fishmeal and fish oil production, 63-65% protein, from fresh anchovy and fish residues
The activity represents the co-production of fishmeal and fish oil in a reduction plant. The life cycle inventories were produced based on a representative sample of 2 Peruvian plants and their activity.~200 fishmeal plants existed in Peru as of 2016. This activity can be used to modelfishmeal production in other geographies, after substituting the fish provision exchanges.
Production of Fair Average Quality (FAQ) fishmeal (63-65% protein) by indirect drying, residual heavy fuel (R500) powered. Data from one plant representing 8% of the total amount of anchovy processed into FAQ fishmeal (48 430 t/y out of 5.2 million t/y * 12%, in 2008-2010). The technology is common in the country for FAQ fishmeal production.
After arrival of the fishing vessel at the floating terminal, the fish is pumped out of the vessel’s hold and conveyed to the plant mixed with seawater in a proportion close to 1 m3 per t of fish. There the fish is separated from the mix of water, fish residues and blood (bloodwater) through a screw drainer. The drained bloodwater is processed in a rotating screen in order to remove the solid residues (flesh, scale, etc.) that are then conveyed to the “solid line” (described below), and the remaining water is processed first in an oil and solids separator and then in a flotation tank where oil is recuperated thanks to its positive buoyancy. The oil is conveyed to the “liquid line” (described below) whereas the remaining water is discharged at sea through a long underwater pipe (e.g. one-km long). In modern plants, the flotation process is accelerated by the release of fine air bubbles at the bottom of the flotation tank. The remaining bulk of the fish is then conveyed by a wire mesh conveyor belt to an automated weighting hopper and then released into large storage pits. From there fish is conveyed to a cooker using a conveyor, whereas additional bloodwater is processed into a specific trommel. There, a continuous cooking occurs by means of an internal rotary screw conveyor, at a temperature of 95 to 100°C in order to coagulate the proteins. The cooking process is indirect, thanks to steam-heated jacket surrounding the conveyor, but still generates odorous fumes. From the cooker the product is conveyed to strainer (or first to a pre-strainer and then to double helicoid press) that allows draining a mix of oil, protein (dissolved and suspended) and water from the solid mass, thanks to the previous cooking step. From the straining process starts the major separation between the liquid line (oily water or “press liquor) and the solid line (presscake), but with further bridging connections.