded over three mesoporous catalyst namely SBA-15, KIT-6 and FDU-12. The catalysts were synthesized, aluminated and characterized using X-Ray Diffraction, N₂ adsorption-desorption, SEM techniques. A decrease in the surface area was observed on all three mesoporous catalyst after alumina loading with negligible effect on the pore diameter. Purely siliceous catalysts were found to give negligible effect on the yield of different product phases. Alumina supported SBA-15 (SAR 30) was observed as the suitable catalyst as compared to Al/FDU-12 (SAR 30) and Al/KIT-6 (SAR 30) for maximizing the biocrude yield with low heavy hydrocarbons (46.3 ± 2.2%), polyaromatic hydrocarbons (17.1%) and acidic compounds (9.1%) content. Therefore series of SBA-15 were synthesized by varying silicon to alumina ratio between 20 and 50 for maximizing hydrocarbons with boiling cut fractions between 195 and 317 °C corresponding to gasoline range hydrocarbons. Al/SBA-15(SAR 40) was found to give highest biocrude yield (∼34.8%) with highest selectivity towards gasoline fraction (23.7 ± 1.9%). GC/MS analysis was used to confirm the presence of aliphatic and aromatics. Highest asphaltene content was observed with Al/SBA-15 (SAR 50).     

Methylcyclohexane production under fluctuating hydrogen flow rate conditions

Energy storage using liquid organic hydrogen carrier (LOHC) is a long-term method to store renewable energy with high hydrogen energy density. This study investigated a simple and low-cost system to produce methylcyclohexane (MCH) from toluene and hydrogen using fluctuating electric power, and developed its control method. In the current system, hydrogen generated by an alkaline water electrolyzer was directly supplied to hydrogenation reactors, where hydrogen purification equipment such as PSA and TSA is not installed to decrease costs. Hydrogen buffer tanks and compressors are not equipped. In order to enable MCH production using fluctuating electricity, a feed-forward toluene supply control method was developed and introduced to the system. The electrolyzer was operated under triangular waves and power generation patterns of photovoltaic cells and produced hydrogen with fluctuating flow rates up to 7.5 Nm³/h. Consequently, relatively high purity of MCH (more than 90% of MCH mole fraction) was successfully produced. Therefore, the simplified system has enough potential to produce MCH using fluctuating renewable electricity.     

Optimal liquid acquisition device screen weave for a liquid hydrogen fuel depot

This paper presents the rationale for choosing the optimal screen type for a fully robust screen channel liquid acquisition device (LAD) to be implemented into future in-space liquid hydrogen (LH₂) fuel depots. Typical Dutch Twill, Plain Dutch, Twilled Square, and Plain Square weaves are initially considered for comparison. From the set of influential performance parameters from Hartwig and Darr [1], bubble point pressure and flow-through-screen (FTS) pressure drop are combined to define a critical mass flux used to make general comparisons between screens. Based off the minimum bubble point pressure to maintain adequate phase separation against adverse depot acceleration levels, the five finest Dutch Twill screens are down selected for the depot. Along with secondary parameters such as wicking rate and screen compliance, a minimum screen area is defined to select the optimal mesh. Results here indicate that the 450 × 2750 Dutch Twill mesh may be the optimal screen weave for a future LH₂ fuel depot.     

Incorporation of fish by-product into the semi-continuous anaerobic co-digestion of pre-treated lignocellulose and cow manure,with recovery of digestate's nutrients

Norway's fish processing industry generates large amounts of fish waste every year. The high-risk waste fraction with most of its oil removed has not yet been tested for energy production. The stability of an anaerobic digestion process that incorporates this material with steam exploded Salix and cow manure was tested using mesophilic, semi-continuous laboratory-scale digesters. The effects of recycling the liquid digestate fraction were also investigated. The removal of ammonium (NH₄⁺) and phosphate (PO₄³⁻) from the rejected digestate using struvite precipitation and bentonite adsorption were tested to generate a nutrient-enriched, final solid fertiliser. Adding 20% fish by-product (volatile solids basis) increased methane yields by 35%, while recycling the digestate caused a slight increase. The NH₄⁺–N levels reached 4–5 g l⁻¹ in the reactors with recirculation and fish feed. Although these levels may threaten methanogenesis, the stability of the process was maintained during the entire period due to the good balance between the lignocellulose, proteins and fats provided by the co-digestion mixture and the positive effects of recirculation. The NH₄⁺ and PO₄³⁻ were successfully removed from the rejected liquid digestate. The reductions using struvite reached 87% and 60% (pH 9.5 and Mg²⁺:NH₄⁺:PO₄³⁻ ratio of 1.2:1:1), while bentonite achieved 82% and 52%, respectively.     

周期反向电流法高电流密度电解精炼铜的研究

模拟铜电解精炼工业生产条件,在小型电解中研究周期反向电流法高流密度电解精炼铜的可行性。并用XRD、SEM及离子体发射光谱研究杂质对铜沉积的结构和组成的影响。研究表明：当电流密度为400A.m^2－,电流周期阴极沉积时间75s溶解时间1．5s,添加剂用量（g.dm^-3）;硫脲0．010、骨胶0．010、Cl^-0．050,有害杂质含量（g.dm^-3):As(V)≤3．0、Sb（Ⅲ）≤0．14、Bi（Ⅲ）≤0．1时能获得表面光滑平整纯度为99．99％的电解铜。以400A.m^-2的周期反向电流电解时,铜沉积的电结晶生长形态为脊状＋块状,晶面择优取向为（220）,少量杂质存在对铜沉积结构有一定影响。     

NaNH2–NaBH4 hydrogen storage composite materials synthesized via liquid phase ball-milling: Influence of Co–Ni–B catalyst on the dehydrogenation performances

The composite NaNH₂–NaBH₄ (2/1 molar rate) doped with different amount Co–Ni–B catalyst was synthesized via liquid phase ball-milling method in the cyclohexane agent. The composition evolution and dehydrogenation performance of the as-prepared sample were characterized by means of XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy) and TG–DTA–MS (Thermogravimetric–differential thermal analysis–mass spectroscopy) measurements, respectively; and the activation energies were calculated by the Achar differential and Coats–Redfern integral method. The composite NaNH₂–NaBH₄ (2/1) with 5 wt% Co–Ni–B catalyst (the sample C5) generated Na₃(NH₂)₂BH₄ successfully after the liquid phase ball-milling. Due to the interaction between functional groups of NaNH₂–NaBH₄ (2/1) with catalyst, Co–Ni–B catalyst not only benefits improving the thermodynamical performance, that is, the initial dehydrogenation temperature is as low as 200 °C and the weight percentage of hydrogen is about 5.05 wt% obtained from TG–DTA-MS curves; but also promoting the kinetics property that the activation energy of the major dehydrogenation stage is only 68.2 kJ mol^?1. Furthermore, it is revealed that the kinetics mechanism of the dehydrogenation performance depends on the synthesis methods and adding catalyst.     

Quantification of the Alternaria mycotoxin tenuazonic acid in beer

Tenuazonic acid (TA) is a major water soluble Alternaria mycotoxin. In the present work, a method for the quantification of TA in beer by liquid chromatography–ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine is described. The method is based on a rapid workup procedure and features a LOD of 2 μg/kg without preconcentration using 400 mg of sample. Validation was performed for a working range of 8–500 μg/kg.     

Supramolecular solvent-based microextraction of Sudan dyes in chilli-containing foodstuffs prior to their liquid chromatography-photodiode array determination

A supramolecular solvent made up of reverse micelles of decanoic acid was proposed for the simple and rapid extraction of Sudan I, II, III and IV from chilli-containing foodstuffs. The procedure involved the extraction of minute quantities (0.5–1 g) of homogenised food sample with an aqueous solution containing 10% THF and 200 mg of decanoic acid, conditions under which the supramolecular solvent (around 330 μL) formed in situ and instantaneously. The overall sample treatment took about 30 min and several samples could be simultaneously treated using conventional lab equipment. No clean-up or solvent evaporation were required before determination of Sudan dyes by liquid chromatography and photometric detection. Extractions were independent of salt addition (up to 1 M), the temperature (up to 60 °C) and the pH (below 4) rendering the method robust. The detection limits of the method were 4.2, 2.7, 6.5 and 7.4 μg kg⁻¹ for Sudan I, II, III and IV, respectively. Recoveries obtained by applying this approach to the analysis of six chilli-containing sauces fortified with Sudan dyes at the μg kg⁻¹ level were in the interval 86–108% with relative standard deviations between 2% and 7%.     

Estimation of forest area near deserts — production of Global Bio-Methanol from solar energy

This paper proposes a new synthesis method for methanol as a future alternative fuel, by the combination of carbon supplied from wood and hydrogen supplied from the electrolysis of water using a solar power generation system in the desert. In the developed countries, more than half of the potential forest area has already been converted into other land uses, while existing forests are well organized and available for wood production. In the developing countries, potential forest sites are expected to be available for wood production, even though they are presently grasslands or secondary forests, while natural tropical forests will not be allowed to be converted into artificial forests. The area available for plantations within 500 km distant from deserts was estimated to be 65 Mha in the world, except for the mountain areas. Biomass production from these sites will be converted annually into 980 Mt methanol with hydrogen from the deserts. This amount is equal to 34% of the world's fuel consumption by vehicles.