Química Sem Fronteiras: o desafio da energia

Abstract

Recebido em 25/7/13; aceito em 21/10/13; publicado na web em 01/11/2013 CHEMISTRY WITHOUT BORDERS: THE ENERGY CHALLENGES. Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great ef...

Energy management: a synthesis of scientific publications on biodigestion for waste management

“…Basso et al (2010) stated that awareness of the importance of the environment has encouraged the study of new renewable and less-polluting energy sources. Following this reasoning, Rocha et al (2013) stated that the resources currently used for energy purposes include coal, natural gas and oil, and that, either by depletion of reserves or by harmful effects on the environment, the search for "energy security" and for renewable energy sources has become essential. Raboni and Urbini (2014) analyzed the production and use of biogas in the European Community and demonstrated that the practice is common, using anaerobic digestion for gas production, aiming at reducing the use of landfills.…”

Aproveitamento De Precursores Lignocelulósicos Para Produção De Acetato De Celulose

“…Os avanços na área de biotecnologia e a crescente difusão do conceito de biorrefinaria têm estimulado o uso integral da biomassa, com o objetivo de agregar valor às cadeias produtivas e diminuir os impactos ambientais. [1][2][3] Para exemplificar essa tendência, a palha da cana de açúcar tem sido amplamente usada para obtenção de etanol; 4 em outro exemplo, resíduos da agroindústria como bagaço de cana, fibra de coco e farelo de soja foram adicionados ao amido de mandioca na obtenção de compósitos na forma de embalagens biodegradáveis (bandejas) para uso na indústria alimentícia. 5 Ribeiro, Carvalho e Geris 5 extraíram furfural (solvente orgânico amplamente usado nas indústrias químicas e farmacêuticas) a partir de sabugos de milho.…”

Energy trends and the water-energy binomium for Brazil

“…Water is required for energy generation, exploration, processing and transport of fossil fuels (EIA 2012). For instance, water is used for drilling and fracturing in oil and gas exploration, large amounts of water is needed for cooling systems in thermo power plants and nuclear power stations, large amounts of water is required for hydropower stations to produce electricity, and feedstock for biofuel production need considerably large amounts of water for their growing (Service 2009, Mekonnen and Hoekstra 2012, Da Rocha et al 2013, Hadian and Madani 2013, Zhang and Anadon 2013.…”

“…Yet, there are concerns that during fracturing processes it could contaminate groundwater and aquifers, which pose water risks (Da Rocha et al 2013). Furthermore, due to the technology available currently there is a concrete possibility to leak CH 4 , CO 2 , H 2 S and Hg from 571 ENERGY AND THE WATER-ENERGY BINOMIUM FOR BRAZIL geological formations to the atmosphere during shale gas extraction that could lead to other major environmental concerns.…”

“…In this way, taking into account the recent advances in the GISELE O. DA ROCHA, JEANCARLO P. DOS ANJOS and JAILSON B. DE ANDRADE exploration of oil from the Pre-salt (estimated to be 9-15 million barrels) and the discovery of shale gas/oil wells up to 245 tcf (EIA 2013, Da Rocha et al 2013), together to the unfavorable social and environmental issues associated to the biofuels, there would be a chance the Brazilian energy matrix could be probably turn back to the fossil fuels again. These represent challenges to the Brazilian policymakers and how they will be solved ahead will have implications not only for Brazil but also to the world at large.…”