TY - GEN A1 - Lenz, Ralf A1 - Schwarz, Robert T1 - Optimal Looping of Pipelines in Gas Networks N2 - In this paper, we compare several approaches for the problem of gas network expansions using loops, that is, to build new pipelines in parallel to existing ones. We present different model formulations for the problem of continuous loop expansions as well as discrete loop expansions. We then analyze problem properties, such as the structure and convexity of the underlying feasible regions. The paper concludes with a computational study comparing the continuous and the discrete formulations. T3 - ZIB-Report - 16-67 KW - Mixed Integer Nonlinear Programming KW - Gas Network Applications KW - Expansion Planning Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-61564 SN - 1438-0064 ER -