The chemical and
refinery industry are both major consumers of energy. More energy efficient
technologies in those industries therefore have the potential to contribute
significantly to energy savings and the reduction of CO2
emissions at the macro-economic level. In order to assess these potentials,
it is important to have a proper overview of the structure of energy
use and CO2 emissions in these industries.
In this study an
overview based on a spreadsheet model containing process datasets for
68 production processes for the production of 53 of the most important
chemicals in terms of production volume and for 16 of the most important
processes in the refinery industry is presented. The model also contains
production volumes for the chemicals included and process volumes for
the various refinery processes for the Netherlands, Western Europe and
the world in 2000. The processes cover approximately 70% of the final
energy use in the chemical and refinery industries.
For the processes
analysed in the chemical industry, both the heat effects of the
chemical reactions and the energy use of the processes are quantified.
The sum of both equals the total energy loss of the processes (i.e.
the amount of waste heat to the environment).
The total final
energy loss in Western Europe for the processes analysed equals 1620
PJf in Western Europe in 2000, the total primary energy loss
equals 1894 PJp. Total CO2 emissions are calculated
as 111 Mt CO2, assuming steam and electricity to be produced
separately (no cogeneration). Three processes (ethylene, ammonia and
chlorine production) contribute approximately 50% to the total energy
loss.
The ultimate theoretical
energy saving potential of the processes is equal to the total energy
loss of the process. The processes with large energy losses in relative
(in GJ per tonne of product) and absolute terms (in PJ / year) are identified.
The energy losses are split into losses due to non-selectivity, which
is an indicator for process selectivity and excess final energy use,
which is an indicator for the efficiency of energy use of a process.
For the majority of processes the excess final energy contribution is
the largest.
Considering those processes for which
a Best Available Technology is known, the yearly energy saving potential
in Western Europe ranges from 10 to 50% for small and large energy consumers
respectively.
For the processes
in the refinery industry, the analysis is focussed on the energy
use of the various processes. The heat effects resulting from the chemical
reactions could not be estimated with reasonable accuracy. Total energy
use of the processes analysed in 2000 in Western Europe is estimated
at 1555 PJf and 1654 PJp. Total CO2
emissions are estimated at 137 Mt CO2. Atmospheric distillation
is identified at the largest energy consumer in the refinery (430 PJf),
followed by catalytic cracking and hydrogen production.
This report presents
an analysis at an intermediate (meso) level. The processes have been
studied as black boxes without analysing the various unit operations
(reactors, separation equipment etc.) within the process. Adding up
the results for all processes yields results for the industries as a
whole (the macro level). Processes with large theoretical energy saving
potentials in relative and/or absolute terms have been identified. Among
these processes are processes that are well known for their large energy
use such as the processes to produce ammonia, chlorine and ethylene,
but also less well known processes such as the processes to produce
acrylonitrile and hexamethylene diamine. These processes could be selected
for more detailed analysis at the micro level. In doing so, actual energy
saving potentials could be determined, taking into account not only
theoretical, but also practical, economic and thermodynamic considerations.
The spreadsheet model can also be extended and improved at the meso
and macro level. Various recommendations are given for improvements
and extensions such as the inclusion of a more sophisticated model section
for the production of electricity and steam and the inclusion of dynamic
elements in the model to analyse past and to project future energy demand
of the chemical and refinery industry.