This value is 1000-fold larger than the crushing energy for marigold flower (800 kJ/kg). Cell wall compositions, cell wall thickness and cell size determine the energy demand (Popper et al.,2011). The Embryophyta (higher plants) and Chlorophyta (microalgae) have the same main composition of cell wall, cellulose. The differences between them are hemicellulose and matrix carboxylic polysaccharides which are filled the gaps of cellulose frameworks. It is believed that the major supporting force is from these cellulose frameworks and they are the main energy consumption sources. Cell wall compositions may not be the major factor that causes the energy difference in disrupting materials. Cell wall thickness and cell size of marigold flower and microalgae (Chlorella and Scenedesmus obliquus) are listed in Pickett Heaps and Staehelin, 1975 and Martinez et al. (1991).