2012 Air Emissions Inventory

Transcription

1 SECTION 3 HARBOR CRAFT This section presents emissions estimates for the commercial harbor craft source category, including source description (3.1), geographical domain (3.2), data and information acquisition (3.3), operational profiles (3.4), emissions estimation methodology (3.5), and the emission estimates (3.6). 3.1 Source Description Emissions from the following types of diesel-fueled harbor craft were quantified: Assist tugboats Crew, supply and work boats Ferry vessels Excursion vessels Government vessels Harbor tugboats Ocean tugboats Assist tugboats Assist tugboats help ships maneuver in the harbor during arrival, departure, and shifts. In general, they escort the ships from the breakwater to the berth upon their arrival and are dismissed at the outer harbor after escorting the ships from berth to the breakwater upon departure. Crew, supply and work boats Crew boats and supply boats are used for carrying personnel and supplies to and from off-shore and in-harbor locations. They may go to and from vessels at anchorage, construction sites, and offshore platforms. Work boats perform duties such as utility inspection, surveying, spill response, training and construction. Port of Long Beach 46 July 2013

2 Ferry vessels Ferries transport people and property to the nearby islands. There are daily ferry trips from Long Beach to Santa Catalina Island that take approximately one hour and 15 minutes to transit one way. Excursion vessels Excursion vessels include harbor cruise and charter vessels for hire by the general public. Excursions in the Long Beach Harbor include daily 45-minute harbor cruises and seasonal whale watching cruises just outside the breakwater. Government vessels The City of Long Beach Fire Department operates harbor craft including two fireboats - the Liberty and the Challenger. In addition, although privately owned, two pilot boats operating at the Port are also included in this category. Harbor and ocean tugboats Harbor tugboats primarily work within the harbor moving and positioning barges. Ocean or coastal tugboats, also called towboats, work mostly outside of the harbor to and from other ports. Port of Long Beach 47 July 2013

3 Recreational vessels are not considered to be commercial harbor craft; therefore their emissions are not included in the inventory. Vessels associated exclusively with oil operations located at the Port are also excluded but are estimated in a separate inventory 24. Figure 3.1 presents the distribution of the 89 diesel fueled commercial harbor craft inventoried for the Port in Figure 3.1: 2012 Distribution Commercial Harbor Craft Ocean tug 10% Work boat 6% Government 7% Crew boat 20% Ferry 12% Tugboat 14% Excursion 15% Assist tug 16% 3.2 Geographical Domain The geographical delineation for harbor craft is the same as that for ocean-going vessels, described in Section Long Beach Gas and Oil Air Emissions Inventory 2005, Prepared by Starcrest Consulting Group, LLC, October Port of Long Beach 48 July 2013

4 3.3 Data and Information Acquisition Harbor craft owners and operators were identified and contacted to obtain key operational parameters Vessel type Number, type and horsepower (or kilowatts) of main engine(s) Number, type and horsepower (or kilowatts) of auxiliary engine(s) Operating hours in 2012 Annual diesel fuel consumption Qualitative information regarding how the vessels are used in service Engine model year Replaced engines The following companies provided information on their fleet of harbor craft: Assist tugboats and harbor tugboats: Crowley Marine Services Foss Maritime Company Millennium Maritime Crew boat and work boats: American Marine Corporation Connolly-Pacific Marine Spill Response Corporation (MSRC) Pacific Tugboat Services Southern California Ship Services Ferry vessels: Catalina Express Excursion vessels: Long Beach Sportfishing Rainbow Rocket Spirit Cruises Government vessels: Long Beach Fire Department Jacobsen Pilots (privately owned) Harbor tugboats and ocean tugboats: Crowley Petroleum Services Sause Brothers Ocean Towing Westoil Marine Services Port of Long Beach 49 July 2013

5 The SCAQMD was also contacted to obtain engine information associated with harbor craft that received grant funding from the Carl Moyer Memorial Air Quality Standard Attainment Program for engine repowers. 3.4 Operational Profiles Tables 3.1 and 3.2 summarize the characteristics of main and auxiliary engines respectively, by vessel type operating at the Port in Averages of the model year, horsepower, or operating hours are used as default values when specific data is not available. Port of Long Beach 50 July 2013

6 Table 3.1: 2012 Main Engine Characteristics by Harbor Craft Type 2012 Air Emissions Inventory Harbor Vessel Engine Model year Horsepower Annual Hours Craft Type Count Count Minimum Maximum Average Minimum Maximum Average Minimum Maximum Average Assist tugboat ,500 2,540 2, ,291 1,480 Crew boat , , Excursion , , Ferry ,300 1,830 1,200 1,500 1,241 Government , Ocean tugboat ,850 2, , Harbor tugboat , , Work boat , Total Port of Long Beach 51 July 2013

7 Table 3.2: 2012 Auxiliary Engine Characteristics by Harbor Craft Type 2012 Air Emissions Inventory Harbor Vessel Engine Model year Horsepower Annual Hours Craft Type Count Count Minimum Maximum Average Minimum Maximum Average Minimum Maximum Average Assist tugboat ,296 1,743 Crew boat , Excursion , Ferry , Government , Ocean tugboat , Harbor tugboat , Work boat Total Port of Long Beach 52 July 2013

8 Harbor craft propulsion and auxiliary engines with known model year and horsepower are categorized by EPA marine engine standards. Harbor craft engines for which model year and/or horsepower information are not available are classified as unknown. Because engine information gathered from harbor craft operators does not identify the specific EPA certification standards or tier level, it is assumed that all 2009 and newer engines with a 25 to 120 hp rating meet Tier 3 emission standards. 25 This assumption is consistent with CARB s harbor craft emission factors, which follow the same model year grouping as the EPA emissions standards for marine engines as shown below. Table 3.3 lists the EPA engine tier levels according to marine engine model year and horsepower. Figure 3.2 provides the population distribution of all harbor craft propulsion and auxiliary engines operating at the Port in Table 3.3: Harbor Craft Marine Engine EPA Tier Levels EPA Tier Level Marine Engine Model Year Horsepower Tier and older -- Tier 1 Tier 2 Tier to hp 2000 to hp 2004 and newer 750 hp 2007 and newer (except for those that meet Tier 3 criteria) 2009 and newer 750 hp 25 to 120 hp or < 0.9 liter engine displacement 25 CFR (Code of Federal Regulation), 40 CFR, subpart 94.8 for Tier 1 and 2 and subpart for Tier 3. Port of Long Beach 53 July 2013

9 Figure 3.2: 2012 Distribution of Harbor Craft Engines by Engine Standards, % Tier 3 12% Unknown 7% Tier 0 20% Tier 2 48% Tier 1 13% 3.5 Emissions Estimation Methodology Harbor craft emissions are estimated for each engine individually, based on the engine s model year, power rating, and annual hours of operation. The Port s harbor craft emission calculation methodology is similar to the methodology used by the CARB emissions inventory for commercial harbor craft emissions operating in California. 26 The basic equation used to estimate emissions from harbor craft engines is shown below in Equation 3.1. Equation 3.1 Where: E = emissions, grams/year Power = rated power of the engine, hp or kw Activity = engine activity, hours/year LF = load factor (ratio of average power used during normal operations as compared to maximum rated power), dimensionless EF = emission factor, grams of pollutant per unit of work, g/hp-hr or g/kw-hr FCF = fuel correction factor to reflect changes in fuel properties that have occurred over time, dimensionless 26 CARB, Commercial Harbor Craft Regulatory Activities, Appendix B: Emissions Estimation Methodology for Commercial Harbor Craft Operating in California. Viewed April Port of Long Beach 54 July 2013

10 3.5.1 Load Factors An engine load factor represents the average percentage of full load applied to an engine or the percent of rated engine power that is applied during the engine s operation. Table 3.4 summarizes the average engine load factors used for harbor craft propulsion and auxiliary engines. The engine load factors are from CARB s emission estimation methodology report 27, except the 31% engine load factor for assist tugboats and harbor tugboats, which are based on actual engine load readings collected in the San Pedro Bay and published in the 2001 Port of Los Angeles EI report 28. Table 3.4: Harbor Craft Engine Load Factors Harbor Auxiliary Main Craft Type Engines Engines Assist tug Crew boat Excursion Ferry Government Ocean tug Tugboat Work boat Emission Factors, Deterioration Rates, and Useful Life Emission factors, deterioration rates, and useful life for harbor craft are based on CARB s latest methodology, with the exception of greenhouse gas emission factors and the calculation of SO x emission factor, which are discussed below. The EF is a function of the zero hour (ZH) emission rate for the engine model year, in the absence of any malfunction or tampering of engine components that can change emissions, deterioration rate, and cumulative hours. The deterioration rate (DR) takes into account the change in the engine s base emissions (ZH emission rates) as the equipment is used, due to wear of various engine parts or reduced efficiency of emission control devices. The zero hour emission factors for commercial harbor craft, included in Appendix C of this report, were obtained from CARB. 29 The cumulative hours reflect the engine s total operating hours. 27 CARB, Emissions Estimation Methodology for Commercial Harbor Craft Operating in California, Appendix B. 28 Port of Los Angeles, 2001 Baseline Air Emissions Inventory, Prepared by Starcrest Consulting Group, LLC, July CARB, Commercial Harbor Craft Regulatory Activities. Appendix B: Emissions Estimation Methodology for Commercial Harbor Craft Operating in California. Viewed April Port of Long Beach 55 July 2013

11 The emission factor is calculated as: Where: 2012 Air Emissions Inventory Equation 3.2 ZH = zero hour emission rate for a given horsepower category and model year when the engine is new and there is no component malfunctioning, g/hp-hr or g/kw-hr DR = deterioration rate (rate of change of emissions as a function of equipment age), g/hp-hr 2 or g/kw-hr 2 Cumulative hours = total number of hours the engine has been in use and calculated as annual operating hours times age of the engine, hours The equation for the deterioration rate is shown in Equation 3.3. Table 3.5 lists the engine deterioration factors for harbor craft diesel engines, and Table 3.6 lists the useful life of harbor craft in years. Equation 3.3 / Where: DR = deterioration rate, g/hp-hr 2 or g/kw-hr 2 DF = deterioration factor; percent increase in emissions at the end of the useful life, % ZH = emission rate for a given engine size category and model year when the engine is new and there is no component malfunctioning, g/hp-hr or g/kw-hr Cumulative hours at the end of useful life = annual operating hours times useful life in years, hours Table 3.5: Engine Deterioration Factors for Harbor Craft Diesel Engines Horsepower Range PM NO x CO HC > Port of Long Beach 56 July 2013

12 CARB defines the useful life of harbor craft as the age at which 50% of the engines are retired from the fleet; it is assumed that 100% of the engines will be retired at the age of twice the useful life. Table 3.6: Useful Life by Harbor Craft Type, years Harbor Auxiliary Main Craft Type Engines Engines Assist tug Crew boat Excursion Ferry Government Ocean tug Tugboat Work boat Harbor Craft Greenhouse Gas Emission Factors Greenhouse gas emissions factors for harbor craft are continuously evolving as more research is conducted and reviewed, so there is some variability in the emission factors recommended; emissions factors for CO 2, CH 4, and N 2 O are sourced from the 2004 IVL study, and are listed in Appendix C. 30 The IVL study establishes the CH 4 emission factor as 2% of the hydrocarbon emission factor. 30 IVL, Methodology for Calculating Emissions from Ships: Update on Emission Factors, Prepared by IVL Swedish Environmental Research Institute for the Swedish Environmental Protection Agency. Port of Long Beach 57 July 2013

13 3.5.4 Harbor Craft SO x Emissions The SO x emissions are a function of sulfur content in the fuel. The SO x emission factors are developed to reflect the use of 15 ppm ultra-low sulfur diesel (ULSD) using a mass balance approach, which assumes that all of the sulfur (S) in the fuel is converted to SO 2 and emitted during the combustion process. While the mass balance approach calculates SO 2 specifically, it is used as a reasonable approximation of SO x. The following example shows the calculation of the SO x emission factor. Equation 3.4 Where: SO x EF = Emission factor for SO x, g/hp-hr ULSD S content = sulfur content of the ULSD fuel, 15 grams of S/1,000,000 g of fuel BSFC = Brake Specific Fuel Consumption, g/hp-hr In the calculation above, the ULSD sulfur content is shown as 15 grams per sulfur per million grams of fuel. Two grams of SO 2 is emitted for each gram of sulfur in the fuel because the atomic weight of sulfur is 32 while the molecular weight of SO 2 is 64, meaning that the mass of SO 2 is two times that of sulfur. According to CARB s methodology for estimating emissions from commercial harbor craft, a brake specific fuel consumption rate of 184 gram per brake horsepower-hour is assumed CARB, Commercial Harbor Craft Regulatory Activities. Appendix B: Emissions Estimation Methodology for Commercial Harbor Craft Operating in California. Port of Long Beach 58 July 2013

14 3.5.5 Fuel Correction Factors Fuel correction factors developed for commercial harbor craft assume engines use diesel fuel with higher sulfur content. To account for the required use of ULSD in harbor craft engines, the fuel correction factors shown in Table 3.6 account for the use of ULSD in harbor craft engines by equipment model year (MY). The fuel correction factor for SO x reflects the change from diesel fuel with an average sulfur content of 350 parts per million (ppm) to ULSD (15 ppm). There is no available data that reflects the effect of different fuels on N 2 O and CH 4 emissions, so it is assumed that the fuel correction factor for NO x is also applicable to N 2 O emissions and the fuel correction factor for HC is also applicable to CH 4 emissions, since N 2 O is an oxide of nitrogen and CH 4 is a component of hydrocarbons. Table 3.7: Harbor Craft ULSD Fuel Correction Factors Equipment MY PM NO x SO x CO HC CO 2 N 2 O CH and older to and newer Improvements to Methodology from Previous Years The emission calculation methodology used to estimate emissions from commercial harbor craft operating at the Port in 2012 is similar to the methodology used in the Port s 2010 and 2011 emissions inventory reports 32. For a comparison of 2012 emissions to 2005 emissions, refer to section POLB, Port of Long Beach 59 July 2013

15 3.6 Emission Estimates Tables 3.8 and 3.9 summarize the estimated harbor craft vessel emissions by vessel type and engine type. Table 3.8: 2012 Harbor Craft Emissions by Engine Type, tons Harbor Craft Engine Type PM 10 PM 2.5 DPM NO x SO x CO HC Assist tugboat Auxiliary Propulsion Assist tugboat Total Crew Boat Auxiliary Propulsion Crew boat Total Excursion Auxiliary Propulsion Excursion Total Ferry Auxiliary Propulsion Ferry Total Government Auxiliary Propulsion Government Total Ocean tugboat Total Auxiliary Propulsion Ocean tugboat Total Harbor tugboat Auxiliary Propulsion Harbor tugboat Total Work boat Auxiliary Propulsion Work boat Total Harbor Craft Total Port of Long Beach 60 July 2013

16 Table 3.9: 2012 Harbor Craft GHG Emissions by Engine Type, metric tons Harbor Craft Engine Type CO 2 e CO 2 N 2 O CH 4 Assist tugboat Auxiliary 1,781 1, Propulsion 14,745 14, Assist tugboat Total 16,526 16, Crew Boat Auxiliary Propulsion 2,793 2, Crew boat Total 2,915 2, Excursion Auxiliary Propulsion 1,712 1, Excursion Total 1,957 1, Ferry Auxiliary Propulsion 10,096 9, Ferry Total 10,221 10, Government Auxiliary Propulsion 1,813 1, Government Total 1,871 1, Ocean tugboat Total Auxiliary Propulsion 7,804 7, Ocean tugboat Total 8,122 8, Harbor tugboat Auxiliary Propulsion 1,839 1, Harbor tugboat Total 1,939 1, Work boat Auxiliary Propulsion Work boat Total Harbor Craft Total 44,407 43, Port of Long Beach 61 July 2013

17 Figure 3.3 shows that approximately 29 to 40% of the Port s total harbor craft emissions are attributed to assist tugs, while 19 to 23% of the total harbor craft emissions are attributed to ferries, 17 to 31% to ocean tugs, 5 to 7% to crew boats, 4% to excursion vessels, 3 to 7% to government vessels, 3 to 5% to harbor tugboats, and 2% to work boats. Figure 3.3: 2012 Harbor Craft Emissions by Harbor Craft Type, % Port of Long Beach 62 July 2013