Establishing hydropyrolysis as an effective technique for the determination and isolation of pyrogenic carbon in samples from the natural environment

建立加氢热解作为测定和分离自然环境样品中热解碳的有效技术

• 批准号: NE/F017456/1
• 负责人: Colin Snape
• 金额: $ 59万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF017456%2F1
• 关键词: Establishing; hydropyrolysis; effective; technique; determination

Pyrogenic Carbon (PC) is the generic term now most commonly used to describe material arising from the incomplete combustion of natural and anthropogenic biomass and fossil fuels. It has been referred to by a variety of other terms, including soot, char, charcoal, microcharcoal, under the collective heading of black carbon. The range of names used reflects not only its compositional complexity but also its importance to several disciplines, encompassing archaeology, the global carbon cycle and palaeoenvironmental reconstruction. The traditional understanding of PC is that it is highly recalcitrant and it is known to persist for thousands of years in soils, with estimated half-lives being about 5,000 years. Dependant on environmental conditions, the presumption of long-term preservation is supported by the high degree of resistance of PC to a range of chemical oxidants. In contrast, there is now considerable evidence that PC can undergo degradation in some environments on comparatively short timescales. For example, most of the PC in a regularly-burned savanna soil has been degraded on decadal timescales. In addition to microbial degradation, it has also been shown that PC is susceptible to photo-oxidation, albeit at a slower rate than more labile forms of organic carbon. Thus, at a fundamental level, the major questions amongst PC researchers are how can the stability of these materials in a range of environments be quantified and what are the mechanisms by which alteration can occur in natural environments? Clearly, to address these questions, universally accepted procedures are needed for the quantification and purification of PC. Unfortunately, current methods based primarily on chemical/thermal oxidation give widely varying results and, consequently, no single procedure has gained acceptance. However, it is possible to remove all the labile organic matter from soils and sedimentary organic matter reductively via a new approach, hydropyrolysis (hypy) with precise results being obtained in a fraction of the time required for other procedures. The goal of this proposal is to carry out the fundamental research necessary to establish the theoretical basis for proving that hypy can provide a universal approach both for PC quantification and for the removal of labile organic matter to isolate PC for radiocarbon, bulk stable isotope measurements, as well as for elucidating and quantifying changes in PC structure arising from environmental degradation. Once hypy has been proven to be a highly effective method form PC quantification and purification, this will then pave the way for the technique being adopted by researchers in many hundreds of institutions worldwide that are involved in aspects of PC research, as well as by the 150+ radiocarbon laboratories that currently exist. This will lead to a number of potential sales of hypy reactor systems, through Nottingham's partner company, Strata. The proposed comparison between hypy and existing oxidation treatments will enable much of the literature to be re-evaluated in terms of identifying where realistic PC concentrations have been reported. Further, proving that PC is a more reproducible proxy for terrestrial stable isotope records than whole peat/coal samples will provide exciting possibilities of using PC as a means to rapidly correlate between disparate sedimentary records and develop records of environmental change, without the confounding influence of organic matter decay.

热解碳 (PC) 是目前最常用的通用术语，用于描述自然和人为生物质和化石燃料不完全燃烧产生的材料。它也有多种其他术语，包括烟灰、炭、木炭、微木炭，统称为黑碳。使用的名称范围不仅反映了其组成的复杂性，而且反映了它对多个学科的重要性，包括考古学、全球碳循环和古环境重建。对 PC 的传统理解是，它具有很强的顽固性，已知它可以在土壤中持续存在数千年，估计半衰期约为 5,000 年。根据环境条件，PC 对一系列化学氧化剂的高度耐受性支持了长期保存的假设。相比之下，现在有大量证据表明，PC 在某些环境中可能会在相对较短的时间内发生退化。例如，经常燃烧的稀树草原土壤中的大部分 PC 已在十年时间尺度上降解。除了微生物降解之外，研​​究还表明，PC 很容易发生光氧化，尽管其速度比更不稳定的有机碳形式要慢。因此，从根本上讲，PC 研究人员面临的主要问题是如何量化这些材料在各种环境中的稳定性以及在自然环境中发生改变的机制是什么？显然，为了解决这些问题，需要普遍接受的程序来定量和纯化 PC。不幸的是，目前主要基于化学/热氧化的方法给出了广泛不同的结果，因此，没有单一的程序获得认可。然而，可以通过一种新方法，即加氢热解 (hypy) 还原性地去除土壤和沉积有机物中的所有不稳定有机物，并且只需其他程序所需时间的一小部分即可获得精确结果。本提案的目标是开展必要的基础研究，以建立理论基础，证明 hypy 可以为 PC 定量和去除不稳定有机物以分离 PC 以进行放射性碳、散装稳定同位素测量提供通用方法，以及阐明和量化环境退化引起的 PC 结构变化。一旦 hypy 被证明是一种高效的 PC 定量和纯化方法，这将为全球数百个涉及 PC 研究方面的机构的研究人员以及其他领域的研究人员采用该技术铺平道路。目前有 150 多个放射性碳实验室。这将通过诺丁汉的合作伙伴公司 Strata 带来大量 hypy 反应堆系统的潜在销售。 hypy 和现有氧化处理之间的拟议比较将使许多文献能够在确定报告的实际 PC 浓度方面得到重新评估。此外，证明 PC 是比整个泥炭/煤样品更具再现性的陆地稳定同位素记录代理，将为使用 PC 作为一种手段来快速关联不同的沉积记录并开发环境变化记录提供令人兴奋的可能性，而不会受到以下因素的混杂影响：有机物腐烂。

项目成果

The efficiency of charcoal decontamination for radiocarbon dating by three pre-treatments - ABOX, ABA and hypy

三种预处理（ABOX、ABA 和 hypy）对木炭去污进行放射性碳测年的效率

• DOI: http://dx.10.1016/j.quageo.2014.02.003
• 发表时间: 2014
• 期刊: Quaternary Geochronology
• 影响因子: 2.7
• 作者: Bird M

Hydropyrolysis as a new tool for radiocarbon pre-treatment and the quantification of black carbon

氢热解作为放射性碳预处理和黑碳定量的新工具

• DOI: 10.1016/j.quageo.2008.11.001
• 发表时间: 2009-04-01
• 期刊: Quaternary Geochronology
• 影响因子: 2.7
• 作者: P. Ascough;M. Bird;F. Brock;T. Higham;W. Meredith;C. Snape;C. Vane
• 通讯作者: C. Vane

Isotopes in pyrogenic carbon: A review

热解碳中的同位素：综述

• DOI: 10.1016/j.orggeochem.2010.09.005
• 发表时间: 2024-09-13
• 期刊: Organic Geochemistry
• 影响因子: 3
• 作者: M. Bird;P. Ascough
• 通讯作者: P. Ascough

Comparison of microscale sealed vessel pyrolysis (MSSVpy) and hydropyrolysis (Hypy) for the characterisation of extant and sedimentary organic matter

微型密封容器热解 (MSSVpy) 和加氢热解 (Hypy) 用于表征现存和沉积有机质的比较

• DOI: 10.1016/j.jaap.2009.10.009
• 发表时间: 2024-09-14
• 期刊: Journal of Analytical and Applied Pyrolysis
• 影响因子: 6
• 作者: Lyndon Berwick;P. Greenwood;W. Meredith;C. Snape;H. Talbot
• 通讯作者: H. Talbot

Variability in oxidative degradation of charcoal: Influence of production conditions and environmental exposure

木炭氧化降解的变化：生产条件和环境暴露的影响

• DOI: 10.1016/j.gca.2011.02.002
• 发表时间: 2011-05-01
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: P. Ascough;M. Bird;S. Francis;B. Thornton;A. J. Midwood;A. Scott;D. Apperley
• 通讯作者: D. Apperley