Biogas Upgrading via Sorption Enhanced Reforming and Ca-Looping

Solution Overview

Problem

The existing methods for upgrading anaerobically produced biogas to bio-methane for use as a fuel in vehicles or for hydrogen fuel cell electric vehicles are energy-intensive and costly, particularly due to the need for CO2 removal, which makes the process less competitive.

Innovation Solution

A method involving sorption enhanced reforming (SER) with Ca-looping that directly processes raw biogas with enhanced methane:CO2 ratio, capturing CO2 without prior separation, and incorporating hydrogen addition to increase methane content, thereby reducing CO2 content to less than 20%, and utilizing a combined system for producing vehicle-grade biomethane and hydrogen from anaerobic digestion of organic waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional CO2 removal methods (water scrubbing, physical/chemical absorption, pressure swing adsorption, membrane permeation) are used to upgrade biogas to bio-methane, then the biogas quality is improved for vehicle fuel use, but energy consumption and processing costs increase significantly

Engineering Contradiction:

Improvebiogas qualityVSAvoidenergy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent combines CO2 removal with methane conversion to hydrogen in a single integrated process. The CO2 that would normally be removed as waste is instead converted into useful hydrogen product through reforming reactions, merging two separate operations (purification and value addition) into one unified process that simultaneously improves biogas quality and generates additional revenue streams

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent converts CO2, which is traditionally viewed as an impurity to be removed at high energy cost, into a valuable resource. By introducing reforming catalysts and controlled conditions, the CO2 is transformed into hydrogen through water-gas shift reactions, turning a harmful byproduct into the desired product and eliminating the need for expensive CO2 removal steps

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Manufacturing precision

If conventional CO2 removal methods are used to upgrade biogas, then the biogas quality is improved for vehicle fuel use, but processing costs increase significantly

Engineering Contradiction:

Improvebiogas qualityVSAvoidprocessing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent combines CO2 removal with methane conversion to hydrogen in a single integrated process. The CO2 that would normally be removed as waste is instead converted into useful hydrogen product through reforming reactions, merging two separate operations (purification and value addition) into one unified process that simultaneously improves biogas quality and generates additional revenue streams

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent converts CO2, which is traditionally viewed as an impurity to be removed at high energy cost, into a valuable resource. By introducing reforming catalysts and controlled conditions, the CO2 is transformed into hydrogen through water-gas shift reactions, turning a harmful byproduct into the desired product and eliminating the need for expensive CO2 removal steps

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Quantity of substance

If hydrogen is added to the anaerobic digestion process to increase methane content to about 80%, then the methane content is enhanced, but the process complexity and operational difficulty increase

Engineering Contradiction:

Improvemethane contentVSAvoidprocess complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent performs preliminary hydrogen addition to the anaerobic digestion process before biogas production. By introducing hydrogen in advance, the methanogenic bacteria can directly produce high-methane-content biogas without requiring subsequent complex upgrading steps. This preliminary intervention simplifies the overall process by preventing the formation of low-methane biogas in the first place

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes key process parameters by introducing hydrogen gas into the anaerobic digestion system. This parameter change (adding H2) fundamentally alters the biochemical pathways, enabling direct hydrogenotrophic methanogenesis that produces biogas with up to 80% methane content, thereby achieving high-quality fuel without complex post-treatment

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3484811B1Method and device for biogas upgrading and hydrogen production from anaerobic fermentation of biological material

Publication Date: 2025.03.26 ZEG POWER

Figure 1~2
Figure 3~4

AI summary

Method and device for biogas upgrading and hydrogen production from anaerobic fermentation of biological material under production of energy rich gases selected among methane (24) and hydrogen (16, 26) or a combination thereof. The method comprises addition of hydrogen gas to a fermentation step (50) to enhance the methane:C02 ratio in the raw biogas (12) produced. At least part of the raw biogas is subjected to a step of sorption enhanced reforming (70) without prior separation of CO2, using CaO as an absorbent to capture CO2 from the raw biogas as well as CO2 released in the reforming reaction. CaO is regenerated in an endothermic reaction (80) using heat at least partially provided, directly or indirectly, by the bio-gas to be upgraded, thereby producing substantially pure hydrogen (15) and substantially pure C02 (23).