Ahead of the worldwide tightening of sulfur emission rules
for ships of all types in 2020, the cruise industry is facing criticism that
its use of scrubbers, its preferred solution for removing sulfur from
smokestack exhaust, is flawed.
A collection of environmental groups has asked regulators to
adopt the use of low-sulfur fuel as the only allowable method of complying with
regulations designed to reduce health problems from sulfur dioxide emissions.
The cruise industry prefers a mix of low-sulfur fuel and exhaust
gas "scrubbers," a type of machine that captures sulfur from heavy
fuel combustion before it can escape into the atmosphere.
Now, on a new website, Carnival Corp. is making its case that scrubbers,
which it calls Advanced Air Quality Systems, are the most effective way to
reduce not only sulfur dioxide but a variety of polluting elements in the
residue of fuel combustion.
The site contains links to several scientific studies
supporting Carnival's position. Mike Kaczmarek, Carnival Corp.'s senior vice
president for marine technology, said the website will "help educate the
public on the environmental benefits of Advanced Air Quality Systems and their
effectiveness as a solution for meeting and exceeding the upcoming IMO [International
Maritime Organization] regulations."

A diagram of what Carnival Corp. calls its Advanced Air Quality System for removing sulfur from smokestack exhaust.
The IMO is the United Nations-sanctioned body that sets a
global regulatory framework for safety, environmental, labor and other types of
policies on the high seas.
The IMO's decade-long tightening of sulfur emission
standards is set to culminate on Jan. 1, when ships of all types the world over
will be required to emit sulfur as if the fuel in question contained no more
than 0.5% sulfur.
Because much of the world fleet, particularly cargo vessels,
uses so-called heavy fuel oil, also known as bunker fuel, which has sulfur
content of 3.5% or higher, the regulation is producing upward price pressure on
low-sulfur fuel.
Bunker fuel is what's left over after gasoline, jet fuel,
diesel and other hydrocarbons are separated from crude oil in refineries.
In one study undertaken in January, the price for bulk crude
delivered in Houston was $56.65 per barrel for 3.5% sulfur fuel and $74.70 per
barrel for low-sulfur fuel.
Energy sector forecasters are raising doubts about the
available supply of low-sulfur fuel as the new rules kick in.
Carnival's website asserts, "If these forecasts are
accurate, the use of Advanced Air Quality Systems will be an important
component in the maritime industry's ability to comply with IMO 2020
regulations."
With an IMO committee now working on support documents for
the Jan. 1 changeover, nearly a dozen environmental groups petitioned the
agency to delegitimize scrubbers. They argued that the technology isn't always
reliable, citing an audit of the Carnival fleet from 2017-18 that turned up 30
examples of scrubbers that either weren't turned on or had unexpectedly shut
down in areas where sulfur emissions were already capped.
Questions have also been raised about pollution from the "wash"
that results when sulfur is captured by water sprayed through the exhaust.
On its new site, Carnival highlights a study in which the
maritime classification society DNV GL found that the level of two key pollutants
in wash water, nitrates and polycyclic aromatic hydrocarbons (PAH), were 90%
lower than the IMO's maximum allowable levels.
Carnival also argues that scrubbers actually exceed
low-sulfur fuel as an anti-pollution technology because in the process of capturing
sulfur, the scrubbing water spray also reduces fine particulates, commonly
known as soot particles, as well as PAH. Both can be cancer-causing chemicals
in some circumstances, according to the Environmental Protection Agency.
Carnival's strategy for reducing sulfur dioxide levels has
been heavily oriented toward scrubbers since 2015, when the sulfur standard was
lowered to 0.1% in special coastal areas around North America under IMO
guidelines.
Since then, it has spent more than $500 million to install
more than 220 scrubbers on 77 of the 100-plus ships in its fleet. Its goal is
to install nearly 400 scrubbers that would eventually cover 85% of the Carnival
fleet.