Influence of pork and bone on product characteristics during the fast pyrolysis of pig carcasses

The characteristics of the products of pig carcass pyrolysis depend on initial feedstock composition, specifically tissue and bone, as well as the interaction between these components. In this work, the raw pork (RP), pig bone (PB), and a mixture of RP and PB to simulate pig carcasses with a mass ratio of 2:1 (RB21) were pyrolyzed at 650 °C and compared to investigate pig carcass pyrolytic product characteristics. The presence of minerals in PB was found to increase the gaseous product yields of RB21 by 16%, especially the CO2, C2H4 and C2H6 yields through steam gasification and steam reforming reactions. These minerals also affect tar product distribution, promoting the cracking of long chain hydrocarbons and the cyclization reaction of hydrocarbons, esters, amides/nitriles to produce more aromatic, O-heterocyclic and N-heterocyclic compounds, respectively. The Brunauer-Emmett-Teller (BET) surface area of pyrolytic RB21 char is 134.025 m2/g and it is a porous material rich in minerals like Ca, P, and K. The addition of RP causes more wrinkles on the surface and reduces its mesopore diameter from 6.263 nm to 5.412 nm. The Ca and P in char are derived from hydroxyapatite occurring in PB, and K presents in RP participates in the crystallization of RB21 char, forming a new crystal compound Ca8H2(PO4)6·KHCO3.