In this work, the effects of the addition of ethanol and diethyl ether (DEE) in a 54 kW mechanical fuel injection diesel engine, operating with diesel-biodiesel blends, were evaluated. The fuel compositions tested were fossil diesel (D100), B20 (20% biodiesel and 80% diesel), B20E (90% B20 and 10% ethanol) and B20E + DEE (95% B20E and 5% DEE). DEE was used as a cetane improver for the ethanol-biodiesel-diesel blend. D100 and B20 were used as references. Its results showed few differences between them, considering performance and emissions. Considering the blends B20E and B20E + DEE, effective reductions in NO x and PM emissions were observed, in relation to D100 and B20, especially in medium and high loads. MBT decreased as a result of the reduction in LHV. The engine efficiency for all the fuels was close, but at the high load the blend B20E + DEE presented the highest efficiency.

Summary Calcium carbonate (CaCO3) scaling is one of the main drawbacks in oil and gas production pipelines and equipment, contributing to the reduction or shutdown of production in petroleum extraction industries. This work shows a new device for the prevention of calcium carbonate scale in oil and gas production units. Three cells containing five ultrasonic transducers each (60 W×40 kHz) were used to reduce carbonate scaling in pipelines. Long-term tests were carried out in a semi-industrial hydraulic system that was properly instrumented to allow us to simulate CaCO3 production by injection of CaCl2·2H2O and NaHCO3. A proof valve was positioned downstream of the equipment. Pressure drop in the valve, scale mass on the pipe samples, and morphology of crystals were evaluated after 2 hours of testing. Well-marked reductions in pressure drop (up to 96%) on the proof-valve and scale thickness (up to 95%) in pipe samples were verified when compared with the system without any scale prevention device. Scanning electron microscopy (SEM) images showed alteration of the geometry and reduction of the particle size as the main reason for the reduction of scaling.

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