The Effect of the Addition of a Fat Emulsifier on the Amount and Quality of the Obtained Biogas

Slaughterhouse waste management is an important technological, economic, and environmental challenge. Recently, more and more attention has been paid to the possibility of obtaining biogas from waste generated by slaughterhouses. The aim of the paper was to examine the effect of an emulsifier addition in the form of a carboxymethyl cellulose solution to create animal waste fermentation media based on the quantity and quality of the generated biogas. The adopted research goal was achieved based on a laboratory experiment of methane fermenting poultry processing waste. The waste was divided into two fractions: soft (tissue) and hard (bone). A fat emulsifier in a concentration of 1%, 2.5%, 5%, and 10% of fresh weight of the substrate was added to each substrate sample made from the above fractions. The emulsifier used was a 55% carboxymethyl cellulose solution, since this emulsifier is most commonly used in food production. The experiment was conducted in order to determine how the addition of an emulsifier (55% carboxymethylcellulose solution) affects the hydration of fats during methane fermentation, as demonstrated on poultry slaughterhouse waste. The samples were subjected to static methane fermentation, according to the methodology of DIM DIN 38414(DIN Deutches Institut für Normung). The experiment lasted 30 days. The total amount of biogas obtained after fermentation was 398 mL·g−1 for the soft fraction and 402 mL·g−1 for the hard fraction. In the case of the soft waste fraction, the addition of carboxymethylcellulose at 1% of the mass to the biogas process increased the amount of obtained biogas by 16%. In the case of the hard fraction, no effect of the addition of emulsifier on the total amount of biogas obtained was identified. In each case, the biogas from substrates with added emulsifier contained less methane and slightly more carbon. The emulsifier added to the soft fraction of slaughterhouse waste from poultry processing allowed cutting the process of methanogenesis by over 50% while maintaining the efficiency of biogas production. In the case of biogasification of bone tissue, no unambiguous effect of the addition of emulsifier on the improvement of process efficiency was identified.

Crosslinking, Filler, or Transition Constraint of Polymer Networks. II

The theory of Part I is developed by application to filler reinforcement of NR and SBR. For unswollen but prestretched networks it quantifies entire stress-strain curves and applies new concepts of extensibility and strain hardening. Constraint of swelling is expressed by a constant Ø, termed linkage reinforcement, and by an effective hard fraction Cm per cm2 of compound. For rubber-filler swelling vc the modified Flory functions F(νc) in Part I need 3% correction.

Intrinsic Linkage Reinforcement ϕ0 from Swelling Measurements of Effective Values ϕ

The writer has introduced for rubber with particulate reinforcement the concept of linkage reinforcement ϕ derived from the volume fraction v of rubber or νc of rubber-filled compound at equilibrium swelling in a solvent. Basic elastomer theory was modified to allow for the filler volume fraction C by an effective hard fraction Cm per cm3 of compound, the Flory or Flory-Rehner function F(νr) being replaced by F(νc), and the measure νc of swelling being a compound index replacing the usual νr. On this development of the basic theory, and defining linkage reinforcement ϕ as the ratio of the effective crosslinking of reinforced networks to the 1/Fo(νr) fix points of corresponding gum vulcanizates :