Biogas Biological Desulfurization System

Product Overview

Biogas produced from anaerobic digestion may contain hydrogen sulfide (H₂S), moisture, carbon dioxide and other components that need to be controlled before downstream utilization or further upgrading.

HUAYI Biogas Biological Desulfurization System is designed for hydrogen sulfide removal using a biological scrubbing and regeneration process. The system can be applied as a pretreatment stage before biogas upgrading or as part of a complete biogas treatment system.

Process Principle

In the biological desulfurization process, hydrogen sulfide contained in the biogas is absorbed by the circulating scrubbing solution in the scrubber.

The H₂S-containing solution is then transferred to the biological regeneration reactor, where a controlled oxidation process converts absorbed sulfide into elemental sulfur and regenerates the scrubbing solution for recirculation.

Sulfur-containing solids are subsequently separated from the circulating liquid, while the regenerated solution is returned to the scrubber.

Main System Components

Depending on project requirements, the biological desulfurization system may include:

• Scrubber with internal packing, spray and demisting components

• Biological regeneration reactor

• Plate heat exchanger for process temperature control

• Sulfur separation or settling equipment

• Scrubbing solution circulation pumps

• Air blowers for biological regeneration

• Nutrient solution dosing equipment

• Alkali dosing equipment

• Sulfur sludge discharge equipment

• Instrumentation and control system

Scrubbing Section

The scrubber provides contact between the biogas and circulating scrubbing solution to remove hydrogen sulfide from the gas stream. The scrubber configuration, internal packing and circulation arrangement can be selected according to gas flow and H₂S removal requirements.

Biological Regeneration

After absorbing hydrogen sulfide, the circulating solution enters the biological regeneration reactor. Controlled aeration supports the biological oxidation process and regeneration of the scrubbing solution.

The regenerated solution can then be recirculated to the scrubber.

Temperature Control

Biological activity is affected by process temperature. A heat exchanger can therefore be incorporated into the circulation system to maintain suitable operating conditions according to the process design.

Sulfur Separation

Sulfur generated during the regeneration process is separated from the circulating solution. The sulfur-containing sludge can then be discharged for further handling according to the project configuration.

Typical Applications

The system can be used for biogas generated from applications such as:

• Agricultural and livestock waste digestion

• Food and organic waste treatment

• Wastewater treatment facilities

• Industrial organic wastewater treatment

• Biogas upgrading projects

• Biogas utilization and gas treatment systems

Customized Engineering

Biogas composition and operating conditions vary significantly between projects. HUAYI can configure the biological desulfurization system according to project-specific requirements, including:

• Biogas flow rate

• Inlet H₂S concentration

• Required outlet H₂S level

• Gas temperature and pressure

• Operating hours

• Downstream gas treatment process

• Site and environmental conditions

• Automation and control requirements

For project evaluation, customers are recommended to provide the available biogas composition, gas flow rate, H₂S concentration and required treated-gas specification.