[Terrapreta] Adriana Downie talks about Best Energies pyrolysis gasifier and making biochar

[Laurens Rademakers]

Adriana Downie talks about Best Energies pyrolysis gasifier and making bio char (Terra Preta)
http://beyondzeroemissions.org/2008/06/03/adriana-downie-best-energies-bio-char-agri-char-pyrolysis

Tue, 2008-06-03 11:20 - admin 
This morning on Beyond Zero we are interviewing Adriana Downey, Technical Manger at Best Energies. Her company is involved in pyrolysis, synthesis gas and biomass waste management. These provide benefits such as reduced waste, cleaner energy, improved soil quality and carbon sequestration; potentially music to our ears here at Beyond Zero. 

Listen to Podcast Scott Bilby: This morning on Beyond Zero we are interviewing Adriana Downey, Technical Manger at Best Energies. Her company is involved in pyrolysis, synthesis gas and biomass waste management. These provide benefits such as reduced waste, cleaner energy, improved soil quality and carbon sequestration; potentially music to our ears here at Beyond Zero. 

Scott Bilby: Good morning Adriana.

Adriana Downie: Good morning to the Beyond Zero team. How are you this morning?

Scott Bilby:Very good thank you, and thank you for joining us in the studio this morning. Several weeks ago we interviewed Tim Flannery and he mentioned the work of Lukas Van Zwieten. Are you aware of the agrichar, or the Terra Preta work, that he is doing?

Adriana Downie: Yes, Lukas's program with the NSW DPI (Department of Primary Industries) in Northern NSW have basically taken some of the agrichar material that we've made here at Best Energies and they've been trialling that material in different agronomic applications to see how the agrichar, when its applied, can help crop-productivity and improve the sustainability of agriculture as well as, and what you guys are more interested in, sequester carbon long-term in soils and also decrease the potent greenhouse gas nitrous oxide emissions from soil.

Scott Bilby: OK and can you tell us a little bit about the demonstration he did? Is it a demonstration garden?

Adriana Downey: Yes, he's got a few trials that are underway. We've got a large pasture trial where we've taken agrichar made from a range of different biomass waste streams such as paper sludge from the paper industry, poultry manure and green waste from council curb-side collection. We've made agrichar out of that waste and he's applied it in the scientific trial in a pasture crop. The first season we did for that was pasture and now we've got corn growing on that crop to measure the soil health benefits as well as the crop productivity. 

Scott Bilby: OK and can you give us some of the stats on how it performed?

Adriana Downie: It's early days yet but the early results that we've have had back have been very promising. We had some good responses, especially from the chars that have inherent nutrient content so if we make char from poultry litter for example there is some fertilizer value in that agrichar so we get an obvious response from that. When we have chars made of things like council green waste, they don't have a high fertilizer value but its the structure of the char in the soil that's showing the benefits, and one of the major findings of that trial is that we can decrease the use of fertilizers that's applied, so in effect farmers can put on less nitrogen fertilizer for the same crop response. 

Scott Bilby: OK and so you are getting results of about 70cm?

Adriana Downie: Yes. It depends on what crop and the different trials but we have had good positive response. Over difference we've tried pastures now with corn. We've got a demonstration garden here at Best Energies as well and in that we've grown beans and sunflowers, so we are starting to build the body of knowledge but overall the effects have been very positive across all of the crops. 

Scott Bilby: Are you improving water retention?

Adriana Downie: The agrichar when it's applied to the soil has a good effect on the general physical structure of the soil. Because the agrichar has a really high surface area, it means that there's lots of pores in the soil which can then retain moisture and act as little reservoirs for the water to be retained in the soil. As well as this, all of the surface area helps to bind nutrients in the soil and also provides a microhabitat for micro organisms in the soil which are essential for the natural processes in the soil which allow micro organisms to flourish. 

Matthew Wright: Backtracking a little bit around the pyrolysis machine that you have developed, or are licensed from an American parent or what have you, can you tell us about how that works and what the feedstock input is, whether it uses centrifugal filtering or whatever and all of that sort of stuff, how it creates hydrogen and carbon monoxide? 

Adriana Downie: Well, basically Best Energies is an Australian company and we have been here for about 25 years and we've been working on various different renewable energy type projects and in recent years we've been focussing on the development of slow pyrolysis technology because we really believe that it's a very holistic technology that can provide solutions across many sectors. So it's a waste management solution, it's a renewable energy solution and it also makes valuable agricultural amendments. So it's a very holistic technology, so we've been focussing on that. 

We started off with a small batch scale pyrolysis unit here and over several years the technology has evolved and we now have a one tenth commercial scale pilot plant, so it takes 300 kilograms an hour of biomass and we are now at the pre-commercial stage of wanting to be able to build the first fully commercial scale pyrolysis plant in Australia. 

Basically, how the technology works is we take waste biomass resources, so for example paper sludge from paper mill, and we dry it using the waste heat from the process and we bring it into a pyrolysis kiln where we heat it up without any oxygen so, as opposed to combusting it or burning it like you would in your fire place at home, we limit any oxygen from getting in there, so we externally heat it and that drives off volatile gases and those gases we can extract. And they have an energy content much the same way as natural gas or LPG gas has. We can then combust that gas and we use that gas to combust underneath the kiln to heat the kiln up; we use it for our drying. But then we can also use it in a gas fired engine to make electricity, and so the process overall we are able to extract more energy out of the biomass to make electricity than what's needed internally to run the process. 

Matthew Wright: What's the calorific value of say crop residuals or that kind of waste? Is it viable that it can run on that because we're not necessarily so keen on native forest feed stocks going into the paper industry, so we want to see that there are other opportunities to use crop residuals and things like that?

Adriana Downie: That's right. There are lots of opportunities. The technology really fits in to the niche market of being able to use low grade biomass. For example, paper sludge is going into landfill at the moment which is of absolutely no value to anyone else and so we're able to then have a resource recovery system so that we can actually extract some value from that material. And the same goes for council green waste. Currently there is a lot of green waste going to landfills so we are actually able to improve the overall resource recovery as well as then displacing the use of fossil fuel so that if we can use that material then it means that more fossil fuels can stay in the ground. 

Matthew Wright: We are obviously very keen on building soil carbon and the like but initially when we've internally discussed this we have wanted that any implementations are going to have local pollution controls. What's the likelihood of atmospheric particulates and things like that from this process? Do you have good scrubbers, or how does it work?

Adriana Downie: As with any processing plant in Australia, we have to meet the EPA regulations as well as the State Planning and Approval Regulations and the emissions standard on new processes being implemented are becoming stricter and stricter so we endeavour to meet all of our EPA standards and do better than that. So we have things like odour control, we have particulate removal and gas clean up so that we can ensure that we meet those strict environmental emissions controls. 

Matthew Wright: In terms of building soil carbon, what was that motivator for you to look at that particular application or did some one from the university come to you, or had you looked at what the Mayans had been doing in the Amazon, or how did that come about?

Adriana Downie: Well, really our company came at it from a renewable energy point of view. So, looking at renewable energy technologies, and like you mentioned we don't want to be cutting down forests and making renewable energy out of them. We were really looking for a technology that was flexible enough to use low grade biomass instead of having to use freshly grown or purpose grown biomass. 

So we really started down that path of looking at the renewable energy industry, particularly in Australia, where the biomass like timber resources, are quite expensive and electricity prices are so low so we needed to find a niche where we can take very cheap, or get paid to take the, biomass so that we could compete with the electricity prices. So really, we came at it from the renewable energy point of view and we very quickly realised that there is this need in agriculture for soil carbon and we have met the terra preta-type thinking half way. 

We then became aware of the research that has been done in the Amazon looking at where the pre-Columbian Amazonian Indian populations where making charcoal and putting it in their soil to help the agricultural productivity and those soils now are between 500 and 7000 years old, and they are still some of the most fertile soils in the Amazon basin. The Amazon basin is an environment where they have huge amounts of rain and everything is against soil carbon remaining in the soil, yet these soils have very high levels of soil carbon. So, being able to replicate or to recreate terra preta soil by us being able to produce and manufacture agrichar and putting it in soil is really an ultimate aim. 

Scott Bilby: Are there government incentives for the pyrolysis plant?

Adriana Downie: Yes, and we're very grateful that at the moment that the trial work that Lukas Van Zwieten is doing with the NSW DPI, we actually have funding from the NSW Department of Environment and Climate Change. They are funding some of the agronomic development work. There is different grant programs in Australia, and hopefully now with the promises during the election of increased funding for renewable energy, we are hoping that will flow down and assist us to get this technology to a commercial scale in Australia. 

Scott Bilby: So, does this give you hope that you will be able to get a commercial plant up and running in the near future? 

Adriana Downie: Yes, and that's why we are here. Really for our company to continue we need to see all of this development work to turn into commercial processes and really, the potential for this technology to deliver benefits on a climate changing scale means that we need to role it out on a huge scale. We need to start with a first commercial plant but then we need to be able to roll it out on mass so that we can actually be making the quantities of agrichar required to sequester large amounts of carbon in soil.

Matthew Wright: For listeners, could you please step though the actual pyrolysis machines so that we can visualise? So you've go the feedstock and it combusts and where it goes and what gases it turns into?

Adriana Downie: Basically, we feed the biomass into a rotary dryer. It travels through the dryer and it dries. We then take it from the dryer into the pyrolysis kiln. That's probably the most important step because its there that we prevent any oxygen from being taken into the kiln so we've got a series of slide valves that operate so that oxygen cannot come into the kiln. 

So then the kiln is an externally heated vessel where we've got hot gases from the syn gas that we burn from underneath. They travel around the kiln and heat it inside. Inside the material gets heated up but because there's no oxygen, it can't combust. It then pyrolyses so as it pyrolyses, it releases the volatile gases and the solid biomass turns into a more aromatic stable forms of carbon, in that very dark rich product that people know as charcoal. 

If you make charcoal, charcoal is the term that's used for wood, but because we make it out of say poultry manure, you call it char or biochar. Best Energies call it agrichar. 

So we make the agrichar. All of the gases that come off we clean up and use them to make our electricity. About half of the carbon that's in the original biomass goes to the energy producing cycle. 

About 50% of the carbon though remains in a very stabilised form in the agrichar product which we then take out and cool down and then it can go into agricultural soil. So, if we take the original biomass and put it in soils, the turnover of that material in the soil, within about 10 years, none for that carbon is there, it's all been turned over by microbes and released as CO2 into the atmosphere. Whereas if we turn it into charcoal and we put that into the soil, it's very stable in the soil and can stay there for a very long time. For example the terra preta soils that are 7000 years old, so it's a very stable form of carbon in the soil. 

Scott Bilby: That sounds very promising indeed. You mentioned the synthesis gas that's produced in the process of pyrolysis. Could you tell us a little bit more about how much cleaner that gas is compared to other gases such as natural gas, LPG?

Adriana Downie: For biomass-to-energy processes there is an improvement of pyrolysis compared to normal combustion or incineration. There's quite a few processes, especially in Europe where they take waste material and they combust it to make the gas. 

Because we make a gas and then we take that gas into an engine, it burns very efficiently because we have the gas phase mixed in with oxygen which is also a gas phase. And they mix very easily and very well, so you have efficient combustion. Compared to if you are tyring to combust a solid where you have to get the oxygen in to all of the solid surfaces, there's room there for inefficiencies unless you have your boiler very well tuned, and so we have a much more efficient combustion process so then the emissions profile from combusting a gas is better than from combusting it as a straight solid as is done as a normal biomass energy type processes. So, we've got an advantage there where we can combust that gas more cleanly. 

The emissions that we get then are typical of emissions from a gas engine, so typical of say when you have landfill gas and you are taking that to a gas engine, the emissions profile we have is very similar to that and we obviously then make that so we can meet the emissions standard and so we put enough gas cleanup on the back end of that so that we are not doing more harm than good. We try to be very rigorous with our environmental control. 

Scott Bilby: Obviously no one can buy one of the pyrolysis machines soon. You said before that you were hoping to get some commercial-grade plant up and running. When will it be when the world sees something like that running and we will actually see commercial-scale sequestration happening?

Adriana Downie: Basically, Best Energies has taken the technology to a point where we have two sizes of commercial scale design. So, we have done all the design work that we can. We are ready now to actually get a project, do the final tweaking of that design for the specific location and feedstock so that we can construct a plant. The construction of a plant will take about 18 months. 

We are working with several clients to look at the feasibility of their processes and then both the need for energy and for the use of their biomass and the market for agrichar to try and put together a business case for implementing one of these plants in Australia and hopefully that will happen very soon and once we've got the first one then the roll out can be quite rapid. 

The challenges that we have is that in Australia electricity is very cheap because we have so much very cheap coal-fired power, as well as a lot of natural gas. 

The other challenge is that as a first time plant, the return on investment that investors need is so high that it's making the economics of the plant quite marginal. So, if I'm going to take the risk as an investor of building the very first one, I want to ensure that my returns are going to be higher than if I go out and build another mining operation for example where people have done it before and know what the risks are and the know what returns they can get. So, to try and interest investment money in Australia at the moment is quite difficult for new technologies, but we are seeing the drivers for this type of technology increasing both with government policy and the improvement in the prices of renewable energy certificates for example. 

Also, companies are starting to realise that climate change is something that is real and here and now, and that their businesses are going to have to introduce it into their contingency plan. 

Especially over the last 12 months, we have seen a definite change of attitude in industry and a willingness to look at these types of projects and to open their minds to looking for climate change solutions as well as the normal things like energy security and waste management that they are used to looking at. 

Scott Bilby: Adriana, I would like to say thank you for the interview this morning. It's been very informative and several times I must admit I have learnt things that I didn't know before and I'm sure our audience is wiser for you coming onto the program. 

Adriana Downie: If they would like to know more information, we have a website www.bestenergies.com.au and there are some links there to articles that have a bit more information about terra preta and agrichar in soils and the pyrolysis technology. 

Scott Bilby: Yes, as we here at Beyond Zero have been reading. Thank you Adriana and it would be wonderful to get you or someone else from Best Energies on in the future so we can see how you are progressing. 

Adriana Downie:Hopefully we will have some good new stories to be told not too far down the track of our first commercial plant. 

Scott Bilby: Exactly. We would love to hear some news on that!

Scott Bilby: Thank you very much. 

Adriana Downie: Thank you. 

Listen to Podcast

Adriana Downie on ABC Catalyst


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