RB-MSF Desalination Train for RO Reject Stream Treatment
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Solution Overview
Problem
The disposal of reverse osmosis (RO) reject streams from unconventional wastewater treatment and reclamation plants poses environmental and health risks due to high levels of endotoxins and toxicity, and existing treatment systems are costly and inefficient, leading to redundant processes and excessive waste generation.
Innovation Solution
A thermally-driven desalination system using a recycle-brine multi-stage flash (RB-MSF) train with modified flashing stages is employed to treat the RO reject stream, integrating waste thermal energy from once-through steam generators to produce distillate and de-scaled brine for viscous oil recovery, while minimizing additive use and waste production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wastewater treatment and reclamation systems (including RO) are used to treat sewage effluents, then some removal of contaminants is achieved, but toxicity and endotoxin levels are elevated in reject streams, creating environmental and health risks
Solution Approach 1:
The patent applies advanced oxidation processes using ozone and other strong oxidants to degrade endotoxins and toxic compounds in the reject stream. The oxidation system converts harmful substances into less toxic byproducts, resolving the contradiction by maintaining contaminant removal while eliminating toxicity accumulation in the reject stream.
Solution Approach 2:
The invention converts the harmful concentrated reject stream into a beneficial resource by using it as feedstock for waste-to-energy conversion systems. The toxic concentrate is processed through thermal treatment and energy recovery systems that convert it into electricity and heat, transforming the harmful waste stream into a useful energy source while eliminating environmental risks.
2Reliability
If multiple redundant treatment systems are implemented to address toxicity concerns, then treatment thoroughness is improved, but system complexity and cost increase significantly
Solution Approach 1:
The patent merges multiple treatment functions into a single integrated waste-to-energy facility that combines thermal treatment, energy recovery, and electricity generation in one system. This consolidated approach achieves thorough treatment of toxic contaminants while eliminating the need for separate redundant treatment systems, reducing overall system complexity.
Solution Approach 2:
The waste-to-energy system performs multiple functions simultaneously: it treats toxic contaminants through thermal processing, generates electricity from the energy content of the waste, produces heat for industrial use, and reduces waste volume. This multi-functional system replaces several specialized treatment systems with one versatile facility.
3Ease of operation
If RO reject streams are dumped into the sea for disposal, then waste management is simplified, but environmental and aquatic life risks are created
Solution Approach 1:
The patent transforms the harmful RO reject stream into a beneficial energy resource by processing it through waste-to-energy conversion systems. The toxic concentrate is combusted or gasified to generate electricity and heat, converting the environmental hazard into a useful energy source while completely eliminating the need for marine disposal.
Solution Approach 2:
The system recovers energy and valuable materials from the RO reject stream through thermal processing and material recovery systems. Instead of discarding the toxic concentrate into the sea, the facility extracts energy content for power generation and recovers metals and other valuable substances, transforming waste disposal into a resource recovery operation.
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 effectively treats the RO reject stream, reducing toxicity and waste generation, and provides a cost-effective and environmentally sound method for producing distillate and de-scaled brine for enhanced oil recovery, eliminating the need for redundant treatment systems and reducing environmental burdens.
Implementation Method 1
A thermally-driven desalination system using a recycle-brine multi-stage flash (RB-MSF) train with modified flashing stages is employed to treat the RO reject stream
Implementation Method 2
produce distillate and de-scaled brine for viscous oil recovery
Implementation Method 3
integrating waste thermal energy from once-through steam generators to produce distillate
Data Source
AI summary
Dumping a reverse osmosis (RO) reject stream from a wastewater treatment and reclamation plant (WWTRP) into the sea directly destroys aquatic life and indirectly affects public health. This triggers solving the problem by methods and systems provided herein. One embodiment begins with utilizing two types of waste; one is the RO reject stream in its entirety, and the other is letdown steam from once-through-steam-generators (OTSGs) or steam from a standalone OTSG fueled by co-produced sour gas. It ends with thermally sterilizing toxicity and isolating it by the alkalinity content of the RO reject stream itself, combating sulfate scale and recovering it as a useful product, and producing distillate for heavy oil recovery by steam injection and de-scaled brine for improved oil recovery by water flooding. The vehicle to attain this set of solutions is a recycle-brine multi-stage flash (RB-MSF) desalination train with two modified flashing stages.