Methandruckspeicher

A methane accumulator has a pressure-resistant storage tank (1) with a closing device (2, 3) for gas feed and gas discharge. It is filled with a solid substituted polyacetylene polymer (5) having the general structural formula -(R<-1 -C=C-R<-2 )<-n - where R<-1 and R<-2 are organic residues. The organic residues R<-1 and R<-2 are preferably a methyl group and a silyl trimethyl group. Use of the mentioned preferable poly(1-trimethylsilyl-1-propyn) results at 35 degrees Celsius with a solubility solution which permits an improved storage capacity by a factor of 3.5 at the same tank volume compared with a normal accumulator at usual filling pressures.