Simulation of an alternative biodiesel process using palm oil as raw material with low energy consumption.

Abstract

The oil price is getting prize record, this is a significative sign that the fossil energy sources are running out. Biofuels that come from vegetable oils or fats and fossil fuels have similar properties. For that reason the use of biodiesel doesn’t require any modification of the actual vehicle fleet, in addition the transport waste gases will be decreased, so it is a good alternative. Nowadays biodiesel is the biofuel with best perspectives, on the other hand the actual production process, the transesterification, has a huge train of separation and purification stages, mostly distillation. Furthermore for the properties of the products this purification stages waste a rather high amount of energy. Recent studies, such as García Jurado et al (2013), proposed an alternative process focused on decreasing the energy waste of the transesterification process. The main achievement is the use of only one device. This device is an extraction column with two different sections: one reactive and one extractive, with a counter-current circulation of reactives. The aforementioned study has achieved high product purities which are established by European Union standards EN14214. In the following paper palm oil, with a wide use in the world of biofuels, will be the raw material that will react with methanol as short chain alcohol. Nowadays the pinch analysis is a tool to integrate and study the energetic requirements of a process. In many cases, the distillation columns are the main contribution to the energy requirements, but the pinch analysis was not taking into account the distillation column. Recent studies (Plesu et al, 2013) proposed a method to calculate the minimum energy requirements of distillation columns based on thermodynamic principles, i.e. the distillation column is considered a heat engine producing separation instead of work. This innovative method will be applied in the present project for first time, to my knowledge. With the aim of getting conclusions about the competiveness of the alternative process will be compared with an actual biodiesel production scheme, available in ASPEN Plus examples. In addition Refecas et al (2013) studied and proposed a new scheme to revalorise the glycerine produced as byproduct of the process, reacted with short chain volatile acids a short chain oil is produced and can be introduced in the biodiesel stream as an additive. This process is an interesting alternative for the glycerine collected as biodiesel byproduct.