Navegando por Assunto "Natural gas"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Análise técnico-econômica da substituição parcial do combustível diesel pelo gás natural em motores marítimos na região amazônica
(Universidade Federal do Pará, 2007-12-07) FRANCO, Alcides Canêjo Linhares; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The international experience indicates the existence of five main elements related to the expansion of the natural gas consumption as following: a) availability of natural gas reserve; b) restriction offers of other energy ones (especially for the electricity generation); c) concern with the environment by a environmental legislation more rigorous, each day; d) the investments attraction by the private companies permission for the distribution and commercialization of the natural gas; e) the generalized permission for the industry, attracting private companies, because of the opportunity of the investment. In this scene, the construction of the gas line Coari (extraction base) Urucu-Manaus with about 670 kilometers of total extension that will be ready on April of 2008, as divulged by Petrobras on 05/21/2007 and will carry 4.7 million cubic meters per day of natural gas in the first phase of operation. The foreseen total investment is of R$2.4 billions. The natural gas will substitute the diesel and the combustible oil used, mainly, in the production of great part of the consumed electric energy in the Amazon State. It will be used also in the industrial and commercial processes, as well as supplying, with safety, auto-machine vehicles (automobiles, pickups, light trucks, bus). This last application stimulated this research, that establish a technical-economic analysis of the partial substitution of the fuel diesel by the natural gas in maritime engines in the Amazon Region, because the boats are vehicles that cross the rivers of this Region and are used for load and passengers transportation. First, it is demonstrated that it is possible, in technical conditions, the conversion of the diesel engines to consume the diesel mixed with natural gas to the taxes of substitution of diesel for natural gas from 5% to 90%, using available technologies that are in the Brazilian market, under the view of energy and environment performances. Later it presents an economic analysis of the conversion, considering the reservoirs for natural gas compressed - NGC offered in the national market and the kits of conversion. The research reveals: a) the economic viability of the enterprise if the weights and the volumes of the natural gas reservoirs are neglected, especially the first one; b) the no economic viability, considering the transport of the reservoirs, in the boats, that had no financial results because of the prices of the taxes resulting of the space occupied by the volumes and the weights of these reservoirs.
Acesso aberto (Open Access)
O GNL como mecanismo de flexibilização no fornecimento de gás natural para geração termelétrica no Amazonas
(Universidade Federal do Pará, 2020-09-14) PEREIRA, Salony Aquino; CUNHA, Edinaldo José de Sousa; http://lattes.cnpq.br/8714515962963079
Convergence between the natural gas and electricity markets is increasing as a result of the increasing liberalization of the natural gas and electricity markets, as well as increasing environmental constraints, projections of global natural gas demand indicate strong growth, especially in the electricity generation segment. The transport of natural gas in its liquefied form, LNG (Liquefied Natural Gas), is an important agent for this convergence as well as for the increasing global integration of the natural gas and electricity markets. It is observed that there is a supply of natural gas to be used, but is currently poorly distributed in the Amazon. Considering that there is only one natural gas supplier to Amazonas and conditions are limited for both new business and high investment price, it is important to evaluate new alternatives for natural gas supply and LNG supply is an interesting alternative. The present study evaluates the feasibility of an alternative model based on the possibilities of LNG supply, acting as a mechanism to flexibilize the supply of natural gas and ensuring a better use of electricity generation capacity today installed in the Amazon.
Acesso aberto (Open Access)
Propriedades Térmicas do (Bio)Butanol e a Fotocatálise do Grafeno com Trifenilamina Dopado com Metais para Geração de H2
(Universidade Federal do Pará, 2019-01-10) MARTINS, Marcelo Gonçalves; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
In this study, the optical properties and electronic structures of the transition metal-doped G-TPA using water as solvent were theoretically investigated in order to evaluate the efficiency in the production of photocatalytic hydrogen. in the Gaussian 09W software, using the B3LYP functional for all structures, and the base 6-31g (d) for the H, C and N atoms, and the LANL2DZ base, applying the effective potentials method for the transition metals (Ni, Pt, Pd, Fe, Os). Through the DOS of each structure an increase of accessible states in the valence layer was observed, as well as the decrease of the gap for all doping and for the structure with two and three radicals of triphenylamine. Through the UV-vis absorption spectrum, there was an improvement in absorption in the range of 490 nm to 615 nm. Another analysis carried out in the sense of energy generation was the evaluation of the thermodynamic potential of the butanol properties as complementary fuel or substitute for conventional fuels. For this, the Gaussian09W allied to the DFT was used again, but combined with the functional ones, hybrid B3LYP with the base set 6-311 ++ G (d, p) and 6-31 + G (d), G3 and G4 , in addition to the CBS / QB3 compounds. The simulations were carried out and the thermodynamic properties were found, such as: the specific molar heat at constant pressure, the enthalpy of formation and the entropy. All the properties were obtained between the temperatures 100K - 1500K and constant pressure of 1atm, in addition the enthalpies of combustion of the butanol isomers were obtained, several ternary mixtures were also proposed where it was possible to compare the enthalpy variations between the fuels: gasoline, ethanol and n-butanol.
Acesso aberto (Open Access)
Sensores de narcóticos, gás natural e syngás utilizando nanotubos de carbono sob ação de campo elétrico externo
(Universidade Federal do Pará, 2021-02-15) AIRES, Júlio Cesar Nunes; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
This work presents an analysis of the molecular dynamics between several illicit drugs: benzoylmethylecgonine, diacetylmorphine, 3,4 methylenedioxymethamphetamine, D-Deoxefedrine, lysergic acid diethylamide and, interacting with a section of carbon nanotubes at low initial temperature, corresponding to 10-3 K, and under a uniform electric field, like a drug detection system. In addition to the analysis of the behavior of natural gas molecules and SYNGAS interacting with a carbon nanotube at an initial simulation temperature of 300K, with all systems being relaxed by 50 ps outside the carbon nanotube, describing each possible arrangement for capture; a constant external electric field was then applied to the systems, longitudinally, along the length of the carbon nanotube, promoting an evanescent effect, capable of trapping them orbiting the carbon nanotube. Simulations for electric field intensities within a range of 10-5 to 10-1 a.u. were performed, to verify the behavior of drugs, while for the molecules that comprise Natural Gas and SYNGAS, a range of 10-8 to 10-1 a.u. was adopted. Average orbital radii were estimated, in addition to a number of thermodynamic properties. Our results indicate that the combination of a uniform external electric field and van der Waals interactions in a carbon-derived nanotube is enough to create an evanescent field of attractive potential, modeling it as a system for the detection of temperature and drug rays .
Acesso aberto (Open Access)
Teoria do funcional de densidade e ensemble canônico para análise termodinâmica do gás natural, gás de síntese e de suas misturas
(Universidade Federal do Pará, 2018-10-05) GOMES NETO, Abel Ferreira; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
In this work we performed a thermodynamic characterization of natural gas, synthesis gas and the mixtures of these two fuels, obtaining predictions based on the density functional theory and on statistical thermodynamics, through the canonical ensemble model. The study initially focused on verifies what method of the Density Functional Theory is more suitable for the thermodynamic analysis of natural gas, where properties were obtained, such as the following thermodynamic potentials: internal energy, enthalpy, Gibbs free energy and entropy. We conclude that B3LYP functional, along with the basis sets 6-311++g(d,p) corresponds to the most recommended method for the thermodynamic prediction of this fuel, the thermodynamic properties of the synthesis gas were analyzed, as well as the effects caused by the synthesis gas when mixed with natural gas. The results showed the synthesis gas can be a possible anti-knock additive, which a mixture containing up to 30% of synthesis gas can raise the resistance of natural gas to heating, reducing only about 15% of the energy their released in the combustion.