Interwaste (Pty) Ltd operates a Class B lined waste disposal facility (“FG Landfill”) in Olifantsfontein, Midrand. In 2016, the company invested in a gas extraction and flaring system that collects gases and extracts them to the flare. The flare combusts methane and other gases and converts them to less harmful gases such as carbon dioxide (CO2) and water vapour. The project was implemented in order to control and assist in reducing the gaseous emissions produced by the decomposition of, predominantly, Municipal Solid Waste (MSW).
Initially, a 250 m3/hr flare was used as a pilot plant in order to determine the volume of gas produced from the waste body. Based on the results, it was decided to construct a 500 m3/hr flare in August 2016. However, it was later discovered that the volume of gas produced was higher than this flare’s capacity. As a result, an internationally designed and manufactured, Clean Development Mechanism (CDM)-compliant flare with a capacity of 2 000 m3/hr was commissioned at the site in November 2016. This flare operates 24 hours, seven days a week.
After a full year’s operation, almost 10 000 000 m3 of landfill gas have been flared, which equates to a net greenhouse gas (GHG) reduction of 60 234 tonnes of CO2 equivalent in the 12-month period. Overall, a total GHG emission reduction of almost 100 000 tonnes of CO2 equivalent have been achieved up to the end of July 2018.
A financial investment of about R15 000 000 was invested towards the designs, piping, extraction systems and the flare. Permanently assigned personnel have been allocated to manage the daily operation and maintenance of the flare. This includes monthly maintenance. Operators are notified of any faults or stoppages on the flare through the use of a tracking and reporting system which monitors the flare daily, generating monthly reports to indicate the quantity of the gases produced and their proportions.
In addition, efficiency testing and air quality tests are conducted, and the results are shared with relevant stakeholders in the communities. Long-term plans include the installation of appropriate gas cleaning technologies to purify the gas and utilise it for electricity on site for landfill operations or as biofuel for the company’s fleet. A similar gas extraction project is planned for the Klinkerstene landfill in Delmas, Mpumalanga, in the future.
Notable benefits are highlighted through the registration of the landfill gas project for carbon credits in order to offset CO2 emissions of other companies when the proposed Carbon Tax comes into effect.
— Arrive Alive (@_ArriveAlive) November 22, 2018