LFG Utilization with CO2 Wash
Landfill gas (LFG), comprised of methane and carbon dioxide in roughly equal proportions along with myriad trace contaminants, is now a largely wasted resource that could provide significant supplemental energy and CO2 for local markets. Since LFG has both explosive and toxic properties which must be mitigated at the landfill site, most installed LFG technology is collection and control oriented, and addresses safety and environmental concerns.
Energy oriented LFG technology recovers methane as electricty, as medium Btu fuel gas or as pipeline gas; unrecovered methane, CO2 and various trace contaminants are usually flared or vented. LFG recovery incentives have risen or fallen in lockstep with the price of natural gas or the avoided cost of electric energy. Acrion has developed CO2 Wash® technology to efficiently remove contaminants from landfill gas. The resultant clean stream of methane and CO2 can be used as medium Btu gas or further refined into products such as: pipeline gas, liquid methane, methanol, and/or commercial liquid carbon dioxide. Purity of Acrion's product gas was continuously monitored in house and tested to ppb levels by an independent lab. This is the report by Atlantic Analytical Laboratories, Whitehouse, NJ.
The following figure shows processing stepts of CO2Wash® process. Utilization of Acrion's process for LFG contaminants removal allows recovery of various methane and carbon dioxide based products.
Below is a summary of CO2 Wash® benefits and improvements upon competitive technologies:
- a variety of methane products enabled from landfill gas,
- food grade liquid CO2 recovered as second product,
- storable, transportable products,
- no commercial separation agent for bulk contaminant removal,
- separation agent, liquid CO2, obtained from raw landfill gas,
- continuous fresh solvent, no regeneration necessary,
- reliable contaminant removal to ppb levels,
- verification of siloxane removal from landfill gas
- verification of sulfur compound removal from landfill gas,
- verification of halogenated compound removal from landfill gas,
- verification of NMOC (non-methane organic compound) removal from landfill gas,
- removal of 'new' contaminants guaranteed,
- well defined contaminant control and disposal.