Effective preservation of raw goat skins for the reduction of total dissolved solids
Abstract Raw hides and skins serve as the raw material for leather making industries. The main constituent of these raw materials is protein with about 70% of moisture and they are susceptible to microbial attack; it is essential to preserve the protein matrix of skin/hide before converting it into leather. Though the preservation of skin/hide by using common salt to an extent of 40–50% (w/w) is widely practised, this method generates a huge amount of pollution in the form of total dissolved solids (TDS) and chlorides (Cl) during leather processing. Therefore various investigating groups have been involved in alternative curing systems. With this view, an attempt has been made to evolve a less-salt (5% salt with sodium meta-bisulphate) and salt-less (sodium meta-bisulphate only) curing system for pollution abatement. The results obtained are discussed on the basis of TDS reduction, control of microbial population in the raw state during curing, changes in physical, biochemical, microbiological, thermal characteristics of the preserved skin and the mechanical properties of the leather made out of the experimental skins.
Alternatives to salt curing techniques: A review
The raw hides and skins are flayed from the animal and processed further to manufacture leather. As the main constituent of the raw skins and hides is protein, they are much susceptible for bacterial degradation. Thus, itis essential to preserve the protein matrix and also to arrest microbial attack temporarily. Several chemical, biocidal and physical methods have been advocated and adopted, preservation using salt remains the popular curing technique worldwide due to ease, cost-effectiveness and the quality of the finished leather produced. The skins/hides preserved with salt (40-50 per cent, green weight basis) generate huge amount of pollution in the form of total dissolved solids (TDS) and chlorides (Cl - ) during leather processing. A great deal of research is being done worldwide in search of a salt-free, alternative curing systems. An attempt has been made to review various alternative curing techniques and their merits and demerits have been described.
Chemical-Looping Combustion of Biomass in a 10 kWth Reactor with Iron Oxide As an Oxygen Carrier
Chemical-looping combustion of biomass was carried out in a 10 kWth reactor with iron oxide as an oxygen carrier. A total 30 h of test was achieved with the same batch of iron oxide oxygen carrier. The effect of the fuel reactor temperature on gas composition of the fuel reactor and the air reactor, the proportion of biomass carbon reacting in the fuel reactor, and the conversion of biomass carbon to CO2 in the fuel reactor was experimentally investigated. The results showed that the CO production from biomass gasification with CO2 was more temperature dependent than the CO oxidation with iron oxide in the fuel reactor, and an increase in the fuel reactor temperature produced a higher increase for the CO production from biomass gasification than for the oxidation of CO by iron oxide. Although the conversion of biomass carbon to CO2 in the fuel reactor decreased with the increase of the fuel reactor temperature, there was a substantial increase in the proportion of biomass carbon reacting in the fuel react...