Research work was oriented into technical and environmental optimisation of some nationally important chemical and process industries in order to develop and test some instruments for sustainable industrial development. These are: an integrated process and environmental analysis, modelling, optimisation of material and energy balance environmental mapping and impact assessment, which together offer a sound estimation of possible improvements in process yield and reduction of environmetal impact. In modelling various effective modern tools from statistic thermodynamics and are process optimisation was used and partly adapted for given circumstances. In most cases thermodynamic properties of the process media were measured and correlated for the first time: N-methylimidazole - water methylamine - acetone - water methanol - formaldehyde - water furfural - acetic acid - water furfural - 5-methylfurfural - water xylenes(o-,m-,p-) - ethanol - water active farmac. component - ethylacetate - water - NaCl The scientific importance of the results is primarilly in providing new technically important data for modelling/calculation of systems behaviour under various thermodynamic conditions.