Syngas: Ensuring Synthetic Quality

Using systems such as gasification, anaerobic digestion, pyrolysis, bioenergy and biofuels have developed considerably over recent years.

With the modern world producing 222 million tonnes of waste (in 2014 when the UK statistics on waste were last updated), and growing demand for renewable energy sources, waste has been revolutionised as a resource instead of simply sent to landfill. 

Syngas is considered a renewable energy source, generating power and heat for the increasing worldwide demand for energy.

Renewable energy is now created in many forms, with an important contributor being the energy generated from biomass. Using systems such as gasification, anaerobic digestion, pyrolysis, bioenergy and biofuels have developed considerably over recent years.

What is syngas?

Syngas – or synthesis gas - is the gas generated from the gasification process, whereby biomass or waste materials are exposed to high temperatures in a controlled-oxygen environment.

The thermochemical conversion produces syngas, which can be used for generating electricity and replacing natural gas. The process converts solid and liquefied slurry or animal waste, as well as ‘standard’ solid biofuels, such as wood chip or recycled wood, into the synthetic gas which can be used for generating electricity and replacing natural gas as an increasingly used form of renewable energy.

Proving quality

With renewable energy targets growing, the UK called for a target of 30% of electricity production to be by green sources by 2030. In 2016, renewable energy represented 17% of energy consumed in the EU and syngas contributes to that proportion along with other biomass energy sources, solar, wind and geothermal.  But ensuring these renewable sources are safe and efficient is a challenge to overcome across the energy industry.

Solid biofuels have emerged as a suitable, low-carbon alternative to coal. These can be used in a loose chip, pellet or briquette form, and can come from a wide variety of sources. SOCOTEC has long been supporting the energy industry in the analysis of solid biofuels, solid recovered fuels (SRF) and refused derived fuels (RDF) to prove the fuel quality is consistent and in line with relevant standards.

Wherever biomass or biopower is being produced, analysis is required to determine the quality of fuel. Ensuring the syngas is clean is essential for meeting environmental emission regulations when the syngas is used in its future processes. 

Impurities within the syngas are not uncommon but can be treated through further processing. Often, sulphur and nitrogen are removed in the reaction process of syngas production but understanding the components of the syngas is important for achieving the highest quality product for heating or energy.

Analysing syngas – how is it done?

Fundamental to any energy source is the quality. Over the last few decades, the UK has made great progress in diversifying its power generation sector, and Britain’s energy landscape contains a broad range of sustainable and innovative fuel sources.

SOCOTEC has a long-established gas analysis laboratory at its Bretby facility, and has analysed mine air and landfill gas for many years.  Noticing an increase in client demand for dissecting the components of their syngas, SOCOTEC has now become one of the first UK laboratories to gain UKAS accreditation for the analysis of syngas. This comprehensive and quality assured suite of analytes includes the percentage of hydrogen, carbon monoxide, methane, oxygen and other hydrocarbons that makes up the syngas using accredited methods which utilise gas chromatography (GC) with thermal conductivity detector (TCD) and flame ionisation detectors (FID).

For hydrogen and carbon monoxide, we use a dual channel GC with TCD & FID; the TCD is used for analysing hydrogen, and is also used for analysing oxygen - this is for quality control purposes to ensure oxygen content is <1%.

Carbon monoxide is analysed by the FID but the sample stream must pass through a methaniser. Acting as a calayst, the methaniser uses heat and hydrogen to chemically alter the carbon monoxide (and also carbon dioxide) into methane so that the FID can detect the gas.

By injecting the sample into the GC at the below measurements, the syngas quality can be determined along with the calorific value (CV).

Typical Analysis of Syngas:

Supporting large-scale renewable electricity projects

OFGEM rewards and incentivises the generation of renewable energy sources, with syngas falling into this category. Understanding the composition of the gas sample is fundamental; when transposing the results to calculate the calorific content, energy suppliers are able to prove to OFGEM that their syngas is of a qualifying percentage and calorific value to generate electricity.