Optimal correlation of non-renewable and renewable generating systems for producing hydrogen and methane by power to gas process

This paper presents an efficient framework for converting renewable energy to gas and reducing Carbon dioxide (CO₂) footprint at the same time. The problem is presented in two levels. The first level is a minimization programming that minimizes operational cost and CO₂ of generators. The CO₂ is forwarded to the second level. In the second level, Carbon Capture and Storage (CCS) is designed to capture CO₂. The CO₂ is combined with Hydrogen and makes Methane (CH₄). The required Hydrogen is obtained from water electrolyzer that is supplied by the solar system. The capacity and size of water electrolyzer, solar system, and CCS is designed by the planning in the second level while this programming maximizes profit from selling Methane. As a result, the first level presents minimization programming (i.e., minimizing cost and CO₂) and the second level presents maximization programming (i.e., maximizing profit). The programming is developed taking into account solar uncertainty. The stochastic programming is implemented to cope with uncertainties. The problem is formulated as binary mixed integer linear programming and solved by GAMS software. The proposed power to gas (P2G) procedure efficiently designs proper solar system and deals with intermittency of solar energy, reduces CO₂ footprint, maximizes profit, and minimizes operational cost of generators at the same time.     

An energy matching method for battery electric vehicle and hydrogen fuel cell vehicle based on source energy consumption rate

The smart cities development requires reducing energy consumption and using as much renewable energy as possible, so the widespread use of new energy vehicles is a very important measure. In this work, for the energy system configuration and energy efficiency balance of new energy vehicles, we propose an energy matching method to study its energy efficiency from the view point for energy life cycle. Nowadays, new energy vehicles mainly include battery electric vehicles (BEV) and hydrogen fuel cell vehicles (HFCEV). Firstly, we proposed the Source to Range (STR) model. Then, based on STR model, we used energy efficiency analysis chart to visually represent the conversion, delivery and consumption of the vehicle energy life cycle. Furthermore, we proposed a Source Energy Consumption Rate (SECR), which is used to evaluate the vehicles energy efficiency. Finally, based on STR model, we obtained the dividing line of the same SECR for new energy vehicles and equivalent fuel vehicles, which provides constraints on the vehicle energy system design. The results show that STR model can provide an effective tool for energy matching and energy efficiency analysis of new energy vehicles, and has a reference for product development of new energy vehicles.     

A techno-economic evaluation of the hydrogen production for energy generation using an ethanol fuel processor

The techno-economic analysis of a process to convert ethanol into H₂ to be used as a fuel for PEM fuel cells of H₂-powered cars was done. A plant for H₂ production was simulated using experimental results obtained on monolith reactors for ethanol steam reforming and WGS steps. The steam reforming (Rh/CeSiO₂) and WGS (Pt/ZrO₂) monolith catalysts remained quite stable during long-term startup/shut down cycles, with no carbon deposition. The H₂ production cost was significantly affected by the ethanol price. The monolith catalyst costs contribution was lower than that of conventional reactors. The H₂ production cost obtained using the expensive Brazilian ethanol price (0.81 US$/L ethanol) was US$ 8.87/kg H₂, which is lower than the current market prices (US$ 13.44/kg H₂) practiced at H₂ refueling stations in California. This result showed that this process is economically feasible to provide H₂ as a fuel for H₂-powered cars at competitive costs in refueling stations.     

Improvement in energy recovery from Chlorella sp. biomass by integrated dark-photo biohydrogen production and dark fermentation-anaerobic digestion processes

Chlorella sp. biomass was used as the sole substrate for the production of hydrogen and methane through integrated dark fermentation (DF) and photo-fermentation (PF), and DF and anaerobic digestion (AD) processes. Prior to use in fermentations, the biomass was pretreated by acid-hydrothermal method, which yielded a maximum reducing sugar yield of 162.9 ± 4.2 mg g-biomass⁻¹. The use of the microalgal hydrolysate to produce hydrogen by DF gave a hydrogen yield (HY) of 47.2 ± 1.1 mL g-volatile-solids⁻¹ (VS). The subsequent use of the hydrogenic effluent in PF gave a HY of 125.0 ± 1.5 mL g-VS⁻¹, while AD of the hydrogenic effluent gave a methane yield of 152.8 ± 1.3 mL g-VS⁻¹. The total energy yield attained by the use of DF alone, the integrated DF-PF, and DF-AD processes were 0.51, 1.86 and 5.98 kJ g-VS⁻¹, respectively. These results indicate that the integrated DF-AD process was effective in recovering energy from Chlorella sp. biomass. However, an energy balance analysis indicated that the process was not energetically feasible due to the high energy demand for the acid-hydrothermal pretreatment.     

Synergistic effects of advanced oxidization reactions in a combination of TiO2 photocatalysis for hydrogen production and wastewater treatment applications

In this paper, the synergistic effects of advanced oxidization reactions in a combination of TiO₂ photocatalysis are comparatively investigated for hydrogen production and wastewater treatment applications. An experimental study is conducted with a photoelectrochemical reactor under a UV-light source. TiO₂ is selected as the photocatalyst due to the high corrosion resistant nature and ability to form hydroxyl radicals with the interaction with photons. The synergetic effects of advanced oxidization processes (AOPs) such as Fenton, Fenton-like, photocatalysis (TiO₂/UV) and UV photolysis (H₂O₂/UV) are investigated individually and in a combination of each other. The Fenton type reagent in the reactor is formed by anodic sacrificial of stainless-steel electrode with the presence of H₂O₂. The influences of various parameters, including pH level, type of the electrode and electrolyte and the UV light, on the performance of the combined system are also investigated experimentally. The highest chemical oxygen demand (COD) removal efficiency is observed as 97.9% for the experimental condition which combines UV/TiO₂, UV/H₂O₂ and photo-electro Fenton type processes. The maximum hydrogen production rate from the photoelectrolysis of wastewater is obtained as 7.0 mg/Wh for the experimental condition which has the highest rate of photo-electro Fenton type processes. The average enhancement with the presence of UV light on hydrogen production rates and COD removal efficiencies are further calculated to be 3% and 20%, respectively.     

概念辨析：建筑评论的思辨实践

建筑评论是一项针对具体对象,将目之所及的事物背后不可视的背景、思想、价值判断、驱动力等,转化为可以言说、可以讨论、具有建筑学和文化社会意义的思辨性活动。[1]这项活动的基础工作之一是概念的辨析与运用。因此,在东南大学建筑学院开设的"建筑评论课",通过课程主题的组织,在帮助学生建立多维批评视野的同时,以概念辨析为切入点,通过基于精读、研究的写作训练,实现思辨性思维的培养、学术素养和写作的培训,以及对建筑评论和中国现当代建筑话语的理解。     

European urban culture,Javier de Mesones-Cabello’s planning practice and its legacy in city of Valladolid

Javier de Mesones-Cabello was an influential and active planner of the 1960s and 1970s in Spain, who passed away in December, 2016. His professional career as a self-taught urban planner was extensively linked to his academic and institutional activities. These connections supported the establishment of relationships with prestigious professionals working in urban planning practice. In planning the 1969 masterplan for the city of Valladolid, in Spain, de Mesones-Cabello made several intellectual references to the Greek urban planner Doxiadis. This masterplan covers a relatively unknown example of directional city growth in a European context. My findings elucidate the extent to which de Mesones-Cabello was influenced by Doxiadis, and the circumstances in which these ideas have continued to dominate thinking about Valladolid's urban development.     

Perceived density,a further attribute of color,revealed by the colors favored in Japan

Colors can be characterized by three main attributes: hue, value, and saturation. But colors also exhibit other phenomenological qualities. In this study, we identify one such secondary attribute of color: perceived density. We discuss the prevalence of dense colors in Japan starting from the “48 Teas and 100 Mice” colors of the Edo period, and develop the concept of perceived density through this aspect of Japanese color preference. When vivid colors were forbidden to commoners during the Edo period, subtle variations of brownish and grayish colors were created. These colors with base tones were not salient, yet they looked dense. Muted colors with paradoxical richness are still common in Japan today. Japanese commodity design often uses muddy colors with white or gray undertones, and deep colors with black undertones. Together they form distinct groupings of relatively dense color. The perceived density of color corresponds to how dense and filled, or thin and airy a color appears. Colors of higher perceived density appear to be more packed and to have mass. Perceived density of color is unusual in that it does not have a monotonic relationship with one of the primary perceptual attributes. High apparent density is observed in a central region of an equi‐hue plane where value or saturation are at intermediate values. We consider two possible explanations of how high values of density can coincide with middling values of value and saturation: characteristics of the spectral reflectance curves, or the complexity of the neural signals that underlie the emergent property.     

Content and diffusion of water and gases in MgAl2O4 spinel crystals synthesized to produce ceramics

Content, evolution and diffusion characteristics of water and gases in fine-crystalline spinel MgAl₂O₄ were studied by kinetic thermodesoption mass spectrometry. Water is the main volatile component by quantity in the spinel structure. From the spinel crystals with an average size of 0.52 μm, water is released in vacuum in three temperature ranges: at 100–200 °C due to desorption from micropores, at 300–600 °C due to near-surface dehydroxylation and at 500–800 °C due to diffusion of water from the crystal bulk. The content of structural water, diffusively released from the crystals, is about 3000 ppm. The coefficients and activation energy of diffusion of water from spinel crystals in the range 500–700 °C were calculated. This allows us to estimate at any temperature the degassing time of the spinel with a certain degree of dispersion and ceramics made of it, and thereby promote the production of high-quality ceramics.     

Effects of Sr2+ substitution on the crystal structure,Raman spectra,bond valence and microwave dielectric properties of Ba3-xSrx(VO4)2 solid solutions

The effects of Sr²⁺ substitution for Ba²⁺ on microwave dielectric properties and crystal structure of Ba_3-xSr_x(VO₄)₂ (0 ≤ x ≤ 3, BSVO) solid solution were investigated. Such Sr²⁺ substitution contributes to significant reduction in sintering temperature from 1400 °C to 1150 °C. Both permittivity (∑_r) and quality factor (Q × f) values decreased with increasing x value, which was determined to be related with the descending values of average polarizability and packing fraction, whereas the increase in τ_f value was explained by the decreased average VO bond length, A-site bond valence. BSVO ceramics possessed encouraging dielectric performances with ∑_r = 12.2–15.6 ± 0.1, Q × f = 44,340 - 62,000 ± 800 GHz, and τ_f = 24.5–64.5 ± 0.2 ppm/°C. Low-temperature sintering was manipulated by adding B₂O₃ as sintering additive for the representative Sr₃V₂O₈ (SVO) ceramic and only 1 wt.% B₂O₃ addition successfully contributed to a 21.7% decrease in sintering temperature to 900 °C, showing good chemical compatibility with silver electrodes, which render BSVO series and SVO ceramics potential candidates in multilayer electronic devices fabrication.