Grass pills are produced by cooking, drying and pressing fresh grass. Grass pills are used as feed for horses and cattle.

Process description

The present data refer to grass pill production in DanGrønt (Ringkøbing) where the main processes are following: 1) grass produced by local farmers is transported to the factory by trucks, 2) grass is cooked (70-80^°C) and pressed until a dry matter content of 30%, 3) the press liquid is evaporated in a two step evaporator until a dry matter content of about 35%, 4) concentrated press liquid and pressed grass is mixed, 5) the mixture is dried in a rotating continuous oven (heated with coal or gas, 800°C at entrance), 6) steam and grass from the oven is separated in a cyclone, 7a) steam is returned to the evaporator and used as heating source in step 3, 7b) the dried grass is grinded and sieved (6-8 mm sieve) and pressed into grass pills in a pressing machine, 9) grass pills are cooled with air and stored for distribution the market.

Condensate from evaporator (step 3) is returned to local farmland through a network of pipelines. Nutrient content of condensate is low and the product does not displace any fertilizers. Transportation of grass from field to factory (average approximately 20 km) is performed by trucks. 

Data collection and treatment

Data have been derived from DanGrønt's (Ringkøbing) green account (2003). Raw material input is a combination of grass and lucerne, but since there are only small differences in processing of grass and lucerne all input has been considered as grass. 

Technical scope

All production processes at the factory as well as administration and product storage are included. Distribution of condensate on local fields is included. Grass transportation to the factory is not included.

Representativity

DanGrønt is among the largest producers in Europe (Danish market around 80%). The factory in Ringkøbing is one out of three factories in DanGrønt producing grass pills. The factory in Ringkøbing is solely producing feed pills whereas the two other factories (Ølgod and Ribe) are producing dried hay in addition. Production data for hay and pills cannot be separated at Ølgod and Ribe production facilities and specific data on pills could therefore only be derived from Ringkøbing. The factory in Ringkøbing is modern and extraordinary heat efficient, and the factory's heat consumption is probably about 40% lower than a Danish average (rough estimate by employee). On the other hand additional electricity is used to achieve heat savings (primarily due to pumping for heat reuse) and electricity consumption is probably about 10 % higher than a Danish average (rough estimate by employee).

Validation

No comparable data sets have been found and data have not been validated.

Inputs and outputs

Inputs and outputs associated with grass pill production are shown in the table below. Data are provided per ton of grass pills (8-10% water content) at the gate of the factory.

1) heat value of fuel (mix of coal and natural gas), 2) for internal transportation at plant (trucks etc.). 

References

DanGrønt (Ringkøbing) green account (2003).

Administrative information

Data URL: http://www.lcafood.dk/processes/industry/grasspillproduction.htm
Version no.: 1.00
Author: Per H. Nielsen, The Institute for Product development.
Data entry: Data have been entered in this format by Per H. Nielsen.
Data completed: April, 2004.