Power-to-Gas integration in the Transition towards Future Urban Energy Systems

Temperature levels play a key role in the thermal energy demand of urban contexts affecting their associated primary energy consumption and Renewable Energy Fraction. A Smart Heating strategy accounts for those supply features requiring new solutions to be effectively renewable and to solve the RES capacity firming. Power-to-Gas (P2G) is the way to decarbonize the energy supply chain as fraction of Hybrid fuels, combination of fossil ones and Renewable Hydrogen, as immediate responsive storage solution. While, Power-To-Heat is conceived as the strategy to modernize the high and medium temperature heating systems by electricity-driven machines to switch from Fuel-to-Heat to Electricity-to-Heat solutions. The authors investigated on different urban energy scenarios at RES share increase from 25% up to 50% in the energy mix to highlight strengths and weaknesses of the P2G applications. Primary Energy Consumption was chosen as the objective function. Three Reference Cities were chosen as reference scenarios. Moreover, the analytical models of P2G was designed and implemented in the reference energy system. The results of the twelve scenarios, four for each Reference City were evaluated in terms of amount of Renewable Heat delivered. Finally, the interaction between P2G and renewable heat production was evaluated.     

S-Zorb吸附剂及其工艺进展

降低燃料油的硫含量是有效控制汽车尾气污染的重要途径之一。常用的燃料油脱硫技术有加氢和非加氢两类,而吸附脱硫是非加氢脱硫的重要方式。S-Zorb工艺是第一种用于燃料油吸附脱硫的工业技术。S-Zorb技术采用的吸附剂由载体和活性组分组成,其中载体主要由氧化铝、氧化硅、氧化铁、氧化钛、氧化钙中的二种或二种以上组成,活性组分一般由氧化锌与一种或几种活性金属组成,最常用的活性金属为0价镍或钴。S-Zorb吸附剂在使用过程中采用与FCC工艺类似的连续流化再生技术进行再生。中国石化于2007年独家买断了S-Zorb成套技术,并根据应用中出现的问题,从设备和工艺上对该技术进行了改进。目前,中国石化已经有9套S-Zorb装置投入运行,用于生产硫含量低于10μg/g的汽油。在S-Zorb装置运行过程中,硅酸锌或其他不可再生锌盐的生成是导致吸附剂失活或活性降低的重要原因。S-Zorb工艺改进的重点在于不断开发S穿透量更高和稳定性更好的吸附剂。     

Corrosion of aluminium,stainless steels and AISI 680 nickel alloy in nitrogen‐based fuels

Nitrogen‐based compounds can potentially be used as alternative non‐carbon or low‐carbon fuels. Nevertheless, the corrosion of construction materials at high temperatures and pressures in the presence of such fuel has not been reported yet. This work is focused on the corrosion of AISI Al 6061, 1005 carbon steel (CS), 304, 316L, 310 austenitic stainless steels (SS) and 680 nickel alloy in highly concentrated water solution of ammonium nitrate and urea (ANU). The corrosion at 50 °C and ambient pressure and at 350 °C and 20 bar was investigated to simulate storage and working conditions. Sodium chloride was added to the fuel (0–5 wt%) to simulate industrial fertilizers and accelerated corrosion environment. Heavy corrosion of CS was observed in ANU solution at 50 °C, while Al 6061, 304 and 316L SS showed high resistance both to uniform and pitting corrosion in ANU containing 1% of sodium chloride. Addition of 5% sodium chloride caused pitting of Al 6061 but had no influence on the corrosion of SS. Tests in ANU at 350 °C and 20 bar showed pitting on SS 304 and 316L and 680 nickel alloy. The highest corrosion resistance was found for SS 310 due to formation of stable oxide film on its surface.     

Throwing New Light on the Reduction of CO2

While the chemical energy in fossil fuels has enabled the rapid rise of modern civilization, their utilization and accompanying anthropogenic CO₂ emissions is occurring at a rate that is outpacing nature's carbon cycle. Its effect is now considered to be irreversible and this could lead to the demise of human society. This is a complex issue without a single solution, yet from the burgeoning global research activity and development in the field of CO₂ capture and utilization, there is light at the end of the tunnel. In this article a couple of recent advances are illuminated. Attention is focused on the discovery of gas‐phase, light‐assisted heterogeneous catalytic materials and processes for CO₂ photoreduction that operate at sufficiently high rates and conversion efficiencies, and under mild conditions, to open a new pathway for an energy transition from today's “fossil fuel economy” to a new and sustainable “CO₂ economy”. Whichever of the competing CO₂ capture and utilization approaches proves to be the best way forward for the development of a future CO₂‐based solar fuels economy, hopefully this can occur in a period short enough to circumvent the predicted adverse consequences of greenhouse gas climate change.     

Effect of methanol gasoline blended fuels on the performance and emissions of SI engine

This article presents experimental results of the effect of methanol gasoline blends as alternate fuels for the spark ignition (SI) engine. As the cost of the gasoline is periodically increasing the quest for the alternative fuels are evolved with which the emissions are reduced along with improved engine performance. A set of experiments have been conducted to investigate the effect of gasoline methanol blends in methanol percentages of M5, M10 and M15 on the engine performance and emissions. A significant reduction in emissions is observed with methanol blends compared to the standard gasoline with improved engine performance and emission characteristics. The fuels blends ranging from M10 to M15 have been found suitable for reduced emissions and improved engine performance.     

Measurement of thermal conductivity,viscosity and density of ionic liquid [EMIM][DEP]-based nanofluids☆

This article studied experimentally the effect of multi-wall carbon nanotubes(MWCNTs)on the thermo physical properties of ionic liquid-based nanofluids.The nanofluids were composed of ionic liquid,1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP],or its aqueous solution[EMIM][DEP](1)+ H_2O(2)and MWCNTs without any surfactants.The thermal conductivity,viscosity and density of the nanofluids were measured experimentally.The effects of the mass fraction of MWCNTs,temperature and the mole fraction of water on the thermo physical properties of nanofluids were studied.Results show that the thermal conductivity of nanofluids increases within the range of 1.3%–9.7% compared to their base liquids,and have a well linear dependence on temperature.The viscosity and density of the nanofluids exhibit a remarkable increase compared with those of the base liquids.Finally,the correlation of the effective thermal conductivity and viscosity of the nanofluids was made using the models in the literatures.     

New quaternary additive for processing fully ceramic microencapsulated fuels without applied pressure

To apply SiC ceramics as a matrix for fully ceramic microencapsulated (FCM) fuels, the equivalent boron content (EBC) factors of elements in the sintering additives should be considered as an important criterion. A previously developed quaternary additive composition based on AlN–Y₂O₃–Sc₂O₃–MgO contained Sc, which has a relatively high EBC factor (8.56 × 10^?3). This study proposes a novel quaternary additive composition (AlN–Y₂O₃–CeO₂–MgO), in which Sc is replaced by Ce (EBC factor = 6.36 × 10^-5). The new additive composition achieved successful densification of the SiC matrix at 1850 °C without applied pressure. FCM pellets containing 36 vol% tristructural isotropic (TRISO) particles were successfully sintered at 1850 °C using the above matrix without applied pressure. The thermal conductivities of the FCM pellets prepared via pressureless sintering with 36 vol% TRISO particles were 43.9 W·m^-1·K^-1 and 25.8 W·m^-1·K^-1 at 25 °C and 500 °C, respectively.     

Role of nanoparticles on nanofluid boiling phenomenon: Nanoparticle deposition

Suspended nanoparticles inside the nanofluids can modify the characteristics of heated surfaces and the physical properties of the base liquids, offering a great opportunity to optimize boiling heat transfer. This paper reviews the mechanisms of nanoparticle deposition and the effects induced by deposited nanoparticles on surface roughness, force balance at the triple line, surface wettability, active nucleation site density, receding and advancing contact angles, boiling heat transfer coefficient and critical heat flux. Both enhancement and deterioration effects on boiling heat transfer coefficient and critical heat flux have been discussed. Most of the existing experimental data confirms the enhancement of critical heat flux using alumina nanofluid, however there is no consistency about its boiling heat transfer coefficient.