Researchers analyzed impacts of creating routes in outstate São Paulo, where heavy vehicles would use LNG in the place of diesel
The substitution of diesel oil by liquefied natural gas (LNG) for cargo transportation in outstate São Paulo would make possible a significant reduction of fuel costs and of greenhouse gas (GHG) emissions, as well as other pollutants. This is the picture presented in a study by the FAPESP Shell Research Centre for Gas Innovation (RCGI), in which four scenarios were analyzed. “Within the best scenario, the use of LNG would reduce fuel costs by up to 40%; equivalent CO2 emissions by 5.2%; particulate materials by 88%; 75% as de nitrogen oxides (NOx); and would eliminate hydrocarbon emissions,” states Pedro Gerber Machado, one of the researchers involved in the project.
The objective of the study, which resulted in an article published in the international Science of Total Environment magazine, was to evaluate the economic and environmental benefits of substituting diesel oil by LNG for the purpose of establishing a Blue Corridor in the State. This concept appeared in Russia and designates routes on which trucks us LNG, instead of diesel oil.
“The methodology initially considered two contexts: one for the geographical regions served by gas pipelines, called Restricted Scenario (RS); and another covering the 16 administrative regions of the State, called State Scenario (SS). Both scenarios originated different versions of the Blue Corridor, with 3,100 and 8,900 kilometers of roads, respectively,” Machado explained.
According to him, in the case of each scenario, two forms of LNG distribution were considered: the first generated two sub-scenarios, a State Scenario with Centralized Liquefaction (SSCL) and a Restricted Scenario with Centralized Liquefaction (RSCL). And the second would be to do the liquefaction locally, in the region where it would be used, which would do away with the need for distributing LNG on highways. From this one, two more sub-scenarios are derived: the State Scenario with Hybrid Local and Central Liquefaction (SSHL); and the Restricted Scenario with Local Liquefaction (RSLL).
Cost comparison – “The RSLL scenario presents the lowest average price difference for the consumer, between LNG and diesel, which means that, in this case, the delivery process of the LNG is more expensive, influenced by the scale factor and by greater operating costs,” Machado explains.
And he continues, “The RSCL scenario offers the lowest gas price for the consumer, that is, 12 dollars per MMBTU (Million British Thermal Units), whereas diesel, in this same scenario, would cost 22.01 dollars per MMBTU. The difference between the price of LNG and diesel, in this scenario, is also the largest of all: 10.01 dollars per MMBTU.”
However, the RSLL scenario was designed within the context of a shorter corridor, where the investment would be US$ 243.40 per meter. This contrasts with the SSHL scenario, which has the lowest investment per meter of the four scenarios (US$ 122.10 per meter).
Emissions avoided – Machado explains that to calculate the GHG and pollutant emissions, only the two macro-scenarios were considered: SS and RS. “When using LGN, the GHG emissions are different from those of diesel oil, due to the CH4 and N2O, which are greenhouse gases with potential for global warming. If the fuel used is diesel, CO2 is responsible for 99% of the emissions of CO2-eq, and if the fuel used is LNG, it represents 82% of the CO2-eq emissions, while CH4 is responsible for 10% and N2O for 8%,” he states.
Regarding the GHG emissions generated by the logistics of transporting LGN, the worst case scenario refers to the SSCL, and corresponds to 1% of the total CO2-eq emitted with the use of trucks. In the SCHL, the logistics represent 0.34% of the emissions, and in the RSCL, the logistics corresponds to 0.28% of the emissions.
As for the pollutants, in the RS scenario, 119,129 tons of emissions of particulate material (PM) would be avoided; 7.3 million tons of NOx; and 209,230 tons of hydrocarbons (HC). In the SS scenario, the benefits are even greater, with reductions of 163,000 tons of MP; 10 million tons of NOx; and 286,000 tons of HC.
The reduction of 5.2% of GHG emissions, observed in the State Scenario, when one compares the burning of natural gas and diesel oil, the result might not be so grandiose, but there are considerable reductions of local pollutants – NOx, PM, and HC: respectively 75%, 88%, and 100%.
“The biggest benefits, both in terms of pollution reductions and in prices of the fuels being discussed herein, are perceived in São Paulo and Campinas, which are regions with greater potential for substituting diesel oil by LNG and where diesel oil is more expensive than in the rest of the State. Our results show that in São Paulo, LNG can be up to 60% cheaper than diesel oil,” says Dominique Mouette, Professor in the School of Arts, Sciences, and Humanities of the University of São Paulo (EACH/USP); principal author of the article; and leader of the RCGI project focusing on the viability of a Blue Corridor in the State of São Paulo.
Regulatory barriers – However, despite the economic and environmental advantages presented, LNG still faces regulatory barriers to its general use in the transportation sector. “It is not regulated to be used as a fuel for vehicles in Brazil. Most of the VNG used here is compressed natural gas (CNG),” states Professor Mouette.
The article published in the international scientific magazine, entitled Costs and emissions assessment of a Blue Corridor in a Brazilian reality: The use of liquefied natural gas in transportation, is signed by researchers: Dominique Mouette Denis Fraga, Drielli Peyerl, Pedro Gerber Machado, Raquel Rocha Borges, Thiago Luis Felipe Brito, Lena Ayano Shimomaebara, and Edmilson Moutinho dos Santos.