The potential role of hydrogen in sector coupling,

hybridization of energy systems and triggering global sustainability

İskender Gökalp ICARE-CNRS, Orléans, France

METU, Mechanical Engineering Department, Ankara, Turkey

Invited Lecture 3rd INTERNATIONAL HYDROGEN ENERGY CONGRESS AND EXHBITION

Gazi University, Ankara, Turkey, 14-16 June 2021 (online)

Outline

I. A tribute to all « hydrogen system » pionniers II. Hydrogen as a « sector coupling » and

« problem solving coupling » agent III. An example from a hot problem: « organic waste to hydrogen »

I. A tribute

45 years ago International Journal of Hydrogen Energy

Vol 1 (1), 1976

Editorial T. Nejat Veziroğlu

IAHE and the Journal

T. Nejat Veziroğlu (1976) IAHE and the Journal.

Editorial, IJHE 1(1) THIS first issue of the International Journal of Hydrogen Energy, the

official journal of the International Association for Hydrogen Energy (IAHE), marks an important step in the "journey" towards a universal hydrogen energy system. Since this journey formally started with the establishment of IAHE, a brief recount of its origins and history to date would be appropriate here (…) The first concerted proposals for a formal organization centered on the subject of Hydrogen Energy were sounded at The Hydrogen Economy Miami Energy (THEME) Conference held in Miami Beach on 18-20 March 1974 (…) We look forward with great confidence to IAHE's First World Hydrogen Energy Conference to be held in Miami Beach, March 1976. This will definitely be a landmark event with a large international participation expected. The preliminary program is included in this issue (…) Your contributed papers will be received with great interest and hope since they will help bring closer the inevitable era of "abundant clean" hydrogen energy.

IJHE 1(1) 1976 First papers Cesare Marchetti

(International Institute for Applied Systems Analysis, Austria) On hydrogen and energy systems

(from the Introduction) THE RUTHLESS maneuvering of the oilmen, and the panic

generated by skillful embargos and great increases in oil prices has focused the attention of politicians, scientists and laymen on the problem of resources and scarcity (…)

On the other side, if one looks at the past history, one sees that man starts shifting from one primary energy to another long before the exhaustion of any particular kind of primary resource. This is clear for wood, and obvious for coal (…)

This introduction has the scope to move the spotlight from the resources to the energy systems. i.e. that complex gadgetry sitting between the primary resource and the final consumer. It is there where the eventual causes of malfunctioning are hidden and where the cures have to be applied.

IJHE 1(1) 1976 First papers E.M. Dickson, J.W. Ryan, M.H. Smulyan

(Stanford Research Institute, Menlo Park, CA.) Systems considerations and

transition scenarios for the hydrogen economy

Abstract System descriptors are given for key hydrogen economy

components. Hypothetical transition scenarios are given for three

generalized social climates with regard to hydrogen: strong government intervention, optimistic and realistic.

All transition scenarios are characterized by five areas related to the density of the hydrogen distribution network

IJHE 1(1) 1976 First papers E.M. Dickson, J.W. Ryan, M.H. Smulyan

Systems considerations and transition scenarios for the hydrogen economy

From the conclusions Although it can be argued convincingly that a combination electric/hydrogen

economy is ultimately inevitable, there is no assurance that the weight of the many incremental individual corporate and governmental decisions will lead society in that direction within the next century. Indeed, for the rest of this century there are so many energy carrier alternatives that blend more readily into the existing order of things that there is a strong possibility that society will "slog" through all the fossil fuel alternatives before settling on hydrogen.

In summary The total lead time for a hydrogen economy is very long. Most of the first major uses will involve "captive" rather than "merchant"

hydrogen. In the year 2000 the importance of the hydrogen economy will be measured mainly

by whether the United States is on a course towards it or away from it. Total hydrogen use, even by the year 2025, would be small compared to the full

potential demand. Yet, in a few sectors, notably commercial passenger aviation, hydrogen use could

reach maturity by 2025.

IJHE 1(1) 1976 First papers K.F. Knoche, H. Cremer, G. Steinborn

(Aachen Technical University, West Germany) A thermochemical process for hydrogen production

Abstract A thermochemical water splitting process of the

iron-chlorine family is presented and the mass and energy flows of this process are discussed in detail. This proposal represents one alternative of a great

variety of closed thermochemical processes of the iron-chlorine family

IJHE 1(1) 1976 First papers J.E. Funk (University of Kentucky)

Thermochemical production of hydrogen via multistage water splitting processes

Abstract This paper presents and reviews the fundamental thermodynamic

principles underlying thermochemical water splitting processes. The overall system is considered first and the temperature limitation

in process thermal efficiency is developed. The relationship to an ideal water electrolysis cell is described and

the nature of efficient multistage reaction processes is discussed (…) A procedure for analyzing thermochemical water splitting processes

is presented and its use to calculate individual state efficiency is demonstrated.

A number of processes are used to illustrate the concepts and procedures.

IJHE 1(1) 1976 First papers G. Neil, D.J.D. Nicholas, J. O'M. Bockris, J.F. McCann

(University of Adelaide) The photosynthetic production of hydrogen

Abstract A systematic investigation of photosynthetic hydrogen

production using a blue-green alga, Anabaena cylindrica, has been carried out.

The results indicate that there are two important problems which must be overcome for large-scale hydrogen production using photosynthetic processes. These are (a) the development of a stable system, and (b) attainment of at least a fifty-fold increase in the rate of hydrogen evolution per unit area illuminated.

IJHE 1(1) 1976 First papers G.G. Leeth (General Electric)

Energy transmission systems

Abstract Various methods of transporting large quantities of energy are compared. The energy source is assumed to be nuclear fission. However, expected significant

effects of alternative energy sources are noted. The associated energy distribution system is essentially ignored. The procedure

consists of evaluating several different thermal, chemical, and electrical energy forms.

Basically, the evaluation is a technical and economic comparison including capital costs and energy loss costs.

Additional qualitative evaluation is accomplished by listing significant features of the various energy modes. Results indicate that hydrogen is superior to all forms of energy transport considered.

An EVA-ADAM system (chemical heat pipe which uses the basic steam methane reaction: CH4 + H2O ↔ CO + 3H2) is intermediate between hydrogen and electricity or hot water. High-voltage electric overhead transmission and hot water are the most expensive systems.

In addition, for the case of a large energy center, all of the pipeline methods of energy transport are superior to electric transmission from the viewpoints of heat rejection and the “getaway” problem

IJHE 1(1) 1976 First papers J.M. Burger (Public Service Energy & Gas Company, Newark, NJ.)

An energy utility company's view of hydrogen energy Abstract

Several areas where the use of hydrogen has been of recent interest to electric and gas utilities are briefly examined.

These are electrical peak-leveling systems with hydrogen as a storable medium, the production of hydrogen as a marketable product in either limited or large quantities, and the use of hydrogen for energy transmission.

The relationship of these applications to utility operations is discussed generally and some numerical estimates on costs are given.

Some research and development needs implied by cost considerations are indicated.

IJHE 1(1) 1976 First papers G.D. Brewer (Lockheed)

Aviation usage of liquid hydrogen fuel—prospects and problems

Abstract If worldwide air transportation is to continue to grow as

forecast, a fuel must be found to supplant petroleum-based kerosene (Jet A).

The new fuel must be available universally without hazard of control by cartel, and must meet fundamental requirements of economics, safety, performance and environmental considerations.

Hydrogen is found to provide this potential. The results of studies performed to investigate the feasibility,

practicability, and potential advantages/disadvantages of using liquid hydrogen as fuel in both subsonic and supersonic commercial transport aircraft for initial operation in the 1990–2000 time period are discussed

IJHE 1(1) First World Hydrogen Energy Conference

Advance Program of the First World Hydrogen Energy Conference. 1st World hydrogen energy conference (1–3 March 1976 Miami Beach, Florida, U.S.A.)

II. Energy Systems and Hydrogen

Energy Systems

Energy systems are made of three main sub-systems. They are (i) the energy source discovery, exploitation, conditioning

and transport system; (ii) the energy source conversion system to useful energies or energy vectors, and (iii) the useful energy or energy vector transmission, distribution and use system.

Both the global energy system and its sub-systems are in fact large scale socio-technical constructions and as such they affect the global society but they are also affected by the social relations in which they are set in.

Energy systems and their sub-systems are furthermore characterized by their network structures and properties.

Therefore, a change in one energy sub-system or of one element of the energy system may affect the global energy system, and because of its socio-technical network properties, the whole society may be affected by this change, for better or worse.

Energy systems and sustainability

The current energy systems (be it for transport, power and heat generation or for industrial processes) are globally not sustainable. They are largely fossil sources based, even if the

renewable power generation is developing at an important rate. The intermittent renewable electricity alone will not

however satisfy the increasing global energy demand and the global decarbonisation targets. Transition to a globally sustainable clean energy

system is needed and a hydrogen based system may play an important role to satisfy this need.

Constaints for a global Hydrogen system

The advent of a hydrogen system should satisfy several constraints simultaneously.

First, hydrogen generation processes should be CO2 free or neutral.

Second, the hydrogen system should permit less centralized, more flexible decentralized and hybridized local energy systems, however allowing their interconnection when needed.

Third, the hydrogen system should open the way to a more circular economy were sector coupling should be the rule and not the exception.

Finally, the hydrogen system should contribute to all the Sustainable Development Goals and not only to some of them.

Hydrogen System as a Large Scale Socio-technical System

The socio-technical large scale nature of energy systems signifies that a sustainable energy system may indeed contribute to all SDGs by diffusing into them its sustainability elements.

In that sense, a hydrogen based sustainable energy system may trigger and consolidate sustainable configurations in all the human activities and needs at a global scale.

This also means that, in order to save/secure all this positive potential, designing the global hydrogen energy system should be done with extreme care, certainly progressively, and by constantly evaluating the precautionary safety / innovation balance

III. Organic Waste to Hydrogen

Organic waste: A hot problem Waste organic streams have a massive potential to be

used as resource for hydrogen production. The examples of such waste streams include

lignocellulosic biomass (e.g. agricultural crop residues, woody biomass and energy crops), sewage sludge, end-of-life tires, plastics, municipal solid waste, olive oil industry waste, black liquor, animal manure…

The organic waste to hydrogen route is a suitable example to demonstrate the “sector coupling, energy system hybridization and decentralization” in short “problem solving coupling” and sustainability securing potential of hydrogen

Sewage sludge to hydrogen and more

Sewage sludge, a residual semi-solid by-product of wastewater treatment plants, contains a significant amount of decaying organic matter (carbohydrates, fats, proteins, organic acids, etc.), micro-organisms, heavy metals and micro-pollutants (sterols, hormones and pharmaceutical residues…)

Sewage sludge is generated daily in massive quantities, everywhere in the world (a renewable energy resource?)

Its disposal is posing huge problems (among which marine mucilage)

Being a very humid waste, conventional thermochemical processes are not suitable for the valorisation of the energetic content of sewage sludge (without drying)

Hydrothermal processes

Sewage sludge has a high potential for its valorisation in the bio-energy sector due to its high organic matter content, approximately 50% on a dry basis

Owing to its semi-solid nature (high water content), hydrothermal treatment of sewage sludge is an economically and environmentally promising technology

The application of subcritical and supercritical hydrothermal processes to sewage sludge is an innovative and sustainable approach

Which also permits the introduction of the microalgae route

Supercritical water gasification of sewage sludge

Water has unique properties at supercritical conditions (i.e. 374°C and 22.1 MPa). The major properties of SCW, such as density, viscosity, dielectric constant, and hydrogen bonding are different from those of steam or liquid water

SCW behaves like a non-polar organic solvent completely dissolving organics. SCW hydrolysis, gasification, dissolution and pyrolysis are taking place at temperatures substantially lower in comparison with the classical gasification and/or combustion

A hydrogen rich gas is produced (with or without the use of catalysts) and phosphorus recovery is also possible

Some of our previous work on the application of SCWG to organic waste streams

Rana, R., Nanda, S., Reddy, SN., Dalai, AK., Kozinski, JA., Gökalp, I. (2020) Catalytic gasification of light and heavy gas oils in supercritical water. JOURNAL OF THE ENERGY INSTITUTE 93: 2025-2032 DOI: 10.1016/j.joei.2020.04.018

Sonil Nanda, Sivamohan N. Reddy, Howard N. Hunter, Dai-Viet N. Vod, Janusz A.Kozinski, Iskender Gökalp (2019) Catalytic subcritical and supercritical water gasification as a resource recovery approach from waste tires for hydrogen-rich syngas production. THE JOURNAL OF SUPERCRITICAL FLUIDS Volume: 154 Article Number: 104627 DOI: 10.1016/j.supflu.2019.104627

Sonil Nanda, Miao Gong, Howard N. Hunter, Ajay K. Dalai, Iskender Gökalp, Janusz A. Kozinski (2017) An assessment of pinecone gasification in subcritical, near-critical and supercritical water. FUEL PROCES. TECHN. 168: 84-96

Yann Graz, Stephane Bostyn, Thierry Richard, Pablo Escot Bocanegra, Emmanuel de Bilbao, Jacques Poirier, Iskender Gökalp (2016) Hydrothermal conversion of Ulva macro algae in supercritical water. THE JOURNAL OF SUPERCRITICAL FLUIDS 107: 182-188

Nanda Sonil, Dalai Ajay, Gökalp Iskender, Kozinski Janusz (2016) Valorization of horse manure through catalytic supercritical water gasification. WASTE MANAGEMENT 52: 147-158

Hydrothermal carbonization of sewage sludge (1) The second Waste to Hydrogen approach applicable to

sewage sludge is the sub-critical hydrothermal process i.e. hydrothermal carbonization (HTC).

This process is performed in an aqueous environment without water vaporizing and may be conducted in a wide range of temperatures from 180 up to 350 °C under pressure ranges from 2 to 6 MPa; typical residence time range is from few minutes to 240 min.

Under those conditions, chemical decomposition of the dry mass occurs and this results in three types of products: i) solid (hydrochars), which account for 45 up to 70% of the mass of the products; ii) the gas phase mainly consists of CO2 (over 90% of the gaseous products), with small amounts of CH4, H2 and CO; iii) liquid fraction (HTC process water) between 5-25 % of products’ mass, it may contain the initial carbon present in the raw material up to 15%.

Hydrothermal carbonization of sewage sludge (2) The following processes occur during HTC: hydrolysis, dehydration,

decarboxylation, polymeric condensation and aromatization. A solid product, hydrochar (consisting 30-40% moisture ), can be

easily filtered from the reaction solution, and has upgraded lignite-like physical and chemical properties (e.g. hydrophobic, high grindability).

In addition, the carbonaceous solid product of HTC has a special morphology, rich surface functional groups and strong chemical reactivity.

Hydrochar can be gasified to hydrogen rich mixtures (co-gasification with lignites is also possible)

Hydrochar is a potential bioresource for energy and biomaterial production, soil quality improvement and carbon sequestration

As for SCWG, the great advantage of HTC is its lower energy consumption eliminating the pre-drying of sewage sludge needed for its disposal in conventional incineration plants.

Some of our previous work on the application of HTC to organic waste streams

Diakaridia Sangare, Stéphane Bostyn, Mario Moscosa-Santillan, Iskender Gökalp (2021) Hydrodynamics, heat transfer and kinetics reaction of CFD modeling of a batch stirred reactor under hydrothermal carbonization conditions. ENERGY 219

Sangare, D., Missaoui, A., Bostyn, S., Belandria, V., Moscosa-Santillan, M., Gökalp, I. (2020) Modeling of Agave Salmiana bagasse conversion by hydrothermal carbonization for solid fuel combustion using surface response methodology. AIMS ENERGY 8: 538-562

Wilk, M., Magdziarz, A., Jayaraman, K., Szymanska-Chargot, M. and Gökalp, I. (2019) Hydrothermal carbonization characteristics of sewage sludge and lignocellulosic biomass. A comparative study. BIOMASS & BIOENERGY 120: 166

Ayoub Missaoui, Stéphane Bostyn, Veronica Belandria, Benoît Cagnon, Brahim Sarh, Iskender Gökalp (2017) Hydrothermal carbonization of dried olive pomace: Energy potential and process performances. J. of Analytical App. Pyrolysis 128: 281–290

Jayaraman, Kandasamy, Gökalp, Iskender (2015) Pyrolysis, combustion and gasification characteristics of miscanthus and sewage sludge. ENERGY CONVERSION AND MANAGEMENT Volume: 89 Pages: 83-91

SCWG and HTC to Microalgea and Hydrogen (1) This approach also allows linking the SCWG and HTC routes

using the process water of sewage sludge HTC as the aqueous medium to cultivate microalgae.

Microalgae are photosynthetic micro-organisms that convert sunlight, water and carbon dioxide to algal biomass.

Microalgae can increase their biomasses 50 times more than that of the fastest-growing plant, switchgrass.

They have a higher growing capacity during the whole year and also they do not need any arable lands for this purpose.

However, there are challenges for the efficient production of microalgae such as the operation of production systems, high cost of installations, and the requirement of large quantities of nutrients.

SCWG and HTC to Microalgea and Hydrogen (2)

For these reasons, the utilization of the aqueous phase from HTC is an excellent approach for algal growth. After extraction of the precious lipidic components

of microalgae, SCWG can be applied to microalgae residues to generate hydrogen rich gases, in solo or in co-SCWG with sewage sludge. The optimization of this integrated process may

offer the scientific bases for the demonstration of a very innovative circular economy system for sewage sludge disposal and valorization.

HTC process water to cultivate microalgae

In the two papers below, we have demonstrated that (i) HTC process water is an excellent medium to cultivate microalgae at a minimum nutriment cost and (ii) the concentrations of TOC, TNb and TP in the HTC process water decreased by approximately 80–82 %, 55–58 % and 88–91% respectively, for all cultivation trials diminishing therefore considerably the risk for the formation of marine

mucilage, if the waste water purification units’ ultimate liquid waste is to be discharged into the sea or rivers

Seray Zora Tarhan, Anıl Tevfik Koçer, Didem Özçimen, Iskender Gökalp (2021) Cultivation of green microalgae by recovering aqueous nutrients in hydrothermal carbonization process water of biomass wastes. Journal of Water Process Engineering Volume: 4 Article Number: 101783 https://doi.org/10.1016/j.jwpe.2020.101783

Seray Zora Tarhan, Anıl Tevfik Koçer, Didem Özçimen, İskender Gökalp (2020) Utilization of hydrothermal process water for microalgal growth. Eurasian J Bio Chem Sci, 3(1):42-47 https://doi.org/10.46239/ejbcs.733899

Final words

The Hydrogen System, if well designed, could trigger a very virtuous circle between several sectors and their problem solving needs, including the marine mucilage problem that Turkey is combatting now But one should attack the causes of this particlar problem,

and not only its periodic manifestations, to forget about it until its next manifestation

The main question of course is: do we have time to wait another 45 years to install the Hydrogen System that the Pioneers were calling for in early 70ies.

45 years ? Remember also…

Jules Verne, 1875

ANTOINE LAURENT LAVOISIER, 1743 - 1794

Antoine Lavoisier: Decomposing water into hydrogen and oxygen and recovering it by combustion, 1789