Advanced Burner Technologies (ABUTEC) and its partner engineered, designed and fabricated a biogas conditioning system to help DC Water in Washington DC remove siloxanes from its digester gas stream, Forester Daily News reports.
When DC water was in the process of installing a combined heat and power facility, it found a problem in removing siloxanes from its digester gas stream. Siloxanes are non-toxic compounds often found in consumer products like detergents, shampoos, deodorants, cosmetics and textiles to help improve texture and feel. While siloxanes alone are not harmful to the human body, burning the compounds creates crystalline silica, which sticks to the hot surfaces inside the internal combustion equipment, coating them in a thick, hard layer. As a result, heat builds up where it should not, causing damage to the equipment.
To remove the siloxanes, ABUTEC and its partner used regenerative non-carbon base media, a proprietary blend of silica gel, molecular sieve and activated alumina.
ABUTEC manufactured a 1.6 MW high-temperature flare (HTF) and modified it for DC Water’s purposes by changing the stack height and temperate controls to provide the proper emissions. The controls on the HTF and biogas conditioning system were customized to communicate efficiently, and the instrument supply was upgraded to comply with Class 1 Div 1 electrical area classification.
The waste-to-energy process at DC Water works by feeding steam from a boiler on each turbine into a CAMBI unit when the turbines are not running. The CAMBI unit produces methane gas from the sludge. The gas is sent through the biogas conditioning system, which absorbs the harmful siloxanes and hydrocarbons in the porous media. After the gas is conditioned, it is sent to second stage compressors, which boost the gas pressure to supply the turbines. The gas is then sent to the ABUTEC HTF, which burns off the harmful emissions.
The DC wastewater treatment facility pumps an average 100 million gallons of water per day and stores 95 millions gallons of treated water.
ABUTEC also created a custom natural gas liquid (NGL) adsorption system to help a natural gas production company in Southwestern Pennsylvania meet pipeline and dew point requirements.