Petrobras Magazine

Committed to the preservation of the environment, the reduction of greenhouse gas emissions into the atmosphere, and the minimization of climate change, Petrobras, through a partnership between its research and development center, CENPES, and Petrobras University, hosted the 2nd Petrobras International Seminar on CO2 Capture and Geological Storage from November 9-12 in Bahia. The objective was to promote an exchange of experiences related to the capture and storage of CO2 and to discuss how to reduce global warming by means of these measures and by the use of clean fuels.

The second seminar provided an opportunity to continue the debates that took place at the International Seminar on Carbon Capture and Climate Change in 2006, as well as to create the opportunity for the presentation of important studies. �The seminar was distinguished by the high quality of the work presented,� emphasized the technical consultant and coordinator of the event, Paulo Cunha. After all, the seminar brought together more than 300 specialists from 13 countries, representing renowned universities, R&D Institutes, energy companies, and governments.

Clean Fuels

Included in the talks presented by Petrobras specialists, it is worth highlighting, in the clean fuels field, the one presented by the coordinator of the GTL (gas to liquids) cell of CENPES, Eduardo Falabella Souza, entitled CTL and the Capture and Storage of Carbon. How Can They Contribute to a Cleaner Energy World? The talk dealt with the chemical transformation of mineral coal into clean liquid fuel and synthetic lubricants, a technological route known as coal to liquids or CTL, and further, the transformation of mineral coal to dymethyl ether (DME), which is considered the fuel of the twenty-first century by researchers worldwide.

�In the technology known as CTL, the coal is gasified, in such a way as to create a mixture of hydrogen and carbon monoxide. These are converted into liquid hydrocarbons using a catalyst by means of a synthesis known as Fischer-Tropsch. It is then possible to produce diesel, lubricants, paraffins, and petrochemical naphtha, used in the manufacture of fertilizers, without sulfur and aromatics, that is to say, clean and with a high performance,� explained Falabella.

The CTL technology, which appeared in Germany in the 1920s, was taken to South Africa, which today has the biggest CTL plant in the world, able to produce 170,000 barrels of liquid fuel per day. The technology is also being researched in China, where significant investments have been made in the installation of the process. CENPES leads the research in Brazil.

In transforming the coal into dymethyl ether, it is gasified, forming a mixture of hydrogen and carbon monoxide, which undergoes a further reaction in the presence of a specific catalyst to produce DME. �The advantages of the product include a clean burning, without the emission of sulfur oxides and particles, no greenhouse gas effects, no damage to the Earths ozone layer, and easy handling, storage, and transportation in liquid form,� said Falabella.

The lecture, The Use of Hydrogen as a Strategy in the Mitigation of Climate Change through Energy Efficiency and the Reduction of Greenhouse Gas Emissions, given by the CENPES senior consultant and researcher, Maria Helena Troise Frank, is also worthy of note considering that hydrogen tends to be a key element in the world energy matrix in the coming decades if it is possible to reduce the costs of its use on a large scale.

�Hydrogen, which can be used to power airplanes, cars, trucks, and ships, is the most abundant element in the universe. Also, it can be produced using renewable energy sources such as solar energy, hydroelectric energy, wind power, thermo-solar energy, and biomass. It can also be obtained from fossil fuels such as natural gas, coal, and naphtha, and from other sources such as nuclear energy. It is a clean fuel, generating few or no emissions, depending on the production process; it makes possible the use of alternative, renewable sources in transportation; and it is an attractive alternative in the case of an oil shortage. It can be stored in gaseous, liquid, or solid form. Distribution can be carried out by truck and pipelines, with hydrogen combined with natural gas or not, or on site, that is, in the actual production location. Hydrogen can be used in internal combustion engines such as automobile motors, stationary industrial or residential generators, and, in more efficient devices, fuel cells, which may be automotive, portable, or stationary, for the generation of electric energy. But the costs involved are still high, with the hydrogen obtained from natural gas having the lowest cost to date,� explained Frank.

Petrobras, she reminds us, is the largest hydrogen producer in Brazil, principally for internal consumption. The company produces about 500 tons per day. The fuel is obtained from natural gas or from gas from a refinery, using in-house technology. The company is, however, engaged in research involving the entire hydrogen technology chain. It is developing a hybrid bus powered by hydrogen and fuel cells and is installing two hydrogen supply stations in Brazil. Studies are in progress on internal combustion engines powered by hydrogen. Mixtures of natural gas and hydrogen, as well as carbon nanotubes for the storage of hydrogen are under study. In addition, the company is part of the Cachet Project, co-financed by the European Union, whose aim is to make viable the production of hydrogen fuel obtained from natural gas. Only in this way, it is believed, will it be possible to develop solutions able to lower the costs of the production, storage, and transportation of hydrogen and to generate energy by means of fuel cells.

CO2 Capture

In the area of CO2 capture, the lecture, Perspectives on CO2 Capture with Membranes in Brazil, given by Professor Wander Vasconcelos of the Federal University of Minas Gerais, and elaborated in partnership with Petrobras researchers Sueli Akemi Hatimondi, Ana Paula Musse, Jailton Ferreira do Nascimento, and Wilson Mantovani Grava, presented a low-cost, practical solution to capture carbon dioxide � the use of ceramic membranes.

�In general, the capture of CO2 is achieved using solvents such as amines, which generate residues that attack the environment and require complex elimination procedures, in addition to requiring ample space. Polymeric membranes can also be used but have the disadvantage of resisting temperatures of less than 45�C. Our proposal is to use systems of separation by ceramic membranes which can be placed in modules and can be adjusted to different requirements. These systems can occupy compact or vast spaces, can be adapted to reactor exhausts, and be installed on platforms, with the advantages of operating continuously or with few stops, of being renewable and reusable after cleaning, of generating a smaller quantity of environmentally harmful substances, of being low cost, of supporting high pressures, high temperatures, and large outflows, and of being able to be combined with other capture techniques. The membranes operate like filters which, in contact with gases, retain the CO2 while permitting the passage of other gases. The CO2 can then be put in adequate locations and destined either for geological storage or for increasing the recovery of oil in new and mature fields. Ceramic membranes have already been successfully synthesized on a laboratory scale. Now, thanks to a wide-ranging partnership between Petrobras and the Federal University of Minas Gerais, we will develop the membrane materials and carry out evaluation and performance trials and tests on a larger scale,� reported Professor Vasconcelos.

Another CO2 capture project to be implemented by Petrobras was presented by the geologist Rodolfo Dino in a lecture, Projects for the Capture and Storage of Carbon in the Reconcavo Basin. This project consists of the installation in the location of a unit to capture the CO2 produced in the advanced recovery of oil carried out in the Miranga field. �After the completion of rigorous tests, we will inject about 400 tons of CO2 per day into the field. In order to avoid the emission of greenhouse gases, harmful to the environment, we will combine the use of amine solvents and membranes and we will monitor the field in real time so as to avoid any possible escape, or act promptly if an escape occurs. The project is forecast to start in 2009,� he said.

Storing CO2

Regarding the storage of CO2, important Petrobras initiatives in the Bahian Reconcavo region, the company�s learning basin, were also highlighted in the same lecture. In this basin, the company has carried out the injection of carbon dioxide into wells for the recovery of mature fields for almost two decades. �We inject 50 tons of CO2 per day, coming from the FAFEN fertilizer plant owned by Petrobras and from the chemical company Oxiteno into an injector well in the land-based Rio Pojuca field, and 150 tons per day into the land-based Buracica field. The CO2 passes through a Petrobras compression station in Camaari; it is dried, pressurized, and transported by carbon dioxide pipelines to a distribution point in Santiago, 60 km east of Salvador; and then it arrives in the fields, says Rodolfo Dino, CENPES coordinator of CO2 geological storage initiatives.

As testimony to its capacity to carry out geological storage not associated with the advanced recovery of oil, Petrobras will also carry out two non-profit experiments with the exclusive objective of reducing the CO2 in the atmosphere. 甓In early 2009, we will inject 50 tons of CO2 per day into a deep saline aquifer located in the Sergi formation, at a depth of more than 1000m, beneath the producing area of the Rio Pojuca field. Also, in the last quarter of 2009, we will inject 120 tons of CO2 per day, at a pressure of 1300 psi, for a period of four years, into the Miranga field in the Marfim formation. The accumulated volume injected will be monitored by 4D seismic recordings and other methods. Proving the technical viability of the method will demonstrate Petrobras� competence in the operation of geological carbon capture processes,� concluded Dino.

Transportation

Regarding the transportation of carbon dioxide, in the lecture The Infra-Structure of Carbon Dioxide Pipelines for the Capture and Storage of CO2, the speaker emphasized the importance of having specific engineering norms for the designing of carbon dioxide pipelines, that is, pipes designed to transport CO2 from the production site to the storage location. After all, the pipelines currently in use worldwide were designed in accordance with design codes for gas or oil pipelines. �It is necessary to take into account specifics related to the carbon dioxide pipeline project, such as the control of the corrosion caused by CO2 contaminated by water, the greater resistance of non-metallic materials to degradation by CO2 throughout the entire length of a pipe, and the need to use materials more resistant to fractures than those used for gas and oil pipelines,� said equipment engineer Eduardo Hippert. To correct this deficiency, he explained, Petrobras, together with other energy companies, are participating in a study presently being conducted by a Norwegian certifying agency, DNV, which will produce specific technical norms for carbon dioxide pipeline projects. The conclusion of the study is foreseen for 2009.

Hippert also emphasized the challenges involved in the installation of a CO2 network of pipelines in Brazil. �In this country, the entire process of obtaining environmental licenses involves challenges, given the large territorial extension and the eventual network of pipelines necessary for the transportation of CO2. Therefore, we have to be prepared,� he concluded.

The Exchange of Knowledge

Referring to the exchange of knowledge dealt with in the talks in the session Networking on Climate Change and Carbon Capture, Paulo Cunha pointed out that �Petrobras, which has a study group specially dedicated to technological research on carbon capture for the mitigation of climate change, also one of the focuses of the CENPES Proclima program, coordinates a network of 20 Brazilian universities in which investments are made to make possible the development of projects related to the entire carbon capture chain. This network is developing about 50 R&D projects in this area and will establish 17 centers of excellence in Brazil for the dissemination of knowledge. In addition, Petrobras is part of the Carbon Capture Project � Phase II and relies on researchers from the Intergovernmental Panel on Climate Change, and, through the activities carried out by the company, interacts with universities and R&D institutes throughout the world.�

Ethics and Legislation

Referring to ethics and legislation, in his speech Strategies for the Implementation of CO2 Capture and Geological Storage in Brazil, Paulo Cunha emphasized that �In the case of Brazil, before formulating our own legislation in the field of the capture and geological storage of CO2, it will be necessary to take into account what is being done globally and what applies to Brazil; public perception; ethical questions; the opinions held by representatives of the Executive Committee of the Kyoto Treaty�s Clean Development Mechanism and the Intergovernmental Panel on Climate Change on the sustainability of the actions proposed; the legislation and the policies regarding natural gas, mining, and analogous themes; and the institutions, throughout the world, which deal with these questions. Also, we will need to analyze the legislation, first in the world, which is being elaborated in Australia to regulate the capture and geological storage of CO2, considering the differences in relation to Brazil, because, in Australia, 83% of the electricity generated comes from coal. Only in this way can Brazil draft legislation regulating the capture and geological storage of CO2 taking into full account the climate challenges which arise. Petrobras, in its sphere of action, is doing its part.