Technological Trends in CO2 Capture, Transport and Utilization

Rita M.B. Alves(1), Fernanda M. Fontes(2), José L. Medeiros(2), Ofélia Q. F. Araújo(2)

(1) Department of Chemical Engineering, Polytechnic School, University of São Paulo, SP, Brazil

(2) Department of Chemical Engineering, Federal University of Rio de Janeiro, RJ, Brazil

rmbalves@usp.br, ofelia@eq.ufrj.br
Environmental changes due to human activities have been the target of several intergovernmental discussions. Greenhouse gases (GHG) have been released into the atmosphere with serious consequences for the environment. Measures have been taken not only to reduce but also to try to reverse the current situation of intensification of global warming due to the greenhouse effect. These measures include reduction of the dependence on fossil fuels by modern society, and methods to control the emission of greenhouse gases, especially CO2. The main objective of this work is to build a technological map in order to support decision-makers aligned to initiatives for reduction of CO2 emission and to the change of paradigm concerning to transform CO2 into renewable raw material for the chemical industry. Analysis of routes that undertake CO2 reduction must take into account the life cycle of the processes to assess if additional CO2 production occurs beyond the amount abated from atmospheric emissions as turning CO2 into fuels and chemicals requires energy input, normally derived from fossil fuels, with associated emissions. New or mature technical solutions should comply with the triple objective of sustainability: economically feasible, environmentally benign and socially beneficial, in a supply chain approach. In this framework, this work presents the CO2 Capture Cycle as well as promising alternatives of its reutilization. The work is oriented to cover CO2 as feedstock, i.e., use of CO2 as raw material to chemicals and fuels with economic application, besides its relevant use in enhanced oil recovery.
This work presents the main drivers for the current emissions control. This work also puts together the key technologies for the capture, transport and use of CO2, currently found in laboratory, pilot plant and commercial scale. These technologies are evaluated and organized according to their level of development in order to build a technological map that associates for short, medium and long term to technological solutions. Therefore, the technological map is constructed in order to facilitate and guide the decision-making for the technologies identified as most promising. The study is divided into three steps. At first, one define the scope of the map and the technological drivers, concluding that the technological destination of the CO2 emission is indistinguishable from the upstream processes of capture and transport, and that the predictive time horizon limit should be two decades. The second step comprises to map the state-of-art of CO2 capture, transport and use technologies, based on articles, patents, reports, technological roadmaps and News. At this stage, the technological development level of the various alternatives is also identified. In the third step, technologies and products are assigned in a time scale according to the maturity level related to CO2 capture, transport and utilization technologies. The resulting technological map is a broad technological vision, which allows companies and organizations to plan their strategy for the development of sustainable processes and products.
This technological vision of CO2 treats routes of conversion to useable products and fuels, not as substitute but rather as a complement to geologic storage. Besides, industrial use and reuse of CO2 supply chain is assessed in a life cycle approach of technological alternatives involving capture, transportation and utilization â?? e.g. chemical and biochemical conversion of CO2, enhanced oil recovery and food industry. In such context, novel technological approaches extend the technology scenario for CO2 supply chain, including conversion to benign, stable compounds for long-term storage or to value-added products for reuse. Among the routes for CO2 utilization, bio fixation is a natural choice as photosynthesis yields biomass, allowing the production of bio products and chemicals through downstream processing routes. In fact, biomass gasification is the most flexible technology for dropping into conventional downstream chemical routes. The beneficial use of alkaline wastes or metallic ions â?? novel methods to react CO2 to neutralize alkaline wastes, or react with metallic ions to form less soluble carbonates that can be removed produced water (oil
& gas industry) is also a relevant application of CO2. Last, this work presents the use of CO2 in Enhanced Oils Recovery (CO2-EOR), i.e., CO2 injection into depleting oil or gas fields to maximize hydrocarbon production.
With such perspective, CO2 utilization in the short term should parallel production routes based on best practice technologies (BPT), driven by emission-capture- utilization synergies. In this sense, production and conversion of synthesis gas exhibits the highest potential of commercial success in the medium term. Nevertheless, it is worth noting that, while the utilization of CO2 has potential to reduce greenhouse gas emissions to the atmosphere, CO2 has disadvantages as a chemical reactant due to its relative chemical inertness. This inertness is the reason why CO2 has broad industrial application as solvent (supercritical CO2, fire extinguisher) and in the food industry. From the standing point of building a low- carbon economy, each potential use of CO2 as reactant has an energy requirement with energy related emissions that must not exceed the CO2 conversion to chemicals. Reverse water gas shift, dry reforming to yield syngas and hydrogenation to methanol are the most prominent alternatives to high volume chemical commodities. A co- existing concept of fossil and biomass feedstock, having generation of syngas as the integration phase, obtained by gasification of biomass, coal and heavy residues, (steam) reforming and/or dry (CO2) reforming of natural gas, coexisting with conversion routes of chemical intermediates to supply the installed petrochemical industries should be an alternative promising.