Blog Archives

Environmental & Economic Impacts of Compressing RNG for use as CNG Vehicle Fuel

Compressing RNG in the form of compressed natural gas (CNG) for vehicle fuel

  Biogas can have impurities removed and upgraded to render it suitable for use as a vehicle fuel. This analysis examines the environmental and economic costs associated with cleaning, upgrading, and compressing RNG for use as compressed natural gas (CNG) used to power vehicles, using a Unisons Solutions biogas CNG (BioCNG) upgrading system and fueling […]

Upgrading Biogas for Pipeline Injection: What are the Environmental and Economic Costs?

Biogas upgrading allows for pipeline injection.

  Biogas can be cleaned to improve the quality, and once upgraded, it can be injected into a natural gas pipeline. In order for the raw biogas to meet quality standards required by pipeline operators contaminants such as sulfur, siloxane, and water vapor need to be removed. The methane component is then separated from the […]

Policies and Incentives for Using Renewable Natural Gas as Vehicle Fuel

Using Renewable Natural Gas as Vehicle Fuel in municipal fleet vehicles

 Federal Policy and Incentives for Using Renewable Natural Gas as Vehicle Fuel The federal Renewable Fuel Standard (RFS) requires obligated fuel suppliers to meet their Renewable Volume Obligation according to the annual volume of petroleum-based fuel they import or produce. One method of achieving this is for affected fuel suppliers to obtain renewable identification numbers (RINs) […]

Technologies for Removing Oxygen from RNG

Oxygen removal from natural gas

Oxygen Removal from Natural Gas Natural gas utilities often set stringent limits for oxygen in renewable natural gas that is injected into their natural gas pipeline network. Since high oxygen levels can promote corrosion of the pipeline infrastructure, utilities tend to set the maximum allowable limit at 0.2%, or even as low as 2 ppm. […]

Nitrogen Removal from Biogas

Capturing methane emissions from landfills key to reducing climate warming

Depending on how much nitrogen is present in the biogas, it may be necessary to remove or reject nitrogen in order to comply with renewable natural gas (RNG) specifications. Since biogas collected from landfill sites is more likely to be mixed with ambient air containing nitrogen, nitrogen removal tends to be more of an issue […]