Development of a sewage sludge waste containing microplastics pyrolysis plant for sustainable hydrogen, syngas and high quality pyrolytic char production

污水污泥主要是水与在废水处理过程中通过物理化学过程(沉淀/过滤)去除的固体(有机和无机)结合在一起。由于对废水处理厂的排放要求越来越严格，以及发展中国家建造更多的废水处理厂，预计未来全球污水污泥的数量将大幅增加。这种增加的污泥产量需要一个经济和环境可持续的处理过程。污泥处置/处理具有挑战性，这不仅是因为产生了大量的污泥，而且还因为其含有高浓度的微塑料、其他有害污染物、病原体和重金属。目前，水处理厂产生的大部分污水污泥是通过生物过程(如厌氧消化)或化学过程(如石灰处理)稳定下来的，所产生的产物用作肥料。微塑料/PFOAs/病原体通过污泥进入农业垃圾填埋场对人类健康和环境产生不利影响。鉴于持续的气候危机、对微塑料的担忧以及竞争日益激烈的出口市场，水处理公司和其他利益相关者正在积极研究利用热解等替代新技术对污水污泥进行热处理，目的如下：*能量回收，以帮助将碳排放降至最低，并推动水务公司实现净零目标。*销毁微塑料和其他潜在污染物，将对环境的任何感知风险降至最低。*降低处置风险和成本。*回收磷和其他高价值元素。这项为期18个月的工业研究项目旨在开发一种热解气化炉(设备和方法)‘PyroPlus’，以满足水务行业的所有上述需求。通过产生清洁、高热值(约20MJ/m~3)的含氢合成气，并通过将微塑料热裂解成不含硫、氮酸和重金属的更小的氢和碳(C1、C2和C3)化合物来消除微塑料，PyroPlus为污水污泥处理带来了阶段性的变化。该项目还旨在开发一种5公斤/小时的连续涂覆方法，通过表面官能化来使热解焦失效。所有竞争的一级、二级和三级污泥处理方案(筛选/沉淀/超滤)都无法完全消除污水污泥中的微塑料和其他固体污染物。具有竞争力的技术专注于分离微塑料，而不是将它们热裂解成更小的化合物，这是它们失败的关键原因。PyroPlus将有助于实现英国的可再生能源目标和气候变化管理义务，但也将有助于保护现有废物处理资产在水行业中的作用。

Sewage sludge is primarily water combined with the solids (both organic and inorganic) that are removed through physicochemical processes (settling/filtration) during the wastewater treatment process. Future global quantities of sewage sludge are expected to rise significantly due to increasingly strict effluent requirements for wastewater-treatment-plants, and the building of more wastewater treatment plants in developing countries. This increased sludge production necessitates an economic and environmentally sustainable treatment process. Sludge disposal/handling is challenging not only because of the large volumes produced, but also because of its high concentration of microplastics, other harmful pollutants, pathogens and heavy metals. Currently, most of the sewage sludge produced by water treatment plants is stabilized via biological processes (e.g. anaerobic digestion) or chemical processes (e.g. liming) with the resultant product used as a fertilizer. Microplastics/PFOAs/pathogens finding their way into the agricultural landfill via sludge has adverse impacts on human health and the environment.Given the ongoing climate crisis, concerns about microplastics and an increasingly competitive outlet market, use of alternative novel technologies such as pyrolysis is being actively investigated by water treatment companies and others stake-holders to thermally treat sewage sludge with the following aims:* Energy recovery to help minimize carbon emissions and drive the water companies towards their net zero targets.* Destruction of microplastics and other potential contaminants to minimize any perceived risk to the environment.* Reduction in the disposal risk and costs.* Recovery of phosphorus and other high value elements.This 18months industrial-research project aims to develop a pyrolysis gasifier demonstrator (equipment and methodology) 'PyroPlus' which responds to all of the above described needs of water industry. PyroPlus brings a step change in the sewage sludge handling by producing clean, high Calorific Value (~20MJ/m3) hydrogen laden syngas and eliminating microplastics through their thermal cracking into smaller hydrogen and carbon (C1, C2 and C3) compounds free from sulphur and nitrogen acids, and heavy metals. The project also aims to develop a 5kg/hr continuous coating method to valorise pyrolytic char through surface functionlisation.All competing primary, secondary and tertiary sludge treatment solutions (screening/sedimentation/ultrafiltration) fail to completely eliminate microplastics and other solid pollutants from the sewage sludge. Competitive technologies focus on separating the microplastics rather than thermally crack them into smaller compounds, a key reason of their failure.PyroPlus will help meeting the UK's renewable energy targets and climate change management obligations but will also help safeguarding the role of existing waste treatment assets in the water industry.