Nitric Acid Cleaning Composition for Calcium Oxalate Scale Removal

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Solution Overview

Problem

Current cleaning and disinfecting solutions for food processing equipment, particularly those with calcium oxalate scales, face challenges in stability, corrosion prevention, and effective removal without mechanical means, which can lead to incomplete cleaning and equipment damage.

Innovation Solution

A novel composition combining nitric acid, sulfuric acid, a compound with an amine and sulfonic acid moiety (such as taurine), and a peroxide source, which maintains stability and effectiveness over time, preventing corrosion and efficiently removing calcium oxalate scales without forming precipitates or causing environmental pollution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high pressure water (200-350 bar) is used to remove scale mechanically, then scale removal efficiency is improved, but capital investment and energy consumption increase substantially

Engineering Contradiction:
Improvescale removal efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the mechanical high-pressure water system with a chemical cleaning composition containing nitric acid, sulfuric acid, peroxide, and taurine. This substitution eliminates the need for capital-intensive pressure-resistant equipment and substantial energy input while achieving effective calcium oxalate scale removal through chemical dissolution.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the approach from mechanical force (high pressure) to chemical parameters (acid concentration, peroxide content, taurine concentration) to achieve scale removal. The cleaning composition uses specific chemical concentrations (e.g., nitric acid 1-10%, sulfuric acid 1-10%, peroxide 1-20%, taurine 1-20%) to dissolve scale without requiring mechanical energy input.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional cleaning methods are used, then some scale removal is achieved, but calcium oxalate scale remains difficult to dissolve under acidic or basic conditions

Engineering Contradiction:
Improvescale removal capabilityVSAvoidscale removal completeness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs a composite cleaning composition combining multiple active ingredients: nitric acid (oxidizing capability), sulfuric acid (proton donation), peroxide (strong oxidation), and taurine (chelating agent). This composite formulation creates synergistic effects that overcome the limitations of single-conventional cleaners, enabling complete dissolution of recalcitrant calcium oxalate scale that resists ordinary acidic or basic treatments.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention utilizes strong oxidizing agents (nitric acid and peroxide) to break down the crystalline structure of calcium oxalate scale, making it soluble. The oxidation process converts insoluble calcium oxalate into soluble oxidation products, achieving complete scale removal where conventional methods fail.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

3Productivity

If strong acids like hydrochloric acid are used for cleaning, then cleaning effectiveness is improved, but corrosion to stainless steel surfaces increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidcorrosion to stainless steel
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical parameters of the cleaning solution by using nitric acid (1-10%) and sulfuric acid (1-10%) at controlled concentrations, combined with peroxide and taurine, to achieve effective cleaning while maintaining stainless steel integrity. The presence of peroxide and taurine moderates the corrosiveness of the acids, allowing effective scale removal without damaging the equipment surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces peroxide and taurine as intermediary substances that mediate between the acidic components and the stainless steel surface. These intermediaries provide additional cleaning mechanisms (oxidation, chelation) that reduce reliance on aggressive acid-metal reactions, thereby preventing corrosion while maintaining cleaning effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If mechanical high pressure cleaning devices are deployed, then scale removal is achieved, but the approach is capital intensive requiring pressure resistant devices

Engineering Contradiction:
Improvescale removal capabilityVSAvoidequipment requirements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical high-pressure cleaning system with a simple chemical application process. The cleaning composition can be applied using standard spray bottles or low-pressure delivery systems, eliminating the need for capital-intensive pressure-resistant equipment, pumps, and safety infrastructure required by mechanical methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 composition exhibits long-term stability and high peroxide content retention, effectively dissolving calcium oxalate scales while preventing corrosion, thus ensuring thorough cleaning and extending equipment lifespan without the need for high-pressure mechanical methods.

Implementation Method 1

nitric acid, sulfuric acid, a compound with an amine and sulfonic acid moiety (such as taurine), and a peroxide source, which maintains stability and effectiveness over time, preventing corrosion and efficiently removing calcium oxalate scales

Methodology Applied
Scientific EffectChemical dissolution: Chemical Bonding

Implementation Method 2

a peroxide source, which maintains stability and effectiveness over time

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

a compound with an amine and sulfonic acid moiety (such as taurine)

Methodology Applied
Scientific EffectChelation: Chemical Bonding

Data Source

PatentUS12065628B2Stable nitric acid blends and uses thereof
Publication Date: 2024.08.20 DORF KETAL CHEM FZE

AI summary

A modified aqueous acid composition comprising: nitric acid; sulfuric acid; a compound comprising an amine moiety and a sulfonic acid moiety; and a peroxide. Also disclosed are methods of using such composition.