Optimization of supercritical CO2 extraction by response surface methodology, composition analysis and economic evaluation of bamboo green wax

Abstract

Bamboo processing is faced with increasing requirements of resource reusability in China. A large amount of waste bamboo green produced in bamboo processing needs to be recycled. Waste bamboo green contains a large number of environmentally friendly wax components. In this study, supercritical CO2 extraction was used to extract bamboo green waste to obtain natural wax. Response surface methodology (RSM) was used to optimize the extraction process and the yield of bamboo green wax under pressure of 20–30 MPa, temperature of 318–328 K, and time of 30–90 min. The extracted bamboo green wax was characterized by gas chromatography and mass spectrometry (GC-MS). RSM optimization shows that under the conditions of 26 MPa, 328 K, and 56 min, the yield of bamboo green wax was the highest at 2.327%. The compositions of esters, fatty acids, sterols and so on in bamboo green wax were characterized by GC-MS. Differential scanning calorimetry (DSC) shows that the melting point of bamboo green wax is 334 K. At last, the economic evaluation of bamboo green wax was made to analyze its potential application prospect. It is supposed that bamboo green waste is a resource for natural wax with potential application value.