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）是目前最常用于描述天然和人为生物质和化石燃料不完全燃烧产生的物质的通用术语。它被称为各种其他术语，包括烟灰，焦炭，木炭，微木炭，在黑碳的集体标题下。使用的名称范围不仅反映了其组成的复杂性，还反映了其对几个学科的重要性，包括考古学，全球碳循环和古环境重建。对PC的传统理解是，它是高度可降解的，已知它在土壤中存在数千年，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长期保存的假设。相比之下，现在有相当多的证据表明，PC可以在相对较短的时间内在某些环境中发生降解。例如，经常燃烧的稀树草原土壤中的大部分PC在十年的时间尺度上已经退化。除了微生物降解外，还表明PC易受光氧化的影响，尽管其速率比更不稳定形式的有机碳慢。因此，在基本层面上，PC研究人员的主要问题是如何量化这些材料在一系列环境中的稳定性，以及在自然环境中发生变化的机制是什么？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，没有单一的程序已获得认可。然而，有可能通过一种新的方法，即加氢热解（hypy），以还原方式从土壤和沉积有机物中去除所有不稳定的有机物，并在其他程序所需时间的一小部分内获得精确的结果。本提案的目标是进行必要的基础研究，以建立理论基础，证明hypy可以提供一个通用的方法，PC量化和去除不稳定的有机物，以隔离PC的放射性碳，散装稳定同位素测量，以及阐明和量化PC结构的变化所产生的环境退化。一旦hypy被证明是一种非常有效的PC定量和纯化方法，这将为全球数百个参与PC研究的机构以及目前存在的150多个放射性碳实验室的研究人员采用该技术铺平道路。通过诺丁汉的合作伙伴公司Strata，这将导致一些潜在的高温反应堆系统的销售。拟议的hypy和现有的氧化处理之间的比较将使许多文献重新评估方面，确定现实的PC浓度已报告。此外，证明PC是一个更可重复的代理陆地稳定同位素记录比整个泥炭/煤样品将提供令人兴奋的可能性，使用PC作为一种手段，以快速相关的不同的沉积记录和发展记录的环境变化，没有混淆的影响，有机质腐烂。

项目成果

Loss and gain of carbon during char degradation

炭降解过程中碳的损失和增加

• DOI: 10.1016/j.soilbio.2016.12.012
• 发表时间: 2017
• 期刊: Soil Biology and Biochemistry
• 影响因子: 9.7
• 作者: Bird M

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

• DOI: 10.1016/j.quageo.2014.02.003
• 发表时间: 2014-08-01
• 期刊: QUATERNARY GEOCHRONOLOGY
• 影响因子: 2.7
• 作者: Bird, Michael I.;Levchenko, Vladimir;Apperley, David C.
• 通讯作者: Apperley, David C.

Chemical Characteristics of Macroscopic Pyrogenic Carbon Following Millennial-Scale Environmental Exposure

千年规模环境暴露后宏观热解碳的化学特征

• DOI: 10.3389/fenvs.2019.00203
• 发表时间: 2020
• 期刊: Frontiers in Environmental Science
• 影响因子: 4.6
• 作者: Ascough P

Dynamics of Charcoal Alteration in a Tropical Biome: A Biochar-Based Study

• DOI: 10.3389/feart.2018.00061
• 发表时间: 2018-06-04
• 期刊: FRONTIERS IN EARTH SCIENCE
• 影响因子: 2.9
• 作者: Ascough, Philippa L.;Bird, Michael I.;Shen, Licheng
• 通讯作者: Shen, Licheng

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

• DOI: 10.1016/j.jaap.2009.10.009
• 发表时间: 2010
• 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