Xylem produces a number of instruments to assist in both the efficient management of biogas production by anaerobic digestion, and associated environmental monitoring.
Anaerobic digestion (AD) is taking its place alongside solar and wind power as a green energy alternative as more governments attempt to address their sustainable energy needs. AD involves the microbial breakdown of biological material to produce methane-rich biogas that can be used directly for heating or powering transportation (e.g. municipal busses), or indirectly to generate electricity. Wastewater sludge is the largest provider of ‘feedstock’ to the UK’s AD biogas industry, but both pastoral and arable farms are now contributing significantly to supplies, as are local authority waste collectors and schools and restaurants.
This is a growth area, with AD biogas plants of all sizes being commissioned throughout the world. As such, efficient management of all parts of the production process is an important consideration, as is care of the environment e.g. waterways and catchment ponds, especially where crops are being grown specifically for biogas production.
Xylem Analytics produce instrumentation for assisting with all parts of biogas production, from pumps and mixers, to environmental analysis. For functional assessment within the bioreactor itself, Xylem say that FOS/TAC or alkalinity ratio, are the most important measurements to be considered.
This is an ongoing indicator of the fermenter’s stability based on Volatile Fatty Acids content (FOS), and buffer capacity (TAC,) which prevents acidification within the reactor. It is here that Xylem’s SI Analytics TitroLine® 5000 auto-titrator comes into its own. This has a built in FOS/TAC method and burette, allowing easy daily analysis of fermentation plant bioreactor performance.
Biogas Plant performance can also be optimised by monitoring the bio-methane potential of the variant feedstock samples, under similar conditions to that of the fermenter (pH, temperature, pressure), over a period of 21 to 28 days using Xylem’s OxiTop® Control respiratory system. Xylem’s OxiTop® C/B measuring heads are specifically designed for the biogas industry as they are able to withstand the corrosion caused by hydrogen sulphide.
In the environment, instruments such as Xylem’s WTW® pHotoFlex® TURB handheld photometer provide an array of photometric data, including Chemical Oxygen Demand (COD), a measure of water’s organic content of wastewater, and ammonia levels. Suitable for the analysis of any waterway or pond associated with biogas production, the WTW® pHotoFlex® TURB also has the ability to measure pH and turbidity on a single meter.
As recently demonstrated at the ‘UK AD & Biogas 2016’ meeting, these products illustrate Xylem’s continued commitment to one of the most exciting green technologies of the century.
