States Must Rehabilitate Diesel (France)

 

Philippe COURTY, retired engineer, Doctor of Science in Chemistry, ex. Deputy Director of the IFPEN Process Results Center, explains how the Diesel engine has been discredited and defends the rehabilitation of this technology. This, pending a massive deployment of green hydrogen and completely carbon-free electricity.

What future?

The future remains uncertain as the time has come for an "all-electric" approach. Europe launched, in 2020, an ambitious business plan aimed at rapidly having free-to-use proprietary batteries and France-Info affirmed: "the State wants to make France the first nation to produce clean vehicles". Thus, in the future world of carbon-free energy, a clean vehicle would run either on hydrogen or in rechargeable electric mode.

However, assuming the problem is solved, these technologies to be eco-labeled should meet a rigorous ecobalance taking into account the energy E1 to produce the technology, the energy E2 produced in the life cycle, the energy E3 to recycle the materials, from the technology to the specifications of the raw materials for manufacturing the new technological product, with necessarily, E2> (E1 + E3). Is that the case ; is this proven to date?

Finally, assuming the validated balance sheet, hydrogen fuel and / or electrical energy should necessarily be produced without the intervention of fossil fuel conversion processes, all co-producers of CO2. At European level and within the framework of an interconnected electricity network, meeting this requirement seems very difficult.

At present

On July 14, a national holiday, the European Commission announced (France Info) that it wishes, by 2035, to ban heat engines, also hybrid ones, in order to achieve carbon neutrality.

However, France alone, Europe itself could not act on the tropospheric concentration of the earth in CO2, if China, among others, continued to exploit its coal, in order to maintain its energy production at competitive cost. !

It is therefore time to “know how to keep reason”. The State should show more flexibility and lucidity in the decisions it will have to take on behalf of the Nation in this technical area. We are part of the EEC, but we are not (yet) attached to it!

Diesel technology under EURO 6; eloquent expertise

In its April 2021 edition, Que Choisir [1] reports on the car and environment survey, conducted by Green Ncap, a European consortium bringing together the prestigious ADAC and the German Ministry of Transport; the Ministry of Ecological Transition and the International Automobile Federation (FIA) for France; similar organizations for Austria, Spain, Italy, Portugal, United Kingdom and Switzerland. The GVI (green vehicle index) project funded by the European Union from 2020 has made it possible to test (emissions) and have (17,400 consumers) evaluated 49 vehicles.

Several Diesels models meeting Euro 6 standards (Dacia, Ford, Mercedes, Peugeot, Volkswagen, Seat and Skoda) are honorably classified, and even, the only three models classified (Skoda, Mercedes, Volkswagen) in the road category are Diesels! Obviously, no Diesel is classified in the city car category.

At the end of 2019, the State entrusted IFPEN (IFP Energies nouvelles) with the expertise of 22 vehicles sold in France, Euro6DTemp approved, following the ongoing Dieselgate investigation. The results were presented to the State on December 16, 2020, and are available on the ifpen.fr website.

The comparison of Diesel and spark ignition (petrol) engines has shown [2]:

    28% higher fuel consumption in gasoline, resulting in 11% higher CO2 emissions

    NOx emissions of 57 mg / km for Diesel with SCR technology (standard, 80 mg / km) against 20 mg / km for gasoline (standard, 60 mg / km).

    Average emissions of fine particles PN 23 (size> 23 nm.) Of 1.1 1010 / km. (standard: 6.1011 / km) for Diesel against 1.6.1011 / km. for gasoline (standard: 6.1011 / km), 15 times higher. However, taking into account the periodic regenerations of the particulate filter (Diesel), the level of fine particle emissions reaches 5.8.1010 / km (2.6 times higher).

    Regarding PN 10 nanoparticles (10 to 23 nm.), The average emissions of gasoline vehicles are twice as high as those of diesel vehicles. In absolute terms, gasoline therefore emits more fine particles and these have the particularity, more impacting on the health plan, of being smaller than those emitted by diesel vehicles [2].

    Average carbon monoxide (CO) emissions of 83 mg / km for Diesel (standard 500 mg / km) against 434 mg / km for gasoline (standard 1000 mg / km).

    Other emissions (hydrocarbons; ammonia); of the same order.

The expertise conducted by IFPEN corroborates the measurements published by ADAC, a year earlier, which are reproduced in appendix 1. Note that diesels, less polluting, are classified by the French State in CRITAIR 2, while gasolines , more polluting in terms of particles, are classified CRITAIR 1…

Attempts to discredit Diesel technology

This technology, applied to passenger cars (passenger cars) around 1958 by Automobiles PEUGEOT, had been a worldwide success. But the implementation, in 2014 (Euro 6B), of strict NOx standards led to Dieselgate, which served it. At the same time, the European Commission authorized manufacturers for three years (2015-2017) to derogate from the standard for gasoline engines, with regard to particles; the doctors of the Air Santé Climat collective affirmed that clean diesel did not exist !!! [3] Finally, the ICTT (February 2019 report) masterfully attributed to Diesel engines two-thirds of the excess mortality caused by air pollution, in France, due to fine particles, and the Mayor of Paris was simply threatening to ban the Diesels in the capital.

This discrediting and the action of certain environmental lobbies then caused very legitimate concern among citizens and the collapse of sales. These had already halved by 2019. TOYOTA, (perhaps hoping to promote its hybrid technology) suddenly stopped producing and marketing VP Diesel, with the exception of 4x4 Hilux and Land-Cruiser. Its Japanese partner IBIDEN, producer of DPF in France [3], then ceased its activity. According to [4], as of 2019, 15,000 jobs were in danger of disappearing out of the 38,000 positions in the technical field.

In early 2019, the press and Experts reacted [4, 5, 6], wondering about this real witch hunt. On March 29, Anne Coudray was surprised at the 8 pm TF1 news; François STAGNARO, journalist at Auto Plus, and his Editor-in-chief Pierre TAYLOR wrote on the first page: “The new Diesels CLEANER than the Essences? Technical truth versus political correctness ”.

It goes without saying that in terms of a win or die strategy, anything goes! Diesel has been spared nothing in recent years to discredit it, and the state has shown remarkable passivity; with the exception of Mr. Bruno Le Maire, Minister of the Economy and Finance, who asked, in the same year 2019, that Euro 6D Temp Diesels, on par with Essences, benefit from the CRITAIR 1 sticker [4]. Unfortunately, it was not listened to, science and politics not always mixing well!

Overview

The implementation of the EURO 6 Full standard causes some emotions and some manufacturers are talking about removing Diesel engines from their catalog.

However, in 2018 [8], and probably still today, Diesel monopolized the top eight places in commercial passenger car sales.

Here it is necessary to re-establish the technical truth.

Traditional petrol engines are depolluted by a particulate filter (FAP) and three-way catalysis, which requires operating at A / F stoichiometry (air on fuel) = 1, otherwise the NOx will no longer be converted into N2 nitrogen and water. The removal of fine particles is more difficult than with a diesel engine, despite a much higher exhaust temperature. However, this high temperature means that the DPF / Gasoline does not clog.

Diesel engines are also depolluted by a particulate filter, oxidation catalysis and SCR catalysis (reduction of NOX with aqueous urea or even ammonia (NH3)). The SCR process has been operational in industry since 1973 (power plants, nitric acid synthesis, gas turbines, incinerators) [9]. Diesel's strong point is its operation in an oxidizing environment (excess air) and its weak point is the temperature of the exhaust gases, which initially start when cold to activate the catalysts (light off). This too low temperature is undoubtedly the cause of the problems with DPF / Diesel in town, which clog up and sometimes require urgent regeneration.

The aforementioned expert results and the Green NCAP GVI study clearly demonstrate that Diesel, to date, is the dominant technology for on-road passenger cars and LCVs. On the road, Diesel consumes much less, emits less CO2, much less particles, and provides the user with an impressive lifespan. It is the same for the agricultural sector, the forestry users (4x4), the Diesel engine also presenting, especially at low speed, an incomparable engine torque.

Urban leadership should be left to mature hybrid technologies. The fleet of Parisian taxis, more than 80% hybrid, it is said, bears witness to this. In urban areas, CO2 emissions are 33% lower than those of a petrol vehicle of the same power [2]. Unlike traditional braking, electric braking with energy production does not produce fine particles.

All electric results from the tightening of antipollution standards, tax incentives, environmental pressure; it is particularly suitable for urban use. The planned change in the cost of electricity, the very high cost of batteries (from € 2,000 for 1 KWh to more than € 20,000 for 100 KWh) could moderate the current trend in sales.

Despite the rise in all-electric power, the Diesel will still have a bright future ahead of it, if potential buyers manage to sort out the true from the false (difficult, fake news sells well!), And above all, if the State is finally decides to intervene in this technical field. The positioning of Euro 6 Diesels in CRITAIR 1 becomes a moral obligation of the State, on the basis of the results of the expertise that it itself has requested.

Bibliography

[1] Que Choisir - “The green car flops” pp. 48-50 April 2021.

[2] Euro6DTemp Emissions Studies for the MTE December 16, 2020 and Study of Euro6DTemp emissions - IFPEN for DGEC - Summary report, Dec. 2020.

[3] Les Echos, France “IBIDEN closes its DPF plant - Nov. 20, 2018.

[4] Le Parisien "le Diesel makes resistance" N ° of March 25, 2019.

[5] Auto Plus n ° 1595 “Are the new Diesels cleaner than gasoline? Technical truth versus political correctness. »March 29, 2019.

[6] COURTY Ph. “Urgent requalification of eco-compatible diesel passenger cars EURO 6D Temp. March 31, 2019. Document sent to the State (PR, PM, MINEFI, MTE).

[7] Auto Plus Vert N ° 1. “New technical solutions to save Diesel” March-April 2019.

[8] Paris Match. N ° 3595 "Diesel resists, Electric takes off" April 5 to 11, 2018

[9] in Handbook of heterogeneous Catalysis, ERTL G. KNÖSINGER H. WEITKAMP J. WILEY VCH. Editor; F.J. JANSEN, “Industrial Experience and Development of SCR Catalysts. "  Flight. 4, 1658 -1661. 1997

 

 

Annex 1: Diesel vs. petrol. ADAC results published by Auto Plus [5]

Model	Engine	CRITERIA	NOx mg/Km.	Mass of particles mg/Km.	Number of particles /Km.
BMW 218 I Active Tourer Steptronic	Petrol	1	14	2,4	1,465 1011
BMW 218D Active Tourer Steptronic	Diesel	2	14	0,2	0,588 1011
Kia Ceed 1.4 T-GDI	Petrol	1	12	0,6	5,687 1011
Kia Ceed 1.6 CRDI	Diesel	2	14	0,3	0,012 1011
Mercedes Classe C200 9G-Tronic	Petrol	1	35	0,5	1,471 1011
Mercedes Classe C220D 9G-Tronic	Diesel	2	13	0,8	0,014 1011
Peugeot 508 1.6 Pure Tech EAT8	Petrol	1	33	0,3	0,970 1011
Peugeot 508 2.0 Blue HDI EAT8	Diesel	2	19	0,1	0,015 1011
Volkswagen Golf 1.5 TSI	Petrol	1	9	0,2	0,925 1011
Volkswagen Golf 1.6 TDI SCR	Diesel	2	19	0,1	0,030 1011

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