金属盐催化生物质热解动力学特性研究

在论述国内外生物质热解技术研究进展的基础上,就金属盐对生物质的催化热解展开动力学研究。以秸秆、稻壳和稻草为原料,利用热重分析仪等实验设备进行热解实验,即在对典型的生物质及生物质和金属盐的混合物进行热解特性实验研究的基础上,分析反应速率与各项物理因素（如金属盐种类、浓度、升温速率等）之间的关系。实验结果表明,金属盐对生物...     

生物质在固定床中的热解试验研究

介绍了用于生物质热解的试验装置及试验方法，研究了升温速率、热解温度两种关键因素对生物质热解产物得率及其分桕的影响。研究结果表明，随热解温度的升高，热解产气量增加，且其中气体产品中的有效成分也在增加，焦油和半焦减少；升温速率增加，热解气得率增加，且气体中有效可燃成分增加。     

废轮胎等离子体热解固体产物性质研究

等离子体热解废弃轮胎的产物包括可燃气、固体产物两部分,本文利用工业分析、元素分析、SEM扫描、XPS表面分析、NMR分析等手段考察了等离子体热解固体产物的特性,并与轮胎工业用碳黑做了对比研究。研究结果表明,废轮胎等离子体热解固体产物可作为热解碳黑进行回收利用。     

适于区域生物质特性的生物质气化技术的研究进展

基于我国生物质综合利用行业发展现状分析,进行生物质发电、生物沼气、生物质成型燃料以及生物液体燃料的市场发展前景和技术发展趋势的综合比较,进而聚焦于生物质气化技术,梳理出其主体发展路线研究进展,结合区域生物质特性,总结出最适于当地生物质特性的生物质气化发展技术,从而进一步推进生物质能行业发展和技术开发。     

含油污泥资源化技术研究进展＊

含油污泥资源化技术的研究,应该重视多种热源热解技术开发,包括微波热解技术的研究。文章着重对含油污泥热解技术的研究进行了总结,包括微波热解技术的进展情况。研究得出:热解技术有望在固体废物处置及其资源化、有机质热解作低碳能源等方面发挥越来越重要的作用。开展含油污泥资源化研究,对解决我国国民经济持续发展过程中面临的能源短缺和环境挑战问题具有重要意义。     

污水污泥低温催化热解实验研究

在实验室研究了不同热解温度下,经污泥低温热解残留物催化作用,污泥低温催化热解产物的产率及特性。结果表明,与无催化剂相比,污泥低温热解所得的液体产率、油品产率、气体产率等明显增加。油品最大产率所需温度从440℃降低至400℃,油品最大产率从20.5%增加到24.5%,油品的品质有一定的提高。     

油田含油污泥与芦苇共热解实验研究

以北方某油田湿地芦苇与油田某污水处理厂剩余污泥为对象,利用同步热分析仪及静态热解炉研究油田含油污泥及含油污泥-芦苇混合物的热解特性,将静态热解过程数据与同步热分析TG(热重分析)、DTG(微分热重分析)、DSC(差示扫描量热分析)曲线结合,计算了终止温度、产物量等。结果表明:不同含油污泥样品其产物生成率差别不大,热解TG、DTG和DSC曲线有较大差别,添加一定比例的芦苇可以使含油污泥热解过程变得匀速缓和,5%(质量比)的芦苇添加量可以使热解残渣恒重温度降低约25℃。混掺芦苇的样品残渣呈分散颗粒状,无聚结现象,对热解结焦将产生一定抑制作用。     

热解含油污泥制备吸附材料浅析

介绍了含油污泥热解技术及热解实验方法,提出热解产生的残渣进行适当处理可成为具有吸附性的材料。进行了含油污泥热解正交实验,得出影响最大的因素分别是热解温度、热解时间、升温速率,并得出最佳的热解温度、热解时间、升温速率等。分析了含油污泥热解的机理,探讨了热解含油污泥制备吸附材料的活化改性,并在此基础上对所制备吸附材料的脱硫性和除油性进行了研究。     

CO变换反应与煤热解耦合反应特性研究

本文在上层为变换催化剂B113下层为新疆伊犁南台子煤粒的固定床反应器中,研究CO变换反应与煤热解的耦合作用。考察了CO变换反应水气比、煤热解温度对耦合反应的影响,研究了耦合热解所得各项产物的特性。结果表明,水气比为1.0、热解反应温度为650℃时耦合热解获得最高的焦油产量,焦油产率为16.36%,比氮气气氛下的焦油产率增加了6.66个百分点,比氢气气氛下增加了4.49个百分点;耦合热解可以得到更低硫的半焦,在终态温度为750℃时耦合热解脱硫率为92.28%;热解气体产物中氢气、甲烷、C2-C4烃类气体含量增加;焦油的羟基数量减少,脂肪烃和芳香烃增多。     

含油污泥热解残渣吸附性能初探＊

含油污泥热解残渣的处理和应用是石油石化企业生产领域急需解决的难题。以含油污泥热解残渣为研究对象,在对其进行无害化处理的基础上,对热解残渣的吸附性能进行了探讨。通过能谱分析可知,热解残渣由碳和无机元素组成,碳元素含量达36.92%;通过SEM电镜扫描、比表面积和孔结构等吸附性质表征研究,含油污泥热解残渣吸附性能优良,对含油污水中的石油类和COD有较好的去除作用。研究结果表明:含油污泥热解残渣可作为一种吸附材料,这项研究为含油污泥热解残渣的资源化利用提供了一条途径。     

The Evaluation of Mesoporous Materials as Catalyst in Fast Pyrolysis of Wheat Straw

In this study, wheat straw was chosen as a biomass sample and the fast pyrolysis of this sample was carried out with or without catalyst at different conditions in a well-swept fixed-bed reactor. Experiments were carried out in a well-swept tubular fixed-bed reactor with a heating rate of 300°C/min, between pyrolysis temperature ranges 300–800°C in the nitrogen atmosphere. The results indicated that a maximum oil yield of 31.9% was obtained at a pyrolysis temperature of 500°C in non-catalytic procedure. Siliceous and Al-MCM-41 materials were evaluated as potential catalysts in the pyrolysis experiments. Mesoporous materials have large pore dimensions with strong acid sites. These acidic sites catalyze some reactions in pyrolysis. The product yields and the quality of bio-oil were influenced with using MCM-41 materials. The bio-oil yield was reduced, whereas the gas yield increased with using a catalyst in the experiments. An increase in the fractions of pure phenol, alkyl phenols, alkenes+alkanes, carbonyls, aromatic, and cyclic compounds and a decrease in the fractions of methoxy phenols, acids+esters, furans, and alcohols were observed in the presence of Al-MCM-41 material. According to all results, the use of Al-MCM-41 materials as catalyst in the pyrolysis can be suggested to obtain both quality fuels and valuable chemicals.     

Capacity of biochar application to maintain energy crop productivity: soil chemistry, sorghum growth, and runoff water quality effects

Pyrolysis of crop biomass generates a by-product, biochar, which can be recycled to sustain nutrient and organic C concentrations in biomass production fields. We evaluated effects of biochar rate and application method on soil properties, nutrient balance, biomass production, and water quality. Three replications of eight sorghum [ (L.) Moench] treatments were installed in box lysimeters under greenhouse conditions. Treatments comprised increasing rates (0, 1.5, and 3.0 Mg ha) of topdressed or incorporated biochar supplemented with N fertilizer or N, P, and K fertilizer. Simulated rain was applied at 21 and 34 d after planting, and mass runoff loss of N, P, and K was measured. A mass balance of total N, P, and K was performed after 45 d. Returning 3.0 Mg ha of biochar did not affect sorghum biomass, soil total, or Mehlich-3-extractable nutrients compared to control soil. Yet, biochar contributed to increased concentration of dissolved reactive phosphorus (DRP) and mass loss of total phosphorus (TP) in simulated runoff, especially if topdressed. It was estimated that up to 20% of TP in topdressed biochar was lost in surface runoff after two rain events. Poor recovery of nutrients during pyrolysis and excessive runoff loss of nutrients for topdressed biochar, especially K, resulted in negative nutrient balances. Efforts to conserve nutrients during pyrolysis and incorporation of biochar at rates derived from annual biomass yields will be necessary for biochar use in sustainable energy crop production.     

Influence of biochar on nitrogen fractions in a coastal plain soil

Interest in the use of biochar from pyrolysis of biomass to sequester C and improve soil productivity has increased; however, variability in physical and chemical characteristics raises concerns about effects on soil processes. Of particular concern is the effect of biochar on soil N dynamics. The effect of biochar on N dynamics was evaluated in a Norfolk loamy sand with and without NHNO. High-temperature (HT) (≥500°C) and low-temperature (LT) (≤400°C) biochars from peanut hull ( L.), pecan shell ( Wangenh. K. Koch), poultry litter (), and switchgrass ( L.) and a fast pyrolysis hardwood biochar (450-600°C) were evaluated. Changes in inorganic, mineralizable, resistant, and recalcitrant N fractions were determined after a 127-d incubation that included four leaching events. After 127 d, little evidence of increased inorganic N retention was found for any biochar treatments. The mineralizable N fraction did not increase, indicating that biochar addition did not stimulate microbial biomass. Decreases in the resistant N fraction were associated with the high pH and high ash biochars. Unidentified losses of N were observed with HT pecan shell, HT peanut hull, and HT and LT poultry litter biochars that had high pH and ash contents. Volatilization of N as NH in the presence of these biochars was confirmed in a separate short-term laboratory experiment. The observed responses to different biochars illustrate the need to characterize biochar quality and match it to soil type and land use.     

泸州市主城区2019年3月至2020年2月大气颗粒物污染特征及防治对策研究

为了解泸州市主城区颗粒物污染变化特征及成因,选取2019年3月至2020年2月空气自动监测数据,运用Origin2017等技术手段对PM2.5与PM10的时间变化特征、污染来源方向以及污染物之间的相关性进行了分析。结果表明:PM2.5与PM10在不同季节的变化趋势均具有较好的一致性,不同站点污染物相关性特征明显。分析表明:泸州市主城区颗粒物污染成因为工业企业排放、机动车尾气、生物质燃烧、燃煤、扬尘以及不利气象条件等,建议对6类污染排放进行管控。     

Extent of pyrolysis impacts on fast pyrolysis biochar properties

A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization.     

Pyrolysis Investigation For Bio-Oil Production From Various Biomass Feedstocks In Thailand

This study investigated the bio-oil production from vacuum pyrolysis of potential biomass feedstocks in Thailand. Experiments were carried out on palm empty fruit bunch, rice straw, rice husk, eucalyptus wood, rubber wood (Hevea Brasiliensis), and Teng wood (Shorea Obtuse) in a lab-scale-fixed bed reactor. The results showed that the product distribution was strongly dependent on temperature and biomass properties. Maximum oil yields, i.e., 50–60 wt %, were reached at 450–550°C. Due to mild temperature, most of alkalis originally present in biomass concentrated in product char, and only traces were detected in oil. Two-third of energy in biomass was in the product oil.     

Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams

The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste.     

Biodegradation during contaminant transport in porous media: V. The influence of growth and cell elution on microbial distribution

This study investigated the interaction between microbial growth and cell elution, and their influence on resultant microbial distribution between the aqueous and solid phases during solute transport in a sandy, low-organic-carbon-content porous medium. Miscible displacement experiments were conducted with salicylate as the model compound, and with different initial conditions (e.g., substrate concentrations and cell densities) to attain various degrees of microbial growth. For each experiment, salicylate and dissolved oxygen concentrations as well as cell densities were monitored in the column effluent. Cell densities were also measured in the porous medium at the beginning and end of each experiment. Total microbial growth was determined in two ways, one based on a cell mass balance for the system and the other based on total amount of salicylate degraded. For conditions yielding a considerable amount of microbial growth, the majority of the biomass was associated with the aqueous phase (68-90%). Conversely, under minimal-growth conditions, most cells (approximately 60-70%) were attached to particle surfaces. Significant cell elution was observed for most conditions, the rate of which increased in the presence of the substrate. The results suggest that the increase in aqueous-phase cells observed for the experiments exhibiting the greatest growth is associated with the production of new cells, and that under appropriate conditions aqueous-phase biomass can contribute significantly to contaminant biodegradation.     

含油污泥资源化技术综述

文章综合论述了溶剂萃取、焦化、热化学洗油及油田调剖处理、焚烧、热解六种污泥资源化处理技术,分析了污泥处理与资源化程度、二次污染物处理工艺、设施投资和运行的直接经济效益、适用范围及特点。研究结果表明,热解处理技术具有较好的应用前景,值得深入研究及推广应用。