EU Emissions Update

EU emissions - what you need to know

EU EMISSIONS UPDATE by Richard Payne

Richard Payne is not only the Customer engineering manager for Cummins G-Drive, but is the exhaust emissions expert for AMPS and Europgen. He has worked closely with the European Commission on the development of the stage V no-road emissions regulation and the Medium Combustion Plant Directive.

Following his delivery on Emissions at the AMPS Conference in March we have reproduced the main body of his powerpoint presentation in the following article.

We are pleased to include 3 related features from AMPS members - Power Electrics, ide systems and Agriemach with their varied approaches on combatting the emissions problem.

Emissions

AGENDA

• Stage V non-road mobile machinery

• Medium Combustion Plant Directive

• UK ‘Specified generator’ legislation

• Local legislation

NON-ROAD MOBILE MACHINERY STAGE VStage V background

• New EU regulation to replace 97/68/EC directive (non road mobile machinery or NRMM directive)

• Published in OJEU Sept 2016 as Regulation (EU) 2016/2016

• Supplementing legislation published May 2017

• Affects mobile generators, primarily rental equipment

Stage V Highlights

• <19 CI kW included, aligned with US T4f

• >560 kW included, aligned with US T4f

• Filter forcing particle number (PN) count from 19-560 kW, not aligned with US T4f

• Gaseous fuel, dual fuel, spark ignition and any other type of mobile RICE included, partly aligned with US

• Formula to adapt THC limit to allow for Methane slip in gas engines/dual fuel engines (no methane limits in US)

• Derogation for ATEX (explosive atmosphere) engine to use stage IIIA limit values.

Limit values – Spark ignition (<56 kW) See Fig 1NRMM – constant speed ELV’s See Fig 2

Limit values - Spark ignition (<56 kW)

SPARK IGNITION

(NOx+THC) / CO / PM (g/kWh)Engine kW (hp) 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025SH: 1 0-19 0-25 <20cc (50) / 205 / NASH: 2 0-19 0-25 20-50cc (50) / 205 / NA

(50) / 805 / NA NRSh-v-1a

SH: 3 0-19 0-25 >50cc (72) / 603 / NA (72) / 603 / NA NRSh-v-1bSH: 1 0-19 0-25 <66cc (50) / 610 / NASH: 2 0-19 0-25 66-100cc (40) / 610 / NASH: 3 0-19 0-25 100-225cc (16.1) / 610 / NA

SH: 4 0-19 0-25 >225cc (12.1) / 610 / NA (8) / 610 / NA

(10) / 610 / NA (see note 1)

NRS-vr-1a NRSh-Vr-1a

NRS-vr-1b, NRSvi-1b

19-30 25-40 <1000cc (8) / 610 / NA NRS-v=-2a19-30 25-40 <1000cc30-56 40-75 all

(2.7) / 4.4 / NA (see note 2)

NRS-v=-2b NRS-v=-3

>56 >75 all See Compression Ignition table NRE****Stage II

• Aligns with US <56 kW (apart from note 1).

• >56kW all types of engine have the same limit values (see next slides)

Note 1Note 2

Stage VFor engines <80cc use limit values from hand held engines (above)

Or alternatively limit values satisfying the equation (THC + NOx) X CO0.784 = 8.57 and CO < = 20.6, (THC + NOx) <= 2.7

NRMM – constant speed ELV’s

CONSTANT SPEED ENGINE (IDENTICAL TO VARIABLE SPEED AT STAGE V)NOx / THC / CO / PM (g/k/Wh) / (PM count/kWh)

(NOx + THC) / CO / PM (g/k/Wh) / (PM count/kWh)kW (hp) 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 A0-8 0-10 (7.5) / 8.0 / 0.40 (0.6)89-19 11-24 (7.5) / 6.6 / 0.4019-36 24-48 (7.5) / 5.5 / 0.637-55 49-74 (4.7) / 5.0 / 0.456-74 75-9975-129 100-173 (4.0) / 5.0 / 0.3

(1.10)

(4.7) / 5.0 / 0.015 / (10^12 (1.10)

(0.4) / 0.19 / 5.0 / 0.015 (0.010) / (10^12) 1.10

130-560 174-751 0.4 / 0.19 / 3.5 / 0.015 (0.010) / (10^12) (1.10)>560 >751 Not Gen 1.10>560 >751 Gen only 6.00Stage II Stage IIIA Stage V 6.00

Effect dates shown are for 'existing types'. 'New type' effect dates are 12 months earlier than dates shown. There is an NH3 limit of 10ppm where a reagent is used. A is gaseous fuelled engine hydrocarbon factor. () applies to compression ignition only, otherwise applies to all engines.

• DPF forcing from 19-560 kW (due to particle number count)

• SCR forcing from 56 kW up (gen-set)

• Methane slip limit for gas engines

Transition programs

• Flexibility program is completely removed

• A limited pre-buy program is allowed – There are restrictions on how long an engine can be held

before it is installed in a machine and the machine placed on the market

– Extended time line for very small manufacturers

Transition Program

MOST OEMS

EMISSIONS CHANGE DATE -2 years -1 year +1 year +2 years +3 years +4 years

Engine Production Previous stage or new stage engine production Only new stage engine production Prebuilt previous stage engine may be placed on the

Engine placing on market

Only new stage engines may be placed on the market market Machine production allowed with Only new stage engines may be installed in machines

Machine Production previous stage engine

Machine with previous stage engine may be placed on the market

Machine placing on market

Only machines with new stage engines may be placed on the market

OEM with a total production (use of NRMM engine) of <100/year, mobile cranes

-2 years

-1 year

+1 year

+2 years

+3 years

+4 years

Engine Production

Previous stage or new stage engine production

Only new stage engine production

Engine placing on market

Prebuilt previous stage engine may be placed on the market

Only new stage engines may be placed on the market

Machine Production

Machine production allowed with previous stage engine

Only new stage engines may be installed in machines

Machine placing on market

Machine with previous stage engine may be placed on the market

Only machines with new stage engines may be placed on the market

Although an engine manufacturer may supply an engine built before the emissions change during this period it has no value since it cannot be built into a machine in time to meeting the machine production date. It is only there for legal reasons to allow machines built outside the EU to be imported.

NOTE: Flexibility engines (stage IIIA in most cases) must be installed in the machine and the machine placed on the market before the start of stage V

MEDIUM COMBUSTION PLANT DIRECTIVE (MCPD)MCPD Scope

• Sets minimum exhaust emission requirements for stationary engines in the EU with a thermal input of 1 MW to 50 MW– approx. 300 kW to 24 MW mechanical power

• It has limits to control emissions of Sulphur dioxide, nitrogen oxides and dust (PM)– There is also a requirement to monitor Carbon monoxide

• It will not prevent national rules that are more stringent;

– for example Germany is expected to introduce a new regulation that will be more stringent than this base and have additional substances regulated

• Member states must assess the need to apply stricter limits in areas of poor air quality

MCPD Derogations

• Plants operating for <500 hours/year may be exempted from the limit values, at the discretion of the member state– Some averaging allowed– Should allow exemption of emergency generator from limit values, but not permitting/registration

• New engines operating for 500-1500 hour/year may be allowed reduced limits that do not require secondary abatement. In this case the NOx limit is increased to 750 mg (2g TALuft) for high speed diesel engines.

• Offshore turbines and engines exempt (may come under IMO)

• Engines used in the propulsion of a vehicle, ship or aircraft exempt

• Research development and testing of MCP exempt– Member states may apply specific conditions to this

• Non-road mobile equipment covered by directive 97/68/EC (replaced by Regulation (EU) 2016.1628 is exempt*

• Plant in Canary Islands, French Overseas Departments, the Azores and Madeira are exempt, but must set limit values to reduce risks to health

• There are a number of other very specific exemptions

* non-road mobile machinery shall mean any mobile machine, transportable industrial equipment or vehicle with or without body work, not intended for the use of passenger- or goods-transport on the road, in which an internal combustion engine as specified in Annex I section 1 is installed.

MCPD application dates

• Member states must transpose the directive into national law by 19 December 2017

• The application date for new plants is 19th Dec. 2018

• The limit values will apply to existing plant from 5-50 MW thermal input from 2025 (registration or permit 1 year before)

• The limit values will apply to existing plant from 1-5 MW thermal input from 2030 (registration or permit 1 year before)

Aggregation

• New plants >1MW that do or could use a common stack shall be aggregated to determine thermal input when defining requirements (application dates and limits)

• A combination of more than 50 MW is included unless covered by chapter III of 2010/75/EU (IED)

Permitting

• All plant within scope will require a permit, even if exempt from limit values– Many facilities that have an emergency generator will not be aware of this– Should be a simple process for a simple plant

• There are record keeping requirements

• There are monitoring requirements

Emission limit values (mg/Nm³) for EXISTING engines and gas turbines

Pollutant

Type of medium combustion plant

Gas oil

Liquid fuels other than gas oil

Natural gas

Gaseous fuels other than natural gas

(1) (2)

SO 2

Engines and gas turbines - 120 - 15

NO X

Engines 190 (3) (4) 190 (3) (5) 190 (6) 190 (6)

Gas turbines (7) 200 200 150 200Dust Engines and gas turbines - 10 (8) - -

Note: corrected to 15% O 2

(1) 60 mg/Nm3 in the case of biogas [40 mg new engines]. (2) 130 mg/Nm³ in the case of low calorific gases from coke ovens, and 65 mg/Nm³ in the case of low calorific gases from blast furnaces, in the iron and steel industry.

(3) 1850 mg/Nm³ in the following cases: (i) for diesel engines the construction of which commenced before 18 May 2006; (ii) for dual fuel engines in liquid mode.

(4) 250 mg/Nm³ in the case of engines with a rated thermal input equal to or greater than 1 MW and less than or equal to 5 MW.

(5) 250 mg/Nm³ in the case of engines with a rated thermal input equal to or greater than 1 MW and less than or equal to 5 MW; 225 mg/Nm³ in the case of engines with a rated thermal input greater than 5 MW and less than or equal to 20 MW. (6) 380 mg/Nm³ for dual fuel engines in gas mode. (7) Emission limit values are only applicable above 70 % load. (8) 20 mg/Nm3 in the case of plants with a rated thermal input equal to or greater than 1 MW and less than or equal to 20 MW.

ENGINE TECHNOLOGY NEEDED…Diesel Engine

• SCR required to meet NOx limit– Retrofit of SCR is possible– Mobile equipment SCR will use up considerable exhaust restriction allowance making exhaust heat recovery more challenging

– Larger SCRs can be used on base load stationary plant leaving more capability for heat recovery

• SO 2 needs < 2000 ppm fuel for other than gas oil

• Modern high speed low emissions engine can meet dust limit– Older existing engines or large medium/low speed engines may not and additionally need a particle reduction system

• Stage V non-road mobile engine will easily meet limits– Stage IIIA non-road mobile (current) will probably not

Stoichiometric (rich burn) Gas Engine

• Three way catalyst (TWC) will be required to meet NOx limit– This also effectively manages CO and unburned hydrocarbon emissions– It is a no-maintenance item requiring no additional fluids– Some exhaust restriction is used by the catalyst but with careful design exhaust gas heat recovery is viable– It is very important that the air/fuel ratio is tightly controlled around lambda 1 requiring electronic feed back control

• Retrofit of a (TWC) is possible but the engine would need to either already have or be retrofitted with such a control system

Emission limit values (mg/Nm3) for NEW engines and gas turbinesPollutant

Type of medium combustion plant

Gas oil

Liquid fuels other than gas oil

Natural gas

SO 2

Engines and gas turbines - 120 (1) - 15 (2)

NO X

Engines (3) (4) 190 (5) 190 (5) (6) 95 (7)* 190 (6)Gas turbines (8) 75 75 10 75

Dust Engines and gas turbines - 10 (10) (11) - -

Gaseous fuels other than natural gas

Note: corrected to 15% O 2

* Different to existing engines (1) Until 1 January 2025, 590 mg/Nm³ for diesel engines which are part of SIS or MIS. (2) 40 mg/Nm3 in the case of biogas [60 mg new engines]. (3) Engines running between 500 and 1 500 hours per year may be exempted from compliance with those emission limit values if they are applying primary measures to limit NOx emissions and meet the emission limit values set out in footnote (4) [Not available to existing engines].

(4) Until 1 January 2025 in SIS and MIS, 1 850 mg/Nm3 for dual fuel engines in liquid mode and 380 mg/Nm3 in gas mode; 1 300 mg/Nm³ for diesel engines with ≤ 1200 rpm with a total rated thermal input less than or equal to 20 MW and 1 850 mg/Nm³ for diesel engines with a total rated thermal input greater than 20 MW; 750 mg/Nm³ for diesel engines with > 1200 rpm. (5) 225 mg/Nm³ for dual fuel engines in liquid mode. (6) 225 mg/Nm³ for diesel engines with a total rated thermal input less than or equal to 20 MW with ≤ 1200 rpm. (7) 190 mg/Nm³ for dual fuel engines in gas mode. (8) These emission limit values are only applicable above 70 % load. (9) Until 1 January 2025, 550 mg/Nm³ for plants which are part of SIS or MIS. (10) Until 1 January 2025, 75 mg/Nm³ for diesel engines which are part of SIS or MIS. (11) 20 mg/Nm3 in the case of plants with a total rated thermal input equal to or greater than

1 MW and less than or equal to 5 MW.

Lean Burn Gas Engine (premixed)

• A low emission lean burn engine can meet the existing engine limits if designed to do so– Many are since it is the same as TALuft

• A lean burn engine can be designed and tuned to meet the new engine limits (1/2 current TALuft) without SCR– This requires leaner running– There is a slight loss of specific fuel consumption and flexibility of the engine

– The exhaust temperature is slightly lower but with a higher flow rate giving lower grade but more heat from exhaust heat recovery systems– System will be sensitive to gas quality

• SCR can be added to give very low NOx emissions if a memberstate introduces lower limits

Lean Burn Gas Engine (high pressure gas injection)

• These engines have similar combustion to a diesel engine

• SCR will be required to meet the NOx limit

UK SPECIFIED GENERATOR LEGISLATIONBackground

• The UK has seen a rapid rise in the number of, and operating hours of, diesel gen-sets in response to demand created by the ‘balancing services’ market

• Many of these gen-set are of older design vintage

• There is concern for local air quality and using up NEC directive NOx allowance

• Additional controls over and above the MCPD are being applied to ‘specified generators’

• MCPD requirements also apply (however, many of these generators would fall out of MCPD emission limit values due to low hours)

Included generators

• Any generator or group of generators (not excluded) from 1 – 50 MWth

• Any generator or group of generators (not excluded) providing balancing services <50 MWth (no lower limit)

• A group of generators are considered a generator if:– on the same site, and;– operated by the same operator, and;– for the same purpose

Excluded from ‘specified generators’

• Back-up (stand-by) generators operated for the purpose of testing for no more than 50 hours per year. Cannot have any other function.

• Back-up (stand-by) generator that has demonstrated a genuine need to test for more than 50 hours per year (needs special approval confirming no air quality exceedance)

• Mobile generator unless connected to– an electricity transmission system or distribution system, or;– other apparatus, equipment or appliances at a site, and is performing a function that could be performed by a generator that is not mobile;

• Generator used at a site which it is not reasonably practicable to connect to the distribution system (needs special approval confirming no air quality exceedance)

• Generators subject to the IED (chapter II or III)

• Generators operating with a defined nuclear safety role

• Generators installed on an offshore platforms or on a gas storage or unloading platform

Tranche A generator

• Tranche A generators are subject to transition arrangements

• The principle behind a Tranche A generator (or group of generators) is that the operator could not reasonably have foreseen the emissions regulation when putting the plant into operation or entering into a balancing services contract

• The inclusion of generators of less than one megawatt was at a later date and therefore a slightly different definition and timings

Tranche B generator

• A tranche B generator is any other generator (other than an excluded generator) or a tranche A generator that has lost its entitlement to be tranche A

• A Tranche B generator must fully meet the emission and administrative requirements of a ‘specified generator’

Tranche B generator

• A tranche B generator is any other generator (other than an excluded generator) or a tranche A generator that has lost its entitlement to be tranche A

• A Tranche B generator must fully meet the emission and administrative requirements of a ‘specified generator’

Emission Limit Values

• Where secondary abatement is used emission values must be meet within:– 20 minutes of commencing operation for a Tranche A or ex. Tranche A engine– 10 minutes of commencing operation for a Tranche B engine

• There must be no persistent visible dark smoke

• Stricter standards may be applied where required by air quality standards

Permitting

• The same process as the MCPD will be used

• Monitoring is required every three years

• The NOx limit value is 190 mg/Nm3 @ 15% O 2 – Same as MCPD for diesel and existing gas engines– Needs SCR for diesel engine– Needs three way catalyst for rich burn gas engine– Achievable with lean burn gas engine

TIME LINE

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

2031

2032

2033

MPCD

<18/12/2018

MPCD new

Typically ELVs do not apply <500 h/y

MPCD exising 5-50 MWth

<

Typically ELVs do not apply <500 h/y

MPCD exising 1-5 MWth

<

Typically ELVs do not apply <500 h/y

SPECIFIED GENERATOR

Tranche A

<01/12/2016

<01/10/2019

5-50 MWth, >500 mg, 50 h/y

5-50 MWth, >500 mg

<

Must not cause AQ exceedance

2014/2015 CA or FIT <01/12/16

Must not cause AQ exceedance

< requirement to meet EVs delayed until qualifying 'balancing contract' ends

<

2014/2015 CA or FIT <01/12/16

< requirement to meet EVs delayed until qualifying 'balancing contract' ends

5-50 MWth, 50 h/y

1-5 MWth

<1 MWth

< 2014/2015 CA or FIT <01/12/16

< 2014/2015 CA or FIT <01/12/16

2014/2015/2016 CA or FIT <31/10/17 or BS <31/10/17

< requirement to meet EVs delayed until qualifying 'balancing contract' ends

requirement to meet EVs delayed until qualifying 'balancing contract' ends >

requirement to meet EVs delayed until qualifying 'balancing contract' ends >

Tranche B

<01/01/2019

1-50 MWth <1 MWth not providing balancing services not included as 'specified generator' <1 MWth providing balancing services

Move to Tranche B if agreement expires (unless installed <01/12/2016 or <MWth) or new one entered into after 31/10/17

Starting operating period Restricted starting operation period Permit Permit and meet ELVs

Emissions - Case Studies

GREEN D+

In a political, economic and industrial environment that is forever putting pressure on companies to operate sustainably and meet tighter emissions targets, Power Electrics are excited to announce their partnership with Green Biofuels, the manufacturers of renewable fuel Green D+.

Made from natural vegetable fats, oils and waste bi-products via a process that uses hydrogen instead of methane, Green D+ burns even cleaner than regular bio-diesel and drastically reduces engine emissions.

So far we have seen demand growing for Green D+ in the events, utilities and construction industries. Festivals and outdoor events that are marketed at younger audiences are seeing a demand for sustainable power grow at an expedient rate. With the building sentiment towards the importance of environmentally sustainable practices and the ability for the millennial generation to call on the power of social media, it is hugely important that events companies support these ethically driven movements or face being ostracised by their audience.

In the utilities industry Green D+ is becoming a no-brainer. Savings can be passed on to the customer meaning they get more for their money over a longer period of time. Previously, bio-fuels have decreased machinery lifespans due to oxidation, polymeric reaction products, soot and sulphur. Green D+ produces none of these harmful bi-products and the fuel can also be run in existing machines, eliminating the need for costly retrofitting or replacement. This has been especially well received in the construction industry where waste products such as ash forming components and Sulphur have a negative effect on the lifespan of machinery.

London is where we have seen the biggest take up of Green D+. The capital has been heavily slated for its problems with air pollution in the past few years and contractors are under increasing pressure to make any kind of reduction in emissions. With Green D+ helping to cut emissions by up to 94%, it’s no surprise London has been the largest source of demand.

We spoke to Green Bio Fuel COO, Magnus Hammick who said: “With an estimated 40,000 lives cut short by air pollution in the UK cleaner air is a public health imperative. Our fossil-free fuel will help vehicles with diesel engines to run cleaner for longer, and help UK cities like London meet their Clean Air Zone targets by 2020.”

There are obvious barriers to the fuel’s universal application, especially in the rental industry where customers see little of the reduction in maintenance costs. The fuel also costs slightly more than regular diesel, meaning less environmentally conscious companies are unlikely to adopt its use whilst regular diesel is still cheaper, or whilst their customer base isn’t demanding them to do so. However, anyone with knowledge of the fuel industry will tell you this is where the future lies. Fossil fuels are a finite resource and the growing number of regulations are making the prospect of cost saving bio-fuels like Green D+ too good to pass up.

www.powerelectrics.com/green-d

Green D+ v Red Diesel Comparison

AROMATICS

RES DIESEL ASTM D975 2D

30% Carbon deposits in fuel system & engine

DREEN D+ PR EN 15490 ASTM D975 2D

NONE: Cleans engine

CETANE VALUE 45-48 70+: Rapid cold start, lower exhaust emissions, less noiseENGINE OIL OK NONE: No sulphur, no oxidation, no polymeric reaction productsEFFICIENCY OK OK: Equal to red dieselEMISSIONS Poor overall Far less on all: 35% less NO x up to 85% les particulatesSULPHUR CONTENT OK: 10-20ppm NONESTABILITY/STORAGE OK Indefinite storage lifeASH, METALS OK NONE: No effect on exhaust after treatment systemsCOLD PROPERTIES -12°C needs additive thereafter No additive storage life

EV CHARGING AND ITS IMPACT ON THE EVENT MARKET

Background The UK government aims to phase out petrol and diesel vehicles by 2040, but research indicates that many regions in the UK are falling short when it comes to providing charging points for electric vehicles. As of 2017 there were 47,000 electric vehicles registered in the UK, however; there were only 173 new publicly available charging points installed that year.

Currently there are almost 17,000 people for every publicly available charging point, with only four areas of the country having higher than average levels of provision. In late 2017 the London Mayor Sadiq Khan announced a £4.5 million investment in EV charging points across the capital but it is clear that more investment is required to plug the charge point gap across the rest of the UK.

Phasing out petrol and diesel vehicles is just one of the many targets included in the government’s 25 year environmental plan. Waste reduction was also highlighted as a key factor that needed to be addressed in order to futureproof Britain from further environmental risk. The change in government legislation has impacted the way outdoor events and festivals are run – with the introduction of solar powered equipment, greener generators and smarter waste management facilities becoming a mainstay over the last few years. Organisers are now more knowledgeable than ever of the importance of sustainability and are increasingly selective when planning their event.

While on-going discussions take place within central government to install more charging points across the UK, Wayne Woodhead (MD) of temporary power specialist ide Systems believes that it is only a matter of time before the demand for EV charging increases at events and festivals.

“The government has made it clear that they want consumers and businesses to transition to electric vehicles, the main issue is ensuring that the right infrastructure is in place to do this.

EV charging is highly regarded as the future of modern day transport and we believe it is our responsibility as a forward thinking business to introduce a cost effective solution to the temporary power market to satisfy the potential demand for EV charging at events and festivals.

We have conducted a great deal of research on EV charging and our engineers have developed an innovative solution which is ideal for charging electric vehicles at remote locations and festivals. We are excited to bring this solution to market and believe that it will help solve problems for our clients and the end user.”

The solution ide Systems has created the Vulcan EV Charging Point, which is designed to charge electric vehicles from a temporary power source and is housed in a high visibility IP54 enclosure. Up to six charging points can be connected in-line and powered from a single 63A three-phase supply or twelve charging points in “low power mode.”

The Vulcan EV Charging Point can be configured to select any phase, and can be set to provide 32A charging or 16A charging if the power is limited. The outputs are fully compliant with European Type 2 charging systems found on the road today and a connection can be made to a vehicle in less than a minute.

When is the solution available? The first ever EV charging station will be set up at the 2018 Showmans Show in October where users will be able to charge their electric vehicles using the ide Vulcan EV Charging Points.

The Vulcan EV Charging Points are now available to hire from any of ide’s three Rental Centres across the UK and can be purchased from the ide Manufacturing Centre in the Midlands.

To find out more about ide Systems’ range of EV Charging points, please email sales@idesystems.co.uk or call +44 (0) 1543 574111.

idesystems.co.uk/

NITROGEN OXIDES ARE A HAZARD TO HUMAN HEALTH

Scientific evidence links NO2 (Nitrogen Dioxide) exposure, ranging from 30 minutes to 24 hours, with adverse respiratory effects including airway inflammation in healthy people – to increased respiratory symptoms in people with asthma.

Ozone or Smog is formed when NOx and Volatile Organic Compounds (VOCs) react in the presence of heat and Sunlight. These particles affect anyone that come into contact with them – they get deep into the respiratory system and alter lung tissue; causing a long term effect on human health.

Most Susceptible: Children, the elderly and people with existing lung disease. This is the motivation for legislators to lower the limits

NOx can be reduced from Lean Burn engines burning many types of fuel, such as Natural Gas, Diesel, and Bio-Fuels, with the aid of Selective Catalytic Reduction – SCR. Unlike the precious metal coating used for Oxidation Catalysts, SCR Catalysts use the base metal Vanadium to assist with this reaction. AdBlue (Urea) is injected, under precise control, upstream of the catalyst and into the hot exhaust gas, where it is mixed efficiently before meeting the catalyst for the reaction to take place. Agriemach offer a high efficiency SCR which can reduce NOx by 99% - for example, a 500mg/ Nm3@5%O2 Natural Gas engine can be

brought down to 5mg – and a 2000mg Diesel can be reduced to 20mg.

However, the NOx limit for engines is usually set by the geographical location of the engine installation and other polluting sources in the same area. EU NOx Limit Values must not be exceeded – so traditionally in order to calculate the NOx limit of a new polluting source, local air quality analysis will be carried out, which will determine the NOx limit for the new engine, boiler, etc. Typical exceedance will be seen in built up areas such as major cities with a lot of traffic. DEFRA have now introduced the new MCPD (Medium Combustion Plant Directive) which will require, primarily, diesel engines to fall in line with a NOx ELV of 190mg/Nm3@15%O2, for any application that exceeds the running hours of an Emergency generator (50 hours per year). This will be across the board, regardless of location. This legislation will not overrule localised specific requirements where in some cases the NOx limit will need to be even lower.

Should operators be fearful of SCR; absolutely not – it is not a new technology, it is now commonly used for on-road vehicles, AdBlue is readily available, and the design and control of Agriemach SCR systems are designed specifically for the stationary engine

market – the hard work has been done. Of course it adds additional cost, a certain amount of added maintenance during regular service intervals, but once up and running, will provide a good reliable service life and will not affect the engine performance – with the added benefit of improving air quality for your children, grandchildren and hopefully generations to follow.

A good question raised during a recent technical meeting was, “why does the MCP Directive not insist on fitting Diesel Particulate Filters to engines when PM2.5 carries known carcinogens?” It could be down to high backpressure, high maintenance, and high cost. There is a need for both Gas and Diesel Engines in the market for many different reasons – the trade-off I understand is that we simply need to keep the lights on and not restrict the engines from operating. Unfortunately, for air quality, it means that Diesel Particulates are not typically the main topic of conversation, as there is limited enforcement due to the operational challenges they can add.

www.agriemach.com