18 December 2019
The main goal of AGROinLOG is the demonstration of Integrated Biomass Logistic Centres (IBLC) for food and non-food products. In Spain, the study to evaluate the potential implementation of the IBLC model was performed in an agroindustry dedicated to the production of animal feed products based on lucerne.
APS has seasonal production, so the two existing production lines (the dehydrated line to produce bales and the pelletization line to produce pellets) are underused along the year, between 1,700 to 2,600 hours (depending on the year), mainly between December and March.
The new business line was created taking advantage of the equipment in the plant outside the agriculture campaign period. The aim was to produce new pellets for different purposes: energy purposes and other bio-commodities (biofuels, bioboards, thermoplastic, activated carbon, adsorbent). Different equipment was purchased during the timeframe of the project. The total investment necessary to adapt its facility and integrate the new business line was between 100,000-200,000 €.
The raw materials selected to produce the bio-commodities were wheat straw, corn stalk and forestry wood. Some characteristics and properties of these raw materials vary significantly depending on the area where these crops are cultivated and on the other parameters like the management of the crop or climate conditions. For this reason, and in order to optimize the percentage of wood needed, a traceability assessment of the wheat straw and corn stalk was performed. We selected the best area to carry out the blends with wheat straw (as a result no wood should be incorporated in the blend in order to fulfil ISO 17225-6, class B) as well as for the blends of maize stalk (results were not as good as the ones obtained with the straw and an amount of wood should be added to fulfil the standard).
With the selected biomass resources, the blends were defined taking into account several considerations. In terms of quality, the blends had to satisfy ISO-17225-6 class A and B and ash-behaviour indexes criteria (sintering, fouling and slagging). At least, 2 blends of straw and 2 of stalk were designed to satisfy some of these criteria. It was key to satisfy economic and quality criteria so that the blend produced could be competitive in the market of industrial pellets from wood resources. A market study was done in order to evaluate the competitor biomass as function of the quality of each blend.
The whole pelletising line and also the dehydrated line were object of study along the project. 55 monitored tests were carried out by APS to assess the production costs of the blends selected.
These production costs were calculated taking into consideration the data collected through these tests, the data related to raw material, the personnel cost, energy cost (electric and thermal), fixed costs as well as the losses along the entire process. Regarding the latter, dry matter losses were assessed through an evaluation of the degradation degree of the raw material under normal conditions, always open-air storage at APS facility and with a height of 8 bales. During storage, measurements were performed to determine the quality changes along 6 months, as a result 0.5 % dry matter losses was achieved for wheat straw and 3.8 % for maize stalk.
It can be concluded that the higher the content of wood in the blend, the higher the production cost, since the pre-treatment of wood is needed (pre-milling and drying). Nevertheless, the prices are quite competitive with the current industrial biofuels, especially with the industrial pellet as main competitor of these blends, which current selling price (in consumer facility) is around 165-190 €/t.
Finally, the blend 60 % straw – 40 % wood showed the best behavior in the combustion tests carried out in CIRCE´s laboratories and was the one selected to be validated in industrial boilers.
Stay tuned to learn more about the results of the validation phase in next news articles!