Use of Solid Acids in Carbonate Based Carbon Capture Systems
- Author (aut): Grayson, Connor
- Thesis advisor (ths): Lackner, Klaus
- Thesis advisor (ths): Fraser, Matthew
- Committee member: Green, Matthew
- Publisher (pbl): Arizona State University
To mitigate climate change, carbon needs to be removed from the atmosphere and stored for thousands of years. Currently, carbon removal and storage are voluntarily procured, and longevity of storage is inconsistently defined and regulated. Clauses can be added to procurement contracts to require long-term management and increase the durability of storage. Well-designed and properly enforced contracts can pave the way to future regulation for long-term carbon management.
This document details a conceptual Framework for the Certification of Carbon Sequestration (FCCS). It is based on a system designed to support negative emissions. It provides the minimum requirements for the development of carbon sequestration standards and certificates of carbon sequestration. It allows the certification of standards so that they in turn produce certification of removed carbon that authenticates durability and verifiability. The framework (i) identifies an organizational structure for the certification system, (ii) clarifies the responsibility of participating entities, (iii) provides certificate designs and usages, (iv) details the requirements to develop measurement protocols, (v) provides mechanisms to support a long-term industry, and (vi) outlines a vision towards durable storage.
Workshop report on socio-economic and technical discussions Direct Air Capture as a technology for the climate transition.
We analyze current approaches to carbon accounting for removed carbon sold on carbon markets, focusing on carbon crediting under the framing of a remaining carbon budget, the issue of durability, and approaches to accounting methodologies. We explore the topic of mixing carbon with other problems in developing carbon accounting methodologies and highlight the open policy questions. We conclude with a suggested framework for accounting for carbon removal accounting that simplifies climate action and enables a world with negative carbon emissions.
Halogens in drinking water sources, such as bromine (Br) and iodine (I) pose no direct health risk, but are critical precursors in formation of cyto- and genotoxic brominated and iodinated (Br-/I-) DBPs. However, few spatial or historic datasets exist for bromine and iodine species in drinking water sources. This dissertation aims to quantify and understand the occurrence and speciation of Br and I in groundwater and surface water serving as source waters for drinking water treatment plants (DWTPs). Aggregation of data from >9000 non-drinking water sampling locations in USA collected from 1930-2017 on halides (bromide (Br-) and iodide (I-)) determined that Br- concentrations were 50 μg/L and 100 μg/L; and I- concentrations were 12 μg/L and 13 μg/L in surface and groundwater respectively. Although, these locations were not drinking water sources, this first of its kind analysis provides potential bounds for Br- and I-. To focus specifically on DWTP sources, a nationwide survey of >250 drinking water sources was conducted between 2018-2020. Br- ion is the only bromine specie, whereas both inorganic (iodide and iodate ions) and organic iodine occur. I- concentrations ranged from 1-250 μg/L and are 4 to 100 times lower than Br- concentrations (10-7800 μg/L, median=80 μg/L). No strong correlation exists between bromide and iodide occurrence (R<0.5, p<0.005). I- was detected in 50% of the samples (75th percentile=5 μg/L) and IO3- was detected in 40% (75th percentile=3 μg/L) of all the samples. To quantify iodine species, tandem ion chromatography and inductively coupled plasma mass spectrometry was applied for the first time in drinking water sources. I- and IO3- peaks were well resolved and have minimum detection limit of 0.4 μg/L and 0.7 μg/L respectively. Organic iodine (Org-I) peaks in select drinking water samples from the nationwide survey were partically resolved ranging from <5 to 40 μg/L. This dissertation provides updated nationwide Br- survey and first ever national I species survey. The data generated through this dissertation will be useful to further Br-/I-DBP formation and toxicity research by providing relevant drinking water sources information. Future research targeting Br- and I- removal is advocated for managing Br-/I-DBPs in watersheds.