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.

加拿大人口稠密的城市在市政污水处理厂（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废气为约65体积%的CH 4和35体积%的CO2。CH 4（“生物甲烷”或“沼气”）和CO2都是温室气体。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，或由于甲烷的全球升温潜能值较高（GWP：28-36）而燃烧。AD是一种权衡;生物固体被消耗，而温室气体被产生。AD是比发电或运输更小的温室气体产生者。然而，污水处理厂是“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废水中溶解的无机碳对海水的影响。其他人已经证明了减少二氧化碳的实验室和中试规模的AD。渥太华市市政污水处理厂（ROPEC）的AD产生约1400万m3/a的沼气。该提案旨在评估废水泥是否会在AD中沉淀出碳酸钙并减少释放的二氧化碳气体总量。从拆除项目中回收的废水泥是钙离子和碱度的廉价来源。混合废水泥粉对AD无机碳酸盐化学的影响尚未被探索，并且是这个较小的，为期两年的两个PDF，一个硕士，六个合作社和两个暑期学生的提案的主题。固/液比，水泥表面积，停留时间，和混合动力学的影响将研究与1 L的气密台式反应器。无机碳固/液气平衡将难以精确地模拟复杂的AD溶液组成，然而，简化理解无机碳酸盐化学模型n AD可能有助于针对未来的CO2释放从市政AD单元。USP Technologies的废水处理经验和Fortera USA的碳捕集技术将有助于研究ROPEC AD中碳酸钙与废水泥的沉淀。