The use of alternative fuels, such as biogas or waste recovery methane gas requires conditioning to allow it to be efficiently and cleanly in a burner system for a boiler, or a turbine for generating electricity. RJ Mechanical has experience taking methane gas from digester lagoons and conditioning it for process steam. Working with Unison Solutions, the leader in biogas technology, we can develop a system to turn waste gas to productive energy.
Methane gas from an anaerobic digester contains moisture that must be removed for it to be usable in a combustion system. Using heat transfer to cool the gas below the dew point, moisture is removed and the gas can be filtered and transferred to a blower or compressor for transmission to the boiler room. A combination of filtration, condensate removal and heat transfer can be used to prepare for efficient combustion.
Siloxanes are chemicals present in many consumer products and can develop from the organic fats and oils present in the anaerobic digesting process in poultry and animal rendering facilities and landfills. After the combustion process in boilers and turbines, siloxanes can result in silica deposits within the equipment. Integrated siloxane removal systems can be incorporated into the fuel gas conditioning system.
After the gas is extracted and the moisture is removed, filtration further conditions the gas by removing small particles that may be present in the gas stream. Media and cartridge filtration systems are available to remove particles down to 3 microns.
Hydrogen Sulfide (H2S) and organic sulfur is present in biogas and removal is often necessary to prevent corrosion of the burner/boiler system, internal combustion engine or turbine. Removal of H2S from the gas stream also reduces Sulphur Dioxide (SO2) emissions from the combustion exhaust system.
Once the gas has been conditioned for combustion in a boiler or turbine, the gas is pressurized to the proper level for the end use system. Low pressure blower skids are typically used in boilers, internal combustion engines for steam, hot water or power generation. Various blower technologies can be selected and integrated into the system for the best fit for the application.
Gas compressor skids are used for turbines, fuel cells and biogas pipeline applications, and are designed to resist the potential destructive effects of biogas. Two-stage condensate removal is incorporated into the compressor system to protect the compressor and the downstream equipment.
RJ Mechanical offers a variety of end-use components to burn biogas for steam generation and hot water heating. Sellers Manufacturing manufactures dual-fuel boiler systems for burning methane gas when it is available, and natural gas as a back-up fuel. A quick 90-degree turn of a fuel switching valve, and a control panel switch is all it takes to transition from one fuel to the other. Sellers methane boilers are available in capacities from 20 Boiler Horsepower (BHP) to 800 BHP, and for pressures from 15 PSIG to 150 PSIG. The unique “immersion-fired” integral burner system incorporates multiple burner nozzles, each of which is dedicated to a single tube. This increases the heat transfer surface area that sees radiant heat (direct flame contact) to over 50% for improved heat transfer efficiency. This single-pass design eliminates thermal shock, allows rapid start-up and response, and reduces the boiler footprint. The simple, rugged design is optimized for use in lower grade methane gas combustion and steam or hot water generation.
Weishaupt provides biogas burner systems for use in steam and hot water boilers. These burners are linkage-less and digitally controlled for precise and highly efficient combustion for modulating applications. Weishaupt also has versions for special fuels and dual-fuel operation that allows simultaneous combustion of biogas and natural gas. Weishaupt burners can also be used with Superior boilers for high-efficiency steam and hot water generation in biogas applications.