Aquafuel tests new biogas cleanup technology

By Susanne Retka Schill
Web news posted April 29, 2009, at 1:34 p.m. CDT

A new biogas cleanup technology has successfully passed first-phase trials conducted by United Kingdom-based Aquafuel Research Ltd. The technology offers a low-cost treatment for landfill gas used in diesel engine electricity generators.

Landfill gas, like sewage gas and other biogases, contains corrosive hydrogen sulfide which shortens the life of the lubrication oil in the engines used for electricity generation. Aquafuel's technology doubles the life of the engine's lubrication oil resulting in reduced oil consumption while reducing downtime and operational costs.

Paul Day, Aquafuel CEO, explained that the company's system reduces costs by treating only the portion of acidic sulfur gases that ends up in the crankcase or about 5 percent of the total gas. "It's [in the crankcase] that the vital damage is done by degrading the lube oil," Day said. "This is where we protect, rather than scrubbing the whole incoming fuel."

The company estimates the process will work for one-tenth the capital and operational cost of conventional biogas scrubbing systems. Aquafuel's technology also senses and remotely monitors hydrogen sulfide levels in incoming gas, and automatically matches the dosing.

Aquafuel has run over 1,000 hours of trials at a European site with very high levels of hydrogen sulfide in the incoming gas flow. Lube oil consumption was reduced 57 percent in the trials. The engine was independently examined after the trials to verify no adverse effects occurred. Due to longer gaps between oil changes, the associated engine downtime was reduced by about 50 percent.

Aquafuel is continuing second-phase trials on the same site to validate its automatic system monitoring the doses of consumables used to cleanup the gas.
Detailed running costs will be calculated at the end of the full trial, but preliminary results indicate the final total savings will be around 30 percent, Day said. All phases of the trial are being monitored and verified by an independent consultant, and a full report will be available on completion. The company expects its technology to be commercially available in the third quarter of 2009.

"Landfill gas is an important energy source worldwide. Unlike natural gas its electricity is renewable, and it prevents emissions of methane, a powerful greenhouse gas," Day said. "Our cost effective technology makes electricity from landfill gas, bio gas and sewage gas more competitive by dramatically lowering operational costs."