|
Title:
|
|
Assessment of carbon-rejection processes as a method of CO2 abatement: IEA Greenhouse Gas R&D Programme United Kingdom
|
|
|
|
Author(s):
|
|
|
|
|
|
Published by:
|
Publication date:
|
|
ECN
|
1-6-2000
|
|
|
|
ECN report number:
|
Document type:
|
|
ECN-C--00-035
|
ECN publication
|
|
|
|
Number of pages:
|
Full text:
|
|
47
|
Download PDF
|
Abstract:
As an alternative to the capture and storage Of CO2, it has beensuggested that processes which recover energy from the hydrogen content and
reject the carbon content of fossil fuels as a solid would be potentially
attractive methods of avoiding CO2 emissions. Such processes avoid the need
to store CO2 for many years in a save repository. The key reaction involved
is thermal decomposition of a fossil fuel. In case of methane decomposition
roughly 50% of the energy remains in the rejected carbon and is not
recovered. Any version of this process that only makes use of the hydrogen
product will therefore have at most a theoretical efficiency of 50%. In
practice the efficiency is likely to be significantly less as the reaction is
strongly endothermic, 75% of the input mass is rejected as carbon. Some
researchers have come to the conclusion that, for such a process to be of
interest, the rejected carbon has to be used rather than just stored
indefinitely. There are 2 major suggestions involving use of the carbon,
which are assessed as part of this study: (1) Use the carbon in established
uses for carbon black; and (2) Use the carbon in the metallurgical industry.
An alternative application of this technology which will also be assessed in
this study has been suggested elsewhere. In the there proposed 'Camol
process', the thermal decomposition of methane is integrated with the
production of other energy products. Carbon is rejected and the hydrogen
produced is reacted with CO2 recovered from power generation to make
methanol. The integrated process claimed to result in a net reduction in CO2
emissions compared to conventional processing of oil for transport fuels,
together with power generation from fossil fuels. The overall objective of
this study is to assess the competitiveness of carbon rejection schemes as
means of CO2 abatement. The scope of work for this study is specified in 3
tasks: (1) different types of carbon rejection processes will be assessed to
establish their performance and costs. The current and future world market
potential for carbon black will be assessed. The world market will be
compared to worldwide CO2 emissions from fossil fuels; (2) the potential use
of carbon black in the metallurgical industry will be assessed; and (3) the
attractiveness of the Camol process as a means of CO2 abatement will be
assessed. The reject carbon produced is not used in the Camol process, it is
either stored or sold. Methanol is used as transport fuel. Natural gas will
be used in the hydrogen generation process and coal in the power generation.
An alternate case will illustrate the effects of using natural gas in both
the hydrogen production and the power generation step. The results will
include derivation of the costs of reducing CO2 emissions. 9 refs.
Back to List