A high amount product of these rendering plants is the technical grade brown lard, which should not be used for animal feeding. However, after proper pre-treating this material can be a cheap feedstock for bio gas oil production. The biggest problem with these materials is that their solid contaminant as well as metal and phosphorous contents can be considerably high, therefore pre-treatment/cleaning is required, otherwise the high concentration of impurities greatly shortens the lifetime of the catalysts.