Guild Associates, Inc. offers high quality and operator-friendly gas purification systems through the use of adsorption based-technologies and is the provider of Molecular Gate® systems licensed from Engelhard Corporation (now part of the BASF Group).  Guild engineers and fabricates modular plants at their facility near Columbus, Ohio that are used to remove N2 and/or CO2 from contaminated gas as well as systems used to remove heavy hydrocarbons for dew point control or for dehydration. Applications include natural gas, coal bed and coal mine methane, landfill gas and biogas.  Peripheral items such as compressors, installation design services and project participation are offered as options.

Since its commercialization in 2001 the Kirkpatrick Honor Award winning Molecular Gate technology has achieved rapid and growing market success with over two dozen projects underway.

Guild also offers adsorption based system for dew point control through the removal of heavy hydrocarbons and water, purification of natural Gas to meet CARB standards, TSA systems for dehydration and for a variety of gas cleanup applications such as CO2 removal from contaminated ethane. 

Market Need

It is well recognized that a large portion of natural gas reserves are contaminated – about 15% in the USA. With all the challenges of producing natural gas a contaminated reservoir is not a welcome result but with cost effective - and equally importantly easily operated and reliable treatment – contaminated gas can be economically brought to market. If blending is not an option, removing the nitrogen (or N2 plus CO2) with a Molecular Gate system can be an economical alternative. With two dozen systems in the market, the proven and cost effective technology is the leading option for upgrading nitrogen contaminated stream.

Processing Costs

The cost to remove nitrogen is case specific and the nitrogen removal system is only part of an overall pipeline quality gas delivery system.  Molecular Gate nitrogen systems handle flows as low as 0.5 MM SCFD at a processing cost that is typically in the range of $1.00/MCF.  To this cost is added the peripheral costs of gas production and delivery.  As flows increase the economy of scale improves the economics such that a 2-4 MM SCFD system will have a capital plus operating cost in the range of 50 cents/MCF and a larger system of 10 MM SCFD will have a processing cost in the range of 35 cents/MCF.

The Molecular Gate technology is focused on this range of flow rates with commercial systems covering this flow range.

An alternative to amines and membrane treating

With thousands of systems in operation, amine treating units are the well proven market solution for CO2 removal, and membrane unit acceptance continues to grow. To these historical routes the Molecular Gate system for CO2 removal is a new option for gas treating.

The Molecular Gate system fits in the gas treating spectrum where site specific drivers exist. These generally include the local use for relatively low quality fuel – since a portion of the feed hydrocarbons are lost with the rejected CO2 a use for this tail gas is a requirement. This requirement also pushes the technology to feeds with lower CO2 levels such that this tail gas is of high enough quality to be uses as fuel.

One example of production with high fuel demands is coal bed methane – where the need for feed compression leads to a home for the tail gas.

As compared to amine plus glycol systems the Molecular Gate system can have the advantages of removing water along with the CO2 thus saving the need for a separate dehydration unit. And unlike membranes the adsorbent is robust and with the prevention of liquid carryover does not degrade.