Distributed Hydrogen Production with Carbon Capture: A Novel Process for the Production of Hydrogen from Biomass

碳捕集分布式制氢：生物质制氢的新工艺

• 批准号: EP/F027435/1
• 负责人: John Dennis
• 金额: $ 22.41万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF027435%2F1
• 关键词: Distributed; Hydrogen; Production; Carbon; Capture

The use of hydrogen as a clean energy carrier is seen by policy makers and industry as a potential way of mitigating climate change arising from the emissions to atmosphere of CO2 arising from the use of fossil fuels. Hydrogen is also, currently, the most desirable fuel for use in the present generation of practicable solid oxide fuel cells. However, to replace fossil fuel with hydrogen requires the hydrogen to be produced either (i) from renewable resources, such as biomass, or (ii) from fossil fuels, with capture and long-term sequestration of the resulting by-product CO2 in the earth. This proposal is concerned with a novel method for the production of hydrogen from biomass, in a clean form suitable for direct use in a fuel cell without substantial gas clean-up. It is also a technique which could lend itself to operation at a range of scales / from small, distributed units, suitable for local sources of biomass or waste (such as in developing countries) to larger, more centralised power stations. Briefly, the process involves:1) The gasification of biomass in CO2 or CO2/steam to syngas containing CO and H2.2) Conversion of the syngas to a pure stream of CO2 and steam by passing it through a packed bed of Fe2O3, where the following reactions variously occur:0.788 CO + 0.947 Fe3O4 = 0.788 CO2 + 3 Fe0.947O (1)0.788 H2 + 0.947 Fe3O4 = 0.788 H2O + 3 Fe0.947O (2)H2 + 3Fe2O3 = 2Fe3O4 + H2O, (3)CO + 3Fe2O3 = 2Fe3O4 + CO2. (4)At an operating temperature of 1173 K, thermodynamic calculations show that eqs. (3) and (4) lie essentially well over to the right where reducing gases are present. Thus, in the packed bed, provided it is sufficiently long, there will be a region of Fe2O3 at the outlet, preceded by a region of Fe3O4. At the entrance to the bed, on the other hand, [CO] and [H2] are high. This means that the Fe3O4 first formed there by reactions (3) and (4) can react further by reactions (1) and (2). Thus, for the Fe3O4 to be reduced to Fe0.947O would require pCO/ pCO2 > 0.49 and pH2/ pH2O > 0.39, which is likely for a typical syngas. Accordingly, at the entrance will be a region of Fe0.947O. As time proceeds, there will, in effect be two fronts moving through the bed: one defining the boundary between Fe0.947O and Fe3O4 and one, nearer the exit, the boundary between Fe3O4 and Fe2O3. The flow of syngas to the packed bed would be stopped just before the Fe3O4 / Fe2O3 front breaks through the bed, to avoid the slip of CO into the outlet stream of gas. Accordingly, the outlet from this bed would be a stream of pure CO2 and some water, which could be condensed out, allowing sequestration of the CO2 if required. A proportion of the CO2 would be recycled to the gasifier. 3) Production of hydrogen. Hydrogen would be generated from the spent bed in 2) by passing steam through it, thus reversing reaction (2). For this to be the case, pH2/ pH2O < 0.39 and so the hydrogen would occur with a front of Fe3O4 propagating from the entrance until it reaches the Fe3O4 left at the end of stage 2).4) Regeneration of Fe2O3. Once the bed is sufficiently converted in 3), air is supplied to the bed to oxidise it back to Fe2O3; the products being depleted air and energy. The heated, depleted air leaves the oxidation reactor at high temperature (ca. 1273 K) and can be used to raise steam.5) Finally, the cycle is repeated, with the supply of syngas re-commenced to the bed regenerated in 4). Hence, by having a number of such beds, arranged in a suitable cyclic operation, it would be possible to operate the gasifier continuously.The overall reaction in the above, assuming that gasification of pure carbon were being undertaken, would be:C(s) + H2O(g) + 2.38 ( 0.21O2(g) + 0.79N2) = CO2(g) + H2(g) + 1.88 N2 Each of the products in this overall reaction would be in a separate stream.

政策制定者和工业界认为，使用氢作为清洁能源载体是缓解因使用化石燃料向大气排放二氧化碳而引起的气候变化的一种潜在方式。氢气也是目前最理想的用于本代实用固体氧化物燃料电池的燃料。然而，用氢代替化石燃料需要氢（i）从可再生资源如生物质中产生，或（ii）从化石燃料中产生，并在地球中捕获和长期封存所产生的副产物CO2。该提议涉及一种从生物质生产氢的新方法，该方法以清洁的形式适合于直接用于燃料电池而无需大量的气体净化。这也是一种技术，可以适用于各种规模的操作，从适合当地生物质或废物来源的小型分布式单元（如在发展中国家）到更大，更集中的发电站。简单地说，该方法包括：1）将生物质在CO2或CO2/蒸汽中气化成含有CO和H2的合成气。2）通过使合成气通过Fe 2 O3的填充床将合成气转化成纯的CO2和蒸汽流，其中不同地发生以下反应：0.788 CO + 0.947 Fe 3 O 4 = 0.788 CO2 + 3 Fe0.947 O（1）0.788 H2 + 0.947 Fe 3 O 4 = 0.788 H2O + 3 Fe0.947 O（2）H2 + 3Fe 2 O3 = 2Fe 3 O 4 + H2O，（3）CO +3Fe 2 O3 = 2Fe 3 O 4 + CO2。(4)At的工作温度为1173 K，热力学计算表明，方程。(3)和（4）基本上位于还原气体存在的右侧。因此，在填充床中，如果填充床足够长，则在出口处将存在Fe 2 O3区域，在该区域之前是Fe 3 O 4区域。在床的入口处，另一方面，[CO]和[H2]都很高。这意味着首先通过反应（3）和（4）形成的Fe 3 O 4可以通过反应（1）和（2）进一步反应。因此，要将Fe 3 O 4还原为Fe0.947O，需要pCO/pCO 2> 0.49和pH 2/pH 2 O> 0.39，这可能是典型的合成气。因此，在入口处将是Fe 0.947O的区域。随着时间的推移，实际上将有两个前沿穿过床层：一个前沿定义了Fe0.947O和Fe 3 O 4之间的边界，另一个前沿（靠近出口）定义了Fe 3 O 4和Fe 2 O3之间的边界。在Fe 3 O 4/Fe 2 O3前沿突破填充床之前，停止合成气向填充床的流动，以避免CO滑入出口气流中。因此，该床的出口将是纯CO2和一些水的流，其可以被冷凝出来，如果需要的话允许封存CO2。一部分CO2将被再循环到气化炉。3)生产氢气。氢气将通过使蒸汽通过2）中的废床而从废床产生，从而逆转反应（2）。在这种情况下，pH 2/pH 2 O < 0.39，因此氢气将以Fe 3 O 4的前沿从入口传播直到其到达在阶段2）结束时留下的Fe 3 O 4而出现。4）Fe 2 O3的再生。一旦床在3）中充分转化，向床供应空气以将其氧化回Fe 2 O3;产物是耗尽的空气和能量。加热的、耗尽的空气在高温下离开氧化反应器（约100 ° C）。5）最后，重复该循环，重新开始向4）中再生的床供应合成气。假设进行纯碳的气化，上述总反应为：C（s）+H2 O（g）+2.38（0.21O2（g）+0.79N2）= CO2（g）+ H2（g）+1.88N2在该总反应中，每种产物都是单独的物流。

项目成果

Measuring the kinetics of the reduction of iron oxide with carbon monoxide in a fluidized bed

• DOI: 10.1007/978-3-642-02682-9_84
• 发表时间: 2009-05
• 作者: C. D. Bohnt;J. Cleeton;C. Miiller;S. A. Scotr;J. S. Dennis

Different methods of manufacturing FE-based oxygen carrier particles for reforming via chemical looping, and their effect on performance

• DOI: 10.1007/978-3-642-02682-9_77
• 发表时间: 2009-05
• 期刊: Biosensors & bioelectronics
• 影响因子: 12.6
• 作者: J. Cleeton;C. D. Bonn;C. Müller;J. S. Dennis;S. Scott

Chemical Looping Combustion: One Answer to Sequestering CO2

化学循环燃烧：封存二氧化碳的一种方法

• 发表时间: 2009
• 作者: C Dennis

Development of Iron Oxide Carriers for Chemical Looping Combustion Using Sol-Gel

• DOI: 10.1021/ie100046f
• 发表时间: 2010-06-02
• 期刊: INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
• 影响因子: 4.2
• 作者: Kierzkowska, A. M.;Bohn, C. D.;Mueller, C. R.
• 通讯作者: Mueller, C. R.

Stabilizing Iron Oxide Used in Cycles of Reduction and Oxidation for Hydrogen Production

• DOI: 10.1021/ef100199f
• 发表时间: 2010-07-01
• 期刊: ENERGY & FUELS
• 影响因子: 5.3
• 作者: Bohn, C. D.;Cleeton, J. P.;Dennis, J. S.
• 通讯作者: Dennis, J. S.