47
T
he demand for safe, efficient and cost-effective compression systems for handling boil-off gas (BOG) in
LNG plants, and especially LNG receiving terminals, is greater than ever before.
The increased size of LNG terminals and LNG carriers has led to an increase in BOG flow of
approximately 20% for single loading and up to 50% for simultaneous loading.
The increase in LNG yield can also be seen in the fact that by the end of 2014 there were more than
370carriers with a capacity exceeding 30 000m
3
, including vessels that are capable of carrying as much as
265000m
3
of LNG. Not only that, but out of 68 vessels ordered in 2014, 85%of themwill have a capacity greater
than 170 000m
3
.
1
Handling the increasing amount of BOG flow in the traditional way adds unnecessary space, weight and
equipment. Combining reciprocating compressors in cold duty with single-body, single-shaft, multi-stage
turbocompressors can be an attractive and favourable economic solution for LNG receiving terminals.
A conventional arrangement: LNG export terminals
The current level of BOG demand can be handled by a concept that features a single-body (barrel-type),
single-shaft, multi-stage, centrifugal compressor. This compressor design is optimised for small and medium
BOG volume flows and is capable of automatic start/stop operation (direct online) from ambient conditions, as
well as from cold conditions with no cool-down required.
Sven-Erik Brink and Christian Belting-Clar, Dresser-Rand
business within Siemens, Germany,
present a safe and
cost-efficient approach to handling boil-off gas.
with care
HANDLE
