Achieving 100 % renewable e-methanol incorporating biomass-fired generation: A techno-economic study

Abstract

Converting renewable hydrogen (${\text{H}}_2$) and carbon dioxide (${\text{CO}}_2$) into methanol is a promising pathway for decarbonizing the chemical industry. The produced renewable methanol can also be used for decarbonizing other sectors, such as shipping and power systems. Achieving 100 % renewable methanol requires both ${\text{H}}_2$ and ${\text{CO}}_2$ sources to be “renewable”. Currently, ${\text{CO}}_2$ from direct air capture (DAC) or biomass can be regarded as the renewable one. However, DAC’s high cost and the challenges in scaling up biomass gasification hinder their practical application in large-scale renewable methanol production. To address the issues above, this paper proposes a novel 100 % renewable e-methanol synthesis technical route (MSTR) incorporating the mature biomass-fired generation (denoted as MSTR-3). Two biomass gasification-based MSTRs (denoted as MSTR-1 and MSTR-2) are introduced as the benchmarks. A fractional programming (FP)-based optimization framework is established to evaluate the techno-economic levels of different MSTRs, with the levelized cost of methanol (LCOM) used as the objective function. The results indicate that the proposed MSTR-3 can trade off the cost and the resource utilization, avoiding the high curtailment of renewable energy sources (RES) and low utilization of carbon from biomass observed in MSTR-1 and MSTR-2. Furthermore, combining inflexible MSTR-2 with flexible MSTR-3 can reduce LCOM from 4310 RMB¹/t (588 USD/t) to 3849 RMB/t (525 USD/t), demonstrating that coordinated planning of flexible and inflexible loads is an effective strategy for achieving both economic benefits and improved resource utilization.