With global trends towards reuse and recycling, the demand for environmentally friendly cylinder remediation and disposal services are on the rise.

Source: ASG

Used high and low pressure cylinders needing remediation

A wide variety of packaged gas applications generate residual or surplus gas and cylinder material waste streams that must be managed and remediated. This can include dangerous and hazardous waste, as well as recyclable items. There is a broad spectrum of packaged gas waste generators across various end-user types and gas suppliers. These operations include small and large private corporations, educational institutions, research facilities, healthcare providers and government agencies. Proper compressed gas cylinder fleet management considers the entire life cycle of a gas container and is a critical function of gas suppliers and end-users.

Fleet management includes regular cylinder maintenance, cleaning, refurbishing, gas service changes and requalification per DOT requirements. Just as importantly, at the end of a cylinder’s project life it needs to be handled in a manner consistence with best practices. This includes recycling and disposal of used cylinders in a safe, efficient and environmentally friendly fashion. In addition to cost and safety there are important regulatory considerations when recycling cylinders so proper handling is critical.

Compressed gas cylinders are hazardous. They pose several safety and environmental risks including risk of explosion, fire, toxic inhalation and contact contamination among other risks. Along with these risks comes potential legal liabilities which must be addressed when disposing of cylinders. Cylinders with unknown contents pose a particularly high risk and should only be handled by qualified personnel with extensive training using the latest field technology and methods. Sometimes specialised equipment is needed for handling gas cylinders. This can especially be the case for situations involving cylinders with inoperable valves. Sometimes field work must be completed before a compressed gas cylinder can be safely transported to a final remediation facility.

Transportation and logistical considerations can be a major factor with cylinder fleet remediation. Full-service remediation companies will typically offer transportation options including everything from pick-up to final disposal. Before cylinders can be transported, they must be made safe for handling.

Cylinder valve combinations typically contain various metals including aluminium, steel and brass. Fibre composites, asbestos and other materials may also be present in addition to the gas contents of the cylinder. At a minimum, a cylinder must be de-pressurised via venting before it can be recycled. Depending on the gas more extensive measures may be required.

Gas cylinder contents can range from inert gases such as helium to highly toxic and / or flammable gases such as phosphine and acetylene. Dangerous gases including phosphine and silane are used in the production of certain semiconductors. Gases like these must be disposed of with great care in order to avoid human injury. Acetylene is commonly used for welding and cutting. The welding process that uses acetylene is known as oxy-fuel welding/cutting. Acetylene is highly flammable and can be volatile if not handled correctly.

Other gases, such as refrigerants, can pose environmental hazards including contamination or ozone depletion. Refrigerant recovery tanks used for servicing air conditioning systems often contain multiple types of refrigerants. Refrigerants must be incinerated or re-captured and separated for re-use to prevent environmental damage and to comply with government regulations. Other types of residual gases may also require recapture or incineration before a cylinder may be taken out of service.

Cylinder contents can also be contaminated with non-gas substances such as water or petroleum products. These contents must be dealt with separately from any compressed gases present.

Most compressed gas cylinders including fire extinguishers, beverage kegs, LPG tanks, medical cylinders, welding and industrial cylinders, acetylene and refrigerant cylinders can be safely recycled in a cost-effective manner.

Ideally, reuse of metals or the entire cylinder and valve can be achieved to avoid landfills. The process of re-use or disposal often includes de-valving, rendering the cylinder useless, removal of markings, recycling of metals and certification. Or, reuse and re-purposing of the cylinder itself can be achieved if it can be recertified for field use per DOT regulations. Sometimes this involves gas service changes and cylinder cleaning and decontamination which must be provided by a federal DOT authorized facility.

It is important to use a waste processing company that provides certification of how a cylinder is recycled and / or disposed of. This certification should be traceable giving customers confidence that cylinders are handled properly.

Cylinder remediation projects range in size. They may be as small as a single cylinder or as large as a multi-location, multi-phase fleet decommissioning of various cylinder types. The impetus behind remediation can be aging of cylinders, cylinder damage, end of project, normal wear and tear, and more.

Remediation projects sometimes require multiple companies working in tandem to coordinate. One or more companies will usually provide services including project management, gas recapture, cylinder gas service changes and requalification, landfilling, metals recycling, front-end sorting, loading and transportation.

All Safe Global (ASG) is one such company that handles projects both large and small with a focus on backend internal processing capabilities supporting front-end project management partners. ASG provides nationwide coverage from locations in Minneapolis, Minnesota and Phoenix, Arizona.

ASG is authorised at the state and federal levels to perform various cylinder remediation functions and specialises in the recycling, requalification, refurbishment, sale and distribution of portable packaged gas cylinders. ASG offers unique, safe, efficient and environmentally friendly recycling and disposal services. ASG often partners with waste management, refrigerant recovery and field remediation companies to offer a full spectrum of packaged gas equipment disposal services. ASG provides certification that cylinders have been recycled or disposed of using correct methods.

ASG also offers products including high-pressure and low-pressure steel and aluminium cylinders for numerous applications including welding, cutting, beverage dispensing, food packaging, medical applications and much more.

Matt Boettner is CEO at All Safe Global.