The 'German Reports'

Published October 1997

Report #1

Hello Gasification Colleagues

In response to our editor's plea earlier this year for more chat on this Network, I thought you may be interested in some comments regarding gasification in Germany.  Having just spent four weeks there, I had the opportunity to see a few gasifiers, talk to many students (and their Professors), other gasifier manufacturers, engine designers, and anyone else unlucky enough to be caught up in discussion relating to gasification.

There were also a few project proposals to review for funding application, and  gasification equipment assessment to see if their design had the capability to match their suppliers glowing specifications!  With so much to cover, I think it is best to make a number of reports so that you don't get too bored ploughing through this in one go.

Gasification is a hot topic in Germany, and with the E.U. funding renewable energy research projects, it is natural everyone who can write a proposal is endeavoring to feed from the public purse.  It was very hard not to believe there wasn't a special training centre hidden away somewhere on how to prepare E.U. funded proposals.  Everyone trying so hard to dress up projects to sound new and exciting.  It was difficult but necessary to point out that just about all there is to know of any relevance is already available in the literature.

Because my own speciality is high performance engine gasification, I was disappointed to find that engine gasifier projects were being proposed using process heat type gasifiers.  It is a widely held belief  to those I questioned, that if it makes gas, you can use it for anything.  Furthermore if you make a  big one and fuel it with rubbish demolition wood (shredded) you can power villages and small towns.  This is tremendous enthusiasm but difficult to accept when none had even small gasifiers operating to commercial standards with engines.

On reflection, I haven't received any reports of reliably operating commercially manufactured wood gasifiers in Germany except our own in Furstenwalde.  Anybody out there like to identify engine gasifiers that can be seen working anywhere in Europe?

Possibly the projects that caused me to bristle most were those proposing gasifier testing with different fuels, and comparing gasifiers ability to gasify standard fuels.  In the first instance it is quite clear from reading the literature that few projects have  gasifiers operating, expertise, and no appreciation of what constitutes a correctly functioning gasifier.  Have a look in your own library and see how many references you can find describing behaviour of the gasifier when it is functioning correctly.  One thing for sure, any gasifier test programme has to be invalid if the gasifier cannot be reliably demonstrated by the manufacturer using his own approved fuel.,  Then having demonstrated the gasifiers reliability, all gasifiers that meet this requirement should have the opportunity to participate in the test programme.  If this isn't done, and some sort of random selection of gasifiers are tested, then whoever is conducting the tests could be seen in less than a credible light.  This is how I commented to those who presented their proposals for scrutiny, and hopefully the rewrites will assist them to get funds eventually.

Whilst on the subject of fuel, at several different meetings I was asked my opinion of densified fuel (briquettes).  As a gasifier fuel, sawdust briquettes worked  O.K. in our Fluidyne gasifier, but other agricultural wastes have individual problems and unlikely to be good fuel.  There is also the point that briquettes are energy consumptive to produce so therefore expensive.  This could be offset if the sawdust is a waste disposal problem and the cost of briquetting charged to the waste source. The cost of the briquettes should then cost no more than that charged for wood chips.  The idea is to produce energy from wood, not use energy to create the fuel.  The debate was lively, and I can only conclude the briquette manufacturers are suggesting that their fuel will solve all gas making problems.  Anybody like to comment on this?

Next report: Engines, turbines and dreamers.

Doug Williams
Fluidyne Gasification Ltd.

Report #2


Being an energy consultant these days is tough, and to have any voice in the market place for your services takes something special.  In Germany or I should say the E.U. Cogen is the in thing, so as one might expect, there are plenty of workshops assembling these systems.

Designed with the precision of a Swiss watch and squeezed with their instrument packages into containers, all they need is a biomass rocket to launch them into the marketplace

Without any doubt the engine manufacturers can build the engines we need, and natural gas engines work quite well although derated on producer gas.  I spoke to several manufacturers of engines about optimising for producer gas and their reaction was sure, how many thousand units?  It was a question I needed to ask for myself, even though it will be a miracle if the market ever demands special engines.

The designers I spoke to were pleased for the opportunity to discuss some of the finer points of producer gas combustion, and learn first hand of our experiences of dual fuelling diesel gen sets.  Our first  Lister engine had clocked up 5,000 hours by March 1985, so they were keen to learn about the life expectancy of standard components.  Without entering a very lengthy technical description, the bottom line is that with clean gas, engine life is the same or slightly better.  The type of problems that can develop using standard engines will of course depend on the features of that specific engine, so I look forward to testing some of the newer gas engine features some are incorporating into their designs.

Here are a few less known facts about producer gas and engines.

"Clean" Producer Gas:

There is more of course, but that is what Fluidyne sells as commercial know why!

The potential for gasified cogen engines in the U.K. using set aside land is considerable.  Our investigations showed that using percentages of that available, some 100,000 30kWe and 25,000 100kWe installations were possible with coppice willow grown on the site.  With generation in such small increments, the power enters existing grids at the farm gates all over the country.  The combined output of these installations 25 Twh/year is equal to Drax in Yorkshire. Energy planners continue to think big however, and maybe in ignorance, overlook the logistical problems of moving large volumes of low density willow to centralised generators. Coppice willow also has special needs as a gasifier fuel, which in large quantities, creates some very challenging processing problems. With such a potential for Cogen, throughout the E.U. one can only wonder at why it is almost impossible to sell gasified installations.  Economics of scale and automation are of course important, but it is a poor excuse to hold back on legislation to enable these projects to get a leg up.  Surely it is time to bite the  bullet, charge the extra for renewables, and stop whingeing about cheap fossil fuel.

There I have to stop as I still have to work with my hands.  We also make water pumping windmills and this week have mud on my boots.  One site I inspected you may have seen at the movies.  Anyone seen "The Piano" with the Oscar winning child star Anna Paquinne? Set on a rugged bush clad beach, the forest has a brooding quality but quite beautiful and only half an hour from the workshop.

Turbines and Dreamers next week.

Doug Williams
Fluidyne Gasification Ltd.

Report # 3

Turbines and Dreamers

In every country where gasification is proposed as a potential replacement for fossil fuel, is almost mandatory to include generation for aero derived gas turbines.  I use the words proposed and potential deliberately, because those who suggest this option have little appreciation of the technical challenges to be overcome.  The situation in Germany is no different and this proposal came up at almost every meeting I had.

From 1983 to 1988,  Fluidyne (our company) was part of the NEI Power Engineering Group, and we were asked to apply our understanding of gasification to gas turbines.  Only two questions were asked:
The answer to question one had to be hypothetical, because the combustion chambers are too short, and the gas / air mixture would be extremely unstable.  This would cause the formation of soot due to incorrect proportional mixing before ignition.  When this soot is added to the submicron carbon blacks and alkaline moisture present in the gas, deposits could be expected to form on the impeller blades and buckets.  Impacted carbon particles would combust in the presence of free oxygen and result in surface pits and ash deposits.  It was predicted that the ash would form an even but unstable skin like coating, that would eventuate in vibrational stresses from the uneven shedding of the skin.

Based on our question one answer, question two allowed us the opportunity to 'imagineer' the attributes of producer gas into a turbine combustion situation.  Our conclusions were that existing gas turbines incorporated principles that made their conversion to producer gas 'difficult', and did not recommend this option of technology adaptation.  We also added that a technology development pathway existed if the market needed producer gas turbines.

End of Story!


While some manufacturers have already begun this work, my own perspective of the gas making process puts turbine projects on hold.  This doesn't mean that our projects will be stuck with engine generation, but only that our long term development programme will provide experienced needed to support these expensive projects.  Although turbine manufacturers have ongoing development programmes, it shouldn't be expected that they find solutions to problems created by the gas maker.

It isn't my intention to destroy the dreams of over enthusiastic promoters of biomass energy.  Indeed we need these people in every strata of our society.  If there is a need, it's to direct  enthusiasm towards that which is achievable and in the process, create the ability to move forward.

Commercial companies who pursue biomass technologies as another string to their manufacturing bow take real chances.  Where the expertise of the technology relies on the employee to get it from paper to plant, the reputation of the company can pass into the hands of the dreamers.

There is little ability within the business sector to question the advice of the consultants relating to gasified projects, which when they fall over, reinforces the cry for more research.  During this visit to Germany I reviewed three projects using 800kWe electrical gasified CHP systems that were in the hands of the dreamers.  None are operational and are in various stages of implementation as I write.

The fact that these three projects have even reached the implementation stage without appropriate scrutiny will create enormous distortions as to the capability of gasified power generation.  It not only reflects badly on those who implement the project, it unfortunately tars all of our capability with the same brush.

Gasification exists within many forms of combustion equipment although few recognise or even pay attention to the phenomena.  The transition from gasification theory to working installations eventually requires hammers on steel to create an environment where the phenomena of gasification (not combustion) takes place.  Every single component, shape, size, position, surface treatment etc create complex inter-related phenomena and performance which determine how the gasifier behaves.

From a manufacturing perspective it is the failure to understand the existence of created phenomena that cause malfunction to so many gasifier designs.  If you set out to design and build gasifiers the knowledge to do so begins at the fuel source.  Each fuel has its own need of preparation, movement into the system, then gasification after which it must be cooled, cleaned then used for whatever ...

I know many who read this gasification digest have interest and personal involvement with this technology.  From whichever aspect of your own input, are you sure that your efforts are moving this technology forward.  Are you also sure you are working with up to date information, because some of the historical information is very misleading.  With the best intentions some of us do create problems for each other instead of providing complimentary support.

My nine trips to Germany have enabled me to share (in condensed form) some insights which quite frankly cause me concerns which I will raise in my German Report No 4 "High Over Europe"

Doug Williams
Fluidyne Gasification

Report # 4

High over Europe

The day I left Germany (22 September) we drove from Oldenburg across the dyke at the top of the Netherlands and down to Amsterdam via a lot of side roads (motorway problems).  With a huge high over most of Europe, the North Sea was like glass and the ever present windmills still and silent.

Our enforced crawl through the side roads of the countryside, highlighted the problems of what must be the best drained overfertilized swamp in the world.

Once in the air I looked down on the high density housing and industrial areas of the Netherlands and Germany, and I don't mind admitting to feeling a little overwhelmed.  Has anyone out there  a calculation of how many Departments to Minister of Energy exist, or how many technical institutions advise or help formulate energy policy.  How many former biomass researchers have rotated their way through Aid Agencies and other institutions?

While you think about that, I have need to step back a few years to 1985, when four of us from New Zealand went to Bandung in Indonesia for the Second International Gasification Conference  It was very expensive to attend  (for those who paid their own way) but here I saw negative gasification (NG) "at work" for the first time.  NG is where everything is explained, but you don't get told how to do it, and when attempted doesn't quite work.  Its nothing that another few failed projects in far away places won't solve however, as no one really checks out these projects.

NG had its origin in the heady days of the oil price crisis, when both governments and Aid Agencies flooded technical institutes, consultancies, etc. with rather large amounts of money.  The idea was to get biomass energy working, but there never was an integration of expertise and infrastructure to ensure this could be achieved.  My concerns for the direction of NG had grown considerably by 1988, and I endeavoured to establish contact with other gasifier manufacturers.  The need to form an association to represent our industry and have input into long term planning and policies was clearly missing.  It didn't happen as commercial manufacturers were too few at that time and busy struggling to survive.

In the nine years since 1988, there has been a  continuous rotation of NG knowledge and it now percolates through most countries' policies towards power generation from biomass.

When it was announced in the U.K. of the Non Fossil Fuel Order (NFFO) it seemed every consultant who drew breath wrote to us wanting to gasify everything but mouse droppings.  The same happened from other EU countries as money came up for grabs to reduce CO2 emissions.  This scramble for money is really a matter of survival, as most institutional activities are struggling for operational funding.  Competing for project funds prevents pooling expertise in a constructive manner, and it does nothing long term for the co-ordination of effort to reduce our dependence on fossil fuels.

So back to reality and I am high over Europe after four weeks of hard work pushing Positive Gasification (PG).

PG is when every question is answered with a lecture, every problem has a solution, and you see your team come alive as their own knowledge is pushed and pulled into alignment.  When the penny of understanding drops, suddenly everything changes, particularly attitude towards biomass energy.  During these four weeks our Russian speaking design team who knew nothing about gasification, went from tree to engine designing each system with a degree of practical skill that doesn't seem to count any more.  All over 50, they are considered unemployable and these men designed, built and commissioned steel mills!  The waste of industrial expertise within the EU will eventually be recognised as the loss of a national asset, but only a dilution of their skills will remain by the time that happens.

We had their skills however, and redesigned our Pacific Class gasifier so that it could be manufactured in the Ukraine.  Moving Fluidyne gasification technology into Russia is to meet the electrical shortages of their industry, and small C.H.P. engine systems are appropriate for their needs.  The ability to meet these needs extend further than just making gasifiers and chopping wood.  The implementation programme needs supporting infrastructure such as operator training, gasifier servicing, fuel supply and replanting of fuel plantations.  Even to create a core team in Germany has taken three years, so to move on again is proving to be a daunting task.

Here are a few questions to ponder.

During the writing of these German Reports, which I must emphasise is pure biased opinion, I have stood up to show that a person is ultimately behind every company name and is responsible for the technology they present.  In my chosen field of engine gasification, there are no competitors, only colleagues struggling to overcome the inertia of dictatorial administrations.

Possibly I have also spoken for the many friends within institutes consultancies and industry who cannot comment in such a public forum.  They don't all agree with my views which keeps me ever vigilant to investigate and improve my own presentation of biomass energy.

Whilst I have named these as German Reports, its problems and comments are universal.  I haven't written this to impress anyone, solicit work, sell equipment, or expand my non existent industrial empire.  Sharing knowledge of each others' activities ultimately benefits us all.

Doug Williams
Fluidyne Gasification