hydrogen

摘要： Water represents a critical nutrient, the absence of which will be lethal within days. Water’s importance for the prevention of nutrition-related noncommunicable diseases has received more attention recently. There are major gaps in knowledge related to the measurement of total fluid intake and hydration status at the population level. It is poorly understood the effects of chronic mild dehydration and fluid consumption on specific health outcomes including obesity. Urolithiasis is the only disorder that has been consistently associated with chronic low daily water intake. Water is an essential nutrient required for life, but until now, it was considered mainly as a universal solvent, which served to prepare the broth of life inside the cells, but the function of water now takes unusual importance with our discovery of the unsuspected ability of the human body to transform the power of light into chemical energy by dissociating the molecule from water, as it happens in plants. The process that we replicated in the laboratory for the first time in 2007, represents a light at the end of the tunnel, in the growing and serious problem of contamination of the mysterious and vital liquid that we call water.

摘要： In order to improve the design of PSA system for fuel cell hydrogen production,a non-isothermal model of eight-bed PSA hydrogen process with five-component(H_(2)/N_(2)/CH_(4)/CO/CO_(2)=74.59%/0.01%/4.2%/2.5%/18.7%(vol))four-stage pressure equalization was developed in this article.The model adopts a composite adsorption bed of activated carbon and zeolite 5 A.In this article,pressure variation,temperature field and separation performance are stimulated,and also effect of providing purge(PP)differential pressure and the ratio of activated carbon to zeolite 5 A on separation performance in the process of producing industrial hydrogen(CO content in hydrogen is 10μl·L^(-1))and fuel cell hydrogen(CO content is 0.2μl·L^(-1))are compared.The results show that Run 3,when the CO content in hydrogen is 10μl·L^(-1),the hydrogen recovery is 89.8%,and the average flow rate of feed gas is 0.529 mol·s^(-1);When the CO content in hydrogen is 0.2μl·L^(-1),the hydrogen recovery is 85.2%,and the average flow rate of feed gas is 0.43 mol·s^(-1).With the increase of PP differential pressure,hydrogen recovery first increases and then decreases,reaching the maximum when PP differential pressure is 0.263 MPa;With the decrease of the ratio of activated carbon to zeolite 5 A,the hydrogen recovery increases gradually.When the CO content in hydrogen is 0.2μl·L^(-1) the hydrogen recovery increases more obviously,from 83.96%to 86.37%,until the ratio of activated carbon to zeolite 5 A decreases to 1.At the end of PP step,no large amount of CO_(2) in gas or solid phase enters the zeolite 5 A adsorption bed,while when the CO content in hydrogen is 10μl·L^(-1),and the ratio of carbon to zeolite 5 A is less than 1.4,more CO_(2) will enter the zeolite 5 A bed.

摘要： The n-π^(*) electronic transition in polymeric carbon nitride(PCN)can remarkably harvest visible light,which thus potentially promotes the photocatalytic hydrogen H2 generation.However,awaking the n-π^(*) lectronic transition has proven to be a grand challenge.Herein,we reported on the awakening of n-π^(*) electronic transition by microwave thermolysis of urea pellet,which yielded the PCN with absorption edge of 600 nm,near 140 nm red-shift from 460 nm of pristine PCN.The n-π^(*) electronic transition endows PCN with an increased photocata lytic H_(2) generation,with a highest H_(2) rate of 61.7μmol h^(-1) under visible light exposure,which is near 6 times higher than that by using the PCN from the thermolysis of urea pellets in an electric furnace(10.6μmol h^(-1)).Furthermore,the n-π^(*) transition in PCN leads to the longest wavelength of 535 nm that can initiate H2 generation,remarkably longer than the absorption edge of pristine PCN(460 nm).This work manifests the advantages of microwave sintering route to awaken the n-π^(*) electronic transition in PCN for an increased photocata lytic performance.

摘要： In the present work,a complete 2D chemical and thermal non-equilibrium numerical model coupled with a relatively simple sheath model is developed for hydrogen arcjet thruster.Conduction heat transfer in the anode wall is also included in the model.The operating voltages predicted by the model are compared with those in the literature and are found to be in close agreement.Power distributions for the various operating conditions are obtained,anode radiation loss primarily determines the thruster efficiency.Higher thruster efficiency was found to be associated with longer arc length.At cathode ion diffusion contribution dominates except at low input current where thermo-field electron current is dominant.

摘要： With increasing importance attached by the international community to global climate change and the pressing energy revolution,hydrogen energy,as a clean,efficient energy carrier,can serve as an important support for the establishment of a sustainable society.The United States and countries in Europe have already formulated relevant policies and plans for the use and development of hydrogen energy.While in China,aided by the“30·60”goal,the development of the hydrogen energy,production,transmission,and storage industries is steadily advancing.This article comprehensively considers the new energy revolution and the relevant plans of various countries,focuses on the principles,development status and research hot spots,and summarizes the different green hydrogen production technologies and paths.In addition,based on its assessment of current difficulties and bottlenecks in the production of green hydrogen and the overall global hydrogen energy development status,this article discusses the development of green hydrogen technologies.

摘要： This study presents a reliable model using Aspen Plus process simulator capable of performing a sensitivity analysis of the downdraft gasification linked to hydrogen production unit. Effects of key factors, including gasification temperature and steam to biomass ratio (SBR) on the syngas composition, calorific value of syngas and hydrogen production are discussed and then the optimal conditions for maximum hydrogen production are extracted. The model is validated by experimental and other modeling data and found to be in great agreement. The sensitivity analysis results obtained by only using air as gasification agent indicate that higher temperatures are favorable for a product gas with higher hydrogen content and calorific value. Moreover, steam consumption as gasifying agent leads to increasing the hydrogen content and heating value of the syngas compared to the use of air as gasification agent. Finally, the results show that the optimal conditions to have the highest value of hydrogen output from sawdust downdraft gasification are 800˚C as gasifier temperature and 0.6 for SBR.

摘要： BACKGROUND Patients with keloids who receive radiotherapy(RT)after surgery can develop refractory wounds that cannot be healed by the patient's own repair system.Such chronic wounds are uneven and complex due to persistent abscess and ulceration.Without external intervention,they can easily result in local tissue necrosis or,in severe cases,large area tissue resection,amputation,and even death.CASE SUMMARY This article describes the use of hydrogen to treat a 42-year-old female patient with a chronic wound on her left shoulder.The patient had a skin graft that involved implanting a dilator under the skin of her left shoulder,and then transferring excess skin from her shoulder onto scar tissue on her chest.The skin grafting was followed by two rounds of RT,after which the shoulder wound had difficulty healing.For six months,the patient was treated with 2 h of hydrogen inhalation(HI)therapy per day,in addition to application of sterile gauze on the wound and periodic debridement.We also performed one deep,large,sharp debridement to enlarge the wound area.The wound healed completely within 6 mo of beginning the HI treatment.CONCLUSION After HI therapy,the patient showed superior progress in reepithelialization and wound repair,with eventual wound closure in 6 mo,in comparison with the previous failures of hyperbaric oxygen and recombinant bovine basic fibroblast growth factor therapies.Our work showed that HI therapy could be a new strategy for wound healing that is cleaner,more convenient,and less expensive than other therapies,as well as easily accessible for further application in clinical wound care.

摘要： Hydrogen-based shaft furnace process is gaining more and more attention due to its low carbon emission, and the reduction behavior of iron bearing burdens significantly affects its operation. In this work, the effects of reduction degree, temperature, and atmosphere on the swelling behavior of pellet has been studied thoroughly under typical hydrogen metallurgy conditions. The results show that the pellets swelled rapidly in the early reduction stage, then reached a maximum reduction swelling index (RSI) at approximately 40%reduction degree. The crystalline transformation of the iron oxides during the reduction process was the main reason of pellets swelling. The RSI increased significantly with increasing temperature in the range of 850-1050°C, the maximum RSI increased from 6.66%to 25.0%in the gas composition of 100%H_(2). With the temperature increased, the pellets suffered more thermal stress resulting in an increase of the volume. The maximum RSI decreased from 19.78%to 17.35%with the volume proportion of H_(2) in the atmosphere increased from 55%to 100%at the temperature of 950°C.The metallic iron tended to precipitate in a lamellar structure rather than whiskers. Consequently, the inside of the pellets became regular, so the RSI decreased. Overall, controlling a reasonable temperature and increasing the H_(2) proportion is an effective way to decrease the RSI of pellets.

摘要： Iron ore powder was isothermally reduced at 1023-1373 Kwith hydrogen/carbon monoxide gas mixture(from 0vol%H_(2)/100vol%CO to 100vol%H_(2)/0vol%CO).Results indicated that the whole reduction process could be divided into two parts that proceed in series.The first part represents a double-step reduction(Fe_(2)O_(3)→Fe_(3)O_(4)→FeO),in which the kinetic condition is more feasible compared with that in the second part representing a single-step reduction(FeO→Fe).The influence of hydrogen partial pressure on the reduction rate gradually increases as the reaction proceeds.The average reduction rate of hematite ore with pure hydrogen is about three and four times higher than that with pure carbon monoxide at 1173 and 1373 K,respectively.In addition,the logarithm of the average rate is linear to the composition of the gas mixture.Hydrogen can prominently promote carbon deposition to about 30%at 1023 K.The apparent activation energy of the reduction stage increases from about 35.0 to 45.4 kJ/mol with the increase in hydrogen content from 20vol%to 100vol%.This finding reveals that the possible rate-controlling step at this stage is the combined gas diffusion and interfacial chemical reaction.

摘要： The effect of hydrogen injection on blast furnace operation and carbon dioxide emissions was simulated using a 1D steady-state zonal model.The maximum hydrogen injection rate was evaluated on the basis of the simulation of the vertical temperature pattern in the blast furnace with a focus on the thermal reserve zone.The effects of blast temperature and oxygen enrichment were also examined to estimate coke replacement ratio,productivity,hydrogen utilization efficiency,and carbon dioxide emission reduction.For blast temperature of 1200°C,the maximum hydrogen injection rate was 19.0 and 28.3 kg of H_(2)/t of hot metal(HM)for oxygen enrichment of 2vol%and 12vol%,respectively.Results showed a coke replacement ratio of 3-4 kg of coke/kg of H_(2),direct CO_(2) emission reduction of 10.2%-17.8%,and increased productivity by up to 13.7%depending on oxygen enrichment level.Increasing blast temperature further reduced the direct CO_(2) emissions.Hydrogen utilization degree reached the maximum of 0.52-0.54 H_(2)O/(H_(2)O+H_(2)).The decarbonization potential of hydrogen injection was estimated in the range from 9.4 t of CO_(2)/t of H_(2) to 9.7 t of CO_(2)/t of H_(2).For economic feasibility,hydrogen injection requires revolutionary progress in terms of low-cost H_(2) generation unless the technological change is motivated by the carbon emission cost.Hydrogen injection may unfavorably affect the radial temperature pattern of the raceway,which could be addressed by adopting appropriate injection techniques.

摘要： Hydrogen production by fermentative bacteria and photosynthetic organisms is depressed at lowtemperature. Here we described single-chamber microbial electrolysis cells (MECs) which were enrichedsuccessfully at 4 oC or 9 oC and operated at these temperatures for the production of hydrogen. The rates ofhydrogen production varied from 0.23±0.03 to 0.53±0.04 m3H2m3d1, the hydrogen yield was in therange 2.66±0.22 2.94±0.02 mol H2mol1acetate, and CH4was not detected in any of the reactors. Theseparate MECs were first operated at 25 oC and the methanogenesis was found to occur in them, however noCH4was produced if the cells were operated at 4 oC or 9 oC. 16S rRNA gene clone libraries constructed forArchaea proved that the growth of hydrogenotrophic methanogens such as Methanobrevibacter arboriphiluscultured in MECs at 25 oC was effectively inhibited under psychrophilic conditions, and the growth of theseorganisms was initially suppressed in these MECs maintained at low temperatures. Bacterial 16S rRNA geneclone library analyses showed that temperature significantly influenced the community structure of the anodebiofilms in MECs, and Geobacter psychrophilus was found to be the dominant psychrotolerant population inMECs maintained at 4 oC and 9 oC.

摘要： In order to improve the energy recovery efficiency, the fermentative hydrogen production from organic fraction of municipal solid waste (OFMSW) was followed by the methane production using the residual of hydrogen production as substrate. Six varieties of typical individual components of OFMSW including rice, potato, lettuce, lean meat, peanut oil and banyan leaves were selected as experimental materials. Experimental results showed that, during the hydrogen production stage, the hydrogen yields were 125, 103, 35, 0, 5 and 0 mL/g-VS for rice, potato, lettuce, lean meat, peanut oil and banyan leaves. The hydrogen composition in the biogas was about 34-59%, 41-56% and 37- 70% for rice, potato and lettuce respectively. The biogas was free from methane. The energy efficiency was 7.9%, 6.8%, 1.9%, 0, 0.1% and 0. During the methane production stage, the methane yields were 232, 237, 148, 278, 866 and 50 mL/g-VS respectively. The methane contents were 42-70%, 57-71%, 73-77%, 59%-73%, 68-80% and 54-74%. The energy efficiency of co-production hydrogen and methane were 56.3%, 58.4%, 28.8%, 39.2%, 81.2% and 8.8% respectively. The total COD removal rate for the whole process of hydrogen and methane production were 72.30%, 81.70%, 32.63%, 47.59%, 97.46% and 11.29%.