兰炭尾气是兰炭（半焦）生产过程中产生的副产品，主要来源于煤的中低温干馏（500～800℃），由于其组分复杂，此前主要用于燃烧发电。随着兰炭行业利润率的走低，行业面临普遍亏损，因此亟须找到一条脱困之路。首先对兰炭尾气的成本进行测算，并对其用于发电的经济性进行分析；再针对利用兰炭尾气制LNG、制液氨及LNG—液氨联产三种工艺方案，从投资、运行成本、能耗、经济效益等维度进行分析测算。结果表明：基于当前兰炭市场行情及上网电价，兰炭尾气直接发电的投资回收期较长，经济性较差；根据LNG及液氨过去12年的历史价格分析可知，LNG—液氨联产方案的效益远高于其他两种产品方案。
关键词: 兰炭尾气 / 综合利用 / 产品路线 / 技术经济分析
Abstract:
Semi-coke off-gas, as a by-product generated during the production of semi-coke, primarily comes from the low and medium temperature (500-800℃) dry distillation of coal. Due to its complex composition, it has previously been used mainly for thermal power generation. With declining profit margins, the semi-coke industry faces widespread losses, and urgently demands a way out. The paper first estimates the costs of semi-coke off-gas, and analyses its economic viability for power generation. It then compares and evaluates the investment, operating costs, energy consumption and economic benefits of three semi-coke utilization process schemes—producing LNG, liquid ammonia, and LNG & liquid ammonia. The results show that given the current market conditions for semi-coke and on-grid electricity prices, direct power generation using semi-coke off-gas features a long payback period and poor economic benefits. Based on an analysis of historical prices of LNG and liquid ammonia over the past 12 years, the scheme of producing LNG & liquid ammonia yields significantly higher benefits than the other two schemes.
Keywords: semi-coke off-gas / comprehensive utilisation / product routes / techno-economic analysis