**7. Conclusion**

The utilization of lignocellulosic biomass waste and unitized fast-growing biomass as carbon-neutral resources by methane conversion by steam explosion pretreatment and its secondary energy (compressed biogas, nitrogen, and electric) was potentially to be the solution to fulfill the SDGs requirement which is renewable and environmentally friendly. This chapter has described the state the art, feasibility study in the full-scale application, and the life cycle assessment that could give deliberation to industry and stakeholders that consider applying the system.

### **Acknowledgements**

The authors gratefully acknowledge the financial supports by a Grant-in-Aid for Scientific Research (A) (Grant No. 20H00664), and the Scholarship (IN: 202136) from Ministry of Education, Culture, Sport, Science, and Technology of Japan.
