Electricity generation process
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Solution Overview
Problem
Current pressure retarded osmosis (PRO) technologies achieve low power densities, making them uneconomic for large-scale implementation, and existing methods for harnessing energy from underground formations are inefficient, particularly in solution mining processes.
Innovation Solution
Integrating an osmotic power generation process with solution mining by utilizing the salinity differential between input and output streams from solution mining to extract latent osmotic energy, employing a semi-permeable membrane to convert osmotic pressure into electricity, which can power the solution mining process and reduce water consumption and waste disposal issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional pressure retarded osmosis (PRO) is used with fresh water and sea water, then osmotic power generation is achieved, but power density is low making the process uneconomic
Solution Approach 1:
The patent changes the key parameter of salinity concentration by using highly concentrated brine from solution mining (near saturation) instead of conventional sea water. This dramatic increase in concentration differential across the membrane directly increases osmotic pressure and power density, making the process economically viable while maintaining the same basic PRO mechanism.
Solution Approach 2:
The patent combines two processes into one system: solution mining for salt extraction and osmotic power generation. The brine stream from solution mining serves dual purposes - as a product stream for salt recovery and as the high-concentration feed for osmosis. This multi-functionality increases economic viability by producing both salt and electricity from the same system.
2Power
If brine stream from underground formation is used as concentrated solution, then power density increases, but membrane fouling risk increases
Solution Approach 1:
The patent applies preliminary filtration and treatment to the brine stream before it enters the osmotic system. By removing particulates, organics, and other fouling substances upstream, the membrane is protected from fouling while still allowing the high-concentration brine to drive osmosis and generate power.
Solution Approach 2:
The patent introduces an intermediary treatment stage between the solution mining brine and the osmotic membrane. This intermediary system includes filtration and possibly chemical treatment to remove fouling substances, acting as a mediator that allows the high-concentration brine to benefit the osmosis process while protecting the membrane from damage.
3Quantity of substance
If solution mining is used to create caverns in salt formations, then natural gas storage capacity is provided, but large amounts of fresh water are consumed
Solution Approach 1:
The patent makes the solution mining process self-sufficient by using the osmotic power generation system to produce electricity that powers the mining operations. This eliminates or reduces the need for external power sources and significantly reduces fresh water consumption associated with conventional power generation, making the process sustainable.
Solution Approach 2:
The patent merges solution mining with osmotic power generation into an integrated system. The brine stream from mining serves dual purposes as both a product stream and an osmotic feed, while the power generated is used to sustain the mining operation. This combination eliminates the need for separate power sources and reduces overall resource consumption.
4Ease of operation
If external power is used to drive solution mining, then mining operations can proceed, but energy costs increase and remote locations are inaccessible
Solution Approach 1:
The patent makes the solution mining system self-powered by integrating osmotic power generation. The system generates its own electricity from the brine stream, eliminating or reducing dependence on external power sources. This enables operations in remote locations without infrastructure while reducing energy costs.
Solution Approach 2:
The patent combines solution mining with power generation in a single integrated system. The osmotic power unit is coupled directly to the mining operation, using the brine stream from mining to generate the electricity needed to drive the mining process. This merger eliminates the need for separate power infrastructure and reduces operational costs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach increases power density, reduces reliance on external power, facilitates solution mining in remote locations, and provides a more efficient osmotic power generation process with lower membrane fouling risks, while also simplifying waste disposal and reducing fresh water consumption.
Implementation Method 1
a semipermeable membrane is used to separate a less concentrated solution from a more concentrated solution. The membrane causes solvent to pass from the less concentrated solution (with low osmotic pressure) to the more concentrated solution (with high osmotic pressure) by osmosis
Implementation Method 2
The membrane causes solvent to pass from the less concentrated solution (with low osmotic pressure) to the more concentrated solution (with high osmotic pressure) by osmosis, and this leads to an increase in pressure on the side of the membrane to which the solvent diffuses due to the increased volume in the confined space. This pressure can be harnessed to generate electricity.
Data Source
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AI summary
An electricity generation process is disclosed. The process comprises injecting an aqueous feed stream into a salt formation to dissolve the salt contained therein, and then extracting a saline stream containing said dissolved salt from the salt formation. The process also comprises converting latent osmotic energy present in said saline stream into electricity by passage through an osmotic power unit comprising a semi-permeable membrane which permits the passage of water but not the passage of salts in which said saline stream is passed over one side of the semi-permeable membrane, a low salinity stream being passed over the other side of said membrane. The process also comprises using an output stream derived from the low salinity stream as the aqueous feed stream.