A breath of fresh air

Increasing environmental awareness is putting pressure on the shipping industry to reduce emissions at port. US-based Tri-Mer Corp believes it has a possible solution.

On June 19, 2008, at a media event held at the Port of Long Beach, test results were announced regarding the cleaning of diesel emissions using Cloud Chamber Scrubber (CCS) technology developed by Tri-Mer Corporation, Owosso, Michigan. The emissions tests covered all sources originating from ships at dock, including auxiliary engines, boilers, and on-board power generators. Barry Wallerstein, executive director of the South Coast Air Quality Management District (AQMD) was a prominent speaker at the meeting. The roster included Wayne Nastri, Region 9 administrator for the US Environmental Protection Agency (EPA).

The Cloud Chamber Scrubber (CCS) achieved reduction rates that effectively establish a new standard for the treatment of high-volume diesel emissions. Performance efficiencies of the CCS, detailed at the event, were high for all target pollutants:
• particulate matter: 98 per cent reduction
• SO₂: 99 per cent reduction
• NO_x: 99 per cent reduction

The Tri-Mer CCS uses patented, “charged droplet” technology to remove particulate matter (PM) and SO₂ pollutants. Diesel particulate is less than 0.1 micron in size and is one of the most difficult particulates to control. The CCS employs a special pre-conditioning process that allows particles to ‘grow’ through adsorption and agglomeration and subsequently be captured in the next stages of the CCS by the charged droplets. The pre-conditioning stage simultaneously removes the SO₂.

NO_x is treated by a selective catalytic reduction (SCR) module which is a factory-integrated option of the CCS system. PM and sulphur that might impede catalyst efficiency and service life are removed prior to NO_x treatment, so exceptional results are consistently achievable.

Tri-Mer Corporation provided all the air pollution control technology, including controls and integration of the SCR. Equipment engineering and manufacturing were completed at its Michigan factory. Tri-Mer also helped coordinate installation and demonstration of the technology. Advanced particulate characterisation equipment was used to calibrate the CCS system. The government agencies and other stakeholders at the port contracted with an independent third-party testing company and laboratory to provide standard testing and analysis of PM, SO₂ and NO_x for independent verification. The ship exhaust was brought to the dock-side CCS system using a capture device that fits over a variety of ship smokestack configurations and was developed by ACTI (Rancho Dominguez, CA), the environmental company that funded the demonstration projects and is offering complete dock-side solutions, including its Advanced Maritime Emissions Control System (AMECS), which is composed of capture equipment coupled with CCS treatment technology.

With the successful demonstration test at the Port of Long Beach, and a similar demonstration on diesel locomotive emissions at Union Pacific, Roseville, California, CCS is now regarded as the first technology to prove consistently-high removal efficiencies when operating at the flow volumes typical for large diesel engines.

The CCS provides a solution to a long-standing problem in controlling diesel emissions near ports, rail yards, and other sources of high-volume diesel emissions. In 2007, The Port of Long Beach, California, handled more than 7.31m containers, and more than 87Mt of cargo. The ports of Los Angeles and Long Beach together account for more than 40 per cent of all containers entering the US.

Idling ships accounted for 1.8stpd of diesel particulate matter (PM) state-wide in 2006, according to the California Air Resources Board, while cargo ships, some of which can emit more diesel exhaust per day than 12,000 automobiles, are responsible for much of the air pollution in the region. They are a leading source of NO_x, SO_x and PM, which have been linked to premature deaths, respiratory illnesses and global warming in many port areas. Moreover, commercial ships, en route and at port, release more SO₂ and particulates than all of the world’s cars, trucks and buses combined, according to a study released in March by the International Council on Clean Transportation, and quoted in a Wall Street Journal article on November 27, 2007. The study further found that ships produced an estimated 27 per cent of the world’s NO_x emissions.

In November 2007, a study in the American Chemical Society’s journal Environmental Science and Technology estimated that under-regulated air pollution from ships results in 60,000 deaths from lung cancer and cardiopulmonary disease each year, primarily along trade routes in Asia and Europe.

CCS technology

The cloud chamber scrubber treats PM2.5, fine, submicron, ultrafine, and condensable particulate as well as PM10 and more coarse particles. It removes any gas treatable by a wet scrubber, including HCl, NO₂, SO₂, Cl₂, NH₃ as well as HF, H₂SO₄, HNO₃, ammonia and amine compounds. This is important because, for the first time, one device can handle particulates and corrosive fumes simultaneously.

CCS is based on new patented discoveries in electrofluidics. It offers proven submicron performance at efficiencies typically greater than 99 per cent thanks to its capability to efficiently ‘grow’ and capture particles smaller than 0.1 micron. It is also highly energy-efficient, requiring just 10W/1000cfm to charge the water droplets, plus moderate pump power for water recirculation. It operates with ultra-low water usage. CCS generates less than 1.5in wg pressure drop across the system. Gas temperature, particle solubility, resistivity, and reactivity have minimal affect on performance. CCS accommodates heavy loadings and is not sensitive to load flux.

Industrial boilers

Tri-Mer’s CCS also lends itself to industrial boilers, particularly those with flow rates of 200,000acfm or lower. In the US, the EPA requires all boiler units with a greater than 10mBtu/h heat input located at major sources of hazardous air pollutants, to be compliant with boiler Maximum Achievable Control Technology (MACT) standards. These dictate limits for PM, HCl, CO, SO₂, Hg and other heavy metals. The current MACT standard was vacated by the courts in 2007.

The situation has been complicated by a tug-of-war between the National Association of Clean Air Agencies (NACAA) and the Council of Industrial Boiler Owners (CIBO). The former represents air pollution control agencies in 53 states and territories and over 165 major metropolitan areas in the US. NACAA has been seeking to have the EPA adopt its model rule, which was released on June 10. This requires tougher standards than those currently required by MACT, but removes the need for case by case reviews. Because the MACT system requires the EPA to set a floor determined by the top 12 per cent of sources, the NACAA has said that if its model is adopted, then the next MACT will be forced to use the stricter limits as its emissions floor. The move attracted criticism from CIBO as the organisation believes the standards are unachievable for the vast majority of sources. This claim has been contradicted by the Institute of Clean Air Companies, which represents the interests of pollution control equipment manufacturers.

Due of the above, a new boiler MACT standard is expected in the summer of 2009 and is widely believed to place more stringent limits on emissions.

As can been seen from Table 1, Tri-Mer’s CCS system reduces the levels of these pollutants to far below that required by current MACT standards for both existing and new industrial boilers. As a result, it is anticipated that existing CCS users will be not be inconvenienced by the introduction of tighter air quality standards.

For more information on the CCS and other emissions reducing technologies, consider visiting www.tri-mer.com or contact Kevin Moss at: kevin.moss@tri-mer.com