Generation of high-purity hydrogen from cellulose by its mechanochemical treatment.

Cellulose was mixed with the hydroxides of lithium and nickel and the mixture was milled, followed by heating to produce hydrogen. Several analytical methods of X-ray diffraction (XRD), thermogravimetry/mass spectrometry (TG/MS) and gas chromatography (GC) were used to characterize the samples. Hydrogen was emitted when heating the milled sample around 400 degrees C together with low concentrations of methane, carbon monoxide and carbon dioxide.

Generation of hydrogen from polyvinyl chloride by milling and heating with CaO and Ni(OH)2.

This work discusses an alternative process option for the treatment of polyvinyl chloride (PVC) by producing hydrogen (H(2)) gas, at the same time fixing chlorine for proper environmental control. In the first-stage, a milling operation is performed in a planetary ball mill to obtain a mixture of PVC sample with CaO and Ni(OH)(2) to be used as feed in the second-step, involving heating of the milled product. Analyses by thermogravimetry-mass spectroscopy (TG-MS) and gas chromatography (GC) showed H(2), CH(4), CO and CO(2) as main constituents.

Simultaneous treatment of PVC and oyster-shell wastes by mechanochemical means.

This work presents a new process for dechlorinating poly-vinyl chloride (PVC) by the use of oyster-shell waste. The process consists of milling of PVC waste with oyster-shell waste, followed by washing the milled sample with water. The milling of PVC and oyster-shell mixture results in size reduction and rupture in bonds, leading to mechanically induced reactions between the two to form CaCl2 and hydrocarbon with C=C bonds.

Mechanochemical decomposition of PVC by using La2O3 as additive.

A polyvinyl chloride (PVC, [CH2CHCl]n) sample was ground with one of the following oxide samples, lanthanum oxide (La2O3) and calcium oxide (CaO), as a reference, to investigate its mechanochemical (MC) decomposition. According to the XRD patterns for the ground products, peaks of lanthanum oxy-chloride, LaOCl which is water insoluble, were observed to appear in the patterns of the mixture samples at a molar ratio of (PVC: La2O3 = 1:2) and (1:4), after 20 min grinding, while the patterns of the ground PVC-CaO mixtures show the formation of CaOHCl, which is water soluble, in the products after 2 h grinding. TG patterns taken for the PVC-La2O3 mixtures ground for different periods of time do not indicate significant weight loss in the range from 200 to 300 degrees C, and this suggests that La2O3 is more effective additive than CaO in the MC decomposition for PVC.