Effect of Metal Oxide on Electrical Resistivity of Conductive Wood Charcoal

To analyze the effect of metal oxide on electrical resistivity of conductive wood charcoal,wood powder of Masson pine was mixed with ferric oxide (Fe_2O_3) and nickel oxide (NiO), respectively,and then the mixed powders were carbonized at high temperature in a laboratory-scale tube furnace in a nitrogen atmosphere. DCY-3 resistivity tester was used to measure electrical resistivity of conductive wood charcoal. When carbonization temperature was 1200 ℃, the electrical resistivity of controlsamples, Fe_2O_3 (4%) added samples, and NiO (4%) added samples was 0.104 Ω·lcm, 0.071 Ω·lcm, and 0.066 Ω·lcm, respectively. When carbonization temperature was 1 500 ℃, the electrical resistivity of control samples, Fe_2O_3 (4%) added samples, and NiO(4%) added samples was 0.091 Ω·lcm,0.052 Ω·lcm, and 0.052Ω·lcm, respectively. And electrical resistivity of conductive wood charcoaldecreased from 0.060Ω·lcm to 0.041Ω·lcm when the ferric oxide addition increased from 2% to 10%.The results showed that the electrical resistivity of conductive wood charcoal decreased with the increase of carbonization temperature. Ferric oxide and nickel oxide could be used as catalysts todecrease electrical resistivity of conductive wood charcoal. And electrical resistivity of conductivewood charcoal reduced with increasing the ferric oxide addition.

Production of Safe Charcoal from Waste Construction Wood Treated With Citric Acid

For practical reuse of wastewater containing citric acid and the production of safe and healthy high-quality charcoal from waste construction wood, basic data regarding the influence of citric acid washing treatments on the physico- chemical property of charcoal was investigated in order to find the benefits of using citric acid for washing out impurities of the wood, owing to its chelate bonding ability with elements such as metals. Parameters obtained for evaluating the benefits were water content, volatile component content, ash content, fixed carbon content, and the heat value of the charcoal. All parameters, except ash content, throughout all carbonization temperatures were not significantly different between the charcoal of the wood treated with and without citric acid. However, the ash content showed significant differences between the charcoal treated with and without citric acid throughout all carbonization temperatures. Regarding the heat value, the highest heat value was shown on the charcoal carbonated at 600?C with the static washing treatment. Dioxins that were higher in content than the control sample were somehow detected in the ash of the charcoal with the shaking treatment. Further investigation is needed for the production of safe and healthy charcoal using waste citric acid.

ZIF-8/纳米纤维素对竹木复合纤维除臭性能的影响

近年来,随着人们生活品质要求的不断提升,具有除臭性能好、吸收性能强和价格成本低廉的纤维材料在婴幼儿、成人除臭纸尿裤等卫生用品中的需求量不断增高。但目前市场上的除臭纤维基本存在除臭性能差、吸水性弱以及成本高的问题,严重制约我国除臭功能性纤维材料的国际竞争力。笔者以国内常见的白竹炭纤维和针叶木纤维为基本原料,以ZIF-8纳米粒子和纳米纤维素(CNF)为除臭改性填料,通过复合加工工艺,制备了兼具除臭和吸水功能的竹木复合除臭纤维,并探究了白竹炭纤维和针叶木纤维原料质量比、改性填料含量对复合除臭纤维微结构、吸水以及除氨气、硫化氢等臭味气体的影响规律。研究结果表明,所制备复合除臭纤维最佳工艺条件为针叶木纤维与白竹炭纤维绝干质量比为70∶30,ZIF-8和CNF的质量分数分别为7%和6%,23℃下风干处理24 h,在该工艺条件下制备的除臭纤维对氨气和硫化氢的消臭率分别为84.56%和83.11%,吸水量为8.4 g/g,除臭纤维性能达到国家标准GB/T 33610.2—2017(消臭率≥70%)的要求。

Progress in the technology of energy conversion from woody biomass in Indonesia

Sustainable and renewable natural resources as biomass that contains carbon and hydrogen elements can be a potential raw materials for energy conversion. In Indonesia, they comprise variable-sized wood from forests （i.e. natural forests, plantations and community forests that commonly produce small-diameter logs used as firewood by local people）, woody residues from logging and wood industries, oil-palm shell waste from crude palm oil factories, coconut shell wastes from coconut plantations, traditional markets as well as skimmed coconut oil and straws from rice cultivation. Four kinds of energy-conversion technologies have been empirically tested in Indonesia. First, gasification of rubber wood from unproductive rubber trees to generate heat energy for the drying of fermented chocolate seeds. Secondly, energy conversion from organic vegetable waste by implementing thermophylic fermentation methods that produce biogas as a fuel and for generating electricity and also concurrently generate organic by-products called hygen compost. Thirdly, gasification of charcoal and wood sawdust for electricity generation. Finally, environment-friendly energy conversion by carbonizing small-diameter logs, sawdust, wood slabs and coconut shells into charcoal. This yielded charcoal integrated with wood vinegar production through condensation of smoke/vapors emitted during carbonization, thereby mitigating the impact of air pollution. Among the four experimental technologies that of integrated charcoal and wood vinegar production had been spectacularly developed and favored by rural communities. This technology brought added value to the process and product due to the wood vinegar, useful as bio-pesticide, plant-growth hormone and organic fertilizer. Such integrated and environment-friendly production, therefore, should be sustained, because Indonesia occupies a significant and worldwide position as charcoal-producing and marketing country. The technology of integrated wood vinegar-charcoal production hence deserves its dissemination throughout Indonesia, particularly to the charcoal industry that still produces charcoal without condensing the generated vapor/smoke, hence polluting the air.

Wood use and forest management by Neolithic millet farmers at the Xinglong site,northern China

The origin and development of agriculture and its relationship with climate change are hotly debated topics among environmental archaeologists.In this study,we analyzed wood charcoal materials from the Neolithic Xinglong site in northern China in order to understand the woody vegetation around the site and how early millet farmers shaped local woodlands.Our results suggest that the area around the Xinglong sites during 8700-7000 yr BP was primarily woodlands,including Prunus sibirica shrubs,Ulmus and Acer forests,and Populus stands near waterways.From 8000 to 7000 yr BP,the warm and humid climate probably contributed to the expansion of Acer,Rhamnus,and Juniperus,and may have facilitated the development of early millet agriculture.Among these ancient wood fragments that we studied,the high percent of Prunus charcoal appears to indicate an abundance of fruit trees,which might have constituted the main component of local vegetation.Meanwhile,the wood taxa illustrate the existence of a variety of ecological habitats,and it is logical to assume that people made full use of the locally available wood resources.Notably,Populus and Ulmus were the dominant sources of fuel.The results of tree-ring curvature analyses indicate that people mainly collected trunks or large branches of Ulmus,Populus,Acer,and Juniperus timbers.We interpret the increasing use of Prunus twigs and the declining percentage of Prunus charcoal in the period between 8000-7000 yr BP as indicating that people started to protect and manage wild fruit trees.They may have started pruning to acquire more food resources as part of the cultural responses and adaptation strategies employed by these early millet cultivators.

添加木炭改善猪粪稻壳好氧堆肥工艺及质量

为促进农业废弃物的资源化利用，试验以猪粪和稻壳为原料，用化学分析和仪器分析相结合的方法，研究了添加不同质量分数（0、2.5%、5.0%、7.5%和10.0%）的木炭对60 d猪粪好氧堆肥过程的影响。结果表明：在堆肥有机质的降解过程中，含-OH、-CH3和-CH2基团的化合物的质量分数逐渐减少，含-C=O、C-O-C、-COO基团和含芳香环类物质的质量分数逐渐增加。添加木炭能促使堆肥物料的降解，随着木炭添加量的增加，在60 d的堆肥过程中，各处理有机碳的质量分数分别降低了12.23%、13.77%、14.88%、15.36%和15.86%，碳氮比分别下降了47.80%、54.98%、56.97%、60.03%和65.73%。与对照相比，添加木炭可延长堆肥高温期的停留时间3～5 d，增加堆肥物料的持水能力并降低堆肥产品的电导率；同时，添加木炭还能减少堆肥初期氨气的挥发，提高铵态氮的质量分数，促使堆肥后期硝态氮的转化。堆肥结束时，添加木炭可使硝态氮的质量分数提高55.86%～89.32%，总氮的质量分数提高20.55%～53.07%，雪里蕻种子发芽率提高17.6%～41.2%，萌发指数达1.02～1.44。研究表明，添加木炭能促进堆肥有机物料的降解，加快堆肥腐熟脱毒，增加堆肥产品总氮的质量分数，提高产品质量。木炭作为一种潜在的猪粪堆肥添加剂，在促进农业废弃物资源化利用方面具有广阔的应用前景。

炭化温度对炭化物微观结构影响的研究

采用扫描电子显微镜、全自动比表面积及孔径分析仪观察与研究了杉木间伐材在不同炭化温度下炭化物的微观结构、孔径分布、比表面积等,揭示了不同炭化温度下孔隙的形成特点与演变规律。实验表明,炭化温度对炭化物的比表面积与比孔容积特性影响很大,较高温度的炭化物具有较发达的孔隙结构与较高的比表面积。电镜观察可知,随着炭化温度升高,炭化物管胞表面沉积物量减少且颗粒变小,纹孔各层膜逐渐被破坏,纹孔开孔率增大,同时根据电镜观察中试样的放电状况可判断出炭化物导电性情况,随炭化温度升高,炭化物的导电性增大。

高活性木炭的制备与孔结构表征

介绍了二步炭化法制备高活性木炭工艺。研究了保温时间和温度对活性木炭吸附性能的影响,并通过ESEM和HRTEM等对其孔结构进行表征。结果表明:二步炭化法可很好地提高木炭的性能,可制得孔径主要集中在0.6～2.0nm的活性木炭;随着保温时间延长,活性木炭的比表面积、孔容积均增大。在较佳实验条件下,所制高活性木炭的比表面积、总孔容积和微孔容积分别为1288.4m2/g、0.784mL/g、0.407mL/g。

功能性木质炭素新材料的研究与开发

木质炭化物的高效开发利用,对解决废弃物资源化、环保、生态环境等问题将起到十分积极的作用。通过述评功能性木质炭素新材料的国内外研究和开发进展,涉及到木质炭素材料吸着特性的研究概况、木质炭化物在环境净化方面的应用、木质系炭素新材料的研发、性能和应用等方面。着重介绍了一些木质系炭素新材料:木陶瓷、木质吸油材料、高电导性材料、保健材料、土壤改良材料、二氧化钛/炭复合材料、烧结炭等。同时对其副产物木醋液的应用领域,如在食品添加剂、消臭剂、医药、农业等方面的应用也做了一些梗概。由此可看出:木质炭化物新利用,高功能化的研发可使古老的木炭衍化为新颖的功能性材料,从而产生更高的经济、社会和生态效益。

木材炭化与炭化物利用研究进展

木材通过炭化可转化为木炭,进一步反应可以制备隔音材料、环境净化材料、导电材料、电磁屏蔽材料以及类似陶瓷结构的仿生材料等新型生物质材料。文中从炭化的方法、机理以及产物的应用等方面对木材炭化的研究进行了综述。

两步炭化法制备高活性木炭

500℃下炭化杉木屑,再将此炭化料在较高温度下,进行第二步炭化,制得高活性木炭。讨论了温度、保温时间、升温速率等因素对产品吸附性能的影响。结果表明,随着温度的升高、保温时间的延长,亚甲基蓝吸附值、碘吸附值、苯吸附值呈现上升趋势;随着升温速率的增大,得率、亚甲基蓝吸附值、碘吸附值、苯吸附值呈现下降趋势。在相对较优的实验条件下,制得了亚甲基蓝吸附值为330 mg/g,碘吸附值1 068.3 mg/g,苯吸附值105.28 %、得率为14.29 %的高活性木炭。研究认为两步炭化有利于进一步提高木炭的比表面积及吸附性能。第二步炭化时,在微量空气的作用下,对木炭产生了活化效果。研究表明,两步炭化法工艺比较简单,对设备要求不高。

木材、竹材及其炭化物负载SiO_2凝胶的比较

采用单一浓度溶胶浸渍和梯度浓度溶胶浸渍2种方法将SiO2溶胶注入竹材、木材、竹炭和木炭4种材料内部,探讨材料微观结构、炭化前后、溶胶浓度以及浸渍方法对材料凝胶负载率的影响。结果表明:竹材的SiO2凝胶负载率低于竹炭,二者的凝胶负载率显著小于木材和木炭;木材和木炭凝胶负载性能差异与所浸渍溶胶的浓度有关;相比于使用单一浓度浸渍,浓度梯度法浸渍可有效提高材料的负载率。

木质炭化物对挥发性有机污染物吸附性能的研究

本文探讨了炭化温度对木材炭化物的得率 ,还原性 ,pH值 ,苯蒸气、三氯甲烷蒸气吸着率的影响。结果表明 ,30 0～ 90 0℃的炭化温度下 ,木炭的得率随着炭化温度升高而下降 ,并在 6 9 8%～ 2 0 6 %的范围内变化。炭化温度为 70 0℃时 ,产物木炭的比表面积最大 ;80 0℃时 ,木炭元素组成中的 (C +H) O的摩尔比值最大 ,这意味着该木炭的还原性最大。木炭水溶液的pH值随着炭化温度上升而增加 ,炭化温度小于 5 5 0℃时呈酸性 ,大于 5 5 0℃时为碱性。炭化温度对木炭环境净化能力有显著的影响 ,6 0 0℃炭化得到的木炭对三氯甲烷蒸气的吸附率最大 ,高达8 5 % ,约为 30 0℃时的 5倍 ;80 0℃炭化得到的木炭对苯蒸气的吸附率最大 ,达 5 % ,约为 30 0℃时的 5倍左右。

木材炭化机理的研究——炭化方法和炭化条件对杉木间伐材炭化物物性的影响

采用一步炭化法与二步炭化法,加盖炭化法与未(不)加盖炭化法对杉木间伐材木 屑在不同炭化条件下进行热解研究,同时结合元素分析方法,探讨了杉木间伐材木屑炭化的固 体产物得率及其基本性质的变化规律。研究结果表明:炭化温度在400-600℃之间,炭化物 得率下降十分明显,此后相对趋于恒定;加盖炭化法的得率高于未加盖法;升温速率对炭化物得率有较大影 响。无论是一步炭化法还是二步法,炭化氛围气为空气时的炭化物固定碳含量及炭化物的还原性较氮气高。 无论氛围气体是空气还是氮气,炭化物的还原性均随着炭化温度升高而升高。

木质炭化物高效开发利用研究综述

木质炭化物的高效开发利用 ,对解决废弃物资源化、环保、生态环境等问题将起到十分积极的作用。文中综述了木质炭化物高效开发利用的国内外研究和开发进展 ,涉及到木质炭化物在环境净化方面的应用和木质系碳素新材料的研发等。

废弃人造板炭化产物分析

为解决废弃人造板的回收利用,提高附加值,该文采用电控炭化炉对不同原料的废弃人造板加热炭化。通过实验测定了炭化过程的温度变化和炭化产物收量及物理化学性质;同时采用气相色谱-质谱联用仪(GC-MS)分析了不同材料来源所得到的木酢液的成分组成。结果表明:由于木材胶黏剂等因素的影响,木酢液pH值呈中性至弱碱性,不同原料制取的木酢液和木炭在物理化学性质上存在一定的差异;成分分析显示木酢液中存在较多含氮成分。通过微观扫描电镜观察发现,炭化产物的微观表面平滑,纹孔开放,沉积物减少。

不同外源添加物对园林绿化废弃物腐熟过程的影响

以北京市香山公园园林绿化剪枝的废弃物为堆腐原料,采用露天高温好氧堆腐技术,通过测定堆腐试验过程中高温期持续天数、pH、EC值、C/N比、发芽指数GI等指标,研究在园林绿化废弃物堆腐过程中分别添加木酢液和炭化物相比添加菌剂及无添加剂时对园林绿化废弃物堆腐过程的影响。结果表明,添加木酢液及炭化物均可加快园林绿化废弃物的腐熟,主要表现为:添加木酢液及炭化物能加速堆体升温并增加高温期持续天数;添加木酢液可有效降低堆体pH、EC值;添加木酢液及炭化物的处理C/N下降率分别为44.50%、41.44%,稍低于添加EM菌剂处理的45.61%,高于空白处理的32.51%,且T值均在0.6以下;添加木酢液和炭化物能有效降解堆体中的植物毒性物质,2组处理的发芽指数高达98.03%和97.27%。

烧结温度对导电木炭特性的影响

以催化炭化工艺经高温烧结制备导电木炭,分析和探讨了烧结温度对木炭导电性能、微晶结构和石墨化度的影响.烧结温度从1,200,℃升高到1,500,℃时,导电木炭的电阻率降至0.052,3,.cm,且导电木炭中石墨状微晶排列由无规则排列逐渐转化为有序排列.导电木炭的拉曼光谱分析结果表明,烧结温度的升高有利于增加导电木炭的石墨状微晶的含量,提高其结晶程度和石墨化度.导电木炭的X射线衍射分析结果表明,在烧结温度升高的过程中,导电木炭晶面的层间距逐渐减小,向石墨化结构转变,当烧结温度升至1,500,℃时,导电木炭已部分石墨化.

商代中晚期的树木利用——洹北商城和殷墟出土树木遗存分析

树木是人类利用的主要资源。树木不仅提供人类赖以生存的生活环境,还为人类提供食物、木材、能源、医药以及其它产品。考古遗址出土的树木遗存,往往与人类活动有关,与考古文化具有同时性。通过对考古遗址出土的树木遗存的分析,再结合其出土的环境背景,能获得古代人类利用树木的信息。本研究对商代中晚期洹北商城、殷墟孝民屯遗址、刘家庄北地出土的大量木炭、木材进行了分析,对殷墟大司空遗址303号墓出土枝叶进行了分子遗传学和形态学研究,结果表明:(1)无论是植物种属的出土概率还是百分比,栎属都是最高的,无论是普通村邑的房址还是窑址,栎属的出土概率和百分比也都是最高的,表明人类对这种木材的喜好。栎属是商代晚期人类主要的薪柴材料,也是刘家庄北地和孝民屯遗址普通村邑的建筑材料。栎属与人类的关系非常密切,在当时的人类日常生活中扮演了重要角色。(2)建筑材料的选择不仅受到聚落周边植被状况的影响,还与木材性质和建筑性质有关。洹北商城的一号、二号建筑基址选用了松木,而刘家庄北地的一处木炭遗迹主要选用了柏木。(3)刘家庄北地出土了栎属、李亚属和枣属的木炭,孝民屯遗址也出土了栎属和枣属的木炭,这从一个侧面说明,古代人类有可能食用这些树木的果实。(4)树木受到自然因素或人为因素伤及形成层的伤害时会产生锯齿状生长轮。刘家庄北地灰沟HG3Ⅰ中出土的大量的带有锯齿状生长轮木炭,锯齿宽度1毫米,间距1毫米,较规则,有可能是人为因素导致。但究竟何种因素导致锯齿形成,有待今后进一步研究。(5)商代晚期刘家庄北地古代先民选用侧柏做井架。(6)同时采用传统的形态学方法与分子遗传学方法对出土枝叶进行研究,能极大地提高鉴定的准确率。通过研究,大司空遗址303号墓随葬品敞口折肩尊的口部数层叠压在一起的植物枝叶是具有药用作用的短梗南蛇藤(Celastrus rosthornianus Loes)。总之,本研究不仅获得了商代中晚期先民因材施用的木材利用特点,而且为现今木材的合理开发和利用提供了史料。短梗南蛇藤的发现,对研究我国医药卫生史、民俗和礼仪以及现代医药的开发具有重要意义。

甘肃河西走廊早期冶炼活动及影响的炭屑化石记录

炭屑化石的显微结构研究是根据木材的解剖特征(组成木材的细胞与组织的形态和排列方式)确定燃烧植物的类型,重建古植被和古环境,探讨人类活动对环境的影响。火石梁和缸缸洼青铜冶炼点位于河西走廊西北部、黑河流域下游巴丹吉林南缘沙地中,散布了大量的炭屑化石遗存。通过炭屑化石3个切面(横切面、径切面和弦切面)显微结构特征研究,比对现代切片标本和木材解剖图版,识别和确定炭屑化石的木材种属,确定2100～1860BC期间的青铜冶炼所用木材为柽柳、杨属、柳属、蓼科4种乔灌木植物,火石梁和缸缸洼地区大量乔、灌群落生长要比目前荒漠生态环境优越的多。先民的青铜冶炼活动导致乔木和灌木植物被大量砍伐,植被盖度急剧降低,对生态环境产生重大影响,是1900BC左右杨属、柳属和蓼科乔灌木植物基本消失的主要原因。