# Blockchain-based Cleaning Certificates for Chemical Tanks

> The TALKE Group is developing a digital solution for tamper-proof documentation of chemical tank cleaning processes in collaboration with Blockchain Reallabor. The system creates digital certificates with digital signatures for each cleaning step, which are stored in a blockchain. The project is still in the planning phase with a planned development period of three years.

**Sector:** Secondary sector · **Industry:** Chemical industry · **Organisation:** TALKE-Gruppe und Blockchain Reallabor · **Maturity level:** Concept

Canonical URL: https://www.sapientblock.com/en/use-cases/talke-gruppe-tankreinigung-digital-zertifizieren

## Documentation status

- **Project status:** Concept
- **Evidence:** Evidence medium
- **Editorial review:** Ufuk Avci, 15 April 2026

## Description

The Blockchain Reallabor Huerth (Fraunhofer FIT, RWTH Aachen) developed a blockchain application for certifying tank cleanings in the chemical supply chain as part of the NRW project. Tank trucks transport various chemicals sequentially; cleaning between transports is safety-critical.

In the chemical industry, tank vehicles are used for different chemicals. After transporting one chemical, the tank must be cleaned according to defined protocols before another chemical can be loaded. Certain combinations are highly dangerous: chlorine after ammonia, acid after alkali. The cleaning certificate proves that the cleaning was properly carried out. The problem: paper-based certificates can be forged. The blockchain system of the Reallabor solves this: the tank cleaning operation enters the cleaning protocol and inspection result with timestamp and inspector identity directly into the blockchain system; the immutable certificate can be immediately verified by logisticians, chemical companies, and authorities. The Blockchain Reallabor NRW-Spezial (March 2024) documents this use case as one of the most practical in the region.

## Benefits

- Companies can strengthen their position as innovative and trustworthy logistics providers while simultaneously minimising compliance risks.
- Blockchain technology ensures the immutability and authenticity of cleaning certificates, preventing fraud and manipulation.
- Automation of certificate verification significantly speeds up processing at the loading site and reduces error rates.
- Paperless documentation improves the efficiency of the entire supply chain and reduces administrative effort.
- Employees require less specialised training for certificate verification as validation is automated.

## Challenges

- Companies must invest in new IT infrastructures and adapt their existing systems to the blockchain solution.
- A central solution for the entire chemical industry is unrealistic, so industry-wide standardisation of digital certificates is necessary.
- Successful implementation requires acceptance and active participation of all actors involved in the supply chain.
- Employees must be trained in handling digital identities and blockchain-based systems.

## Technology foundation

The system uses a blockchain database to store digital signatures of cleaning certificates, not the complete certificates themselves. Each participant receives a digital identity with private and public keys, ensuring the authenticity and immutability of the cleaning records.

## Sources

- [Blockchain Reallabor NRW Spezial](https://blockchain-reallabor.de/wp-content/uploads/2024/03/BLOCKMAG-SPEZIAL-NRW-1.2.pdf)