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2 Antonino La Rocca et al.
At the terminal of arrival, the regasification process of LNG returns it back
to gas state before its transport in the pipeline network. Again energy
consumption is required and, moreover, a huge amount of cold is produced. The
recovery of cold may be of capital interest because it has a relevant
environmental impact, usually on the sea near the regasification site, and, by an
energetic point of view, it is not a suitable operation to waste a lot of energy.
So it is possible to consider both the production of electrical energy
recovering the energy available as cold, using the cryogenic stream of LNG
during regasification as cold source in an improved CHP Plant (Combined Heat
and Power), and to utilize directly cold in some suitable process where cold is
need.
This paper, after a survey of the natural gas market, deals with some
feasible process utilizing waste cold from regasification of LNG, showing an
application in order to produce electric energy and another case study which
reutilize cold directly.
Key words: LNG regasification, energy efficiency, energy from waste,
CHP plants.
1. Introduction
Nowadays the international markets are afflicted by a deep economic
crisis. In Europe many countries was obliged to reduce their expenses, to
increase taxation, to cut wages and jobs; many firms was obliged to restructure
their factories and these policies led particularly to an increasing
unemployment. In the Euro Area the unemployment rate in March 2012 reach
the value of 10.9%, an increasing value from the value of 9.9% only one year
ago. Among the European countries Spain and Greece have the highest values
of unemployed, reaching respectively the values of 24.1% and 21.7% (data:
Eurostat website).
On the other side in the world the energy production and consumption are
still increasing, but this is due only to the growing economies. European Union
registers a negative trend in the primary energy production and, moreover, it has
pledges to cut its energy consumption by 20% by 2020.
The emerging economies connected to BRIC countries (Brazil, Russia,
India and China) collectively consume around 27% of the world’s primary
energy demand, 17% of oil demand, 19% of gas demand and nearly half of
global coal demand.
All these scenarios are reported in the latest IEA World Energy Outlooks.
In these reports we can see an increasing demand of energy and the linked
request to stop the climate change, related the use of fossil fuels.
So the main keywords are: convert to renewables and use in a better way
all the energy resources, performing also the CCS, i.e. the Carbon Capture and
Sequestration, for fossil fuels if it is possible.