低温胺吸收与矿物碳化相结合的碳捕获和固碳策略

乙醇胺（MEA）吸收法是一种高能耗的碳捕获和固化（CCS）方法,其原因是解吸塔中胺的再生（100~120 ℃）以及CO2的压缩都需要较高能耗。本文介绍了一种新的活性热液相固化（rHLPD）方法,其将MEA吸收法碳捕获工艺与矿物碳化技术结合起来（rHLPD-CS）。结果表明,在较低的温度（60 ℃）下,矿物（硅灰石CaSiO3）碳化分离了MEA-CO2溶液中捕获的CO2,同时形成了抗压强度约为121 MPa的整体材料。这表明,使用rHLPD-CS技术不仅可以降低MEA-CO2中CO2的分离和压缩所消耗的能量,而且还可以使CO2形成增值产品,具有作为建筑和基础设施材料的潜力。     

我国碳捕获、利用与封存(CCUS)技术的发展现状与展望

CCUS是在CCS的基础上发展起来的。CCUS作为一种未来减排温室气体的战略性技术,逐渐受到国际社会的关注。尽管起步较晚,但我国近些年对CCUS技术也给予了积极的关注和高度重视,包括政策鼓励、扶持和资金投入力度等,因此在CCUS基础理论和技术研究、工业示范方面也取得了一些重要的进展。但总体来说CCUS在我国仍处于研发和示范阶段,仍存在许多制约其发展的突出问题,相信随着基础理论和技术研发的不断推进,制约其发展的成本、能耗、安全等问题也将迎刃而解,CCUS技术的环境效益和社会经济价值也将凸显。     

矿物聚合物的合成及其对Cr(Ⅵ)的解毒与固化

以煤矸石为原料、水玻璃和NaOH为碱性激发剂合成矿物聚合物,以添加硫化物的矿物聚合物对Cr(Ⅵ)进行解毒与固化,对固化体进行了检测.结果表明,当硫化物与Cr(Ⅵ)的摩尔比大于3∶1时,矿物聚合物中总铬的浸出浓度小于1 mg/L时,铬固化率大于99％,对Cr(Ⅵ)的最大固化量为1.2％.添加硫化物的矿物聚合物对Cr(Ⅵ)的解毒与固化是基于氧化还原反应,S2-被氧化为S2+(平均化合价),Cr(Ⅵ)被还原为Cr(Ⅲ),Cr(Ⅲ)被矿物聚合物中的-OAl(-)(OH)3吸引并固化在非晶质结构中.     

矿物聚合物的合成及其对Cr(Ⅵ)的解毒与固化

以煤矸石为原料、水玻璃和NaOH为碱性激发剂合成矿物聚合物,以添加硫化物的矿物聚合物对Cr(Ⅵ)进行解毒与固化,对固化体进行了检测.结果表明,当硫化物与Cr(Ⅵ)的摩尔比大于3:1时,矿物聚合物中总铬的浸出浓度小于1 mg/L时,铬固化率大于99%,对Cr(Ⅵ)的最大固化量为1.2%.添加硫化物的矿物聚合物对Cr(Ⅵ)的解毒与固化是基于氧化还原反应,S2-被氧化为S2+(平均化合价),Cr(Ⅵ)被还原为Cr(Ⅲ),Cr(Ⅲ)被矿物聚合物中的-OAl(-)(OH)3吸引并固化在非晶质结构中.     

有机胺CO2吸收技术研究现状与发展方向

CO₂排放量迅速增加,严重威胁人类生存环境及气候变化,如何减少碳排放量是关注热点。化学吸收法是捕集CO₂的主要方法之一,其脱除CO₂的实质是利用碱性吸收剂溶液与烟气中CO₂逆向接触并发生化学反应,形成不稳定盐类,而盐类在一定条件下会逆向分解释放出CO₂而再生,从而实现CO₂从烟气中分离脱除。以醇胺溶液为吸收剂的化学吸收法技术开发相对成熟,且分离效果好、操作简单,在电力、钢铁、水泥、化工等行业得到广泛应用。醇胺溶液是化学吸收法的核心,目前应用于工业减排的醇胺溶液包括一级醇胺溶液、二级醇胺溶液、三级醇胺溶液以及空间位阻胺等。综述了4种典型的醇胺溶液和低浓度烟气吸收法胺液的国内外研究现状,介绍了国外三菱重工的KM-CDR工艺、壳牌康索夫脱硫脱碳工艺、陶氏化学Ucarsol溶剂的配套工艺、西门子氨基酸盐溶液的配套工艺、Powerspan的ECO₂工艺,同时对阿尔斯通的富氧燃烧技术进行了总结;国内在碳捕集方面研究时间较短,在“双碳”计划推动下,...     

碳化氨水中总碳含量和总氨含量的分析及测定

用过量CaCl2将含碳离子和含氮离子分别转变为CaCO3和NH4+(或NH3和NH4+),通过甲醛法测定上清液中氮量计算得到碳化氨水中总氨浓度,用EDTA滴定过量Ca2+得到碳化氨水中总碳浓度.结果表明,总碳和总氨浓度的测定结果与理论值间的相对误差分别在1.0%和1.5%以内.该方法能快速准确测定碳化氨水溶液中含碳量和含氨量,进而得到氨水吸收CO2过程中CO2负载量.     

水泥工业几种CO2捕获技术的评估

以MEA化学吸收法为参考标准，通过对参考水泥厂进行适当的技改，对纯氧燃烧法、冷却氨水法、膜分离法及两种钙循环法进行CO2捕获技术评估。结果表明，在定义的条件下，这几种CO2捕获技术的CO2减排当量为73%~90%，CO2减排能耗为1.63~4.07 MJ/kg CO2，而MEA化学吸收法CO2减排当量为64%，减排能耗为7.08 MJ/kg CO2；从成本的角度分析，纯氧燃烧法熟料生产成本和CO2减排成本均最低；对于燃烧后CO2捕获技术，参考技术MEA化学吸收法，比其他被评估技术更易于技术改造，其具有对水泥生产的影响小、设备放置不受限制等优势；与水泥生产联系更紧密的是纯氧燃烧法和集成式钙循环法，这两种技术被评估为更具挑战性；由于不同评估指标的技术参数不同，无法评估哪种方法最好，一般水泥厂可以从CO2减排当量和减排能耗上选择，但视具体情况而定，例如空间需求、现有的基础设施或运营经验等。     

化学吸收法与变压吸附法用于水泥厂CO2捕集的对比分析

本文对化学吸收法和物理变压吸附法（PSA）碳捕集技术工程在单位投资、运行成本和能源消耗方面进行了对比分析,结合水泥厂自身系统和可利用资源特点,分析了水泥厂采用化学吸收法碳捕集在成本优化、空间利用和未来发展适应性上的优势。通过分析对比,水泥厂碳捕集工程采用化学吸收法在单位投资成本、运行成本和对吸收剂的适应能力方面,均优于PSA法,建议水泥厂优先采用化学吸收法碳捕集技术。     

萃取富集原子吸收法测定水中的铅和铬(Ⅵ)含量

采用ＡＰＤＣ－ＤＤＴＣ－ＭＩＢＫ体系萃取富集水样中的铅和铬（Ⅵ）,并利用空气－乙炔火焰原子吸收法测定基含量。建立了优化的测定条件,并对可能存在的元素作了干扰实验。本法测定铅和铬（Ⅵ）的相对标准偏差分别为３．１％和２．２％,回收率为９７．５％和１０１．１％。     

原子吸收法测定水中微量的Cr(Ⅲ)和Cr(Ⅵ)

在0.15mol·L~(-1)H_2SO_4介质中,以氯化三辛基甲胺(TOMAC)为萃取剂,Cr(VI)被TOMAC定量萃取,而Cr(Ⅲ)不被萃取。将Cr(Ⅲ)氧化成Cr(Ⅵ)后可测水中总铬含量,通过差减法求出Cr(Ⅲ)含量。该方法快速、准确,可用于测定水中痕量的Cr(Ⅵ)和Cr(Ⅲ)。     

二氧化碳矿物碳酸化固定的技术进展

CO2矿物碳酸化固定可实现CO2的永久封存,环境风险性小,但苛刻的反应条件、过低的反应速率是困扰该技术发展的瓶颈.对CO2矿物碳酸化固定的工艺路线、所用原料及其强化措施的研究现状做了详细评述;指出以工业固体废弃物为原料,结合运用超重力强化传递反应技术与碳酸酐酶高效催化性能,实现烟气CO2分离、碳酸化固定、固体废弃物资源化利用多过程集成耦合的原位CO2固定技术是适合我国现阶段国情的CO2重要控制措施.     

温室气体CO2矿物碳酸化固定研究进展

将温室气体CO2以碳酸盐（如CaCO3、MgCO3）的固体形式永久储存起来,即CO2矿物碳酸化固定,是减少大气中CO2含量,解除温室效应的一种全新方法。从温室气体CO2矿物碳酸化固定所需的原料、化学及热力学、反应动力学机理等方面,分析了此种方法的特点,同时评述了CO2矿物碳酸化固定的6种典型工艺路线,以及国外有关温室气体CO2矿物碳酸化固定的研究热点。最后指出以工业固体废弃物为原料的间接工艺路线是温室气体CO2矿物碳酸化固定的具有较好应用前景的技术途径。     

高温碳化温度对碳纤维性能的影响

对经过相同预氧化、低温碳化和不同高温碳化处理的碳纤维样品进行了拉伸强度、拉伸模量、密度的分析,找出了2种原丝在经过碳化工艺处理后拉伸强度、拉伸模量、密度与高温碳化温度的相关性,并对其影响机理进行了研究。研究结果表明:在一定的温度范围内碳纤维拉伸强度随着高温碳化温度的提高而增加,在高温碳化温度达到一定值时,碳纤维拉伸强度将下降;碳纤维拉伸模量均随着高温碳化温度的提高而增加;碳纤维密度均随着高温碳化温度的提高而降低。     

Optimal strategy for carbon capture and storage infrastructure: A review

To effectively reduce CO₂, CO₂ mitigation technologies should be employed tactically. This paper focuses on carbon capture and storage (CCS) as the most promising CO₂ reduction technology and investigates how to establish CCS strategy suitably. We confirm a major part of the optimal strategy for CCS infrastructure planning through a literature review according to mathematical optimization criteria associated with facility location models. In particular, the feasibility of large scale CCS infrastructure is evaluated through economic, environmental, and technical assessment. The current state-of-the-art optimization techniques for CCS infrastructure planning are also addressed while taking numerous factors into account. Finally, a list of issues for future research is highlighted.     

Graphene-based sorbents for iodine-129 capture and sequestration

The capture and sequestration of iodine-129 (¹²⁹I), a long-lived byproduct of nuclear fission, is essential to the implementation of advanced nuclear fuel cycles and effective nuclear waste management. Current state-of-the-art technologies inherently require silver to bind iodine, e.g., silver-loaded silica aerogels or silver-loaded zeolite (AgZ), which are very expensive and an environmental concern. It is highly desirable to develop alternative cost-effective adsorbents for iodine capture and sequestration. Herein, we report graphene-based nanomaterials including graphene powder and graphene aerogel as novel iodine sorbents showing exceptional adsorption capability and kinetics. By measuring iodine sorption capacities and uptake rates in an I_2(g) saturated environment, graphene sorbents display impressive iodine sorption capacities with powdered samples achieving mass gains in excess of 85 mass%, and aerogels exceeding 100% mass gains. A direct correlation among specific surface area, defect concentration, and maximum sorption capacity has been established, and the sorption kinetics of the graphene for iodine capture was determined.     

Tension of carbonization for carbon fiber

The mechanical properties of carbon fiber, especially tensile modulus, are closely related to the orientation of crystals. Hence, the stretching of carbon fiber during carbonization is of importance. In this study, the tension arm between the carbonization furnaces was used to stretch carbon fiber. The relationships among the stretching tensions of the first stage carbonization (< 800°C) and the second stage carbonization (> 1200°C), the aromatization index for oxidized polyacrylonitrile fiber, and the properties of carbon fiber are discussed.     

Conservation tillage for carbon sequestration

World soils represent the largest terrestrial pool of organic carbon (C), about 1550 Pg compared with about 700 Pg in the atmosphere and 600 Pg in land biota. Agricultural activities (e.g., deforestation, burning, plowing, intensive grazing) contribute considerably to the atmospheric pool. Expansion of agriculture may have contributed substantially to the atmospheric carbon pool. However, the exact magnitude of carbon fluxes from soil to the atmosphere and from land biota to the soil are not known. An important objective of the sustainable management of soil resources is to increase soil organic carbon (SOC) pool by increasing passive or non-labile fraction. Soil surface management, soil water conservation and management, and soil fertility regulation are all important aspects of carbon sequestration in soil. Conservation tillage, a generic term implying all tillage methods that reduce runoff and soil erosion in comparison with plow-based tillage, is known to increase SOC content of the surface layer. Principal mechanisms of carbon sequestration with conservation tillage are increase in micro-aggregation and deep placement of SOC in the sub-soil horizons. Other useful agricultural practices associated with conservation tillage are those that increase biomass production (e.g., soil fertility enhancement, improved crops and species, cover crops and fallowing, improved pastures and deep-rooted crops). It is also relevant to adopt soil and crop management systems that accentuate humification and increase the passive fraction of SOC. Because of the importance of C sequestration, soil quality should be evaluated in terms of its SOC content. This revised version was published online in August 2006 with corrections to the Cover Date.     

膜吸收法回收烟气中CO_2的过程研究

对膜吸收法回收CO2技术进行了研究,针对膜吸收CO2的特点,筛选出了适合的膜组件和有机胺配方溶液,建立了1套用于连续吸收和解吸试验的模拟装置,并进行了连续试验。研究了气体流量、溶液流量、吸收温度等操作条件对吸收效果的影响,考察了配方溶液在降低碳回收过程能耗方面的优势,在CO2捕集率达到80%时,新配方溶液再生能耗较相同浓度的乙醇胺溶液降低了29.7%。     

Equilibrium and absorption kinetics of carbon dioxide by solid supported amine sorbent

The equilibrium and conversion‐time data on the absorption of carbon dioxide (CO₂) with amine‐based solid sorbent were analyzed over the range of 303–373 K. Data on CO₂ loading on amine based solid sorbent at these temperatures and CO₂ partial pressure between 10 and 760 mm Hg obtained from volumetric adsorption apparatus were fitted to a simple equilibrium model to generate the different parameters (including equilibrium constant) in the model. Using these constants, a correlation was obtained to define equilibrium constant and maximum CO₂ loading as a function of temperature. In this study, a shrinking core model (SCM) was applied to elucidate the relative importance of pore diffusion and surface chemical reaction in controlling the rate of reaction. Application of SCM to the data suggested a surface reaction‐controlled mechanism for the temperature of up to 40°C and pore‐diffusion mechanism at higher temperature. Published 2011 American Institute of Chemical Engineers AIChE J, 2011     

Effect of the presence of trace sulfur dioxide on piperazine-based amine absorbents for carbon dioxide capture

The effect of the presence of trace SO2 in industrial flue gas on the amine-scrubbing-based absorption process for CO2 capture has been a matter of concern.This study aimed to investigate the effect of trace SO2 on the CO2 capture process using piperazine-based amine absorbents,focusing on SO2-resistance capability,SO2/CO2 absorption selectivity,and cyclic stability.The presence of trace SO2 not only restrains CO2 absorption,but also promotes the formation of carbamate within the piperazine-based amine ab-sorbents.Remarkably,the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO2-resistance capability by promoting the formation of carbamate,while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO2-resistance capability.The work offers valuable insights into the efficient application of novel amine absorbents for CO2 capture from practical industrial flue gas.