Bio-oil production from low-rank coal by catalytic microwave pyrolysis using reservoir rock and activated carbon catalyst

To manage environmental challenges, clean coal technology is still urgently required. Low-rank coal (LRC) dominates the global coal industry. An improved method to turn LRC into clean energy, such as biooil, is microwave pyrolysis (MP). Low heating efficiency and the dominance of heavy tars in the end products are the key pyrolysis problems, nevertheless. In this investigation, MP was employed to treat LRC using the catalysts and receptors RC+Fe2(SO4)3 and AC+Fe2(SO4)3, respectively. The distribution of the product and the process variables (time, temperature, and power) were evaluated. According to the results, RC+Fe2(SO4)3 and AC+Fe2(SO4)3 changed the distribution of the product by increasing up the rate of temperature rise and ultimate temperature of MP. Bio-oil produced from MP+1.0%RC+24.6%Fe2(SO4)3 was 40.0%, 4.4% higher than the conventional pyrolysis (CP), when compared to CP at the same conditions (620 °C and 60 min). Using MP+1.0%AC+24.6%Fe2(SO4)3, 44.4% bio-oil was generated while there was an 8.8% increase overall. The maximum bio-oil production with 1.0%RC+24.6%Fe2(SO4)3 was observed at 60 min, 620°C, and 600W, producing 41.9% bio-oil. The maximum bio-oil production was seen using 1.0%AC+24.6%Fe2(SO4)3 at 120 min, 620 °C, and 450W, producing 49.2% bio-oil. The outcomes of the studies could serve as a foundation to produce clean fuels in the future that use LRC to lower carbon emissions globally

为应对环境挑战，洁净煤技术仍存在迫切的应用需求。低阶煤（Low-rank coal, LRC）在全球煤炭产业中占据主导地位。将低阶煤转化为生物油等清洁能源的改良工艺之一为微波热解（Microwave Pyrolysis, MP）。然而，微波热解仍存在加热效率低下、最终产物中重质焦油占比过高等核心问题。本研究采用微波热解技术处理低阶煤，分别使用RC+Fe₂(SO₄)₃与AC+Fe₂(SO₄)₃作为催化剂与吸附剂，对产物分布及工艺变量（反应时间、反应温度与微波功率）开展了系统评估。研究结果显示，RC+Fe₂(SO₄)₃与AC+Fe₂(SO₄)₃可通过提升微波热解的升温速率与终温，优化产物分布格局。在相同工况（620℃、60min）下，采用MP+1.0%RC+24.6%Fe₂(SO₄)₃制备的生物油产率可达40.0%，较传统热解（Conventional Pyrolysis, CP）提升4.4%；采用MP+1.0%AC+24.6%Fe₂(SO₄)₃时，生物油产率可达44.4%，整体提升幅度达8.8%。当使用1.0%RC+24.6%Fe₂(SO₄)₃时，在反应时间60min、温度620℃、功率600W的工况下可获得最高生物油产率，达41.9%；而使用1.0%AC+24.6%Fe₂(SO₄)₃时，在反应时间120min、温度620℃、功率450W的工况下可实现最高生物油产率49.2%。本研究成果可为未来以低阶煤为原料制备清洁燃料、降低全球碳排放提供理论支撑与技术基础。