华北平原地区玉米秸秆连续供应模型的建立及应用

Establishment and application of crops straw supply model for north China plain area

为保证秸秆连续稳定的供应,提高秸秆资源利用率,该文建立了基于秸秆田间收集-秸秆集中存储-秸秆利用的连续供应模型,并以华北平原地区(山东肥城)为例,确定了秸秆收储站的选址与数量,并分析了田间收集、初级运输、收储站存储、次级运输和原料装卸等5个环节的成本和能耗。结果表明,收集肥城市10万t玉米秸秆应用点的最优选址地理坐标为(N116.741,E36.069),运用层次分析法确定收储站的优化选址与数量,拟建立10个收储站,秸秆供应成本约为169.14元/t,其中,按秸秆供应环节分析,收集成本和运输成本占比较高,分别占总成本的55%和23%;按运行成本分析,秸秆收购成本、人工成本以及燃料动力费占比较高,分别占总成本的41.39%、30.14%、25.90%。秸秆供应总能耗为186 MJ/t,其中,运输和打捆环节燃油能耗较高,分别占总能耗的45%和34%。该文建立的秸秆供应模型,对指导中国不同地区建立合理的秸秆供应模型提供参考,为秸秆综合利用过程中的原料持续稳定供应,节约供应成本和能耗具有积极的指导意义。

Straw is important biomass feedstock. Due to the collection, storage and many other problems, their supply system can’t be steady, and there are more than 200 million tons of straw resources not utilized effectively. In order to ensure a steady supply of straw and to increase the utilization rate of straw resources, we established a straw supply model based on straw collection in field - straw centralized storage - straw utilization. And taking the area of the North China Plain （Feicheng, Shandong Province） as an example, we got the site selection and the number of the straw collection and storage station and power plant, and analyzed the cost and energy consumption in the process of straw supply, which included field collection, primary transportation, storage in straw collection and storage station, secondary transportation and straw handling. The results showed that the straw supply model could reasonably analyze the point of straw application site, build and optimize the location and number of storage stations, and could reduce the construction investment, personnel and equipment of storage stations effectively, thus saving supply costs and energy consumption. So the straw supply model could be applied in practical calculation. The annual yield of corn stalk was up to 453 000 t in Feicheng, Shandong Province. Among them, the collectable amount was 100 000 t. The geographical coordinate of the optimal location was 116.741°N, 36.069°E when the available quantity of straw resource was about 100 000 t. The analytic hierarchy process was used to get the optimal location when the number of collection and storage stations was 10, and the transportation cost of straw delivery was about 169.14 yuan/t. Among them, analyzed by supply chain, the portions of straw collecting costs and transportation costs were higher, accounting for 55% and 23% of the total costs respectively. Analyzed by economic evaluation index, the portions of straw purchasing costs, labor costs, and fuel and power costs were higher, accounting for 41.39%, 30.14% and 25.90% of the total costs respectively. The total energy consumption of straw supply system was 186 MJ/t, among which the higher fuel consumption occurred in links of transportation and baling, accounting for 45% and 34% of the total energy consumption respectively. Through optimization, we centrally established 10 collection and storage stations. Compared with the original program that collection and storage station was established in every township, this program could reduce costs by 4.6%, and reduce energy consumption by 4.12%. It could save the initial investment cost of collection and storage stations by 25.85%; the primary transport costs increased by 4.81%, but the secondary transport costs was reduced by 19.68%. The straw supply model in this paper provides an instructional reference for establishing a reasonable straw supply model in different areas in China, and has a positive guiding significance for keeping steady straw supply, effectively reducing the cost of supply, and reducing energy consumption.