Overseas Biogas Projects

Biogas and Biomethane | Ammonium-Based Biological Desulfurization

To accelerate the research, development, and innovation of new technologies and equipment for the high-value utilization of biogas and biomethane, and to strengthen the promotion and application of advanced and practical technologies by enterprises as well as the demonstration and leadership of typical scenarios, the Society will, at an appropriate time, release a series of innovative technologies and typical case studies on the high-value utilization of biogas and biomethane. This initiative aims to expedite the formation of a pathway involving “technological breakthroughs—scenario validation—industrial application—system upgrades,” thereby providing strong support for promoting high-quality development in the biogas industry.

01 Background:

Against the backdrop of the global energy transition and the “dual carbon” goals, the efficient and clean utilization of biogas has become a consensus within the industry. However, the hydrogen sulfide (H₂S) contained in biogas is highly corrosive to equipment and causes secondary pollution, posing a key bottleneck that limits its high-value utilization. Against this backdrop, independently developed technologies—such as basic biological desulfurization—have successfully overcome technical barriers thanks to advantages including operation at ambient temperature and pressure, safety, environmental friendliness, and low operating costs. These technologies have become a shining example of “Made in China” making its mark in the global environmental protection sector.

Schematic Diagram of the Basic Bio-Desulfurization Process

02 Process Characteristics

First, it offers exceptional adaptability to operating conditions. The system can easily handle gas supply fluctuations caused by feedstock variations and operates stably with hydrogen sulfide concentrations ranging from low levels to ultra-high concentrations of up to 40,000 ppm. Second, it delivers stable and reliable operation. The optimized spray tower design and comprehensive anti-clogging measures have significantly reduced the frequency of shutdowns for maintenance in overseas projects. Third, it offers outstanding safety and environmental benefits. The system operates in a fully enclosed manner, with the byproduct being elemental sulfur sludge that can be recycled; there is no risk of hazardous waste, and it fully complies with stringent environmental standards. Fourth, operation and maintenance are simple and cost-effective. Fully automated control and unmanned operation effectively address the shortage of O&M personnel in overseas projects, and the compact equipment ensures highly competitive capital and operating costs.

03 Suitable Applications

Alkaline biological desulfurization can be widely applied to the desulfurization and purification of biogas produced from livestock and poultry manure, slaughterhouse waste, food waste, landfill gas, food processing and certain industrial wastewater, and straw anaerobic digestion. It is suitable for various biogas projects in agriculture, animal husbandry, food processing, municipal solid waste, and certain industrial wastewater sectors, and can also be used for biogas purification to produce biogas.

04 Application Cases

Shandong Lanlvqing Environmental Technology has successfully implemented multiple systematic solutions in Southeast Asia, a region rich in biogas resources: Thailand Pea Starch Project: A complete set of alkaline biological desulfurization equipment with a processing capacity of 36,000 m³/d, independently developed by the company, has successfully entered the Southeast Asian market, providing strong support for the high-value utilization of regional biogas. Vietnam Paper Mill Project: Facing extreme operating conditions with an inlet hydrogen sulfide concentration as high as 20,000 ppm, the 20,000 m³/d alkaline biological desulfurization system demonstrated exceptional purification capabilities. With a purification efficiency exceeding 99.8%, the purified biogas achieved a methane content of 62.5%, and the outlet hydrogen sulfide concentration was stably maintained below 40 ppm, fully meeting the operational requirements of downstream power generation units and enabling the efficient conversion of waste into energy.

A Clear Path to High-Quality Development in the Biogas Equipment Manufacturing Industry: 1. Technological Confidence: Moving from “Following” to “Leading”—The biogas purification sector has shifted toward independent innovation and international export, establishing a technologically competitive system with global standing. 2. Value Upgrade from “Equipment” to “Solutions”: What is exported is not just individual pieces of equipment, but “turnkey” systemic solutions that include process design, equipment manufacturing, installation and commissioning, and operation and maintenance, thereby achieving a move up the value chain. 3. Brand Building: From “Business” to “Responsibility”: By helping developing countries address energy and environmental challenges, Chinese environmental protection companies are shaping a responsible and committed brand image on the global stage, contributing “Chinese wisdom” to advancing the global energy transition.