Carbon dioxide emission reduction from anaerobic digesters by calcium carbonate precipitation with waste cementitious materials.

通过废弃胶凝材料沉淀碳酸钙来减少厌氧消化池的二氧化碳排放。

• 批准号: 577234-2022
• 负责人: Omelon, SidneySJO
• 金额: $ 21.09万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761067
• 关键词: Carbon; dioxide; emission; reduction; anaerobic

Canada's densely populated cities treat their sewage in municipal wastewater treatment plants (WWTPs). Some municipalities use anaerobic digestion (AD) to stabilize sewer sludge. AD off-gas is approximately 65 % CH4 and 35 % CO2 by volume. Both CH4 ("biomethane" or "biogas") and CO2 are greenhouse gases (GHG). Biogas can be burned to produce electric power with a negative carbon footprint, or to produce thermal energy and/or steam, or flared because of the higher global warming potential (GWP) of CH4 (GWP: 28-36). AD is a trade-off; biosolids are consumed while GHGs are generated. AD is a smaller GHG producer than electrical power generation or transportation. WWTPs are, however, "(a)n overlooked source of carbon emissions". One recent study measured the impact of dissolved inorganic carbon from large Chinese municipal WWTP effluents on seawater. Others have demonstrated lab- and pilot-scale ADs with reduced CO2. ADs at the City of Ottawa municipal wastewater plant (ROPEC) produce ~14 million m3/a of biogas.The proposal is to asses if waste cement precipitates calcium carbonate in the AD and reduces the total carbon dioxide gas released. Waste cement recovered from demolition projects is an inexpensive source of calcium ions and alkalinity. The effect of mixing waste cement powder on AD inorganic carbonate chemistry has not been explored, and is the subject of this smaller, two year proposal for two PDFs, one masters, six co-op and two summer students. Solids/liquid ratio, cement surface area, residence time, and mixing dynamics effects would be studied with a 1 L gas-tight benchtop reactor. The inorganic carbon solid/liquid gas equilibria would be difficult to model exactly with the complex AD solution composition, however a simplified understanding of inorganic carbonate chemistry model n AD may be useful for targeting future CO2 release from municipal AD units. Logistical, economical, and geographical aspects of this project will also be modeled and assessed.The wastewater treatment experience of USP Technologies, and the carbon capture skills of Fortera USA would assist with investigating the precipitation of calcium carbonate in ROPECs ADs with waste cement.

加拿大人口密集的城市在城市污水处理厂（WWTPs）处理污水。一些城市使用厌氧消化（AD）来稳定下水道污泥。AD废气的体积约为65% CH4和35% CO2。CH4（“生物甲烷”或“沼气”）和CO2都是温室气体（GHG）。沼气可以燃烧以产生负碳足迹的电力，或产生热能和/或蒸汽，或燃烧，因为CH4的全球变暖潜能值（GWP: 28-36）较高。AD是一种权衡；在消耗生物固体的同时产生温室气体。与发电或运输相比，人工智能是一个较小的温室气体排放源。然而，污水处理厂是“一个被忽视的碳排放源”。最近的一项研究测量了中国大型城市污水处理厂排放的溶解无机碳对海水的影响。其他人已经展示了实验室和中试规模的减少二氧化碳的ADs。渥太华城市污水处理厂（ROPEC）的ADs每年产生约1400万立方米的沼气。该提案旨在评估废水泥是否会在AD中沉淀碳酸钙，并减少排放的总二氧化碳气体。从拆迁项目中回收的废水泥是一种廉价的钙离子和碱度来源。混合废水泥粉对AD无机碳酸盐化学的影响还没有被探索，这是这个较小的，为期两年的提案的主题，两个pdf，一个硕士，六个合作项目和两个暑期学生。采用1l气密台式反应器研究固液比、水泥表面积、停留时间和混合动力学效应。无机碳固/液气平衡很难用复杂的AD溶液组成精确地建模，然而，对无机碳酸盐化学模型的简化理解可能有助于确定未来市政AD装置的二氧化碳释放。还将对该项目的后勤、经济和地理方面进行建模和评估。USP技术公司的废水处理经验和Fortera USA公司的碳捕获技术将有助于研究废水泥在ROPECs ADs中碳酸钙的沉淀。