The renewable energy facility is designed, built, owned and operated by a regional energy service provider to collect the LFG, and use it as a fuel source to power generators. The facility is designed to generate 4.8MW, and requires treatment of a source H2S concentration of 1,700 ppm at 1,600 SCFM. The facility’s air emissions permit requires the H2S concentration to be below 200 ppm.
To meet the H2S specification, MV supplied four 12’ diameter by 11’-8” tall vessels, with a total media capacity of 4,368 ft3 of media. Designed media bed life is 170-days. The treated LFG has an H2S concentration in the 0-10 ppm range. The facility bypasses a portion of the LFG and re-blends it with the treated LFG. The blended LFG is targeted to an H2S level to comply with the air permit. By operating the system in this manner, it cuts operating cost of the H2SPlus System by 12%.
This facility was the first installation of an H2SPlus System at a landfill. Since 2006 a single 8’ diameter by 12’ tall vessel has been successfully treating 150 SCFM of LFG from 2,000 ppm H2S down to 100 ppm, to meet facility air permits. This gas was then being utilized to generate power. In 2008, a second system was supplied to remove hydrogen sulfide from another location at the landfill. In 2010, two additional treatment vessels were added to keep up with the ever increasing LFG production. Originally the LFG was utilized as boiler fuel at a local school. Over time as LFG production increased the landfill installed a power generation plant to maximize the beneficial use of the LFG.
To meet the needs of increased LFG production at the facility three 10’ diameter by 12’ tall vessels were added at a second location at the landfill. This system was further expanded in 2010, with the addition of two 12’ diameter by 12’ tall vessels. The expanded H2SPlus System treats a total flow of 1,450 SCFM. The H2S concentrations are reduced from 2,000 ppm to below 100 ppm.
An environmental systems project includes a 10.2MW power plant, with two turbine packages and associated equipment, tied directly into the local power grid. The landfill gas is piped to the power generation facility. The gas is required to be treated to below 200 ppm in order to comply with the facility’s air permit.
MV supplied a six-vessel H2SPlus System, utilizing 14’ diameter tanks with a 12’ straight sidewall. To achieve the outlet requirement, MV designed the system with a bypass and blend approach, treating 5,500 SCFM down to 0 ppm and combining with the other 1,500 SCFM on the outlet to achieve a total H2S outlet of less than 200 ppm. The six-vessel system holds 8,568 ft3 of media for a bedlife of 7 months. Currently the site is treating the entire flow of gas to the turbines as they have realized significant maintenance cost savings as well as significantly more run time.
MV received the RFP for this landfill gas desulphurization system in 2012. At that time, the owner was utilizing a liquid redox sulfur treatment system and determined the operating costs of the system were well over $7/lb. of H2S removed. Opex includes site maintenance personnel and electricity. Specifications required the landfill gas, with a flow rate of approximately 1,500 cfm, be reduced from an inlet concentration of 1,200 ppm H2S to less than 5 ppm. The desire to reduce operating costs was a key factor in guiding their decision to search for alternative H2S removal solutions. The site has a very strict air emissions permit as well.
MV Technologies was awarded the contract through a general contractor, developing a three-vessel H2SPlus System for the municipal landfill. Utilizing our system, the owner was able to see operating costs reduced to less than $2/lb. of H2S removed. Additionally, since the H2SPlus System requires less operator attention, the site maintenance personnel are now able to focus on other tasks at the landfill. Each vessel, operating in parallel, contains 1,050 ft3 of MV’s enhanced BioActive Media, designed with a 180-day replacement cycle. The use of gas analyzers was successfully incorporated into the system, allowing the end-user to gather real-time data of inlet and outlet H2S concentrations. An O2 sensor is used to control the quantity of air introduced for the on-line media regeneration.