Composition for Recovering Bitumen from Oil Sands

Abstract

An improved composition for recovering bitumen from oil sands is used in the traditional “hot water” extraction process. An aliquot of a solvent mixture is mixed with bitumen ore and water. A pH builder is added and following mixing primary and secondary froths are recovered. The solvent mixture contains a monoterpene, nonionic surfactant, a short chain alcohol and a short chain ketone. Primary and secondary froth recovery is at least 80% at temperatures of about 35° C. Only very small amounts of solvent are used, and all solvents are biodegradable.

Description

CROSS-REFERENCE TO PRIOR APPLICATIONS[0001]Not applicable.U.S. GOVERNMENT SUPPORT[0002]Not applicable.BACKGROUND[0003]1. Area of the Art[0004][AREA OF ART][0005]2. Description of the Background[0006]Almost all of the energy used on our planet come ultimately from the Sun. Fossil fuels represent the photosynthetic products of long-dead photosynthetic organisms. Generally, fossils of macroscopic terrestrial organisms yield materials that range from peats to coals. Generally, microscopic marine and freshwater aquatic photosynthetic organisms have left us with “oil” or, more properly, petroleum. When aquatic photosynthetic organisms (“algae” and “zooplankton”) die and are entrapped in sediments, the organic matter is modified by heat and pressure and the resulting organic fluids migrate and become trapped by overlying geological structures to form “oil reservoirs” which can be tapped to form oil wells. However, large amounts of aquatic organic matter become deposited with clay minerals ...

AI Technical Summary

Benefits of technology

[0018]An exemplary embodiment of the invention relates to a two part composition useful for extracting bitumen from bituminous sand ores (oil sands). This combination is particularly useful for extracting bitumen from high grade 10% to 14% bituminous sand ores as a full or partial replacement for the conventional hot water / caustic soda process. Typically, the combination recovers 80% of the bitumen using a small amount of the composition and at temperatures no greater than 35° C. The basic rate of recovery can be increased by increasing the temperature and / or the amount of composition employed. Cost benefit analysis can be used to select the optimum combination of temperature and volume of composition. The composition can be used directly in existing extraction equipment. It is likely that specially designed equipment could yield even better recoveries.

Problems solved by technology

The environmental problems currently attributed to oil sand mining are largely related to these removed byproducts.

During the transport to the plant, the bituminous ore is conditioned, causing complex physical and chemical changes to occur that break the surface tension between hydrocarbon and water components.

Bitumen itself contains naturally occurring water-soluble organic acids and surfactants, but these do not become fully active until the pH and temperature conditions are sufficiently high.

A main disadvantage of this conventional extraction procedure is the large amounts of energy that are required for heating the hot water used for bitumen separation from the ore.

A further disadvantage is that the caustic soda employed in the process is toxic and corrosive and requires careful and expensive regeneration or disposal procedures.

The energy required for the hot water process is produced by burning hydrocarbons and results in the production of large amounts of carbon dioxide.

This greatly increases the amount of greenhouse gases attributable to oil sands even before refining and use as conventional motor fuels.

In addition, the large volume of water used for processing becomes contaminated by the added sodium hydroxide and soluble organic and inorganic components extracted from the bitumen.

This necessitates complex processing to reclaim the water and isolate the local environment from harm.

However, this comes as the expense of introducing a considerable amount of organic solvent (d-limonene) and into the process.

To the extent that this solvent dissolves into the bitumen, it can be recovered and recycled by distillation; however, there is a considerable energy cost in such recovery.

Apart from the cost of the d-limonene, the main cost of the Ophus process seems to be that of the energy to heat the water.

The conventional process has not yet been superseded by improved technology and continues to be plagued by a number of environmental problems.

First is energy usage.

Conventional procedures require large amounts of energy for heating the hot water used for bitumen separation.

Obviously, this natural gas is not free.

The requirement to heat the extraction water significantly increases the cost of the recovered bitumen.

Second is the problem of environmental pollution; the current extraction process requires huge amounts of natural gas for the heating water.

This burning of natural gas generates large amounts of carbon dioxide and diverts natural gas from electric power generation and other uses where it could actually moderate overall carbon dioxide production.

An additional environmental problem is produced by the processing of smaller bitumen and mineral particles remaining in an intermediate water layer, called middlings which are pumped onto a separation vessel similar to the one mentioned above.

Pollutants enter the ecosystem creating numerous hazards for the wildlife as well as humans.

Many birds migrating across the country landing in waters to rest, and toxic components in the water can lead to an 80-90% death rate.

Aboriginal communities that live around the river are becoming increasingly worried about how the animals they eat and their drinking water are being affected.

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