Natural gas is an important fossil fuel, but one which is in finite supply. Alternatives are therefore needed. One such alternative is the upgrading of biogas to green gas*.

Biogas is a general term for gas produced through an anaerobic fermentation process. This is a process in which biological material is broken down in an oxygen-free environment. Biogas primarily consists of a mixture of methane (CH₄) and carbon dioxide (CO₂). When used to power natural gas engines, biogas can be converted directly into (green) electricity and heat, but if the heat is not utilized immediately, it is lost. A better alternative is to upgrade the biogas to green gas, a process that has no waste streams.
 
Green gas fits the mindset of today’s society in which energy savings and CO₂ reduction are a universal concern. During the process of upgrading the biogas, using the Pentair Haffmans process, CH₄ and CO₂ are divided into separate streams and recovered, instead of being expelled. The technique used by Pentair Haffmans makes it possible to recover 100 percent of the CH₄, so the environmentally-harmful ‘methane slip’ that is usually produced when other techniques are used is completely eliminated. This results in a higher yield of the CH₄ product and no emission of the harmful CH₄ greenhouse gas. An additional advantage of Pentair Haffmans, process is that the CO₂ byproduct is recovered and can be sold as a useful product. This results in an extra source of income.

Since green gas has the same specifications as natural gas, it is fully compatible with the existing natural gas infrastructure and applications. It is expected that by 2030 around 20 percent of the demand for natural gas will be met with green gas. Green gas is therefore an important energy source, both by now and in the future.

* biogas upgraded to natural gas specifications

Industries	Process	Basic nutrient for the anaerobic fermentation	CH4 / CO2 ratio
Agriculture sector, breweries, distilleries	Mono-fermentation	Vegetable-based material (corn silage, spent hops, spent grain, etc.)	55% / 45%
Cattle farms	Co-fermentation	Manure (cow, pig, chicken) with vegetable-based material	55% / 45%
Compost-processing industry	VFG	Vegetable-based material	55% / 45% 70% / 30%
Potable water companies, water authorities, STP, Industrial wastewater treatment systems	Water treatment	Vegetable-based material	65% / 35%
Waste-processing industry	Dumping site	Various types of waste (e.g. vegetable-based and chemical)	+

Read here more about green gas.

Biogas flyer