**Hui Li 1,\*,**†**, Xue Min 1,**†**, Mingwei Dai <sup>1</sup> and Xinju Dong <sup>2</sup>**


Received: 26 August 2019; Accepted: 3 September 2019; Published: 9 September 2019

**Abstract:** Anhui Province (AHP), a typical agriculture-based province in China, has a significant amount of biomass resources for the development of biomass power plants. By the end of 2016, 23 straw based biomass power plants were established in AHP, aggregating to 6560 MW capacity, which is now ranked second in China. This paper presents the current development status and GHG (Greenhouse Gas) mitigation effect of the straw based biomass power plants in Anhui Province. Total biomass production in 2016 was calculated as 41.84 million tons. Although there is huge biomass potential in AHP, the distribution is heterogeneous with a gradually decreasing trend from north to south. Furthermore, the installed capacity of power generation is also unmatched with the biomass resources. Based on a calculation made in 2016, approximately 3.44 million tons of CO2-eq were mitigated from the biomass power plants in AHP. The large-scale development of biomass power plants remains a challenge for the future, especially in areas of AHP with a low biomass density.

**Keywords:** biomass resource; power plant; GHG emission mitigation; Anhui

### **1. Introduction**

Global energy demand was 14,050 Mtoe (million tons of oil equivalent) in 2017, with a growth rate of 2.1%, and global energy-related CO2 emissions increased by 1.4%, reaching a historically high value of 32.5 GT [1]. China has a large population and rapid growth of the population, industrialization, and urbanization, and the energy consumption has sharply increased, up to 3053 Mtoe in 2017, of which more than 70% of energy consumption was supported by coal [2,3]. Due to this coal-dominated energy consumption, greenhouse gas (GHG) and particulate matter (PM) pollutants are released during the coal utilization process, leading to a negative impact on health and the environment in China and globally [4–9]. Therefore, preferential concern and policies for clean energy associated with the "Energy Revolution" and "Fight Against Pollution" in China have received an intense level of support [10].

Presently, biomass energy plays a significant role in energy production, and is listed as the fourth largest energy source worldwide after oil, coal and natural gas [11,12]. With carbon-neutral, clean and sustainable characteristics [13–15], biomass has been proven to be promising renewable energy in China with a theoretical maximum potential energy of 18,833 PJ in 2030 [16]. To utilize biomass energy, current technologies including combustion, liquefaction, pyrolysis/gasification, digestion, and fermentation have been widely used in developing countries [17,18]. Among various technologies, biomass power generation is a high-efficiency approach for biomass utilization that has been promoted and developed for sustainable energy output, and that also offers a flexible approach for straw disposal [19,20]. By the end of 2011, the global installed capacity of biomass plants was 72 GW with total electricity generation of 265–529 TWh [21]. The installed capacity of biomass power generation in China has gradually increased, as showed in Figure 1, a total value of 18,790 MW in 2016, most of these plants are fueled by agricultural residues and forest products. The growth rate decreased from 2013 to 2016, indicating that the large-scale development of biomass power plants is accompanied by some problems, including the biomass supply capacity, fuel cost, and environmental impacts [2,22–24]. The environmental impacts of biomass power plants mainly include landfill, water and ash treatment [25–27]. Zhao and Li [28] performed a numerical example analysis of biomass power plant and noted that pollutant emissions during straw transportation were neglected. Research on the physical, mental and social impacts of small-scale biomass power plants indicated that air pollutant was the main concern of local people [29]. Zhang et al. [30] indicated that the cost of a straw-based power plant is indeed high, most of which was the fuel cost. Nguyen et al. found that the environmental performance of straw power plants was worse than that of natural gas [31]. In addition, although some studies have emphasized the potential for negative net GHG emissions from biomass power plants, the recognition of GHGs mitigation is not fully understood [10]. Therefore, some studies have indicated that the development of biomass power plants should be more steady in China [32,33].

**Figure 1.** Installed capacity of biomass power generation in China from 2012 to 2016. Note: The original data were obtained from the database of National Renewable Energy Information management Centre in China.

Anhui Province (AHP), see in Figure 2, located in eastern China (N29◦41 –N34◦38 , E114◦54 –E119◦37 ), is a typical agricultural Province, with a huge amount of biomass resources, such as forest and agricultural residues [34]. The government of Anhui province has been strongly encouraging and supporting the construction and development of biomass power generation plants. "The research report of the "13th Five-Year Plan" for Straw Power Generation in Anhui Province" published by the Anhui government proposed installed capacity of approximately 1600 MW by the end of 2020. According to the statistical data from the Anhui Energy Administration, a total of 23 grid-connected straw-based biomass power plants with an installed capacity of 660 MW were built and operational from 2006. Even with policy support, the development of biomass power plants still needs a systematic study on feedstock analysis and environmental impact assessment. Therefore, in this study, we investigated the current status and GHG emissions from straw-based power plants in Anhui Province. First, the development, operation, and profitability of power plants were discussed in

detail. In addition, the production, distribution, and availability of biomass resources in AHP were examined. Finally, the potential mitigation of greenhouse gas emissions attributed to straw-based power plants was calculated. The results can provide valuable information to policymakers and will be useful for the development of straw-based power plants in China.

**Figure 2.** Location of Anhui province in China.

#### **2. Materials and Methods**

With the aim of producing comprehensive information about the biomass resources, operational condition and mitigation of GHGs associated with biomass power plants in AHP, data were obtained from official and provincial reports, yearbooks, online reports, and other sources. Data and information about biomass resources were obtained from the Anhui statistical yearbook (2012–2016), agricultural mechanization statistics report for Anhui (2012–2016) and the national agricultural mechanization information website (Appendix A.1). Data and information related to the operational condition of biomass power plant were obtained from the Anhui Energy Bureau. The methods used to calculate the biomass potential and GHG mitigation were the crop-to-residue index and the CM-092-V01 method, respectively (see Appendix A for further details).

## **3. Results and Discussion**
