Abstract: A conventional method of pyrolytically decomposing plastic to make low-molecular compounds is poor in efficiency of use of energy due to high heating temperatures (at least 600° C. and 800° C. at maximum). The invention provides that a functional powder is heated to a predetermined temperature and pieces of plastic to be disposed are caused to be contacted with the heated powder, the functional powder including a powder which does in an aqueous solution state show alkalinity, and a photo-catalyst effect powder.

Abstract: A method for simply decomposing and disposing organic substances while preventing occurrence of toxic substances, which method is directed, firstly, to a technique wherein photocatalyst powder is applied from the upper side with liquefied organic substances, and the photocatalyst powder is heated to between 50 and 400° C., secondly to a technique wherein photocatalyst powder is contacted with gaseous organic substances while the photocatalyst powder being heated to between 50 and 400° C., thirdly to a technique wherein an organic substance to be decomposed is introduced, in a state of gas, liquid or solid, into a suspension of photocatalyst's finely divided particles and is heated in a range of temperatures between 50 and 100° C., and fourthly to a technique wherein organic substances are decomposed at two or more stages.

Abstract: A conventional method of pyrolytically decomposing plastic to make low-molecular compounds is poor in efficiency of use of energy due to high heating temperatures (at least 600° C. and 800° C. at maximum).

Abstract: The preparation of an oxidation catalyst is described, represented by the following general formula:Ni.sub.a Co.sub.b Fe.sub.c Bi.sub.d L.sub.e M.sub.h Mo.sub.f O.sub.g ;in which L is phosphorous, arsenic or boron and M is potassium, rubidium or cesium; and wherein a and b have a value of from 0 to 15, a + b being 2 to 15, c is 0.5 to 7, d is 0.1 to 4, e is 0 to 4, f is 12, g is 35 to 85 and h is 0.01 to 0.5. The oxidation catalyst is useful in a process to produce acrolein by oxidizing propylene in vapor phase.