Energy crops are one of the best options for obtaining an acceptable amount of biomass per unit of area and time. Moreover, as a fuel, their biomass has certain advantages from an environmental perspective over other, conventional fuels. By conducting tests with energy crops we can gain an understanding of how different plant species adapt to different cultivation systems, identify their needs, production potential and chemical and energy-related characteristics, and find out how to optimize production costs in economic, energy-related and environmental terms.
- CEDER has irrigable agricultural land located in an area with a continental Mediterranean climate. A polycarbonate greenhouse (28 m x 9 m) with automatic climate control systems (temperature and moisture), shadow screen, heating system with biomass pellets, heated-table, cooling system, and micro-sprinklers is also available. The Biomass Unit has equipment necessary for conducting fieldwork and for monitoring, measuring and recording data.
Pilot plants for biomass classification and particle size reduction
This set of pilot facilities incorporates a number of technologies focusing on the industrial-scale study of biomass particle size reduction and separation, ranging from crushing bulky materials (e.g. bales and trunks) to fine milling to produce fuels with particle size below 1 mm. Plants are equipped with slow-rotation mills, hammer mills, bladed mills and sieves (with one or more sieving stages), along with a dynamic separator for making very fine particle size cuts.
- The crushing capacity for bulky material is 1000 kg/h with output sizes of less than 30 mm. During fine milling, particles can be reduced from 30 mm to less than 100 µm. Energy consumption and performance are evaluated for all the processes involved.
Drying pilot plants
There are two pilot facilities that have been set up for drying biomass: a conventional rotary-drum dryer, and a hybrid solar dryer designed and patented by CEDER-CIEMAT. Although the technology for indirect drying through parallel flows in rotary dryers is well known within the industry, solar drying applications – assisted by low-temperature heat – have made little impact on the market. Hybrid solar drying is mostly used in facilities that generate wet sludge, such as wastewater treatment plants.
- Rotary dryer: hourly evaporation capacity between 150 and 300 kg of water.
- Hybrid solar dryer: hourly evaporation capacity between 30 and 60 kg of water.
- Variables for heat and electricity consumption can be obtained for both dryers.
Facilities and equipment for pelleting biomass
There are two facilities, both of which are equipped with KAHL flat-die technology. One of the facilities comprises a small, highly versatile and easy-to-handle press (20 to 40 kg/h), which is used for conducting rapid pelleting tests using small amounts of product. The other facility is larger and is equipped with a dosing and mixing line, and has a capacity between 200 and 400 kg/h of pellets. These facilities make it possible to conduct research on the behaviour of biomass and mixtures and to obtain data on the energy consumption and performance of the pelleting process.
- KAHL 14-175 flat-die machine with dosing hopper and variable speed.
- Pelleting plant with KAHL 33-500 press equipped with a mixing and dosing system. There is a cooling and bagging system and the possibility of adding steam.
Biomass harvesting and logistics equipment
Several mechanical harvesting equipment is available at CEDER-CIEMAT to optimize the logistic chain of the different types of biomass, allowing us to obtain baled or crushed materials directly.
- A Biobaler WB-55 harvesting and baling system driven by a VALTRA T194D tractor, that has been adapted for forestry work, and a self-loading trailer. The trailer is equipped with a versatile crane and can move wood chips, crushed or bundled biomass, and up to 20 bales. This equipment allows simultaneous clearing and baling operations from energy crops and scrubs, such as rockrose, heather, broom, and gorse. CEDER-CIEMAT develops new working methods based on this and other equipment with the aim of enhancing the viability of forest areas that are currently not managed and have a high risk of suffering virulent wildfires due to the great amount of continuous biomass per hectare.
Harvesting and baling of biomass crops with BIOBALER WB-5
- A López Garrido biomass crushing and harvesting equipment driven by a Valtra T194D tractor, which has been adapted for forestry work. The tractor’s inverted driving cab allows to control the crusher that works on the backside of the tractor while suspended in the air. On the front area, there is a 5 m3 and 1400 kg of maximum load trailer to store the crushed material, which is transported from the crusher through an air current.
- 200 HP tractor.
- Maximum working slope of 25%.
- Copes with moderate levels of stoniness.
- Adaptations for the harvesting of difficult species such as Cistus ladanifer.
- Data-acquisition system: Operating and biomass-related variables: fuel consumption, performance within a cleared area, bales collected (moisture content and weight), speed, time per bale, environmental variables (temperature, RH), and slope.
- The research that has been conducted since 2015 on different types of scrublands has made it possible to evaluate harvesting performances ranging from 1 to 3 tonnes of dry matter per productive hour, and from 0.2 to 0.6 cleared hectares per productive hour.
- Naarva E20 accumulating felling head. It is designed to cut and harvest wood of a diameter between 20 and 23 cm. Cuts are done with a guillotine. Thanks to the accumulating grippers, it is possible to harvest several trees before bending the gripper and unloading the trees.
Essential oils steam distillation equipment
Drones for agro-forestry applications
The recollection, process and analysis of multispectral images obtained from a DJI Phantom 4 Multiespectral drone. Thanks to these images, it is possible to obtain vegetation indexes to take better decisions in the agricultural and forestry sector.