Biogas is a renewable energy source produced through the anaerobic digestion of organic matter and has long been recognized as a valuable alternative to traditional fossil fuels. Typically, biogas is composed of various impurities such as moisture, hydrogen sulfide, volatile organic compounds (VOCs), and other trace gases that can cause corrosion in pipelines and compromise the integrity of existing natural gas infrastructure. Furthermore, biogas has a lower energy content when compared to natural gas, due to the presence of carbon dioxide, nitrogen and oxygen. Thus, to increase the energy content and guarantee its efficiency, cleaning (removing traces of contaminants from biogas) and improving biogas (i.e. increasing calorific value through the removal of CO2) are important aspects so that biogas be ready to be injected into the gas pipeline network or used as fuel for gas vehicles (Bio-CNG).
Recently, Quadrogen Power Systems, Inc. (“Quadrogen”) launched its new technology for its IBUS (“Integrated Biogas Upgrading System”) system., known as ORCA ("Optimized Reduced Cost Arrangement"). With years of knowledge and experience in the biomethane production sector from biogas and with more than 100 references in North America, South America, Europe and Asia, Quadrogen's innovative ORCA technology offers a reliable, economical and complete for biomethane generation, which is a versatile and modular solution for the use of renewable energy.
The transformation of biogas into biomethane is processed as follows:
- 1st Stage: Biogas Pretreatment – Feed biogas is directed to a pretreatment system to remove impurities such as sulfur, siloxanes and VOCs.
- 2nd Stage: Compressor – The biogas is compressed by a high-efficiency rotary compressor (screw type) before being sent to the PSA system (Pressure Oscillation Adsorption System).
- 3rd Stage: PSA System – The biogas upgrade is made for use in natural gas pipelines, using the PSA system. Nitrogen, oxygen and carbon dioxide are adsorbed by the process and the resulting gas is biomethane.
- 4th Step: Vacuum Blower – The blower module that promotes vacuum removes contaminants captured in the adsorption bed and facilitates ventilation of the PSA exhaust stream.
The IBUS ORCA is designed based on each customer's specific requirements and offers a complete cleaning and upgrade solution. It has reduced dimensions, with optimized space and piping and a layout designed for greater functionality and ease of use. The IBUS ORCA can be supplied as an automated and/or manual system, according to customer specifications. This system offers ease of assembly and installation on site, and is easy to operate and maintain.
PSA's proprietary biogas upgrade technology is a unique integrated rotary valve system that allows the adsorption and separation of contaminating gases efficiently without the need for complex controls and multiple opening and closing valves.
PSA technology improves overall project profitability, reducing costs and providing greater reliability, flexibility and better environmental performance. The PSA system is compact and skid-mounted for easy installation and integration, with proven reliability for robust and continuous operation, being simple to operate, with quick start-up and shutdown. This technology is the market leader in performance, with methane recovery rates of up to 99%, with low operating costs, using a minimum amount of consumables and utilities.
The conversion of biogas into biomethane not only brings environmental benefits, but also presents economic opportunities. Biomethane can serve several purposes, including heating, power generation and as a clean fuel for vehicles. Its compatibility with natural gas infrastructure allows for decentralized energy production, empowering local communities and businesses to become producers of renewable natural gas. Local communities and businesses with access to organic waste streams, such as agricultural waste or wastewater treatment plants, can become producers of renewable natural gas.
By capturing and utilizing methane from organic waste, the process helps mitigate greenhouse gas emissions that would otherwise be released into the atmosphere during the natural decomposition of organic matter.
Thus, the conversion of biogas into biomethane not only generates additional revenue, but also promotes a sustainable and circular economy.
Case Study: IBUS ORCA 1000, in Texas - USA
Currently installed in Texas, USA, Quadrogen's IBUS ORCA will process 1,000 SCFM (Sft3/min) of anaerobic digester feed biogas, which contains approximately 50% of methane, 40% of carbon dioxide and the remainder nitrogen, oxygen and water . The gas also has concentrations of parts per million (ppm) of hydrogen sulfide, ammonia and VOCs. The moisture in the biogas will be initially removed by cooling and the dry biogas will be sent to pre-treatment units to remove hydrogen sulfide, ammonia and VOCs. The clean pre-treated biogas will then be sent to a compressor, where it is pressurized and directed to the PSA system. With the help of vacuum blowers, the PSA captures impurities (carbon dioxide, nitrogen and oxygen) and eliminates them through an exhaust stream. The biomethane stream leaving the PSA will have a purity greater than 97% (according to the requirements for gas pipelines in the state of Texas - USA) and with a recovery rate greater than 98%.
The IBUS ORCA is a project built in a container, which comprises the compressor, E-house, all electronically automated valves (post-biogas cleaning) and instrumentation, as well as the biomethane product analyzer. This facilitates integration on site, addressing challenges related to mobility, rapid implementation, cost-effectiveness and flexibility.
Based on a vision of transforming the energy future, Quadrogen strives to be a reliable supplier of complete systems for biomethane, hydrogen production, carbon capture and recovery of industrial gases from biogas. IBUS ORCA represents continuous innovation dedicated to providing clean, sustainable and financially attractive technological solutions.
The transformation of biogas into biomethane represents a crucial step towards this sustainable and decarbonized energy future. By harnessing the potential of organic waste, this process not only addresses environmental challenges but also creates economic opportunities, locally. As the world seeks cleaner alternatives to traditional energy sources, biomethane stands out as a promising and versatile solution, with the potential to revolutionize the energy landscape.
Nelson Chan is an engineer and has over 25 years of experience as a senior commercial executive, technical manager and sales engineer, as well as business development and design of industrial-scale biogas cleaning and upgrade systems. For more than 20 years, Nelson has been developing solutions for purifying and separating gases in the renewable energy and clean technology segment.