Stricter emission legislation for heavy duty (HD) internal combustion engines are set up around the world that can be accomplished by developing new technologies and it reduces fossil fuel dependency. It can be achieved by utilizing more sustainable fuel sources, with respect to greenhouse gas emissions, particulates and NOx. The purpose of the project is to study a dual fuel engine using alcohols such as methanol or ethanol together with Diesel fuel. Both fuels are direct injected. As a first test of concept, a standard high pressure diesel fuel injection system run with ethanol, was used in this study to characterize high pressure sprays in a in a high pressure/temperature spray chamber with optical access. The fuel used was E100 with 200 ppm lubricating additive and toluene to increase UV light absorption. A high energy laser pulse was used to ignite the ethanol spray. Increased knowledge about fundamental mechanisms of the fuel-air mixing processes are vital for a compression ignition engine to control and optimize combustion and reduce engine out emissions. Spray behavior and characteristics in a Diesel like environment were investigated. Experiments were run at a gas density of ~25kg/m3 at ~550C and ~60 bar representing a HD engine at low loads. High speed video images of back-lit natural and UV light illumination was used to create shadow-graph images to investigate spray parameters such as cone angle, liquid and vapor penetration length and lift-off length. The injection pressure of ethanol was varied between 500 and 2200 bar. The results for different injection strategies gave a reasonable picture of the fuel air mixing processes along with flame development and propagation. It was shown that high injection pressures could be achieved with the Diesel injection system. Ethanol in Diesel like combustion is a step towards utilizing alcohols in HD engines.