Nitric Acid Cleaning Compositions for Stable Soil Removal
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Solution Overview
Problem
Existing acid cleaners for stainless steel surfaces face challenges such as inefficiency in removing fatty soils and soap scum, environmental concerns due to phosphorus and sulfuric acid use, and instability at high temperatures, leading to phase separation and loss of activity.
Innovation Solution
Aqueous, concentrated nitric acid cleaning compositions using a blend of polyethoxylated fatty alcohols and nonionic glucamide surfactants, which are phosphate-free and sulfuric-free, providing enhanced stability and efficacy in removing fatty soils and soap scum, even at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphoric acid is used in acid cleaners, then good mineral solubility and soil suspension properties are achieved, but effluent disposal problems arise due to phosphorus environmental and drinking water issues
Solution Approach 1:
The patent removes phosphoric acid from the cleaning composition entirely, replacing it with nitric acid as the sole acid component. This extraction of the harmful phosphorus element eliminates the effluent disposal problem while maintaining cleaning effectiveness through nitric acid's superior soil suspension and mineral solubility properties.
Solution Approach 2:
The patent changes the acid parameter from phosphoric acid to nitric acid, altering the chemical composition to achieve both environmental compliance and effective cleaning. This parameter change enables the composition to meet effluent regulations while maintaining or improving soil suspension properties.
2Reliability
If sulfuric acid is used in acid cleaners, then cleaning effectiveness is achieved, but environmental concerns arise due to sulfuric acid use
Solution Approach 1:
The patent extracts and removes sulfuric acid from the cleaning composition, replacing it with nitric acid. This elimination of sulfuric acid addresses environmental concerns while maintaining cleaning effectiveness through nitric acid's superior performance in removing fatty soils and soap scum.
Solution Approach 2:
The patent adopts nitric acid as a single-use, non-persistent acid that decomposes more readily in the environment compared to sulfuric acid. This disposable approach to acid usage reduces long-term environmental accumulation and concern while providing effective cleaning.
3Reliability
If acid cleaners are used to remove contaminants from stainless steel, then corrosion resistance is improved, but the compositions become unstable at high temperatures causing phase separation
Solution Approach 1:
The patent changes the acid parameter from phosphoric or sulfuric acid to nitric acid, which has superior thermal stability in the context of maintaining phase homogeneity at elevated temperatures. This parameter change preserves corrosion resistance while preventing phase separation during storage and use.
Solution Approach 2:
The patent creates a composite cleaning composition combining nitric acid with specific surfactants (polyethoxylated fatty alcohols and nonionic glucamides) that work synergistically to maintain phase stability at high temperatures. This composite formulation prevents phase separation while preserving the acid's corrosion protection benefits.
4Productivity
If conventional acid cleaners are used, then general cleaning is achieved, but fatty soil and soap scum removal is inefficient
Solution Approach 1:
The patent introduces nonionic surfactants (polyethoxylated fatty alcohols and glucamides) as intermediary agents that mediate between the nitric acid and fatty soils/soap scum. These surfactants lower surface tension and enhance the acid's ability to penetrate and remove stubborn organic soils, significantly improving fatty soil removal effectiveness.
Solution Approach 2:
The patent creates a composite cleaning system combining nitric acid with specific nonionic surfactants that work synergistically. This composite formulation enhances the cleaning action against fatty soils and soap scum while maintaining stability and effectiveness, achieving both speed and reliability in soil removal.
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
The compositions maintain stability and effectiveness in cleaning stainless steel surfaces, effectively removing soils and soap scum, suitable for CIP applications, with improved temperature stability and reduced environmental impact.
Implementation Method 1
Acid cleaning is a process by which a solution of a mineral and/or organic acid in water sometimes in combination with a wetting agent or detergent or both, is employed to remove iron and other metallic contamination, light oxide films, soil and similar contaminants
Implementation Method 2
The compositions can remove both organic and inorganic soils in the same operation
Implementation Method 3
a solution of a mineral and/or organic acid in water sometimes in combination with a wetting agent or detergent
Data Source
AI summary
Concentrated nitric acid cleaners employing the use of ethoxylated fatty alcohols, including a blend of polyethoxylated fatty alcohols, provide enhanced cleaning on metal and other surfaces, particularly stainless steel. Methods of use, including enhanced fatty soil removal and organic soil removal (such as soap scum) are also disclosed.