Non-Caustic Acid Cleaning Solution for Beer Kegs

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Solution Overview

Problem

Current methods for cleaning beer kegs are inefficient in removing beerstone and protein residues without leaving chemical residues, pose health risks to workers, and have environmental concerns due to the use of caustic solutions, and lack cost-effectiveness and recyclability.

Innovation Solution

An aqueous solution of phosphoric acid, nitric acid, and surfactants is used for cleaning beer kegs, with a total nitric acid content of 12 wt % or less, which effectively removes residues without caustics, is safe, and can be recycled repeatedly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If caustic cleaning solutions (sodium hydroxide/potassium hydroxide) are used to remove protein-based soils, then cleaning effectiveness is improved, but worker safety deteriorates due to high pH hazards

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidworker safety
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the pH parameter from extreme alkalinity (12-14) to mild alkalinity (7-9), replacing caustic cleaners with non-caustic oxygenated cleaners. This parameter change maintains cleaning effectiveness for protein-based soils while eliminating the high pH hazards to worker safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses inexpensive non-caustic cleaners that can be disposed of after use, replacing expensive caustic cleaners that require neutralization and careful handling. The disposable nature of these cleaners eliminates safety hazards while maintaining cleaning effectiveness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Object-affected harmful factors

If non-caustic alkaline cleaners are used to improve worker safety, then worker safety is improved, but beerstone removal capability deteriorates

Engineering Contradiction:
Improveworker safetyVSAvoidbeerstone removal capability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention merges non-caustic alkaline cleaners with acid cleaners (phosphoric acid, nitric acid, or sulfuric acid) into a single cleaning solution. This combination provides both the safety benefits of non-caustic cleaners and the beerstone removal capability of acid cleaners, eliminating the need for separate treatment steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses composite cleaning solutions containing multiple active ingredients (non-caustic alkaline cleaners, acids, surfactants, and oxygenated compounds) that work synergistically to remove both protein soils and beerstone while maintaining worker safety.

Inventive Principle:
Principle #40Composite materials

3Reliability

If acid cleaners are used to remove beerstone, then beerstone removal capability is improved, but chemical residue formation worsens

Engineering Contradiction:
Improvebeerstone removal capabilityVSAvoidchemical residue
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the acid concentration parameter to weak acid levels (0.1-5% phosphoric acid, 0.1-2% nitric acid, or 0.1-1% sulfuric acid), which are sufficient to remove beerstone but weak enough to prevent harmful chemical residue formation. The pH is maintained between 2-7, ensuring effective cleaning without excessive acidity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies different cleaning agents to different types of soil: non-caustic alkaline cleaners target protein-based soils while weak acids target calcium and magnesium beerstone deposits. This localized approach removes all soil types effectively without leaving harmful residues from either component.

Inventive Principle:
Principle #3Local quality

4Reliability

If caustic cleaning solutions are used to achieve complete protein soil removal, then cleaning completeness is improved, but environmental impact worsens due to non-recyclability

Engineering Contradiction:
Improvecleaning completenessVSAvoidenvironmental impact
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The invention enables recovery and recycling of the cleaning solution by using non-caustic, non-corrosive ingredients that do not degrade equipment or require neutralization. The solution can be filtered, reused, and disposed of environmentally friendly, eliminating the need to discard hazardous caustic waste.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The invention uses inexpensive, biodegradable cleaning ingredients that can be safely disposed of or recycled without environmental harm. The non-caustic formulation allows the solution to be treated as a disposable or recyclable resource rather than hazardous waste, reducing environmental impact while maintaining cleaning completeness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 solution achieves complete cleaning of beer kegs without caustic use, ensuring worker safety, environmental friendliness, and significant cost savings through recyclability, with the ability to maintain cleaning efficacy over multiple uses.

Implementation Method 1

Sodium hydroxide (NaOH) and potassium hydroxide (KOH) utilize extremely high (e.g., 12-14) pH to hydrolyze (i.e., break down) soil to remove it

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

an aqueous solution of phosphoric acid, nitric acid and one or more surfactants... effectively removes residues

Methodology Applied
Scientific EffectChemical dissolution:

Implementation Method 3

formulators have included surfactants (i.e., detergents) and sometimes chlorine bleach (i.e., sodium hypochlorite) or hydrogen peroxide along with the caustic to assist wetting and protein removal

Methodology Applied
Scientific EffectSurfactant action: Surfactant

Implementation Method 4

assist wetting and protein removal

Methodology Applied
Scientific EffectWetting: Wetting

Implementation Method 5

craft brewers began using a new generation of non-caustic, alkaline, oxygenated cleaning solutions instead of using caustic

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS8211239B1Method of cleaning beer kegs and other brewery processing equipment
Publication Date: 2012.07.03 BIRKO CORP

AI summary

A method for cleaning used beer kegs employing an aqueous solution of phosphoric acid, nitric acid and one or more surfactants, e.g., a detergent and/or wetting agent. Preferably, the aqueous cleaning solution has a total nitric acid content of 12 wt % or less. Complete cleaning can be achieved without using any caustic. The cleaning solution can be recycled repeatedly to clean multiple kegs on numerous occasions over a period of time, e.g., several weeks.