Análise técnico-econômica da substituição parcial do combustível diesel pelo gás natural em motores marítimos na região amazônica

Abstract

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.