Extracting value from onion waste - Evaluation of pyrolysis to improve the sustainability of onion production and reduce costs on the journey to Net Zero

洋葱种植和包装作业产生了大量的废物，这些废物目前被送往堆肥和处理，其成本由每个种植者支付，作为其分级收费的一部分。这对农业企业来说是一项重大成本，并带来了重大的环境和物流挑战。为减少废物量和寻找更具成本效益的处理战略已作出重大努力，但这仍然是种植者的主要财政负担。目前的项目旨在确定热解（气化）是否可以为洋葱行业面临的挑战提供解决方案。来自其他领域的经验表明，这种方法对各种生物废物流具有潜力，但没有处理洋葱废物的经验，也没有处理类似废物流的经验。该项目将确定热解是否可以增加洋葱废物的价值和/或降低与废物处理相关的成本。这项工作还将评估废物产量的季节性变化，以确定这可能如何影响商业开发。先前的研究表明，在高水分的基质中，热解效率会降低，低能量/成本的减湿策略将作为项目的一部分进行评估。热解也有可能产生有价值的产出，可以在农业和包装操作中利用，例如用于土壤改良的生物炭和用于洋葱储存的能源。热解过程产生的所有潜在效益将被量化，以便完成对该过程的全面成本效益分析。这将为企业提供投资这项技术的信心。

Onion growing and packing operations produce significant volumes of waste which is currently sent for composting and disposal, the costs of which are covered by each grower as part of their grading charges. This represents a major cost to the farming businesses and presents significant environmental and logistical challenges. Significant efforts have been made to reduce waste volumes and to find more cost-effective strategies for disposal, but this remains a major financial burden for the growers.The current project aims to establish if pyrolysis (gasification) could offer a solution to the challenges faced by the onion industry. Experience from other areas indicates that this approach has potential for various biological waste streams, but there is no experience with onion waste and little experience with comparable waste streams.The project will establish if pyrolysis can add value to the onion waste and/or reduce costs associated with waste disposal. The work will also evaluate seasonal changes in waste output to determine how this might affect commercial exploitation. Previous work suggests that pyrolysis efficiency is reduced in high moisture substrates and low-energy/cost moisture reduction strategies will be evaluated as part of the project.Pyrolysis also has the potential to generate valuable outputs that can be exploited in both the farming and packing operations, such as biochar for soil improvement and energy for onion storage. All the potential benefits arising from the pyrolysis process will be quantified so that a full cost-benefit analysis of the process can be completed. This will be used by the business to provide them with confidence to invest in this technology.