(587l) Industrial Symbiosis at an Industrial Park in Trinidad and Tobago: A Focus on Carbon Dioxide

Lee Chan, T. G., The University of the West Indies
Janes, D. A., The University of the West Indies

Trinidad and Tobago (T&T) is known for having high carbon
dioxide (CO2) emissions per capita. This twin-island state, which is
rich in oil and gas, is renowned as being the largest emitter of CO2
in the Caribbean. In 2016, T&T was ranked as the country with the second
highest CO2 emissions per capita with a value of 25.72 metric tonnes1.
A significant proportion of the emitted CO2 originates from
industrial sources and in 2014, it was reported that 74% of T&T’s CO2
emissions resulted from the industrial sector2.

In Trinidad there is a large industrial park, the Point Lisas
Industrial Estate, which houses the majority of the petrochemical industry. This
industrial park contains several ammonia, methanol, urea, urea-ammonium
nitrate, melamine and cement plants. Therefore, in an aid to reduce the level
of emissions, ways in which the industrial park could be improved from an
ecological standpoint need investigation. Before any suggestions for
improvement can be made, the industrial park as it currently exists should be
evaluated. To this end, a linear input-output model was developed of a simplified
industrial park, which would exhibit the main characteristics of the large
industrial park. The purpose of the model was to assess the current level of
industrial symbiosis within the park, and highlight potential areas for
improving its level; that is, sharing and reuse of resources to create shared
value. MATLAB® was employed as the modelling environment.

From the material flow network and input-output tables developed,
it was found that there exists an embryonic level of industrial symbiosis in
the industrial park, but there is substantial room for growth. The existing culture
of industrial symbiosis is based on the commercial interests of the local
industrial community, rather than being fuelled by government subvention. CO2
is one of the by-product streams being exchanged between companies. The ammonia
plants produce waste streams of high-content CO2 that are reutilised
in the production of downstream products. The analysis found that the overall CO2
content of these available “high-content” streams was in excess of the quantity
of CO2 currently reused industrially.

There are many useful valuable products into which CO2
could be incorporated, including urea, inorganic carbonates, methanol and
salicylic acid. Potentially, CO2 could also be reused in enhanced
oil recovery. Ideally the allocation of the available CO2 streams
should be done taking into account the techno-economic efficiency and
environmental and social impacts. A few accordingly-suitable CO2-consuming
plants were added to the input-output material flow network model.

This enhanced model was used to investigate the optimum means of
reusing as much as possible of the CO2 produced, took into account
economics, environmental impact and the transportation of CO2. Notwithstanding
that the development of new CO2-consuming plants would need
increased capital investment, this input-output analysis suggests revenue could
be profitably realised from CO2-derived products. Nevertheless, ultimately
to significantly reduce CO2 emissions, in addition to the
high-content CO2 sources, less attractive flue-gas generated CO2
emissions and suitable separation processes need to be incorporated into the
network.  Thus attention needs to be directed toward strategies, which enhance
the nascent industrial symbiosis, for appropriately allocating the CO2
in these low-concentration waste-streams amongst potential consumers.


1 Knoema
World Data Atlas. (2018). “Trinidad and Tobago – CO2 emissions per
capita”. [retrieved 01/04/2019]. Available from:

Factor CO2. (2014). “Projection of the Business as Usual (BaU) and
measures scenarios of carbon emissions for the electrical energy generation,
industry and transportation sectors”. Port of Spain, Trinidad and Tobago


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