The effect of urea pretreatment on the formaldehyde emission and properties of straw particleboard

For manufacturing low-formaldehyde emission particleboard from wheat straw and urea-formaldehyde （UF） resins using urea treatment for indoor environments, we investigated the influence of urea treatment on the formaldehyde emission, physical and mechanical properties of the manufactured particleboard. Wheat straws were treated at three levels of urea concentration （5%, 10%, 15%） and 95℃ as holding temperature. Wheat straw particleboards were manufactured using hot press at 180℃ and 3 MPa with two types of UF adhesive （UF-45, UF-91）. Then the formaldehyde emission values, physical properties and mechanical properties were considered. The results show that the for- maldehyde emission value was decreased by increasing urea concentration. Furthermore, the results indicate that the specimens under urea treatment have better mechanical and physical properties compared with control specimens. Also specimens under urea treatment at 10% concentration and UF-91 type adhesive have the most optimum physical and mechanical strength.

Scenario analysis for the energy demand and carbon emissions in low carbon city

This paper takes the climate change and low carbon economy development as the study background, based on the analysis of energy demand and carbon emissions status, which is aimed to provide the low carbon development path in Chinese cities. The method of scenario analysis can be used to predict long-term strategy for the uncertainty future development, and it was introduced to the field of social forecasting and public policy research, such as the environmental strategic planning, policy analysis, and support of decision in resource management, which can be used to explore the possible development trend and target of the results from the macro perspective. Scenario analysis has been gradually applied to the study area on low carbon economy, energy forecasting and other fields in recent years, and there have been many research results in different aspects. This paper takes the scenario analysis as basic study theory, spreading out the present situation of its application in low carbon city and some issues that need further study. As a tool for predicting the future development in low carbon city, the method of scenario analysis has been providing a powerful reference for policies and their executants.

Realizing Low Carbon Emission in the University Campus towards Energy Sustainability

Energy consumption increases with intensity of human activities. People consume energy for movement and other activities and the more fossil-fuel based energy used, the more carbon dioxide (CO2) emission. Since carbon dioxide is the major element of the greenhouse gases (GHG), this phenomenon has a serious implication for global warming and consequent climate change—a scenario that calls for sustainable development. This research considers the emission of CO2 from energy use within the campus of Universiti Teknologi Malaysia. Two major sources of energy consumption were identified, namely: electricity and transport. The emission for electricity was estimated based on electricity meter reading and the conversion rate in accordance with the stand-ardized conversion factors for fuel mix of the purchased electric energy as given by PTM (Pusat Tenaga Malaysia), while the associated CO2 emission for transport was estimated based on the number of miles driven (VMT—Vehicle Miles Travel) within the campus, emissions produced per litre of gasoline, and fuel economy of vehicles plying the campus in line with the Code of Federal Regulations USEPA and consistent with the Inter-governmental Panel on Climate Change (IPCC) guidelines. It was observed that high CO2 emission resulted from electricity energy consumption, and the highest emission in the transport sector was produced by commuting vehicles while emission from service delivery for cooling, lighting and other equipment was similar to national average.

Evaluation of formaldehyde emission from particleboard using the large chamber and desiccator method at various loading ratios

We studied formaldehyde emission from uncoated particleboard with 16-mm thickness using the large chamber and the desiccator method. A chamber of 28.4 m3 was installed to simulate a mobile home. The formaldehyde off-gassing properties of particleboard were evaluated using the chamber. The relationship between the concentration obtained by the chamber and the values by the desiccator test was discussed in this study under different conditions of conditioning day, air exchange, and loading ratio. These two methods were compared and discussed regarding the formaldehyde emission level. Three loading ratios, 0.429 m2/m3, 0.264 m2/m3, and 0.132 m2/m3, were chosen to represent different applications of particleboard products. There was strong correlation between emissions and air exchange rates at equal product-loading ratios in the large chamber, the related coefficient R 2 exceeded 0.90. There was also an indication of a generic correlation between the large chamber and the two-hour desiccator test with a single product designated loading ratio, air exchange rate, and climatic conditions.

CO2 emission driving forces and corresponding mitigation strategies under low-carbon economy mode:evidence from China's Beijing-Tianjin-Hebei region

On account of the background of China's "new normal" characterized by slower economic growth, this paper analyses the low-carbon economy status quo in the Beijing-Tianjin-Hebei region and empirically investigates the relationship between carbon dioxide(CO_2) emissions and its various factors for China's Beijing-Tianjin-Hebei region using panel data econometric technique. We find evidence of existence of Environmental Kuznets Curve. Results also show that economic scale, industrial structure, and urbanization rate are crucial factors to promote CO_2emissions. However, technological progress, especially the domestic independent research and development, plays a key role in C0_2 emissions abatement. Next, we further analyze the correlation between each subregion and various factors according to Grey Relation Analysis. Thereby,our findings provide important implications for policymakers in air pollution control and C0_2 emissions reduction for this region.

Effects of formaldehyde on fermentable sugars production in the low-cost pretreatment of corn stalk based on ionic liquids

Low cost processing of lignocellulosic biomass is of great importance for sustainable chemistry and engineering.Herein,a low cost system composed of 1-butyl-3-methylimidazolium chloride([C_(4)C_(1) im]Cl),HCl and formaldehyde(FA)was developed for the pretreatment of corn stalk at 80℃.The efficiency of this technology was compared with that in dioxane system or without FA addition.Due to FA stabilization,the extent of acid-hydrolysis of carbohydrate fraction can be significantly decreased while 70%above of lignin was removed with the pretreatment of[C_(4)C_(1) im]Cl/HCl/FA system at 80℃for 2 h.A maximum reducing sugar yield of 93.7%and glucose concentration of 7.0 mg·ml^(-1) were subsequently obtained from enzymatic hydrolysis of the slurry.There were great differences in compositions of small molecule degraded products obtained with FA addition or not.The present[C_(4)C_(1) im]C_(l) based system exhibits great potential of substituting volatile organic solvents(i.e.dioxane)in developing low cost lignocellulosic biomass pretreatment at low temperature.Also,this work would gain insight into understanding on the roles of stabilization methods on the economic improvement of IL based biomass processing.

Evaluation of the Implementation of a Low Emission Zone in Lisbon

The city of Lisbon, like many others in the EU region, introduced a Low Emission Zone (LEZ) as a tool for improving air quality in its city centre. This kind of emission reduction schemes is always controversial since it might lead to significant changes in the daily behaviours of its inhabitants. In order to evaluate the effects of the measure, an estimation of the impact of the introduction of the Lisbon LEZ was performed. Real traffic counting and fleet characterization combined with CORINAR-based emission inventory methodology allowed to estimate the impacts of three different scenarios applied to the “business as usual” condition (current vehicle fleet) ranging from “no circulation from non- compliant vehicles” to an “aggressive fleet renewal”. Results highlight the high percentage of atmospheric emissions of PM10 and NOx that might result from certain fleets like taxis and buses, especially because there was an emphasis in standardized/normalized estimations (emissions per 1000 vehicles) in order to allow different strategic approaches. The total reduction of PM10 emissions associated to each scenario vary between 6 ton.year-1 (scenario 2) and 8 ton.year-1 (scenario 1), or 25% and 34% less emissions. In terms of NOxemission reductions vary between 6 ton.year-1 (scenario 2) and 57 ton.year-1 (scenario 1), or 1% and 7% less emissions. The Lisbon LEZ is therefore much more efficient in reducing PM10 emissions compared to NOx. Major reduction in PM10 and NOx emissions are to be expected with a moderate intervention in the (relatively old) taxi fleet in Lisbon while for passenger cars the impact is limited. However in absolute terms and due to its urban mileage passenger cars should also continue being included in Lisbon LEZ. Simultaneously, an effort in the increase of dedicated lanes for public transport should be made, for further reductions in PM10 and NOx emissions.

MAGNETIC ACOUSTIC EMISSION CHARACTERISTICS OF HYDROGEN ATTACKED LOW CARBON STEEL

Hydrogen attack occurred in low carbon steel and steel 25CrMo which had been exposed in hydrogen under 18MPa at 450 and 500℃ for 240,480 and 720 h.The methane bubbles and microcracks grow along grain boundaries.The degree of hydrogen attack increases with increasing exposure time and temperature.Magnetic acoustic emission(MAE) was used to detect the degree of hydrogen attack.The results show that the characteristics of MAE for samples of low carbon steel and steel 15CrMo with hydrogen attack have changed obviously comparing to the samples without hydrogen attack,and the MAE signals was sensitive to the degree of hydrogen attack at the last stage of hydrogen attack.The magnetic detection way,as a new method of nonrestrictive testing of hydrogen attack,can be used to detect the hydrogen attack in practice.

Excitation of extremely low-frequency chorus emissions: The role of background plasma density

Low-frequency chorus emissions have recently attracted much attention due to the suggestion that they may play important roles in the dynamics of the Van Allen Belts.However, the mechanism(s) generating these low-frequency chorus emissions have not been well understood..In this letter, we report an interesting case in which background plasma density lowered the lower cutoff frequency of chorus emissions from above 0.1 f_(ce)(typical ordinary chorus) to 0.02 f_(ce)(extremely low-frequency chorus).Those extremely low-frequency chorus waves were observed in a rather dense plasma, where the number density N_e was found to be several times larger than has been associated with observations of ordinary chorus waves.For suprathermal electrons whose free energy is supplied by anisotropic temperatures, linear growth rates(calculated using in-situ plasma parameters measured by the Van Allen Probes) show that whistler mode instability can occur at frequencies below 0.1 f_(ce) when the background plasma density N_e increases.Especially when N_e reaches 90 cm–3 or more, the lowest unstable frequency can extend to 0.02 f_(ce) or even less, which is consistent with satellite observations.Therefore, our results demonstrate that a dense background plasma could play an essential role in the excitation of extremely lowfrequency chorus waves by controlling the wave growth rates.

Implement of Low Carbon Logistics Park Based on Minimizing Carbon Emissions

Based on the development of modem logistics park in China, and with the thought of minimizing carbon emission, the development of Logistics Park was analyzed and the necessity of developing low carbon Logistics Park was proposed. Low carbon emission in Logistics Park was planned. In the end, operation and implementation strategies of low carbon parks were put forward so as to create favorable environment for the re- alization of low carbon emission in Logistics Park.

Optimization and Regulation Policy for Land Use Changes Based on Low-carbon Emission in Developed Regions of China

Land use and cover change(LUCC) is one of the important causes of the Earth’s carbon cycle imbalances resulting from failure in optimizing land use. The solution to this problem has been the hotspot of research in land and environmental science. We took 'low carbon', 'energy saving' and 'high-efficiency' as the goals of land use optimization,and integrated Markov-CA(Cellular Automaton),the Grid-Fractal model and GIS,in order to study carbon emission objective function,to establish a simulation method for land use spatial allocation optimization,to evaluate the effect of the method on carbon emissions. Regulation policy on three types of land use spatial allocation was proposed,including 'low-carbon type', 'low-carbon-economic type' and 'economic type'. We applied the method to analyze the land use spatial allocation in Taixing City of the 'Yangtze River Delta' regions in China,and obtained the following results:(i) The three optimization types would improve carbon emissions by 3. 21%,1. 80% and 0. 36% respectively in 2020,compared with 2010;(ii) The actual planning for 2020 was close to the 'low-carbon-economic type';(iii) The optimization method and regulation policy,combining local optimization and global control,could meet the sustainable multi-objective requirements for low-carbon constraints of land use spatial allocation. The result of this research could also serve as a reference for exploration into patterns of regional low-carbon land use and measures for energy saving and emission reduction.

No-catalyst growth of vertically-aligned AlN nanocone field electron emitter arrays with high emission performance at low temperature

The A1N nanostructures with a wide band-gap of 6.28 eV are considered as ideal cold cathode materials because of their low electron-affinity. Many methods have been devoted to fabricating A1N nanostructures, but high growth temperature over 800℃ and the use of the catalysts in most methods limit their practical application and result in their poor field-emission behaviours in uniformity. This paper reports that without any catalysts, a simple chemical vapour deposition method is used to synthesize aligned A1N nanocone arrays at 550℃ on silicon substrate or indium tin oxide glass. Field emission measurements show that these nanocones prepared at low temperature have an average turn-on field of 6 V/μm and a threshold field of 11.7 V/μm as well as stable emission behaviours at high field, which suggests that they have promising applications in field emission area.

Continuous Emission Spectrum Measurement for Electron Temperature Determination in Low-Temperature Collisional Plasmas

Continuous emission spectrum measurement is applied for the inconvenient diagnos- tics of low-temperature collisional plasmas. According to the physical mechanism of continuous emission, a simplified model is presented to analyze the spectrum in low temperature plasma. The validity of this model is discussed in a wide range of discharge parameters, including electron tem- perature and ionization degree. Through the simplified model, the continuous emission spectrum in a collisional argon internal inductively coupled plasma is experimentally measured to determine the electron temperature distribution for different gas pressures and radio-frequency powers. The inverse Abel transform is also applied for a better spatially resoluted results. Meanwhile, the result of the continuous emission spectrum measurement is compared to that of the electrostatic double probes, which indicates the effectiveness of this method.

Coking and decoking chemistry for resource utilization of polycyclic aromatic hydrocarbons(PAHs)and low-carbon process

Low-carbon process for resource utilization of polycyclic aromatic hydrocarbons(PAHs)in zeolitecatalyzed processes,geared to carbon neutrality-a prominent trend throughout human activities,has been bottlenecked by the lack of a complete mechanistic understanding of coking and decoking chemistry,involving the speciation and molecular evolution of PAHs,the plethora of which causes catalyst deactivation and forces regeneration,rendering significant CO_(2) emission.Herein,by exploiting the high-resolution matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry(MALDI FT-ICR MS),we unveil the missing fingerprints of the mechanistic pathways for both formation and decomposition of cross-linked cage-passing PAHs for SAPO-34-catalyzed,industrially relevant methanol-to-olefins(MTO)as a model reaction.Notable is the molecule-resolved symmetrical signature:their speciation originates exclusively from the direct coupling of in-cage hydrocarbon pool(HCP)species,whereas water-promoted decomposition of cage-passing PAHs initiates with selective cracking of inter-cage local structures at 8-rings followed by deep aromatic steam reforming.Molecular deciphering the reversibly dynamic evolution trajectory(fate)of full-spectrum aromatic hydrocarbons and fulfilling the real-time quantitative carbon resource footprints advance the fundamental knowledge of deactivation and regeneration phenomena(decay and recovery motifs of autocatalysis)and disclose the underlying mechanisms of especially the chemistry of coking and decoking in zeolite catalysis.The positive yet divergent roles of water in these two processes are disentangled.These unprecedented insights ultimately lead us to a steam regeneration strategy with valuable CO and H_(2) as main products,negligible CO_(2) emission in steam reforming and full catalyst activity recovery,which further proves feasible in other important chemical processes,promising to be a sustainable and potent approach that contributes to carbon-neutral chemical industry.

Low Carbon Building Design Optimization Based on Intelligent Energy Management System

The construction of relevant standards for building carbon emission assessment in China has just started,and the quantitative analysis method and evaluation system are still imperfect,which hinders the development of low-carbon building design.Therefore,the use of intelligent energy management system is very necessary.The purpose of this paper is to explore the design optimization of low-carbon buildings based on intelligent energy management systems.Based on the proposed quantitative method of building carbon emission,this paper establishes the quota theoretical system of building carbon emission analysis,and develops the quota based carbon emission calculation software.Smart energy management system is a low-carbon energy-saving system based on the reference of large-scale building energy-saving system and combined with energy consumption.It provides a fast and effective calculation tool for the quantitative evaluation of carbon emission of construction projects,so as to realize the carbon emission control and optimization in the early stage of architectural design and construction.On this basis,the evaluation,analysis and calculation method of building structure based on carbon reduction target is proposed,combined with the carbon emission quota management standard proposed in this paper.Taking small high-rise residential buildings as an example,this paper compares and analyzes different building structural systems from the perspectives of structural performance,economy and carbon emission level.It provides a reference for the design and evaluation of low-carbon building structures.The smart energy management system collects user energy use parameters.It uses time period and time sequence to obtain a large amount of data for analysis and integration,which provides users with intuitive energy consumption data.Compared with the traditional architectural design method,the industrialized construction method can save 589.22 megajoules(MJ)per square meter.Based on 29270 megajoules(MJ)per ton of standard coal,the construction area of the case is about 8000 m2,and the energy saving of residential buildings is 161.04 tons of standard coal.This research is of great significance in reducing the carbon emission intensity of buildings.

Re-understanding and Thinking about Environmental Impact of Coal-fired Power Plants under Ultra-low Emission

From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact assessment of ultra-low-emission thermal power projects were discussed from the aspects of evaluation criteria,evaluation grade and scope,pollution control technical lines,environmental benefit accounting,and total emission control,and corresponding recommendations were put forward.

Study on Carbon Emission Driving Factors and Low-carbon Policy of Transportation Industry in Henan Province

The transportation industry is the basic industry of national economic development. At the same time, it is the only industry in China that has continuously increased CO2 emissions, and the high energy consumption problems have not been solved. Henan province, as a major energy consumption province, it is urgent to improve the supply quality of transportation industry. The paper uses the IPCC calculation method for carbon emission to calculate the CO2 emissions of transportation industry in Henan province from 2004 to 2014. Then, this paper uses the LMDI method to decompose the CO2 emission in the transportation industry and give the proposal to reduce the CO2 emission according to the CO2 emission drivers.

Energy Emissions Profile and Floating Solar Mitigation Potential for a Malaysia’s State

The establishment of the National Low Carbon City Master Plan(NLCCM)by Malaysia’s government presents a significant opportunity to minimize carbon emissions at the subnational or local scales,while simultaneously fostering remarkable economic potential.However,the lack of data management and understanding of emissions at the subnational level are hindering effective climate policies and planning to achieve the nationally determined contribution and carbon neutrality goal.There is an urgent need for a subnational emission inventory to understand and manage subnational emissions,particularly that of the energy sector which contribute the biggest to Malaysia’s emission.This research aims to estimate carbon emissions for Selangor state in accordance with the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories(GPC),for stationary energy activities.The study also evaluates the mitigation potential of Floating Solar Photovoltaic(FSPV)proposed for Selangor.It was found that the total stationary energy emission for Selangor for the year 2019 was 18,070.16 ktCO2e,contributed the most by the Manufacturing sub-sector(40%),followed by the Commercial and Institutional sub-sector;with 82%contribution coming from the Scope 2 emission.The highest sub-sector of Scope 1 emissions was contributed by Manufacturing while Scope 2 emissions from the Commercial and Institutional.Additionally,the highest fuel consumed was natural gas,which amounted to 1404.32 ktCO2e(44%)of total emissions.The FSPV assessment showed the potential generation of 2.213 TWh per year,by only utilizing 10%of the identified available ponds and dams in Selangor,equivalent to an emission reduction of 1726.02 ktCO2e,offsetting 11.6%Scope 2 electricity emission.The results from the study can be used to better evaluate existing policies at the sub-national level,discover mitigation opportunities,and guide the creation of future policies.