加快生物质废弃物吸附增强制可再生氢气

作为全球性的优质能源载体,氢的主要生产方式包括碳氢化合物（例如天然气、煤炭和生物质）的热化学过程以及使用电力来源与可再生能源（如风能或太阳能等）的水电解过程。目前的水电解技术在大规模制氢方面经济竞争力亟待提升。本文指出：为了在2060年实现碳中和,迫切需要开发绿氢制备新技术,大力发展可再生制氢和低碳制氢。具有碳捕集、利用和封存的碳氢化合物低碳制氢（蓝色）技术将占重要地位,随后逐步转向可再生制氢（绿色）,并有望全面实现零碳制氢,进而对长期低碳化社会的发展至关重要。文章提出我国生物质资源非常丰富,但生物质废弃物制氢的技术成熟度仍然较低,迫切需要开发从生物质中高效生产可再生氢气的新技术,以显著提高氢气产量并降低成本;吸附增强反应代表了一种可用于可持续生产氢的有前景的新技术;氢气的产率和纯度可以通过过程强化得到显著提高,制氢过程的强化可以在多功能反应器中实现,其中重整和/或气化、水煤气变换和CO₂移除步骤可将重整/水煤气变换反应催化剂和CO₂捕集剂混合而集成到一个反应器中。最后指出：由于该过程潜力巨大,因此应助推耦合气化和吸附增强反应过程从生物质废弃物中生产可再生氢气的工艺过程,以加快推进碳中和进程。     

The technical feasibility of biomass gasification for hydrogen production

Biomass gasification for energy or hydrogen production is a field in continuous evolution, due to the fact that biomass is a renewable and CO₂ neutral source. The ability to produce biomass-derived vehicle fuel on a large scale will help to reduce greenhouse gas and pollution, increase the security of European energy supplies, and enhance the use of renewable energy. The Värnamo Biomass Gassification Centre in Sweden is a unique plant and an important site for the development of innovative technologies for biomass transformation. At the moment, the Värnamo plant is the heart of the CHRISGAS European project, that aims to convert the produced gas for further upgrading to liquid fuels as dimethyl ether (DME), methanol or Fischer–Tropsch (F–T) derived diesel. The present work is an attempt to highlight the conditions for the reforming unit and the problems related to working with streams having high contents of sulphur and alkali metals.     

不同CO2捕集技术的CO2耦合绿氢制甲醇工艺研究

大量的化石燃料燃烧导致温室气体排放增加,全球气候变暖。世界各国以全球协约的方式减排CO₂,我国也由此提出“碳达峰·碳中和”目标。CO₂捕集以及转化制液体燃料和化学品是双碳目标下行之有效的碳减排措施之一,不仅可以实现CO₂的资源化利用,同时也缓解了国家能源安全问题。本文以燃煤电厂烟气CO₂捕集和CO₂合成甲醇为研究对象,分析了基于四种不同CO₂捕集技术的CO₂耦合绿氢制甲醇工艺。对四种不同CO₂捕集技术的CO₂制甲醇工艺进行了严格的稳态建模和模拟,分析和比较了不同CO₂捕集技术情景下的CO₂制甲醇工艺的技术和经济性能。结果表明,MEA、PCS、DMC和GMS情景的单位甲醇能耗分别是7.81、5.48、5.91和4.66 GJ/ t CH₃OH,GMS情景的单位能耗最低,其次是PCS情景,但随着更高效相变吸收剂的开发,PCS情景的单位甲醇产品的能耗将降低至2.29~2.58 GJ/t CH₃OH。四种情景的总生产成本分别是4314、4204、4279和4367 CNY/ t CH₃OH,PCS情景的成本最低,更具有经济优势。综合分析表明PCS情景的性能表现最好,为可用于燃煤电厂最佳的碳捕集技术,为CO₂高效合成燃料化学品提供方向,缓解化石燃料短缺和环境污染问题。     

不同CO2捕集技术的CO2耦合绿氢制甲醇工艺研究

大量的化石燃料燃烧导致温室气体排放增加,全球气候变暖。世界各国以全球协约的方式减排CO₂,我国也由此提出“碳达峰·碳中和”目标。CO₂捕集以及转化制液体燃料和化学品是双碳目标下行之有效的碳减排措施之一,不仅可以实现CO₂的资源化利用,同时也缓解了国家能源安全问题。本文以燃煤电厂烟气CO₂捕集和CO₂合成甲醇为研究对象,分析了基于四种不同CO₂捕集技术的CO₂耦合绿氢制甲醇工艺。对四种不同CO₂捕集技术的CO₂制甲醇工艺进行了严格的稳态建模和模拟,分析和比较了不同CO₂捕集技术情景下的CO₂制甲醇工艺的技术和经济性能。结果表明,MEA、PCS、DMC和GMS情景的单位甲醇能耗分别是7.81、5.48、5.91和4.66 GJ/ t CH₃OH,GMS情景的单位能耗最低,其次是PCS情景,但随着更高效相变吸收剂的开发,PCS情景的单位甲醇产品的能耗将降低至2.29~2.58 GJ/t CH₃OH。四种情景的总生产成本分别是4314、4204、4279和4367 CNY/ t CH₃OH,PCS情景的成本最低,更具有经济优势。综合分析表明PCS情景的性能表现最好,为可用于燃煤电厂最佳的碳捕集技术,为CO₂高效合成燃料化学品提供方向,缓解化石燃料短缺和环境污染问题。     

Solid oxide fuel cells in combination with biomass gasification for electric power generation

Biomass, a source of renewable energy, represents an effective substitute to fossil fuels. Gasification is a process that organics are thermochemically converted into valuable gaseous products(e.g. biogas). In this work, the catalytic test demonstrated that the biogas produced from biomass gasification mainly consists of H_2,CH_4, CO,and CO_2, which were then be used as the fuel for solid oxide fuel cell(SOFC). Planar SOFCs were fabricated and adopted. The steam reforming of biogas was carried out at the anode of a SOFC to obtain a hydrogen-rich fuel.The performance of the SOFCs operating on generated biogas was investigated by I–V polarization and electrochemical impedance spectra characterizations. An excellent cell performance was obtained, for example,the peak power density of the SOFC reached 1391 mW·cm~(-2) at 750℃ when the generated biogas was used as the fuel. Furthermore, the SOFC fuelled by simulated biogas delivered a very stable operation.     

生物质能源转化技术与应用(Ⅳ) ——生物质热解气化技术研究和应用

生物质能源是惟一可再生、可替代化石能源转换成气态、液态和固态燃料以及其他化工原料或者产品的碳资源。随着化石能源的枯竭和人类对全球性环境问题的关注,生物质能源替代化石能源利用的研究和开发,已成为国内外众多学者研究和关注的热点。本系列讲座主要讲述以生物质资源为主要原料,通过不同途径转化为洁净的、高品位的气体、液体或固体燃料。本讲主要对生物质的热解气化方式进行了介绍,着重介绍了生物质气化集中供气、供热、发电、合成液体燃料、制氢等技术方面的研究和应用现状,并指出了目前存在的主要问题,提出了我国在生物质气化领域的重点研究方向。     

Thermoneutral tri-reforming of flue gases from coal- and gas-fired power stations

The treatment of flue gases from fossil fuel fired power stations by tri-reforming with natural gas or by coal gasification could become an attractive approach for converting the CO₂, H₂O, O₂, and N₂ contained in these flue gases via syngas processing into useful products, such as methanol, hydrogen, ammonia, or urea. The present study determines the constraints for achieving such thermochemical reactions under conditions of thermoneutrality, by reacting the flue gases with water, air, and natural gas or coal at 1000–1200 K. The implications of such reactions are examined in terms of CO₂ emission avoidance, fuel saving, economic viability, and exergy efficiency.     

二氧化碳加氢合成低碳烯烃的研究进展

大气中逐年升高的二氧化碳浓度对全球环境产生了严重的影响。通过可再生能源得到的H₂与CO₂反应生成低碳烯烃,不但可以使CO₂得到资源化利用,还能减少低碳烯烃的生产对于石油资源的依赖。该技术还有望实现从海水中得到燃油。本文主要对CO₂加氢合成低碳烯烃的热力学、反应机理和催化剂研究进行了综述。目前,该反应中使用的催化剂以Fe系为主。文中简要介绍了直接转化催化剂中的载体、助剂和双金属活性组分对反应性能的影响以及经甲醇路线制低碳烯烃的双功能催化剂在该反应中的应用。高性能催化剂的设计以及反应机理的探索是CO₂加氢合成低碳烯烃未来的发展方向。     

生物质热化学法制氢技术的研究进展

介绍木质生物质热化学法生产氢气的四条主要技术路线,分别是生物质气化制氢、生物质热解油制氢、生物质超临界水气化制氢、源于生物质的小分子有机物催化重整制氢方法,着重从化学反应机理、热力学模拟、催化剂种类、工艺开发、工业化进展等方面总结生物质热化学制氢技术的最新研究进展,分析了各类小分子制氢的热力学规律,并指出工业化过程存在...     

ALTERNATIVE GENERATION OF H2, CO AND H2, CO2 MIXTURES FROM STEAM-CARBON DIOXIDE REFORMING OF METHANE AND THE WATER GAS SHIFT WITH PERMEABLE (MEMBRANE) REACTORS

A new process is proposed which converts CO₂ and CH₄ containing gas streams to synthesis gas, a mixture of CO and H₂ via the catalytic reaction scheme of steam-carbon dioxide reforming of methane or the respective one of only carbon dioxide reforming of methane, in permeable (membrane) reactors. The membrane reformer (permreactor) can be made by reactive or inert materials such as metal alloys, microporous ceramics, glasses and composites which all are hydrogen permselective. The rejected CO reacts with steam and converted catalytically to CO₂ and H₂ via the water gas shift in a consecutive permreactor made by similar to the reformer materials and alternatively by high glass transition temperature polymers. Both permreactors can recover H₂ in permeate by using metal membranes, and H₂ rich mixtures by using ceramic, glass and composite type permselective membranes. H₂ and CO₂ can be recovered simultaneously in water gas shift step after steam condensation by using organic polymer membranes. Product yields are increased through permreactor equilibrium shift and reaction separation process integration.

CO and H₂ can be combined in first step to be used for chemical synthesis or as fuel in power generation cycles. Mixtures of CO₂ and H₂ in second step can be used for synthesis as well (e.g., alternative methanol synthesis) and as direct feed in molten carbonate fuel cells. Pure H₂ from the above processes can be used also for synthesis or as fuel in power systems and fuel cells. The overall process can be considered environmentally benign because it offers an in-situ abatement of the greenhouse CO₂ and CH₄ gases and related hydrocarbon-CO₂ feedstocks (e.g., coal, landfill, natural, flue gases), through chemical reactions, to the upgraded calorific value synthesis gas and H₂, H₂ mixture products.     

基于二氧化碳、水、太阳能的绿色化工精炼

化石资源为人类提供了不可或缺的化学品、材料以及燃料,但也造成了大量二氧化碳排放。生物质是可以生产低碳化工产品的可再生资源,但要占用有限的可耕地资源。提出了直接以二氧化碳、水和太阳能为原料的绿色化工精炼。采用光电板收集太阳能并转化为电能,电能通过膜式水电解池产生氢气,氢气通入新型生物反应器并在自养菌的作用下把二氧化碳还原为聚三羟基丁酸酯(PHB)。此新型生物反应器解决了因气体溶解性低而影响传质速度的关键技术,微生物干重产出达0.18 g·L^-1·h^-1,其中PHB质量分数约50%。PHB不仅是优良的可生物降解塑料,也是可用于生产C₃～C₄有机低分子和芳香烃的平台化合物。在磷酸催化作用下,PHB可转化为与汽油相当热值和元素组成的C₄～C₁₆燃料油。分离PHB后的细菌生物质残渣可水热分解获得生物油和富氮水相产物。此生物油具有比植物生物油更高的热值,而水相产物可作为营养物用于培养微生物。     

High-efficiency and pollution-controlling in-situ gasification chemical looping combustion system by using CO2 instead of steam as gasification agent

Using CO₂ as gasification agent instead of steam in in-situ coal gasification chemical looping combustion (iG-CLC) power plant can eliminate energy consumption for steam generation, thus obtaining higher system efficiency. In this work, a comparative study of iG-CLC power plant using steam and CO₂ as gasification agent is concentrated on. The effects of steam to carbon ratio (S/C) and CO₂ to carbon ratio (CO₂/C) on the fuel reactor temperature, char conversion, syngas composition and CO₂ capture efficiency are separately investigated. An equilibrium carbon conversion of 88.9% is achieved in steam-based case as S/C ratio increases from 0.7 to 1.1, whereas a maximum conversion of 84.2% is obtained in CO₂-based case with CO₂/C ranging from 0.7 to 1.1. Furthermore the effects of oxygen carrier to fuel ratio (φ) on system performances are investigated. Increasing φ from 1.0 to 1.4 helps to achieve char conversion from 75.9% to 88.9% in steam-based case, by contrast the char conversion can achieve 66.3%-84.2% in CO₂-based case within the same φ range. In terms of iG-CLC power plant, recycling partial CO₂ to the fuel reactor improves the overall performance. Approximately 3.9% of net power efficiency are increased in CO₂-based plant, from steam-based plant. Higher CO₂ capture efficiency and lower CO₂ emission rate are observed in CO₂-gasified iG-CLC power plant, expecting to be 90.63% and 85.18 kg·MW^-1·h^-1, respectively.     

MoS_2基催化剂上生物质基合成气制乙醇

生物质作为重要的可再生绿色能源,由于资源丰富,分布广泛,S、N含量低,CO_2零排放等优点,必将为实现可持续发展起到举足轻重的作用。乙醇作为一种最具潜能的汽油添加剂及化石燃料替代品,具有辛烷值高,无污染等优点。因此,催化生物质基合成气制乙醇作为可再生能源开发的途径之一,极具研究价值及工业价值。综述MoS_2基催化剂上生物质基合成气制乙醇的重要研究进展,指出利用合成气催化制乙醇的效率还有待进一步提高,尚未达到实际应用要求。改性MoS_2基催化剂对乙醇选择性较高,但烃类及CO_2副产物较多。为了促进乙醇的生成,今后合成气催化制乙醇应深入系统的研究碱金属和过渡金属共同促进的MoS_2基催化剂,并借助科学技术发展运用新方法和新思路,制备高效、稳定的催化剂。     

Ce掺杂La0.7Sr0.3Cr0.5Fe0.5O3-δ材料的制备及其电化学性能

近年来化石燃料大量消耗导致环境污染日益严重,固体氧化物电解池(SOEC)能够高效、环境友好地将CO₂转化为CO等高附加值化学品,因此受到广泛关注。开发高效稳定的SOEC需要采用性能优异的电极材料,La_0.7Sr_0.3Cr_0.5Fe_0.5O_3-δ(Sto-LSCrF)钙钛矿氧化物因其优异的氧化还原稳定性受到了高度重视。为进一步提高Sto-LSCrF燃料电极材料电解CO₂的能力,在Sto-LSCrF的A位掺杂Ce来调控Ce_0.08La_0.62Sr_0.3Cr_0.5Fe_0.5O_3-δ(Ce-LSCrF)中可移动氧空穴含量以便提高其对CO₂的吸附/活化能力,进而改善其电化学性能。同时对材料的相结构、氧空穴含量以及其对CO₂的吸附/脱附能力进行详细的表征和分析。此外,我们还探究了Ce-LSCrF的电化学性能,发现与Sto-LSCrF相比,Ce-LSCrF燃料电极表现出较高的电解性能,也显示出较好的恒压稳定性,电解性能的增强归因于Ce-LSCrF晶格中较多的可移动氧空位可有效吸附/活化CO₂,以上试验结果表明Ce-LSCrF是性能优异的CO₂电解材料。     

绿氢重构的粉煤气化煤制甲醇近零碳排放工艺研究

在“碳达峰、碳中和”的背景下，传统煤制甲醇工艺存在CO₂排放强度大、能耗高等问题成为制约煤制甲醇工艺发展的瓶颈问题。本研究基于外源性的绿氢，重构粉煤气化煤制甲醇工艺，省掉了空分单元、变换单元，开发了短流程低温甲醇洗单元，提出了粉煤气化集成绿氢的近零碳排放煤制甲醇新工艺。从碳元素利用率、CO₂排放、成本分析等角度对新工艺进行了评价。结果表明，与传统煤制甲醇工艺相比，新工艺碳元素利用率从41.50%提高到95.77%，CO₂直接排放量由1.939降低至0.035 t·(t MeOH)^-1，通过分析H₂价格与碳税对产品成本的影响发现，当氢气价格和碳税分别为10.36 CNY·(kg H₂)^-1和223.3 CNY·(t CO₂)^-1时，两种工艺的产品成本相当。新工艺不仅减少了煤制甲醇过程碳排放，而且可以提高可再生能源就地消纳能力，具有良好的应用前景。     

Electrolytic cell engineering and device optimization for electrosynthesis of e-biofuels via co-valorisation of bio-feedstocks and captured CO2

Utilizing CO₂ in an electro-chemical process and synthesizing value-added chemicals are amongst the few viable and scalable pathways in carbon capture and utilization technologies.CO₂ electro-reduction is also counted as one of the main options entailing less fossil fuel consumption and as a future electrical energy storage strategy.The current study aims at developing a new electrochemical platform to produce low-carbon e-biofuel through multifunctional electrosynthesis and integrated co-valorisation of biomass feedstocks with captured CO₂.In this approach,CO₂ is reduced at the cathode to produce drop-in fuels(e.g.,methanol)while value-added chemicals(e.g.,selective oxidation of alcohols,aldehydes,carboxylic acids and amines/amides)are produced at the anode.In this work,a numerical model of a continuous-flow design considering various anodic and cathodic reactions was built to determine the most techno-economically feasible configurations from the aspects of energy efficiency,environment impact and economical values.The reactor design was then optimized via parametric analysis.     

温度对厌氧耗氢产甲烷的影响研究进展

化石燃料燃烧过程中大量排放的CO₂引起了人们对CO₂生物甲烷化的关注。厌氧有机物生物降解过程中，与CO₂生物甲烷化相关的主要是厌氧耗氢产甲烷菌。近年来，研究者们关注温度对厌氧耗氢产甲烷过程的影响，对推动厌氧耗氢产甲烷工艺的发展有着重要的意义。本文从厌氧耗氢产甲烷技术原理出发，介绍了厌氧生物降解过程中耗氢产甲烷菌的重要作用，归纳了32种仅利用H₂和CO₂产CH₄的专性耗氢产甲烷菌，展示了氢气可以来源于化石燃料、生物质、水的分解和工业气体，综述了不同温度范围下厌氧耗氢产甲烷的效能，总结了不同温度变化方式对厌氧耗氢产甲烷的影响，并从氢气来源和温度变化等方面提出了展望。     

钙基吸附剂循环吸附性能对增强式生物质气化制氢的影响研究

钙基吸附剂循环CO₂吸附性能对增强式生物质气化连续高效制氢起重要作用。采用将CaO颗粒分散在惰性载体中的方法并结合挤压成型技术制备了合成吸附剂颗粒。为了筛选循环吸附性能较好的吸附剂，在热重分析仪上进行了循环吸附性能测试。基于热重测试结果开展了吸附剂循环利用条件下的增强式生物质气化制氢实验。结果表明：添加惰性载体能延缓CaO烧结，提高吸附剂的循环吸附能力；挤压成型过程会破坏吸附剂原有孔隙结构，导致吸附剂颗粒吸附性能不同程度降低，其中CaSi75p、CaAl75p和CaY75p三种吸附剂循环性能较好；添加以上三种吸附剂颗粒均可显著提高生物质气化合成气中H₂浓度及产率，5次循环过程中气体成分和产率变化不大，表明吸附剂循环吸附能力和稳定性较好。     

An evaluation of autotrophic microbes for the removal of carbon dioxide from combustion gas streams

Carbon dioxide is a greenhouse gas that is believed to be a major contributor to global warming. Studies have shown that significant amounts of CO₂ are released into the atmosphere as a result of fossil fuels combustion. Therefore, considerable interest exists in effective and economical technologies for the removal of CO₂ from fossil fuel combustion gas streams. This work evaluated the use of autotrophic microbes for the removal of CO₂ from coal fired power plant combustion gas streams. The CO₂ removal rates of the following autotrophic microbes were determined: Chlorella pyrenoidosa, Euglena gracilis, Thiobacillus ferrooxidans, Aphanocapsa delicatissima, Isochrysis galbana, Phaodactylum tricornutum, Navicula tripunctata schizonemoids, Gomphonema parvulum, Surirella ovata ovata, and four algal consortia. Of those tested, Chlorella pyrenoidosa exhibited the highest removal rate with 2.6 g CO₂ per day per g dry weight of biomass being removed under optimized conditions. Extrapolation of these data indicated that to remove CO₂ from the combustion gases of a coal fired power plant burning 2.4 × 10⁴ metric tons of coal per day would require a bioreactor 386 km² × 1 m deep and would result in the production of 2.13 × 10⁵ metric tons (wet weight) of biomass per day. Based on these calculations, it was concluded that autotrophic CO₂ removal would not be feasible at most locations, and as a result, alternate technologies for CO₂ removal should be explored.