Sewage sludge treatment is a critical step of wastewater treatment plants (WWTP) to produce clean water, mineral matter and bio-energy. Techno-economic feasibility and performance of different process alternatives significantly depend on configuration and operating conditions. Thus, energy analysis of four sewage sludge treatment pathways is carried out in this work, including: i) high concentration digestion, dewatering and drying (HDDD); ii) thermal hydrolysis, high concentration digestion, dewatering and drying (THDDD); iii) low concentration digestion, dewatering and drying (LDDD); and iv) drying and incineration (DI). The energy and material balance of each pathway is simulated. Especially, the potential energy integration arrangement is put forward by efficient biogas utilization. The investigation results indicated that THDDD route has the optimal energy integration efficiency without additional natural gas input. Meanwhile, the surplus biogas of THDDD route is 4.7 ton/day, which is higher than that of HDDD (2.1 ton/day) and LDDD (0.3 ton/day). Techno-economic analysis results indicated that the total investment of HDDD process is the lowest (91.8 M$), and its operating cost (8.9 M$/year) is also lower than THDDD (9.0 M$/year), LDDD (9.9 M$/year) and DI (9.9 M$/year). From the viewpoint of waste reutilization, HDDD can be a promising alternative of energy efficient sewage sludge treatment route. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.