7. Ejemplos: de la teoría a la práctica
7.3. Evaluación de servicios y cuidados
Anaerobic digestion (AD) is a commercially available and widely used biological process for converting biomass into biogas, which is a mixture of methane, carbon dioxide and traces of other gases. Current feedstocks for AD typically include manures, sewage sludge, food processing residues, food waste, as well as some crops such as maize and agricultural residues like grass silage. These feedstocks are broken down by bacteria to fatty acids and alcohols, with these intermediate products converted into methane and carbon dioxide, water and some remaining solid material (digestate). The biogas produced can be burnt to produce heat and power, or upgraded by separating out and cleaning up the biomethane for use as a transport fuel or for injection in to the gas grid.17
Ligno-cellulosic feedstocks such as grassy and woody energy crops, straw and wood, are not commonly used today in AD as they are very slow to break down. This is because their molecular structure is poorly accessible to microorganisms and their enzymes. AD pre-treatment technologies
17 E4tech, Ecofys, 2018. Innovation needs assessment for biomass heat. Available from:
are therefore designed to improve the accessibility of the sugars within these ligno-cellulosic
feedstocks. These technologies include physical, chemical or biological methods, and combinations of thermal and chemical processes. The most appropriate pre-treatment technology depends heavily on the feedstock composition, including moisture content, lignin content, and presence of other
material such as stones. Costs and energy requirements will also be heavily influenced by the AD plant scale and availability of waste heat.
Figure 18: Value chain for AD with pre-treatment
AD biomethane for transport is at TRL 9 already (when using common feedstocks such as manures, sewage sludge, food wastes, maize and grass silage), but less mature otherwise. Many AD plants already mix straw with animal slurries (as manure), but use of only steam-treated straw in AD is at the early stages of commercialisation (TRL 7-8; CRL 1-2) with one large demonstration plant
operating, and there are a range of other thermal/chemical pilot activities. Alkaline pre-treatment of straw for AD using sodium hydroxide is apparently at full scale in China (although specific project details remain scarce).18 Fiberight will be launching its first commercial plant (TRL 8; CRL 2) in Maine towards the end of 2018 that will convert MSW into biomethane.19 Pre-treatment of energy grasses and wood for AD is at research stage.17 So in summary, AD with pre-treatment technology is at the early stages of commercialisation, as it is being sold by some developers, mainly in China and Germany.17 However, the efficiency of these technologies is yet to be proven.
4.5.2 Major players in this technology
Anaerobic digestion with pre-treatment is still a relatively new field of interest, and as such as the key active players in this technology (Table 12) are only a small sub-set of all the large number of companies worldwide active in anaerobic digestion without pre-treatment. The vast majority of the companies identified are located in the EU, along with one in the USA and two in China. It is possible that there are more Chinese companies active in AD + pre-treatment than could be identified, as sources state that alkaline pre-treatment is at full scale in China,20 so it is likely that there is more than two companies developing these plants.
Table 12: Major players active in the anaerobic digestion + pre-treatment industry Company name
Location of headquarters
Total capacity in the EU* (ktonnes/year)
Total capacity in the RoW* (ktonnes/year)
18
Clemens, J., 2016. Straw fermentation technology sharing. Available from: http://www.bngsummit.com/wp- content/uploads/2016/11/11.straw_clemens.pdf
19
Company feedback
20 Clemens, J. (2016) Straw Fermentation Technology Sharing, available from: http://www.bngsummit.com/wp-
(country)
Planned Operational Planned Operational
Air Liquide France - - - 8.1*
Biobang Italy - - - - Biogas Systems GmbH Austria - 0.43 - - BioGTS Finland - - - - CaviMax Ltd. UK - - - - Chifeng Yuanyi Biomass Technology Co., Ltd. China - - - - DeTong (Chengdu DeTong Environmental Engineering) China - - - - E-PIC S.r.l Italy - - - -
Fiberight (AD) USA - - 46 -
Future Biogas Limited** UK - 5.1 - - HoSt Netherlands - - - - Lehmann Germany - 0.41 - - MWK Bionik Germany - - - - Rika Biogas Technologies Ltd. UK - - - - Verbio Germany - 10 - - Xergi Denmark - - - -
‘Current capacity’ covers plants which are operational and in commissioning, ‘planned capacity’ covers plants which are planned and under construction
*Air liquide constructed the upgrading facility for an AE + pre-treatment plant, but it is not clear who developed the pre- treatment technology
**Future Biogas Limited use the technology of Biogas Systems GmbH
4.5.2.1 Strengths and weaknesses of key players
Compared to the other advanced biofuel production routes, there are a fairly large number of companies involved in developing pre-treatment technology for anaerobic digestion. Many of the players are established anaerobic digestion companies, with experience of the technology and supply chains, which is a strength in terms of existing revenues and staff skills. There is a large opportunity in terms of the number of existing AD plants that already generate revenue onto which pre-
treatment could be added relatively quickly, and established AD companies would be well positioned to carry out this retrofit work. However it should be noted that the majority of the players in this sector are still small firms that cannot pursue dozens of projects simultaneously.
There are a wide range of possible pre-treatment technologies which can be used with anaerobic digestion, and which are still being developed and scaled-up. Partly this is because different
yet converged on one or two optimal technologies, which could be a weakness in terms of establishing supply chains or further technology development.
4.5.3 Current and planned production capacity
Existing production capacity in the EU is dominated by two demonstration plants run by Future Biogas and Verbio. There are two planned AD + pre-treatment plants outside the EU, one planned plant in the UK by Rika Biogas Technologies Ltd., and one under construction by Fiberight. Verbio has recently purchased DuPont’s facility in the USA which had capacity to produce 83 ktonne/year of ligno-cellulosic ethanol. They intend to produce renewable natural gas at the plant, but the scale at which it will be operated is not publicised, so the capacity of this plant is not included in Figure 19. Information on the capacity of the planned plants was not available so they are not shown in the graph, and the capacity of the Fiberight plant is an estimation only. The lack of information on planned plants may reflect the fact that AD + pre-treatment is a novel technology being developed within the much larger and more established AD industry, so planned plants are not well publicised. It may also be because individual plants tend to be smaller, so there is likely to be less publicity around the awarding of large government grants for these plants.
Figure 19 AD with pre-treatment: current installed capacity, planned capacity and production volumes for the EU28 compared to the rest of the world
Current installed capacity of AD + pre-treatment in Europe (Figure 20) is comprised of two plants in the UK, two in Germany and one in Austria. For several operational plants (in Germany, France and Denmark) no information on their capacity was available, so they do not show up in Figure 20. As highlighted above, information was not available on any planned plants.
Figure 20 AD with pre-treatment: current installed capacity, planned capacity and production volumes by EU Member State, covering top 6 MSs by installed capacity
4.5.4 Plant and production costs
Limited information was available on the capex cost of AD + pre-treatment plants. The only first commercial plant currently being planned has a cost significantly lower than that of some other technologies such as hydrolysis with fermentation.
Table 13: Capex and opex costs for AD with pre-treatment plants Technology
status
Plant capacity (ktonnes/year)
Capex cost (million €2016)
Opex cost (million €2016 / year) Pilot 8.1 - - Demonstration 2.5-10.2 - - First of a kind commercial 46 61 - Commercial - - -
Data is based on all plants, whether planned, operating or shut; note that the min and max of the cost range do not necessarily correspond to the min and max plant capacity within that range
4.5.5 EU market share
The EU has a dominant market share in the AD + pre-treatment industry (Table 14) in terms of number of companies, number of plants and production capacity, based on the information available. No information was available on current production volumes.
Table 14: EU28 market share of AD + pre-treatment industry. Number of companies (HQ) Number of plants* Production capacity *(ktonnes/year) Known economic value** (million €) EU 12 10 16 - Rest of World 4 7 54 -
Number of companies (HQ) Number of plants* Production capacity *(ktonnes/year) Known economic value** (million €) Global total 16 17 70 - % EU 75% 59% 23% -
*Number of plants and production capacity refers to plants which are currently operational, in commissioning, under construction or planned; **Known economic value was calculated based on known production volumes and estimated 2G biofuel prices. For prices and methodology see Appendix C.