Implications of Ammonia Emissions from Post-Combustion Carbon Capture for Airborne Particulate Matter

Abstract

Amine scrubbing, a mature post-combustion carbon capture and storage (CCS) technology, could increase ambient concentrations of fine particulate matter (PM2.5) due to its ammonia emissions. To capture 2.0 Gt CO2/year, for example, it could emit 32 Gg NH3/year in the United States given current design targets or 15 times higher (480 Gg NH3/year) at rates typical of current pilot plants. Employing a chemical transport model, we found that the latter emission rate would cause an increase of 2.0 μg PM2.5/m(3) in nonattainment areas during wintertime, which would be troublesome for PM2.5-burdened areas, and much lower increases during other seasons. Wintertime PM2.5 increases in nonattainment areas were fairly linear at a rate of 3.4 μg PM2.5/m(3) per 1 Tg NH3, allowing these results to be applied to other CCS emissions scenarios. The PM2.5 impacts are modestly uncertain (±20%) depending on future emissions of SO2, NOx, and NH3. The public health costs of CCS NH3 emissions were valued at $31-68 per tonne CO2 captured, comparable to the social cost of carbon itself. Because the costs of solvent loss to CCS operators are lower than the social costs of CCS ammonia, there is a regulatory interest to limit ammonia emissions from CCS.

Public Health Costs of Primary PM2.5 and Inorganic PM2.5 Precursor Emissions in the United States

“…Interannual variability in meteorology should have a minor influence on these results, affecting seasonal or annual marginal health effects generally less than 10%. − Studies ,− suggest that the influence of climate change on PM 2.5 concentrations is negligible in short-term assessments and relatively small even in the long term.…”

“…Estimating the social costs of air pollution, i.e. the damages imposed on human health and the natural environment, plays an important role in policy research, such as benefit-cost analyses of air quality laws , and regulations; , externality analyses of energy and transportation systems; − and climate and energy technology assessments. − PM 2.5 , particulate matter having a diameter of 2.5 μm or less, is especially important because PM 2.5 is strongly associated with premature mortality − and accounts for more than 90% of the monetized social costs. ,, PM 2.5 is a complex mixture of various chemical compounds, sizes, and shapes. There are active research efforts to understand where PM 2.5 toxicity comes from. − Nevertheless, PM 2.5 is currently regulated on a mass concentration basis by the U.S. EPA because other metrics do not have sufficient epidemiological and toxicological evidence to support regulatory rule-making…”

Climate and health benefits of increasing renewable energy deployment in the United States*

“…Our model results, along with CO 2 reduction costeffectiveness, do not represent full benefit-cost analyses of individual projects. Ideally, a full benefit-cost analysis for an individual project would include: site specific generation profiles and detailed electrical dispatch model runs for RE; full health benefits and impacts of emissions changes from coal with CCS [39,46,47]; full life cycle impacts for fossil fuel use changes, including increases in the case of coal with CCS [39,[48][49][50]; impacts of captured CO 2 , especially if it is used for enhanced oil recovery [45,51]; electricity price effects [52,53], and impacts from RE manufacture and installation [54][55][56][57].…”

A Comprehensive Evaluation of Off-Gas Emissions from a Catalyst-Aided, Amine-Based, Post Combustion Capture of CO2 from Industrial Exhaust Gas Streams

“…An increase in nitrogen deposition may result from ammonia emissions. This may lead to eutrophication and soil acidification in the ecosystems due to excess nitrogen (Heo et al, 2015). In the presence of sulfate or nitric acid, ammonia will form particle ammonium sulfate and ammonium nitrate which plays a role in PM2.5 formation resulting health implications.…”