IV. Industrial Processes Sector NITRIC AND ADIPIC ACID PRODUCTION IV.1. Nitric and Adipic Acid Production IV.1.1 Sector Summary he production of nitric and adipic acid results in significant nitrous oxide (N2O) emissions as a by-product. Nitric and adipic acid are commonly used as feedstocks in the manufacture of a variety of commercial products, particularly fertilizers and synthetic fibers (USEPA, 2012a). T Combined global emissions of N2O from nitric and adipic acid production are shown in Figure 1-1. Globally, emissions have declined by about 13% (17 MtCO2e) over the past decade; however, over the next 20 years—2010 to 2030—emissions are expected to increase steadily (~20%) growing by 24 MtCO2e over the time period. This trend is largely due to increased demand for fertilizer (nitric acid is an input) and increased demand for synthetic fibers (adipic acid is an input). In 2030, the United States, South Korea, Brazil, China, and Ukraine are expected to be five largest emitters of N2O from nitric and adipic acid production. Figure 1-1: N2O Emissions from Nitric and Adipic Acid: 2000–2030 160 142 135 140 125 118 120 Ukraine 100 e 2 China 80 Brazil MtCO 60 South Korea 40 United States 20 Rest of World 0 2000 2010 2020 2030 Year Source: USEPA, 2012a. Over the coming decades, increased demand for adipic acid in Asia is expected to contribute to higher N2O emissions from adipic acid production, while abatement control technologies employed at adipic acid production facilities in the 1990s in the United States, Canada, and some countries of the EU are expected to reduce N2O emissions (USEPA, 2012a). Overall, increased global demand for adipic acid is expected to have the effect of higher annual N2O emissions resulting from adipic acid production. In addition, global N2O emissions from nitric acid are expected to increase as demand for nitrogen-based fertilizer increases. Although concerns about nutrient run-off have caused some countries to reduce their demand for nitrogen-based fertilizer, growing world demand for agricultural commodities is expected to have the effect of increasing nitric acid production and, consequently, N2O emissions. GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-1 NITRIC AND ADIPIC ACID PRODUCTION Global abatement potential of N2O in nitric acid and adipic acid production is 98 and 115 MtCO2e in 2020 and 2030, respectively. These results are depicted in the sectoral marginal abatement cost (MAC) curves in Figure 1-2. As the MAC curves show, roughly 45% of the maximum abatement potential in each -1 year is achievable at relatively low carbon prices (between $2 and $10 tCO2e ). Figure 1-2: Global MAC for Nitric and Adipic Acid: 2010, 2020, and 2030 $60 $50 $40 $30 e 2 $20 2010 2020 $/tCO $10 2030 $0 0 20 40 60 80 100 120 140 -$10 -$20 -$30 Non-CO2 Reduction (MtCO2e) The following section provides a brief explanation of the manufacturing processes that result in the formation of N2O emissions. Next we discuss the projected emissions from these processes out to 2030. Subsequent sections characterize the abatement measures and present the cost of implementation and operation for each. The chapter concludes with a discussion of the MAC analysis approach unique to this sector and the regional results. IV.1.2 N2O Emissions from Nitric and Adipic Acid Production N2O emissions are closely correlated with the production of nitric and adipic acid. The following section discusses global production activity data, typical emissions factors, and baseline emissions estimates of N2O from nitric and adipic acid production. The MAC analysis presented here starts by assuming the projected emissions presented in USEPA’s 2012 Global Emissions Report (2012a). This analysis then derives industry activity from the USEPA emissions projections based on current industrial activity. IV.1.2.1 Nitric Acid Production and Emission Factors Ammonium nitrate production represents the largest demand market for nitric acid, with the majority of nitric acid being consumed by ammonium nitrate producers. The demand for ammonium IV-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES NITRIC AND ADIPIC ACID PRODUCTION nitrate products, especially fertilizer, is the main driver of nitric acid demand. Nitric acid production levels closely follow trends in fertilizer demand (Mainhardt and Kruger, 2000). Trends in fertilizer demand vary widely across different regions of the world. For example, in Western Europe, because of concerns over nutrient runoff and nitrates in the water supply, use of nitrogen-based fertilizer has been significantly reduced in the past couple of decades (USEPA, 2012a). Despite this trend, the European Fertilizer Manufacturers Association (EFMA) is predicting modest growth in demand of 1.3% annually over this decade. In other parts of the world, a continued desire to secure domestic fertilizer production capacity to supplant reliance on imports in combination with expansions in capacity for large fertilizer consuming countries are expected to result in a net increase in nitrogen-based fertilizer production capacity between 2010 and 2015 (IFA, 2011). Globally, over the next several decades, increases in food consumption and demand for agricultural products will continue to put upward pressure on fertilizer demand, which, in turn, is expected to increase the demand and consumption of nitric acid. The actual number of nitric acid production plants globally is unknown. Previous reports cited by the Intergovernmental Panel on Climate Change (IPCC) have suggested the number to be between 255 and 600. More recent estimates suggest that between 500 and 600 plants were in operation in 2010 (Kollmus and Lazarus, 2010). The actual number is uncertain because many nitric acid plants are often part of larger integrated chemical facilities that manufacture products using nitric acid—in the production of a wide range of chemical products such as fertilizer and explosives (Kollmus and Lazarus, 2010; Mainhardt and Kruger, 2000). As noted earlier, global nitric acid production is expected to increase over time. Projections in nitric acid production levels by country are not publicly available. The IPCC reports that N2O emissions factors for nitric acid production also remain relatively uncertain, because of a lack of information on manufacturing processes and emissions controls. The emissions factor is estimated, based on the average amount of N2O generated per unit of nitric acid produced, combined with the type of technology employed at a plant. The IPCC uses a default range of 2 to 9 kilograms N2O per ton of nitric acid produced. As a result, emissions factors for nitric acid production plants may vary significantly based on the operating pressure of the plant, the type of nitrogen oxide (NOx) control technology (if any) deployed on the plant, and whether N2O abatement has been implemented. As shown in Table 1-1, N2O emission rates increase as the plant operating pressure increases. Furthermore, non-selective catalytic reduction (NSCR) is very effective at destroying N2O, whereas other technologies used to control NOx emissions, such as selective catalytic reduction (SCR) and extended absorption, do not reduce N2O emissions. Table 1-1: IPCC Emissions Factors for Nitric Acid Production N2O Emissions Factor Production Process (relating to 100% pure acid) Plants with NSCRa (all processes) 2 kg N2O/tonne nitric acid ±10% Plants with process-integrated or tailgas N2O destruction 2.5 kg N2O/tonne nitric acid ±10% Atmospheric pressure plants (low pressure) 5 kg N2O/tonne nitric acid ±10% Medium pressure combustion plants 7 kg N2O/tonne nitric acid ±20% High pressure plants 9 kg N2O/tonne nitric acid ±40% Source: IPCC, 2006. a Non-selective catalytic reduction (NSCR) The IPCC notes that emissions factors as high as 19.5 kilograms N2O per ton of nitric acid produced have been previously estimated. In addition, some estimates indicate that 80% of the nitric acid plants GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-3 NITRIC AND ADIPIC ACID PRODUCTION worldwide do not employ NSCR technology, which makes it more likely that the default range of potential emissions factors provided by the IPCC underestimates the true emissions baselines (Mainhardt and Kruger, 2000). Therefore, the uncertainties associated with these emission factors may be higher than listed in Table 1-1. However, no uncertainty assessments other than the IPCC’s have been published, so without more information, this analysis relies on the published values above. IV.1.2.2 Adipic Acid Production and Emission Factors Adipic acid is used primarily in the production of synthetic fibers, predominantly as a precursor for the production on nylon 6,6 (The Chemical Company [CC], 2010a). As a result, production of adipic acid is closely correlated with the world’s nylon production. Worldwide, the largest single use of adipic acid is in carpet manufacturing, accounting for 30% of the market (USEPA, 2012a; Chemical Week, 2007). Global demand for adipic acid is expected to increase over the next few decades, particularly in Asia, driven primarily by the growth in demand for synthetic fibers (i.e., nylon 6,6), particularly for use in carpet manufacturing. Nylon 6,6 accounts for approximately 90% of adipic acid demand; demand for nylon is a strong indicator of future adipic acid demand (CC, 2010b). Future production of adipic acid is expected to closely following the demand trend for synthetic fibers. Figure 1-3 shows the share of adipic acid production capacity by country in 2010. Figure 1-3: Adipic Acid Production Capacity by Country: 2010 Germany, 16% France, 11% China, 22% South Korea, 5% Japan, 5% Singapore, 4% United States, Brazil, 3% 30% Italy, 3% Ukraine, 2% India, 0% Global capacity in 2010 was approximately 3 million metric tons, concentrated in the United States (30%), the European Union (29%), and China (22%) (Schneider, Lazarus, and Kollmuss, 2010; USEPA, 2012b). In the same year, global production of adipic acid was approximately 2.5 million metric tons (CC, 2010a).