BIOGAS emissions monitoring

The environmental benefits of biogas technology are often highlighted as a valid and sustainable alternative to fossil fuels. Together with the reduction of greenhouse gas (GHG) emissions, biogas can increase energy security as a reliable renewable energy source.

As a renewable energy source, it allows utilisation of agricultural by-products, municipal solid waste and some industrial/commercial waste, resulting in a lower environmental impact when compared to combustion-based strategies.

The by-product of anaerobic digestion is a reliable material for agricultural uses, providing a nutrient-rich substance that can be used as a fertiliser. Biogas digesters also have the additional co-benefit of generating energy for lighting and heating. When biogas is cleaned and upgraded to biomethane, this can be used as a vehicle fuel or injected into national natural gas grids. This provides greener power and reduces carbon in our atmosphere.

Although a main objective of the biogas industry is the reduction of fossil fuel consumption, with the final goal of mitigating climate change, anaerobic digestion produces several greenhouse gases, including carbon dioxide, methane and hydrogen sulphide. Consequently, dedicated emissions monitoring should be undertaken.

The composition of biogas can be quite variable, often being corrosive, dirty, wet and produced at low pressure. Due to this, measuring biogas composition accurately can be a challenge.

Biogas composition monitoring includes:

• CH4 and H2S measured during the methanation process to provide a good overall view of the performance of the degradation process and bacterial activity. A decrease in methane content can be a first sign of organic overload, provided that the feedstock mix has not recently changed.
• In all biogas production facilities, there is an H2S removal system (scavenger or H2S scrubber). Monitoring the levels of H2S at the inlet and outlet of the H2S scrubber is paramount for evaluating scrubber efficiency and for adhering to environmental regulations.
• CH4, H2S, CO, CO2 and O2 Continuous Stack Emissions Monitoring required for environmental compliance.

How do you know your monitoring equipment is monitoring your biogas emissions accurately?

Gas analysers must be properly calibrated with the correct types and concentrations of calibration gases. If monitoring equipment is not properly calibrated, it will lead to inaccurate measurement and evaluation.

Three Areas Where Quality Specialty Gases Are Necessary for Successful Bioenergy Plants:

1. Process Monitoring

• To determine potential instabilities and the overall condition of the plant.
   

2. Process Optimisation

• Gas production and economic performance.
   

3. Plant Safety

• Monitoring for emissions of explosive gas mixtures and toxic gases.
   

4. Personal Safety

• Monitoring airborne gases and vapour for occupational health and safety
   

CAC Gas provides specialty gases for waste management processes as well as for gas detection, process gas analysis, and laboratory applications including applications such as combustion efficiency, landfill & soil remediation, agriculture environmental, and emissions measurement applications. Whether the emission is stack gas, fugitive emissions, air quality or vehicle emissions, we supply the calibration gas to meet the exacting standards required.

Gas standards TO 14,15 and 17 are available for a variety of applications to measure (VOC’s) Volatile Organic Compounds in ambient air & soil contamination. Other specialised gas mixtures are available for a variety of VOC’s.

CAC GAS provides EPA Protocol calibration gas mixtures prepared and analysed in strict accordance with the most current guidelines: EPA Traceability Protocol Assay and Certification of Gaseous Calibration Standards. In addition, we supply ISO 17025 and ISO 17034 Continuous Emissions Monitoring gas standards for CO2, CO, O2, NO, NO2 and SO2. All gas mixtures are traceable to BIPM though NIST, NPL, NMI or other national measurement authorities, and certified by UKAS, NATA, DAkkS or other ILAC MRA signatories to ensure compliance with local and international regulations.

Requests for calibration gas mixtures can be complex and require considerable inquiry with our customers to determine the appropriate gas mixture for their application. In some situations, gas analysers have the ability to measure a large variety of gases but not necessarily at the same time. Determining whether the analyser has the ability to meet the customer requirement is often challenging and requires discussion with the manufacturer and customer to determine if the gas analyser can technically meet the customer requirement.

We see this as a core part of our business culture — to consult with and advise our customers — ultimately allowing us to propose specific solutions to meet the customer’s requirements. With years of experience in calibration gases and analysers, and many CAC Gas personnel originating from the analyser side of the business, we are capable of promptly understanding the application and what our customers want to achieve.

CAC Gas & Instrumentation manufacture, source and supply specialty gas mixtures & gas control equipment for a wide range of applications whether you are operating an anaerobic digestion plant, managing a landfill site or controlling a Biogas or Biomass project.

As a total solution provider, CAC GAS supplies gas generators, mixers and calibrators along with a complete gas control product range including regulators, outlet panel, manifolds and gas distribution systems. Specialty calibration gas mixtures come in multiple cylinder sizes to ensure customer requirements are attained.

With locations in both Sydney and Singapore, CAC Gas also has the logistic expertise to import and supply specialty gas mixtures globally.