(492a) Creating More Value from Asphaltenes Using Continuous Oxy- solubilisation Process | AIChE

(492a) Creating More Value from Asphaltenes Using Continuous Oxy- solubilisation Process


Ashtari, M. - Presenter, University of Calgary

A Northern Alberta facility for bitumen upgrading processes 4000 tons of asphaltenic pitch every day via solvent deasphalting[1]. Increased asphaltene production in northern Alberta facilities, leads to searching for processes for better utilization of that material. Asphaltene presence in petroleum has negative effects on viscosity, density and elemental composition of the crude oil. Due to the problems that asphaltene particles can cause along production lines like well bore plugging, fouling and coke formation, dealing with their separation and trying to extract valuable products from them by further processing is of significant importance [5, 6].

Existing technologies for processing asphaltenes such as delayed coking or gasification only add a small amount of value and need high capital investment. So, With regard to big problems which asphaltene could create in oil, new technologies are needed that can directly transform asphaltenes using fewer processing steps and low Capital Intensity infrastructure, and can produce increased yields of high economic value products, such as transportation fuels or petrochemicals, while reducing the environmental pollutions [6].

Exploring alternative extensive uses of asphaltene pitch in search of potential valuable products led us to a variation of the Wet Air Oxidation (WAO) process commonly used for organic wastes processing. As so far known, WAO is a destructive technology based on the oxidation of wastes at high temperature and high pressure in liquid phase. In that system, molecular oxygen dissolved in the wastewater reacts with hydrocarbons and carbohydrates. The oxidation process depends on the solubility of oxygen at high temperature and high pressure. High temperature could increase reaction rates and production of free radicals [7, 8].

The concept proposed here is that by controllably oxidizing asphalthene particles in water, the inter-core links between asphalthene molecules can be broken and simultaneously partial oxidation -Oxycracking- can release small molecular weight oxidized molecules while decreasing the size of aromatic associations.

According to our chemical studies, the material produced from this process is of similar characteristics to fulvic and humic acids which could be used in agricultural applications as fertilizers, sewage purification, radionuclide, CO2 sequestration and surfactants [9].

This work focuses on wet air oxidation of asphaltene particles as potential new technology for producing fulvic or humic acids which could be used as fertilizers commercially. For this purpose, at first the optimum operating conditions had obtained in batch mode and then continuous pilot set up was designed, built and tested based on batch experiments results to evaluate maximum solubilisation of asphaltene particles in water.