上吸式固定床生物质气化炉模拟优化

为了提高上吸式固定床生物质气化炉的燃气产物产量和品质,通过模拟试验对气化炉进行优化设计,使生物质气化炉装置的流场分布均匀,氧化层和还原层反应充分。通过热态试验分析生物质气化炉炉内床层温度分布、燃气产物成分、气化强度、产气率与入炉空气量的关系,得到该上吸式固定床生物质气化炉的最佳入炉空气量条件。结果显示：优化设计后的气化炉气化效率达到70%以上,有效提高了生物质炉的气化能力。     

固定床移动层下吸式生物质气化炉的研究

1前言我国生物质资源丰富，如能有效地利用，将会大大缓解农村常规能源的紧张状态。针对浙江省农村电力不足，同时又有大量谷壳用作燃料，且燃烧效率很低（约10％左右）的情况，浙江省能源研究所与中国水稻研究所进行了小型移动式生物质气化发电系统的研究。本文就该系统固定床移动层下吸式生物质气化炉的设计及试验情况作一介绍。2气化炉的主要结构小型移动式生物质气化发电系统主要由气化炉、净化冷却装置和发动机组成，其中气化炉为固定床移动反应层下吸式气化炉，其结构具有如下特点：（1）气化炉主要由内外两个简体组成。内筒从炉栅网…     

生物质气化/燃烧双反应器的冷态试验研究

采用所搭建的生物质气化/燃烧双反应器冷态试验台,研究了生物质气化效果的影响因素.双反应器中气化炉内径为211 mm,高为1.7m,为移动床形式;燃烧炉内径为100mm,高为5m,为循环流化床形式.2个反应器由气动返料装置进行连接,通过炉内的灰循环实现耦合.在此试验台上进行了物料循环量的试验研究,考察了循环量与燃烧炉一次风速、下返料风速的关系,通过理论计算,得到了气化炉循环灰所携带的热量和物料在气化炉内的停留时间,为热态试验台的设计提供理论基础.     

生物质循环流化床气化炉的数学模型研究

以试验为基础，根据有关化学动力学、快速流态化模型等资料，结合原料的宽筛分特性，建立了生物质循环流化床气化炉的数学模型，并用Ｑｕｉｃｋ－Ｂａｓｉｃ语言编制程序。利用模型对循环流化床木粉气化炉的运行参数进行模拟计算，模拟结果与试验数据符合良好，在一定程度上证明了模型的有效性和可靠性。利用该模型不仅能选择气化炉的最佳运行工况，而且可为同类反应器设计提供理论指导。     

户用型生物质气化炉主要技术性能的试验研究

在实验台上针对改进型户用生物质气化炉进行了主要技术性能的试验研究,其中包括生物质原料、鼓风量、气化强度等参数对气化性能的影响,净化装置的脱除效果研究以及焦油回流装置对气化指标的影响等。实验表明,生物质原料的有关参数对气化性能有明显影响;鼓风量是气化炉生产负荷最简单迅速的调节手段之一,鼓风量存在一个最佳运行的鼓风量范围;户用型气化炉设计的净化装置脱除效果显著;焦油回流装置设计合理,提高了燃气品质和气化效果。     

中部出气的上吸式固定床气化炉及其自动控制的料斗供料系统设计

改进的固定床上吸式生物质气化炉,以锥形下料裙将气化炉分成气化室与储料室两部分,出气口设在下料裙死角处。输出的产出气温度在300℃以上、灰分少、热值高,气化效率高,兼具上吸式与下吸式气化炉的优点,有效解决了常规上吸式气化炉产出气中焦油含量高、热值低问题。自动控制的料斗供料方式保证了气化炉运行的可靠性与安全性,扩展了生物质木料的适用范围。实现产出燃气在蒸汽锅炉中代替煤、木材、油燃烧,可有效解决中小企业的用能问题,达到节能减排的目的。     

固定床气化炉烧废木料运行特性的试验研究

根据生物质气化原理,设计了上吸式中间排气固定床气化炉,并用废木料对其进行实验,研究原料特性,空气量与生产能力的关系,并分析了燃气成分、热值,及炉内温度分布的数据.证明上吸式中间排气固定床气化炉的可行性.     

串联交替式炉膛高热值生物质气化炉数值模拟及试验研究

对串联交替式炉膛高热值燃气生物质气化炉进行了研究,气化炉以木质颗粒为燃料、空气-水蒸气为气化剂,采用Fluent软件数值模拟了气化炉内水蒸气入口距离炉栅位置高度h、水蒸气入口流量Vs与空气入口流量V03个参数对燃气组分CO,H2和CH4体积浓度的影响。采用正交试验优化了上述3个参数,并试验测试了3个参数下燃气组分CO,H2和CH4体积浓度及燃气热值。数值模拟与试验结果表明,当h为175 mm,V0为0.92 m3/h,Vs为1.33 m3/h时,生物质燃气热值Q最大值为10.46 MJ/m3,比单一空气气化剂作用下提高了107.95%。     

生物质直燃与气化对碳化硅石墨坩埚腐蚀的影响

文章以生物质颗粒为燃料,分别利用生物质燃烧机和上吸式气化炉对碳化硅石墨坩埚进行加热,并研究了生物质中富含的碱金属在迁移过程中对碳化硅坩埚腐蚀情况的影响。研究结果表明:与坩埚原样相比,以上吸式气化炉作为热源时,损坏的坩埚中仅O元素的含量出现了明显增加,而以生物质燃烧机作为热源时,损坏的坩埚中K,Na和O元素的含量均出现了大幅度增加;上吸式气化炉对碳化硅石墨坩埚的腐蚀机理是高温氧化腐蚀,而生物质燃烧机对碳化硅石墨坩埚的腐蚀机理是基于高温氧化腐蚀的碱金属腐蚀。以生物质作为燃料时,上吸式气化炉特有的对碱金属的过滤滞留效应减轻了碱金属对坩埚的腐蚀程度,从而使上吸式气化炉在有色金属冶炼领域中具有更理想的应用前景。     

生物质气化炉供风器的流场模拟及试验

利用计算流体力学(CFD)技术对用于气化炉供风的梅花形和环形两种供风器的流场进行数值模拟和流场对比分析,并对分别装有这两种供风器的生物质上吸式气化炉系统的反应床层温度和产气成分等气化性能进行测试比较.结果表明:环形供风器供风时,其流场没有漩涡,主管风速和各支管风速衰减方向相逆,使供风互补趋于均匀并形成较大的供风平面;梅...     

生物质固化成型的微观机理

通过对生物质固化成型微观机理的研究,建立了生物质固化成型的微观接触几何模型,确定了压辊对原料的正压力与生物质颗粒表面斜角之间的数学关系,正压力F的大小与颗粒表面斜角a_i的余弦成正比关系。通过对固化成型分子微观机理的研究,说明了固化成型燃料燃烧点低的原因。建立了生物质固化成型的能量微观机理,并从表面能角度揭示了固化成型燃料能量密度增加、燃烧值提高的机理。     

生物质热解气化制备二甲醚合成气的灰关联分析

通过制备二甲醚合成气的生物质慢速热解气化实验,得到了热解气化炉中主要可调节参数热解温度、进料速率等与生物质热解气中H_2、CO等含量的数据.利用灰色关联方法,分析了主要可调节参数与生物质气中H_2、CO含量及H_2/CO比值的关系.结果表明:热解温度对生物质气中心、CO含量及H_2/CO比值的影响最为明显(其关联度为(0.705,0.760,0.641)),进料速率次之,罗茨风机抽气速率最弱;CO含量受3个主要可调节参数的影响最为明显(其关联度为(0.760,0.628,0.709)~T).根据该实验制备H_2/CO比值接近2的二甲醚合成气的目标和灰关联分析结果,提供了增大H_2/CO比值的方法.找出了热解气化炉中的可调节参数中影响生物质热解气体产物H_2、CO含量的主要参数,为生物质热解气化合成二甲醚中制备较高含量的H_2、CO及合适H_2/CO比值的合成气提供了前提条件.     

沈阳市发展生物质颗粒燃料的制约因素和对策研究

阐述了沈阳市推广生物质颗粒燃料的必要性及重要意义,分析了生物质颗粒燃料在沈阳市推广应用过程中存在的问题,并针对这些问题提出了一系列解决方法与对策.对生物质颗粒燃料的商品化和大规模利用进行了展望,指出生物质颗粒燃料在沈阳地区具有良好的发展前景.     

应用神经网络方法预测生物质的热值

应用人工神经网络方法对生物质的热值进行了预测,网络的训练数据集来自美国Biomass Feedstock Composition and Property Database of U．S．Department of Energy。神经网络以生物质的工业分析结果作为输入数据．采用56组数据对网络进行训练,以7组数据对网络进行验证,对网络输出值与实际值进行比较,相对误差在0．08％以内。人工神经网络成功地预测各种生物质的热值,说明人工神经网络能够处理生物质的热值与工业分析各组分间的非线性关系。     

生物质颗粒燃料冷成型技术试验研究

对环模生物质颗粒燃料成型机影响成型的各主要因素进行了分析及试验研究,给出不同生物质原料、粒度、含水率、环模孔长径比等因素与颗粒成型率及吨料电耗的关系,找出生物质颗粒燃料的最佳成型条件。     

Renewable energy consumption and industrial production: A disaggregated time-frequency analysis for the U.S.

This paper aims to analyze the interaction between renewable energy consumption and industrial production for the U.S. over the 1981–2018 period. We contribute to the existing literature by the disaggregation of renewable energy sources (hydropower, geothermal, and biomass), by the consideration of time and frequency through wavelet techniques and the time-varying Granger causality test recently proposed by Shi et al. (2018). Based on monthly data, wavelet results show a positive co-movement between industrial production and biomass energy consumption at low frequencies, meaning in the long term only. The bootstrap rolling-window Granger causality test indicates a bi-directional predictability between renewable energy consumption and industrial production in crisis and turmoil periods only. These results are found to be robust to the inclusion of control variables (non-renewable energy consumption and crude oil prices) and to the selection of the lag length for the corresponding VAR model.     

Relationships between cellulosic biomass particle size and enzymatic hydrolysis sugar yield: Analysis of inconsistent reports in the literature

Cellulosic ethanol made from cellulosic biomass is a promising alternative to petroleum-based transportation fuels. Enzymatic hydrolysis is a crucial step in cellulosic ethanol production. In order to better understand the mechanisms of enzymatic hydrolysis, relationships between cellulosic biomass particle size and enzymatic hydrolysis sugar yield have been studied extensively. However, the literature contains inconsistent reports. This paper presents an analysis of the inconsistent reports on the relationships in the literature. It discusses the differences in the reported experiments from five perspectives (biomass category, particle size definition, sugar yield definition, biomass treatment procedure, and particle size level). It also proposes future research activities that can provide further understanding of the relationships.     

基于灰色关联度和BP神经网络研究生物质热解产气特性

首次使用灰色关联度知识,用理论和数据分析了影响生物质热解产气率和产气热值的各种因素的程度大小:热解终温>物料特性(主要是挥发份)>加热方式>填实率>物料粒径。基于回归模型的预测精度不高,采用3层改进BP神经网络方法,以热解终温、物料、加热方式、填实率和物料粒径作为输入项,建立了生物热解产气率和产气热值的模型。并使用该模型预测4个不同热解实验的产气率和产气热值,最后预测值的相对误差分别为:7 30%和4 50%,证明网络的预测结果较好。     

Variability and plasticity of productivity,water-use efficiency,and nitrogen exportation rate in Salix short rotation coppice

Short rotation coppice (SRC) willow plantations may play an important role in the future for biomass production purposes. However, the high planting density schemes combined with the frequent harvests occurring in such plantations could rapidly deplete soil resources. The use of genotypes able to produce greater amounts of biomass by using the least water and nutrients may help mitigating this risk. This study aimed at assessing among six willow genotypes (1) the variability of traits related to productivity (e.g. aboveground dry biomass or stem height), leaf and wood nitrogen (N) contents, N exportation rate and water-use efficiency (WUE) as estimated through bulk leaf carbon isotope discrimination (Δ¹³C), (2) the relationships among traits, and (3) the plasticity of these traits and of the relationships among them across different sites. The six genotypes were grown under SRC at three sites in northern France differing primarily in pedoclimatic characteristics for two years. A significant genotypic variability was found for all traits, except for the N exportation rate. The pedoclimatic context impacted the values of all traits, and the genotypic ranking for traits related to productivity and for Δ¹³C. Δ¹³C was negatively correlated with total shoot dry biomass and/or height irrespective of the site, meaning that the most productive genotypes were also the most efficient to use water. In conclusion, no antagonism was detected between biomass production and WUE. The most productive and most water-use efficient genotypes were the ones responsible for the highest nitrogen removal from the plantation during harvest.     

Carbon stock estimates for forests in the Castilla y León region, Spain. A GIS based method for evaluating spatial distribution of residual biomass for bio-energy

Analysis of aboveground biomass and carbon stocks (as equivalent CO₂) was performed in the Castilla y León region, Spain. Data from the second and third Spanish Forest Inventories (1996 and 2006) were used. Total aboveground biomass was calculated using allometric biomass equations and biomass expansion factors (BEF), the first method giving higher values. Forests of Castilla y León stored 77,051,308 Mg of biomass, with a mean of 8.18 Mg ha⁻¹, in 1996 and 135,531,737 Mg of biomass, with a mean of 14.4 Mg ha⁻¹, in 2006. The total equivalent CO₂ in this region’s forests increased 9,608,824 Mg year⁻¹ between 1996 and 2006. In relation to the Kyoto Protocol, the Castilla y León forests have sequestered 3 million tons of CO₂ per year, which represents 6.4% of the total regional emission of CO₂. A Geographic Information System (GIS) based method was also used to assess the geographic distribution of residual forest biomass for bio-energy in the region. The forest statistics data on area of each species were used. The fraction of vegetation cover, land slope and protected areas were also considered. The residual forest biomass in Castilla y León was 1,464,991 Mg year⁻¹, or 1.90% of the total aboveground biomass in 1996. The residual forest biomass was concentrated in specific zones of the Castilla y León region, suitable for the location of industries that utilize biomass as energy source. The energy potential of the residual forest biomass in the Castilla y León region is 7350 million MJ per year.