Environmental Engineering Reference
In-Depth Information
Large tankers made crude oil shipping so inexpensive
that the distance from market became almost irrelevant
(Ratcliffe 1985). Between 1884, the year of the first
such vessel, and 1921 record tanker capacities rose from
just over 2000 dwt to more than 20,000 dwt, and then
they stagnated for over a generation. In 1959 came Uni-
verse Apollo, the first 100,000-dwt ship; in 1966 the
record-sized 150,000-dwt Tokyo Maru of Ishikawajima-
Harima Heavy Industries; and later in the same year the
210,000-dwt Idemitsu Maru. By 1973 there were 366
very large or ultralarge crude oil carriers, with the largest
vessels in excess of 300,000 t (Kumar 2004). The long-
term trend clearly pointed to ships of 1 Mdwt. But the
growth peaked with the launching of Seawise Giant in
1975 and its enlargement three years later.
The world's largest ship was hit in 1988 during
the Iran-Iraq war, it was subsequently relaunched as the
564,650-dwt (nearly 459 m long). Jahre Viking—and
now, renamed yet again (Knock Nevis)—is moored in
Qatar as a floating storage and offloading unit. Super-
tankers reached their limit because of operational consid-
erations. Very large ships have to reckon with the depths
of sea routes and the long distances needed to stop; acci-
dental oil spills affect marine life and pollute beaches and
shores for years to come; and the penalties sought, as
illustrated by the Exxon Valdez Alaska spill on March
24, 1989, can reach billions of dollars and tanker insur-
ance becomes prohibitively expensive. Also, megaships
could find only a handful of ports in which to moor, los-
ing the flexibility with which multinational oil companies
use their tankers.
Shipments of natural gas in liquefied natural gas (LNG)
tankers (fig. 12.6) are much more expensive. These ves-
sels carry CH
4
at
162
C in four or five insulated spher-
ical containers. They were used for the first time in 1958
to ship Algerian gas to the Britain (Methane Pioneer) and
France, and in 1960 (Bridgestone Maru) to take Indone-
sian gas to Japan (Corkhill 1975). By the year 2005 there
were 29 liquefaction facilities in 17 locations in Africa
(Algeria, Libya, Egypt, Nigeria), the Middle East
(Oman, Qatar, United Arab Em¯rates), Asia (Brunei,
Indonesia, Malaysia), Australia, Alaska, and Trinidad.
Scores of LNG tankers, most with capacities in excess of
100,000 m
3
, carried about one-quarter of globally
traded natural gas to 40 regasification sites in Japan,
South Korea, the United States, Europe, and the Carib-
bean (IEA 2005). LNG terminals are relatively compact
but require extensive security zones; their throughput
densities range between 2 kW/m
2
and 60 kW/m
2
;
Qatar's LNG terminal, the world's largest, rates 2.8
kW/m
2
. Regasification terminals are equally compact,
with throughputs between 6 kW/m
2
and 50 kW/m
2
.
Increasing LNG trade has led to many new designs for
offshore regasification terminals known as floating stor-
age and regeneration units.
Pipelines are the least expensive choice for moving
hydrocarbons on land, thanks to their compactness (a
1-m-diameter line can carry 50 Mt oil/a), cleanliness,
reliability, safety, and hence excellent environmental
acceptability. The first long-distance oil lines were laid
in the United States during the 1870s, but worldwide
expansion began only after WW II. U.S. lines from the
Gulf to the East Coast were eclipsed by the world's
longest crude oil pipelines laid during the 1970s to
move Western Siberian crude oil to Europe. The Ust'-
Balik-Kurgan-Almetievsk line, 2120 km long and with a
diameter of 120 cm, can carry annually up to 90 Mt of
crude oil from a supergiant Samotlor oil field to Euro-
pean Russia, and then almost 2500 km of large-diameter
lines are needed to move this oil to Western European
