Real-World Emission Factors of Gaseous and Particulate Pollutants

1 day ago - Key Laboratory of Cities' Mitigation and Adaptation to Climate Change in Shanghai, China Meteorological Administration; State Key Laborato...
0 downloads 5 Views 2MB Size
Article Cite This: Environ. Sci. Technol. XXXX, XXX, XXX−XXX

pubs.acs.org/est

Real-World Emission Factors of Gaseous and Particulate Pollutants from Marine Fishing Boats and Their Total Emissions in China Fan Zhang,† Yingjun Chen,*,†,‡ Qi Chen,§ Yanli Feng,§ Yu shang,*,§ Xin Yang,¶,‡ Huiwang Gao,$,@ Chongguo Tian,∥ Jun Li,⊥ Gan Zhang,⊥ Volker Matthias,# and Zhiyong Xie# †

Key Laboratory of Cities’ Mitigation and Adaptation to Climate Change in Shanghai, China Meteorological Administration; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China ‡ Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P.R. China § Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, P.R. China ¶ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P.R. China $ Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education of China, Qingdao, China @ Laboratory for Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China ∥ Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, P.R. China ⊥ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, P.R. China # Helmholtz-Zentrum Geesthacht, Institute of Coastal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany S Supporting Information *

ABSTRACT: Pollutants from fishing boats have generally been neglected worldwide, and there is an acute shortage of measured emission data, especially in China. Therefore, on-board measurements of pollutants emitted from 12 different fishing boats in China (including gill net, angling, and trawler boats) were carried out in this study to investigate emission factors (EFs), characteristics and total emissions. The average EFs for CO2, CO, NOx, PM, and SO2 were 3074 ± 55.9, 50.6 ± 31.7, 54.2 ± 30.7, 9.54 ± 2.24, and 5.94 ± 6.38 g (kg fuel)−1, respectively, which were higher than those from previous studies of fishing boats. When compared to medium-speed and slow-speed engine vessels, high-speed engines on fishing boats had higher CO EFs but lower NOx EFs. Notably, when fishing boats were in low-load conditions, they always had higher EFs of CO, PM, and NO2 compared to other operating modes. The estimated results showed that emissions from motor-powered fishing boats in China in 2012 (232, 379, and 61.8 kt CO, NOx and PM) accounted for 10.7%, 10.9%, and 19.3% of the total CO, NOx and PM emitted from nonroad mobile sources, which means significant contribution of fishing boats to air pollution, especially in southern China areas. ments for plume tracking.15−17 However, almost all of the studies focused on low-speed or medium-speed large engines installed on ocean-going vessels and coastal transport ships. Very few studies have involved fishing boats with high-speed engines generally,18−23 and those were aimed at energy savings, impact of fuel on emissions, etc. Fishing boats are typically used

1. INTRODUCTION Ship emissions have significant negative impacts on climate change, ambient air quality and human health, especially in coastal areas. For instance, ship emissions impact the greenhouse gas budget through CO2, CH4, and N2O,1−4 the solar radiation budget through black carbon and sulfur containing particles,5−7 human health through hydrocarbons, CO and fine particles,1,8−10 and acid rain through NOx and SO2.11−14 In previous decades, the main compounds emitted from ships have been investigated by methods such as engine tests in laboratories, on-board studies and aircraft measure© XXXX American Chemical Society

Received: August 4, 2017 Revised: November 24, 2017 Accepted: November 24, 2017

A

DOI: 10.1021/acs.est.7b04002 Environ. Sci. Technol. XXXX, XXX, XXX−XXX

Article

Environmental Science & Technology

gaseous O2, NO2, NO, N2O, CO, CO2, and SO2 were measured using a flue gas analyzer (Photon II, Madur, Austria), whose detection parameters was introduced in a previous study.16 In addition, an air velocity meter was placed in the tube for the online measurement of the flue gas flow. (See SI S.1 for full details.) 2.2. Test Boats and Operating Modes. The technical parameters of the 12 marine fishing boats (TB5/TB6 and TB7/ TB8 are two pairs of fishing boats with almost the same technical parameters) selected for this study are shown in Table 1. According to a field survey of 569 fishing boats in China,27

in large numbers and are active in nearshore areas in countries with developed fisheries, such as China. Pollutants emitted from fishing boats might have significant influence on ambient air and human health in typical coastal areas, which should not be neglected. China has the biggest fishery output as well as the largest population of fishing boats in the world with a large amount of fuel consumption. But most of the fishing boats are equipped with engines older than 10 years that can lead to the increase of fuel consumption. Moreover, there is no fuel and air pollutants emission standard for fishing boats in China. According to the Food and Agriculture Organization of the United Nations, China has the biggest fishery output in the world, harvesting approximately 73.66 million tons (sum of aquaculture production and capture production), which accounted for 42.1% of the worldwide total amount of fisheries in 2015.24 Statistics showed that there were approximately 1.04 million fishing boats by the end of 2015 in China, including 0.67 million motor-powered fishing boats, with total power amounted to 22.57 million kW.25 The fuel consumption of fishing boats in China is substantial, accounting for 41.7% of the total fuel consumption of ships in 2011.26 An investigation of fishing boats in China27 showed that the use of old engines was a significant problem. Approximately 80% of the diesel engines used in the fishing boats were older than 5 years and 54% were older than 10 years, and fuel consumption could increase by 10% and 15% compared to the boats with engines less than 5 years old. Furthermore, some phased out diesel engines were still in use in China, accounting for 12.7% of the total number of fishing boats. Almost all the fishing boat engines are high-speed engines, which are much different from cargo ships that always use low-speed or medium-speed engines. The emission levels of pollutants from high-speed engines of fishing boats are still unclear. Emission standards as well as policies about emission reductions for fishing boats are still not in place. There is a serious shortage of data concerning emission factors (EFs) of fishing boats, not only in China, which could lead to a disregard of fishing boat emissions or wrong estimate of fishing boat emissions by referencing emission factors from other types of ships. Therefore, on-board tests of fishing boats in China for exhaust gas pollutants were carried out in this study. The data were collected from 12 fishing boats with different engine capacities and activity modes. Gaseous emissions from the diesel engines, including CO, CO2, SO2, and NOx were measured directly from the funnel, while total particulate matter (PM) was also collected on different filters through a dilution system. Based on the data, the following factors were valuated and discussed: (i) fuel-based emission factors for different activity modes, calculated based on the carbon balance method, (ii) fuel-based average EFs and comparison with other kinds of ships tested, (iii) EFs and characteristics of PM and its components, and (iv) the total amount of pollutant emissions from marine fishing boats and their distributions in China.

Table 1. Technical Parameters of the Test Boats vessel ID

engine power (kW)

GB1 GB2 AB1

91 178 129

AB2

176

TB1 TB2 TB3 TB4 TB5 TB6 TB7 TB8

88 132 235 235 265 265 397 397

vessel type gill net gill net angling boat angling boat trawler trawler trawler trawler trawler trawler trawler trawler

ship length × width (m)

material

vessel age (year)

20 × 4.3 27 × 5.6 21 × 4.3

wooden wooden wooden

10 7 6

22.7 × 4.8

wooden

5

× × × × × × × ×

wooden wooden wooden wooden metal metal metal metal

8 5 6 7 10 10 1 1

13 13 22.5 24 29 29 34 34

3.5 3.5 4.2 5.2 5.4 5.4 5.6 5.6

the distribution of fishing boats based on main engine power is presented in SI Figure S2, which shows that 85.4% of the engines were less than 400 kW. All the engine powers of the test boats in this study were between 88 and 397 kW. Most of the test boats were trawler, which is one kind of the most widely used types and the most fuel consumed type in China (trawlers account for 19.1% of the total quantity, 47% of the total power and 52% of the total fuel consumption of fishing boats in 2015); the other two kinds of test boats are gill net and angling boat in this study (they could account for 59%, 35%, and 36% of the total quantity, total power and fuel consumption of fishing boats in 2015). Therefore, the test fishing boats in this study can be regarded as representative of the fishing fleet of China and it can be expected that they give an indication of the emissions from the entire fishing fleet in China. Based on the actual operating situations, several activity modes were tested, including idling, maneuvering, cruising, and operating, with details shown in SI Table S1. 2.3. Fuel Type. The fuels used for the test boats were all different kinds of diesel oil obtained from small-scale refineries, except for TB7 and TB8, which used heavy fuel oil as fuel (diesel oil was used only for starting the engine). There is no compulsory standard for the fuel quality for fishing boats in China, which means that all kinds of qualities of fuels can be used. The results of the fuel analyses are presented in Table 2, which shows that the fuel quality of tested fishing boats varies widely. 2.4. Data Analysis. The carbon balance formula was used to calculate the EFs for all exhaust gas components. We assumed that all the carbon in the fuel was transformed into carbon-containing gases (CO, CO2, and HC) and particulate matter. Therefore, the EF for CO2 was calculated as follows:

2. EXPERIMENTAL METHODS 2.1. On-Board Emissions Test System. A combined onboard emissions test system (Supporting Information (SI) Figure S1) was used to measure the emissions from the fishing boats under actual operating conditions. The diluted system had four main parts, namely, two particulate samplers, an eightstage particulate sampler, and a secondary diluted system for the online measurement of black carbon (BC). Additionally, B

DOI: 10.1021/acs.est.7b04002 Environ. Sci. Technol. XXXX, XXX, XXX−XXX

Article

Environmental Science & Technology Table 2. Results of the Fuel Quality Analysis

carbon (C) % hydrogen (H) % oxygen (O) % nitrogen (N) % sulfur (S) % kinematical viscosity (40 °C) mm2/s kinematical viscosity (100 °C) mm2/s flash point (closed) °C fire point °C gross calorific value MJ/kg kcal/kg net calorific value MJ/kg kcal/kg

GB1

GB2

AB1

AB2

TB1/ TB2

TB3

TB4

TB5/ TB6

TB7/TB8 (diesel)

TB7/TB8 (heavy fuel)

85.96 12.76