Björn Müller November 2013

Transcription

1 Björn Müller November 2013

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3 Based on the source of biomass, biofuels are classified broadly into two major categories: First generation biofuels are derived from sources such as sugarcane, corn and others. Sugars present in these biomass are fermented to produce bioethanol, an alcohol fuel. But to turn food based resources into biofuels is highly controversial Second generation biofuels on the other hand utilize non food based biomass sources such as agriculture and municipal waste or it derives from energy crops such as Miscanthus, Hemp, Bamboo or fast growing timber varieties. It mostly consists of lignocellulosic biomass which is not edible and is a low value waste for many industries.

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5 Wood is the oldest and remains until today the largest biomass energy source; examples include forest residues (such as dead trees, branches and tree stumps), yard clippings, wood chips and others. The best known byproduct in the agriculture is straw from corn cultivations as corn is grown in most climate zones all over the globe as well. From all the corn species rice and wheat are the 2 most important ones. One of the biggest newcomers of second generation biofuels in the tropical zones of the globe today are the residues of the Palm Oil production the: PKS or Palm Kernel Shell and the EFB or Empty Fruit Bunches. This is one typical example where the demand for first generation fuels is driving up the availability of their residues Then there are plenty of other byproducts from agricultural industries such as Molasses from Sugar Cane, Stalks from Cotton growers, Husks of Coconuts, Corn, Maize, Soybeans etc., Shells from all kind of Nuts, Seeds and Fruits

6 Straw: Moisture (%) Calorific Value (GJ/t) Calorific Value (kwh/kg) Calorific Value (kcal/kg) Bulk Density (kg/m3) Yellow straw 15 14,4 4,00 3, Grey straw 15 15,0 4,17 3, Straw including corn 15 15,0 4,17 3, Canola/Rape Straw 15 15,0 4,17 3, Miscanthus or Giant/King Grass 10 15,9 4,40 3, Straw Pellets 8 16,0 4,44 3, Grain (wheat, barley...) 15 15,0 4,17 3, Rapeseed 9 24,6 6,83 5, Wood: Moisture (%) Calorific Value (GJ/t) Calorific Value (kwh/kg) Calorific Value (kcal/kg) Bulk Density (kg/m3) Old Wood Chips 40 10,4 2,89 2, Fresh wood chips 55 7,2 2,00 1, Wet Saw Mill Dust 40 4,5 2,92 2, Dry Saw Mill Dust 20 15,2 4,22 3, Fresh Willow chips 50 8,0 2,21 1, Old Willow chips 30 12,2 3,38 2, Pine Bark 50 7,7 2,14 1, dry Saw Dust 20 15,2 4,2 3, Dry Beech Logs 20 14,7 4,08 3, Fresh Beech Logs 45 9,4 2,61 2, Wood Pellets 6 17,5 4,90 4, Others: Moisture (%) Calorific Value (GJ/t) Calorific Value (kwh/kg) Calorific Value (kcal/kg) MSW ,0 2,50 2,150 Bulk Density (kg/m3) Heavy Fuel Oil 42,7 11,86 10, Heavy Crude Oil 40,4 11,22 9, Used Oil 42,0 11,67 10, Coal 10 25,0-28,0 6,9-7,0 6,020 Natural Gas 39,0 10,83 9,314 Lignite/Brown Coal ,1-5,5 4,588 Light Fuel Oil 34,2 9,5kwh/Itr 8,200kcal/Itr

7 Several factors to be looked at when going into biomass projects

8 When turning biomass into energy it is mostly necessary that there s a stable and continuous supply of raw materials. Same sources can be differently depending on the regions they grow and concepts that work in one place might not do in another. For example rice straw: China is a huge country with a large diversification of climates. In the North there are vast Tundras that allow only one harvest per year while in the tropical South the rice can be planted the whole year round and even at a higher yield per hectare. So when trying to turn the straw into energy the logistical challenges are very different in each location and the cost to get the material to site are not comparable. But when looking at the rice husk in each place the conditions are almost the same as the husking is mostly done in the mill and it comes there for free with the rice itself. So dealing with industrial residues is often preferable as they occur in one place at mostly stable rates the whole year round.

9 After fixing the source it is important to have steady consumers that take the product you intend to make. Here 2 factors are to be thought of most: The distance to the consumer and what form of product the customer can handle and use. Ideally in our sample above right next to the rice mill you have a consumer e.g. a cement factory that can burn the husks as they are. Which is frankly speaking not so ideal for Virtus!! But if that cement factory also wants to make use of the straw and/or if it s far away then we have to look at the infrastructure (does the cost saving and reduction of the carbon footprint justify the use of alternative fuels) and the form we deliver. Generally a cement kiln needs 2 kinds of fuel; a solid form where the gravel enters the kiln (calciner) and an fast combustible form at the end (main burner).

10 To stick with my sample this cement factory could use 3 types of fuel: The husks themselves if the location does allow that Pellets from either straw or husks for the main burner as they easily combust Or Briquettes made from straw or husks for the calciner as a slower burning fuel

11 The more energy you need to make your product the smaller you margin gets. The simplest way to turn biomass in a usable form to generate energy is to produce a homogenous product that can be burned directly. This is often the case for wood chips or large husks such as coconut. Off cuts, stumps or full husks are normally too big and to various in size and shape to be burned without treatment as most combustion equipment have fully automated feeders. In such case a one step size reduction is usually enough But often the residues we have to handle are fresh and thus have pretty high moisture contents (fresh wood about 40%, EFB up to 65%). In that case just shredding is not enough and dryers are needed unless the boiler can accept high levels of moisture. To cut the energy cost for drying they are normally heated with the biomass that is on hand but that on the other side cuts the overall output!

12 In case the user is not specified or the distances are too far then we need to look into densification processes. Here we are normally talking of 2 ways: Pelletizing or Briquetting The Briquetting is the most efficient way to densify biomass as it can handle larger input materials. Also the dies are bigger and thus it requires less power to make Briquettes. But industrial Briquettes cannot be handled by all boilers and the marketing is more difficult. Commercial Briquettes are highly standardized in Europe and the US but going to all the procedures required can be a pain. Moisture requirements for making Briquettes are not that strict. 5-15% are ok, in some cases up to 20%.

13 Pellets are products that can be sold widely and their marketing is rather easy. Many industrial boilers can handle Pellets and the numbers of homes using pellets is growing steadily. Pelletizing requires more energy for each step. As the pellet diameters are usually small (if sold in the EU they are 6mm or 8mm, for industrial use in Asia they are max. 12mm) the input material needs to be ground down to a size that is for soft materials about the same as the die diameter and for hard material about 60-70% of the die diameter. Further the moisture range for Pelletizing is pretty narrow, input material should be at 10-12%. And thirdly the Pelletizing process requires more power as the material has to pass to relatively small die holes. Compared to Briquetting the power consumption for Material Preparation (Shredding/Grinding) and the Pelletizing itself is about 60-80% higher.

14 Models and their use

15 For the Shredding process Virtus offers 3 machine series. L-series for small scale joineries covering a range from kg/h W-series for small, medium and large recycling operations at rates from 200kg/h up to 7-8t/h. X-series for industrial scale recycling operations up to 20t/h

16 For the granulating of biomass for chip sizes below 20mm Virtus offers 2 lines of machines E-series for small applications and applications where the input material is soft or has been pre-shred covering rates from 300kg/h up to 3t/h H-series for all applications where solid pieces need to be ground down to small chip sizes in one step up to large industrial scale operations. Further they can be used in a 2 step operation where fine chips are needed at a high rate.

17 For the compressing of biomass Virtus offers 2 own machine types U50-U70 series are hydraulic briquette presses which we have produce for Amis for several years. The type number equals the briquette diameter of each type (50,60 and 70mm) and they cover a range from kg/h as single version. We also can built those as Twin versions which means we have 2 compressing units on one storage silo and then the rates are double. U-75 is a mechanical briquette press that is under construction right now. Here the compression is done through a piston that is actuated from a crank shaft. The crank shaft driven via v-belts from an electrical motor and has large fly wheels mounted on each end to overcome the pulsating workload.

18 Virtus decided not to make Pelletizers for several reasons, one of it is that there are too many players in this market already. Yet we have contacts to several Pellet Mill manufacturers, German and Chinese. So if a project includes the complete process from raw material to pellet we will join with them but will not market their products under our brand. Another big part in most of the projects is the drying and also here we decided that we will stay away from. One reason is that those dryers are usually very large and shipping them from China doesn t make sense and secondly we are not specialized in that and we are afraid the learning curve would be too long!!

19 Aside from further developing the machines we have and adding new types to them we are also looking into new fields One very interesting field is the so called Torrefaction. This is a kind of roasting process that turns any kind of biomass into bio coal (NOT charcoal). During this process the material looses about 10% of its energy content but the overall energy density increases by 70%. The result is a homogenous fuel with the same properties non regarding its origin. It is further very easy to grind into smaller sizes and it is highly hydrophobic. This means it can be stored outside as it will not absorb water and it will not deteriorate during long distance transportation under wet or humid conditions. As the material is completely dry and free of micro organism there s also zero risk of self ignition. We think that this process is a solution for many problems of the South East Asian area as here is plenty of biomass on hand but the markets are limited. So to enable this area to conquer bigger markets its products have to be modified so they can withstand long distance transportation and high humidity conditions.

20 If you want to get more information about any processes or machines described in this presentation please feel free to contact me!