Addressing Measurement Challenges in Biogas

Accurate, reliable measurement in the biogas industry is essential to optimise production processes, reduce maintenance and enhance safety.

This presentation explores some of the areas where measurement is essential and discusses the challenges in this measurement task.

MTL have launched a new product, the MTL GIR6000 which addresses these challenges with an innovative solution.

Iain Gordon – Product Line Manager, MTL Gas Business Biogas Asia Pacific Forum 27 - 30 April 2015, Kuala Lumpur

Landfill gas monitoring

Flare stack monitoring

Gas-to-grid / Biogas upgrader monitoring

Combined heat & power

Key elements of a typical Biogas plant

1. Collection and storage of Biomass

Typical raw materials (Biomass) are collected into a central pit or basin and mixed: • Animal (cows, pigs, chickens) and waste • Food & Alcohol production residue (apple juice, wine, oil, sugar, beer, brewer grains) • Residues from food & vegetable packing plants • Leftovers from restaurants, greenhouses, milk and dairy production and past-dated foods • Organic fraction of Municipal Solid Waste (MSW) • Residues from biofuel production • Slaughterhouse waste • Plant waste: maize, sugar, beets, grains, grass, straw

Feedstock for Biogas varies greatly – this presents a process & measurement challenge to optimise production!

2. Fermentation process

Anaerobic digestion: • A fermentation tank where micro-organisms digest the biomass in a sealed, light-proof vacuum at 30-40°C.

• Digestion time varies with feedstock from several hours to several weeks depending on the feedstock

• Raw gas is stored in the hood of the tank, a balloon or another storage vessel

Fermentation process requires control to optimise its output – without measurement there is no control!

What is Biogas and what are the challenges?

2% 2% 1% Composition of a typical Biogas 5% Methane (CH4)

Carbon Dioxide (CO2) 30% 60% Water Vapour (H2O)

Nitrogen (N2)

Oxygen (O2)

Trace Gases (NH3, H2, H2S)

Composition varies depending upon the feedstock and the process. Upgraders are used to maximise the CH4 content before use up to 98%.

Measurement is critical to the upgrading process

3. Gas processing

Raw Biogas exits the anaerobic digester and is processed to improve the gas: • Gas is cooled • Dried of water vapour • Particles are removed • Hydrogen Sulphide is scrubbed

• Further upgrade may involve removing the CO2

Final Methane content may be as high as 98%

and H2S as low as 5 ppm, depending upon the intended use. • Gas-to-grid • Combined Heat & Power • Process & Domestic Heat • Biogas fuel for transport

Upgrading of the gas optimises quality and energy content

1. Combined Heat & Power

• Large internal combustion engines • GE Jenbacher, MWM, MTU, Wartsila, • Typically from 8 to 16 cylinders • Turbocharged for efficiency • 1 MW power output or more • Often containerised for portability

• Gas fuels a large stationary engine • Rotational energy drives a generator • Electricity is produced

• Gas must be carefully measured

• <200ppm max H2S is desired

• H2S pollutes oil & damages valve seats • Corrosion or premature failure may occur • Monitoring helps reduce maintenance and engine lease costs • Oil change cycle frequency may need increasing

2. Gas-to-grid

• Biogas can be processed to remove the CO2 to • Gas quality and composition is carefully create Bio-methane. monitored to avoid polluting the national grid system. This is normally done with a Gas • Cleaning techniques must be used to dry, Chromatograph which provides high accuracy remove impurities and to upgrade the Methane repeatable online measurement content (>95%) to resemble the qualities of Natural Gas. • Growing crossover of Oil & Gas EPC’s developing scrubber technologies, such as UOP • Bio-Methane of suitable final quality can be and Mustang. supplied into the national Gas grid.

• Governments, pay lucrative feed-in tariffs for supplying bio-methane into the grid.

• Standards for this are being created / regulated.

3. Upgraders / Scrubbers

Application is to measure the Biogas before and after the upgrader process.

Upgraders may use many different techniques, such as: • Amine • Water • Pressure Adsorption • Membrane • Organic Solvent

Accurate online analysis is necessary to ensure control of the scrubber process.

4. Flare stack

• Some of the gas on a Biogas plant is flared.

• Application is to measure the Biogas before the flare stack and provide feed-forward control to optimise the combustion process.

• Stack is designed to optimise the burning process, reduce emissions and noise.

• Accurate analysis prior to flaring means an intelligent flare can correct for changes in gas composition to ensure efficiency.

• The analyser may also act as a safety and monitoring device to ensure that the flare can cope with highly explosive gas compositions.

Users – Who is interested to measure Biogas? Gas- Potential Customer/User System Influencer Operator EPC To- Supplier grid

Biogas plant Design System Owner Consultant Builder Gen-set Electricity /EPC

Industry Expertise Gen-set OEM

Maintenance Engine Company Builder

These users have concerns on biogas measurement related issues!

Product development to meet your Biogas needs • Over 30 years of gas experience and over 40 years of hazardous areas

• New MTL GIR6000 analyser meets customers specification through advanced features

• Customised platform concept available from global support network

Global product for a global reach

Decision to buy driven by Process Engineer fulfilment of his RESPONSIBLE for the specification, confidence WHOLE plant. in product, AVAILABILITY

RELIABILITY

Assertive to

Increased operating Needs to REDUCE EFFICIENCY, decreased operating expense DOWNTIME and minimal and maintenance COSTS MAINTENANCE

*phase 2 release

Dedicated sensors measure up to six gases

MTL GIR6000 The next generation in biogas measurement

To find out more and to see our MTL GIR6000…. Visit Booth 15 under EATON Corporation

© 2014 Eaton, All Rights Reserved. © 2014 Eaton, All Rights Reserved. MTL GIR6000 Product Value Markets Applications Architecture Competition Approvals & Reference Introduction Proposition Certification Materials

Our solutions help you to…

1 Reduce your operational costs

2 Optimise your productivity

3 Increase plant availability

4 Gives you peace of mind