On-Board Ammonia Production via Exhaust Gas Recirculation

Solution Overview

Problem

Existing on-board ammonia production systems for selective catalytic reduction (SCR) in engines are costly, complex, and heavy due to the need for additional components to supply oxygen and water, which increases the size and weight of the system.

Innovation Solution

The system produces a first exhaust flow with higher NOx concentration and directs a portion of a second exhaust flow to a reformer, combining it with the first exhaust flow upstream of an ammonia-producing catalyst, utilizing oxygen and water from the exhaust gas to streamline ammonia production, eliminating the need for an air pump and water supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If additional components are added to supply oxygen and water during ammonia production, then ammonia production capability is improved, but system size, weight, and complexity increase

Engineering Contradiction:

Improveammonia production capabilityVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The system uses the engine's own exhaust gas as the source of oxygen and water for ammonia production, eliminating the need for external supply systems. The exhaust gas is recirculated through the reformer and ammonia synthesis reactor, creating a self-contained ammonia production loop that reduces system complexity while maintaining production capability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The exhaust gas serves multiple functions: it provides oxygen for the reformer reaction, water for ammonia synthesis, and acts as the carrier gas for the ammonia production process. This multi-functionality eliminates the need for separate oxygen and water supply systems, reducing overall system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If additional components are added to supply oxygen and water during ammonia production, then ammonia production capability is improved, but system weight increases

Engineering Contradiction:

Improveammonia production capabilityVSAvoidsystem weight

Core Design Contradiction:

ProductivityVSWeight of moving object

Solution Approach 1:

The system uses the engine's own exhaust gas as the source of oxygen and water for ammonia production, eliminating the need for external supply systems. The exhaust gas is recirculated through the reformer and ammonia synthesis reactor, creating a self-contained ammonia production loop that reduces system complexity while maintaining production capability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The exhaust gas serves multiple functions: it provides oxygen for the reformer reaction, water for ammonia synthesis, and acts as the carrier gas for the ammonia production process. This multi-functionality eliminates the need for separate oxygen and water supply systems, reducing overall system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If additional components are added to supply oxygen and water during ammonia production, then ammonia production capability is improved, but system size increases

Engineering Contradiction:

Improveammonia production capabilityVSAvoidsystem size

Core Design Contradiction:

ProductivityVSVolume of moving object

Solution Approach 1:

The system uses the engine's own exhaust gas as the source of oxygen and water for ammonia production, eliminating the need for external supply systems. The exhaust gas is recirculated through the reformer and ammonia synthesis reactor, creating a self-contained ammonia production loop that reduces system complexity while maintaining production capability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The exhaust gas serves multiple functions: it provides oxygen for the reformer reaction, water for ammonia synthesis, and acts as the carrier gas for the ammonia production process. This multi-functionality eliminates the need for separate oxygen and water supply systems, reducing overall system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 reduces the cost, complexity, and size of the ammonia production system by utilizing exhaust gas oxygen and water, enhancing the efficiency and effectiveness of on-board ammonia production for SCR systems.

Implementation Method 1

directing a portion of the second exhaust flow to a reformer

Methodology Applied

Scientific EffectReforming reaction: Chemical Transport Reactions

Implementation Method 2

a catalyst facilitates a reaction between exhaust-gas ammonia and NOx to produce water and nitrogen gas

Methodology Applied

Scientific EffectSelective catalytic reduction: Catalysis

Data Source

PatentUS7767181B2System and method for ammonia production

Publication Date: 2010.08.03 CATERPILLAR INC

AI summary

A method of ammonia production for a selective catalytic reduction system includes producing a first exhaust flow and a second exhaust flow. The first exhaust flow has a higher NOx concentration than the second exhaust flow. The method also includes directing a portion of the second exhaust flow to a reformer. The method further includes combining the portion of the second exhaust flow directed to the reformer with the first exhaust flow upstream of an ammonia-producing catalyst.