竹格填料与PVC填料在冷却塔中的节能效率与环境影响研究

本研究针对电厂冷却塔领域的能源成本及水资源短缺等问题,系统分析了新兴竹格淋水填料的节能效率及对环境影响等特性,并与市场占有率最高的PVC填料进行了对比。结果发现,竹格填料的阻力性能优于PVC填料,而热力性能较差;在6个月实际应用试验中,使用竹格填料的电厂,比使用PVC填料节约529.2 t标煤;生命周期评价结果显示,PVC填料的能源需求总量(CED)为3420 MJ,竹格填料的能源需求总量仅为561 MJ,比PVC填料减少6倍;从环境影响指数(BEES)看,PVC填料替换为竹格填料后,各主要影响指标降低了1.5~10.5倍不等。结果表明,竹格填料是替换PVC填料的良好选择,具有很好的推广价值。

Recent advances in functional utilisation of environmentally friendly and recyclable high-performance green biocomposites: A review

Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.

Microplastics pollution:Economic loss and actions needed

Microplastics originate from plastic bottles of water and soft drink,plastic bags,tire wear,plastic agricultural mulches and 3D printing[1,2].These small fragments of wastes being 1μm to 5 mm pollute the environment and threaten human health and ecosystem services including crops and others,leading to economic losses[1–3].It is predicted that by 2030,plastic productions will be leading environmental pollution in terms of carbon footprint and toxic chemicals[4],making U.S.the world’s largest plastic waste generator[5].Based on reports from the United Nations Environment Assembly(UNEA)and the United Nations Environmental Program(UNEP),plastics in the environment annually burden the global economy by$19 billion,causing concerns for long-term ecological sustainability and the Global Goals[6].It is reported that about 8.3 billion tons of plastic waste have been created,leading to 4.9 billion tons discarded through landfilling globally[7],causing a yearly financial loss of more than$13 billion[8].

In-Situ Chemosynthesis of ZnO Nanoparticles to Endow Wood with Antibacterial and UV-Resistance Properties

Hybrid wood materials have attracted considerable attention because they have combined advantages of both wood and inorganic compounds. This work investigated the microstructural morphology, thermal stability, ultraviolet（UV） stability, and antibacterial property of composites made from wood/ZnO hybrid materials through a facile in-situ chemosynthesis methods. The X-ray diffraction（XRD） and thermogravimetric analysis（TGA） results indicated that the synthesized ZnO particles had an average grain size of about 10.8 nm. The scanning electron microscopy（SEM） observations showed that ZnO nanoflowers self-assembled with nanosheets were presented in wood cell lumens and increased with increasing Zn^（2＋）concentrations. ZnO nanoparticles were also generated in the wood cell wall, which was confirmed by the results of energy-dispersive spectroscopy（EDS）. The TGA tests also indicated that the thermal stability of wood/ZnO hybrid materials was improved after the formation of ZnO inorganic particles. Finally, the results of antibacterial efficacy tests and UV resistance tests revealed that ZnO nanoparticles showed a promising future as antimicrobial agents against Escherichia coli（E.coli） and UV resistance agents for wood protection.

Is engineered wood China’s way to carbon neutrality?

China emits more than 25%of the world’s carbon dioxide(https://ourworldindata.org/co2-emissions),and in December 2021 the country’s daily carbon trading volume hits a new highest record.Together with the EU and USA,China bears a great responsibility to limit global warming to 2℃,and therefore recently launches a plan to be carbon-neutral be-fore 2060(https://ourworldindata.org/co2-emissions).However,its rapid urbanization challenges this initiative as the boom-ing building and construction industry constitute more than 1/3 of the total energy consumption,which undesirably in-creases carbon emissions(IEA,2019;Duan et al.,2021).Although China has built five new nuclear power stations and closed down more than 1000 coal-fired power plants,it is still highly insufficient to meet the country’s goal to be carbon-neutral(https://climateactiontracker.org/countries/china/).

Plastic crisis underscores need for alternative sustainable-renewable materials

The current global plastic crisis is triggered by several factors including increased costs of petrochemical feedstock and Covid-19 disruption of the transport sector(Yuan et al.,2021).This disruption of world-wide supply chains of polyethylene,polypropylene and other petroleum-based hydrocarbon chemicals has significantly increased shortage and prices of plastics in for example Europe over the last year,hence calling for sustainable alternatives to conventional plastics(WMW,2021,European Plastic Manufacturers sound the Alarm Bell on Supply Chain Disruption,Waste Management World.).This is critical due to extensive use of the non-biodegradable personal protective equipment(PPE)masks in the current pandemic,which might be even worse than the shortage of polyolefins at the moment(Deng et al.,2022).

Microwave torrefaction of empty fruit bunch pellet:Simulation and validation of electric field and temperature distribution

Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly.This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity.The simulation results were compared with the experimental findings us-ing the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass(empty fruit bunch pellets).The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor,showing the uniqueness of microwave heating.According to the simula-tion results,the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile.The simulated temperature profile demonstrated a logarithmic increase of 120°C/min at the first 50 s followed by 50°C/min until 350 s.The experimental temperature profile showed three different heating rates before reaching 300°C,including 78.3°C/min(50-120°C),30.6°C/min(121-250°C),and 105°C/min(250-300°C).The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.

Ban fluorinated organic substances to spark green alternatives

Per-and polyfluoroalkyl substances(PFAS)do not readily biodegrade and are therefore routinely found in the environment as ubiquitous contaminants in wildlife and humans worldwide[1,2].These“forever chemicals”are among the major chemical threats to wildlife and human health nowadays and are used in consumer products,including waterproof rain wear,pizza boxes,Teflon,and firefighting foam[3,4].Due to their resistance to metabolism and excretion biomagnifying in food webs to high concentrations[5,6],PFAS can bind to proteins and affect the immune system that increase the risk of clinical and infectious diseases and autoimmunity[7–9].

Nucleophilic amino acids as a renewable alternative to petrochemically-derived amines in glycerol epoxy resins

The standard epoxy resin curing agents revealed are from unsustainable petroleum-based sources,which produce poisonous exhaust when cured.Amino acids,a bio-based epoxy curing agent with amino and carboxyl groups,are another potential curing agent.Water-soluble epoxy resins cured with lysine(Lys),glutamic acid(Glu),leucine(Leu),and serine(Ser)as amino acids were inves-tigated.The results showed that the water-soluble epoxy resin(glycerol epoxy resins,GER)was cured with Lys and Glu after reacting.Fourier transform infrared(FT-IR)spectroscopic analysis of the GER-Lys showed that the amino and carboxyl groups of Lys primarily reacted with the epoxy groups of GER.The elongation at break of Lys-cured GER(GER-Lys)cured at 70℃ with a molar ratio of 1꞉0.75 was 75.32%.The fact that elongations at break of GER-Lys(79.43%)were higher than those of GER-Glu(17.33%),respectively supports the decrease of crosslinking density by the amino acid-cured GER reaction.The potential of Lys and Glu alternatives for petrochemical amines is demonstrated and provides promising opportunities for industrial application.