ISCF WAVE 1 AGRI TECH: Formulating novel fertilisers and land conditioners from bioenergy wastes

面对传统磷的有限来源，以及高度能源密集和价格敏感的氮，农业面临着保持或增加粮食产量并同时减少其碳影响的挑战。化肥价格受原油价格的强烈影响，反映了制造过程的能源密集程度。有限的养分资源正在枯竭，而养分则通过作物收割从土地上流失。因此，有必要确定可以安全地应用于作物的替代营养素来源，以维持可以以较低的碳影响和较少的环境破坏生产的粮食生产。作为减少碳排放的一种手段，可再生能源部门的扩散导致生物质能源计划的增长。根据英国政府的政策，农业用地是英国农业的“预期”水槽，因为这些废物来源营养丰富。然而，许多限制限制了使用状态：高度可变的组成（空间和时间上）;存在不良化合物和污染物（过量的金属;塑料残留物）;营养含量低于人造肥料（适用的数量较多）;后勤限制（源的空间分散）;时间限制（施用限于某些时期，因此需要临时储存）;作物反应的不确定性。这些不利因素导致其成为反倾销运营商的处置成本（2013年平均为3.73英镑/吨）。灰同样受到不一致的成分和其他不期望的特性的困扰，因此大量的灰被填埋。对于碳酸盐和火山灰来说，它们的处置意味着营养物质从循环中流失，给可再生能源行业带来了高昂的成本。这些限制提出了开发替代产品或工艺的明确需求，这些替代产品或工艺可以为生物能源和农业部门提供有吸引力的解决方案。总体目标是从生物能源残留物中开发商业上可行的，高质量的，一致的，可持续的肥料。四个主要考虑因素是理解原料在制造产品中的行为的核心：营养素保留，形式和加工过程中营养素的稳定性;以及营养素是否将由其他来源补充以满足规格。考虑到上述陈述，总体目标将通过以下方式实现：（i）单个废物流（灰分和碳酸盐）和假定的肥料产品的物理化学特性，包括识别其他合适的废物（ii）评估反应条件对肥料产品上营养物质可用性和潜在有毒元素存在的影响，特别是详细了解氮保留，磷形态和可用性以及长期稳定性控制因素。(iii)灰和碳酸盐混合物对植物生长的影响的量化以及与传统无机肥料的比较。(iv)确定农业中使用的假定肥料产品的立法要求和商业考虑，作为传统肥料应用的实际替代品对实验室中选定的处理和反应条件以及温室试验中的植物生长进行广泛测试，将代表并逐步实现配制产品在农业环境中的适用性，商业化和可行性。这种方案的好处是减少对磷和氮有限肥料资源的依赖，促进粮食安全，遵守废物分级制度和资源回收。

In the face of finite sources of conventional phosphorus, and highly energy-intensive and price-sensitive nitrogen, agriculture is challenged to maintain or increase food production and simultaneously reduce its carbon impact. Fertiliser prices are strongly influenced by the crude oil price, reflecting the energy intensity of the manufacturing process. Finite nutrient sources are being depleted, whilst nutrients are lost from the land through crop harvest. It is therefore necessary to identify alternative sources of nutrients which can be safely applied to crops to sustain food production which can be produced with lower carbon impacts, and less environmental damage. The proliferation of the renewable energy sector, as a means of reducing carbon emissions, has resulted in the growth of biomass to energy schemes. Agricultural land is the "expected" sink for digestate in the UK according to government policy since these waste sources are nutrient-rich. However, a number of limitations restrict the use digestate: highly variable composition (both spatially and temporally); undesirable compounds and contaminants presence (excessive metals; plastics residues); lower nutrient content than in manufactured fertilisers (higher volumes applied); logistical constraints (spatial dispersion from source); temporal constraints (application limited to certain periods, thus need for interim storage); uncertainties of crop responses. These undesirable factors have resulted in it being a disposal cost to the AD operator (average £3.73/t in 2013). Ash is similarly plagued by inconsistent composition and other undesirable characteristics and so significant quantities are being disposed of in landfill. For both digestate and ash, their disposal means that nutrients are lost from the cycle, incurring high costs to the renewable energy industry. These limitations present a clear need for development of an alternative product or process which can present an attractive solution to both the bio-energy and agricultural sectors alike.The overarching objective is to develop commercially viable, high quality, consistent, sustainable fertilisers from bioenergy residues. Four main considerations are central to understanding the behaviour of the feedstocks in making a product: nutrient retention, form, and stability of the nutrient during processing; and whether the nutrient will be supplemented by other sources to meet a specification. Considering the aforementioned statements, the overall aim will be achieved through the following:(i) Physico-chemical characterisation of individual waste streams (ash and digestate) and putative fertiliser products, including the identification of other suitable wastes(ii) Assessment of the effects of reaction conditions on nutrient availability and potentially toxic elements presence on the fertiliser product, especially to understand in detail nitrogen retention, Phosphorus speciation and availability and long term stability controlling factors. (iii) Quantification of the impact of ash and digestate mixtures on plant growth and comparison against traditional inorganic fertilisers.(iv) Identification of legislative requirements and commercial considerations of the putative fertiliser products for use in agriculture as factual alternatives to conventional fertiliser applicationsExtensive testing on selected treatments and reaction conditions in the laboratory and plant growth in glasshouse trials will represent and step towards the applicability, commercialisation and viability of the formulated product in an agricultural setting. Benefits of such scenario are reduction in the dependence on phosphorus and nitrogen finite fertiliser resources, contribution to food security and compliance with waste hierarchy and resource recovery.