Han Shi

Study on Industrial Metabolism of Carbon in a Chinese Fine Chemical Industrial Park

Carbon metabolism of a chemical industrial park remains scarce in literature, due to overwhelming data collection workload and intricate interfirm flow examination. Based on five-year intensive data collection and verification, this research presents the findings of one-year static carbon metabolism in a typical Chinese fine chemical industrial park. As to the total direct carbon input (0.38 million tons), 32% concern chemicals production, while the remaining 68% are related to energy conversion. Three common metrics, carbon efficiency, C factor, and E factor are applied to assess the performance of carbon flows. Based on an analysis of 380 raw chemicals and 130 chemical products, performance of the three kinds of chemicals, pharmaceuticals, dyes, and other fine chemicals, and the chemical industrial park as a whole are considered and compared with similar industrial area, respectively. The carbon efficiency of chemicals production is 69%, while the other 31% ends up in waste. The interfirm carbon flow accounts for 3.4% of the carbon inputs in raw chemicals. Pursuing local environmental goals (i.e., abatement of odor, chemical oxygen demand, and solid waste) results in greater CO(2) emissions, which runs against protection of the global environment. Options to improve carbon efficiency were also discussed from three aspects. This study lays groundwork for quantifying greenhouse gas emissions, benchmarking carbon efficiency, and conducting life cycle assessment on the park level.

Coupling mass balance analysis and multi-criteria ranking to assess the commercial-scale synthetic alternatives: a case study on glyphosate

Quantitative and systematical assessment of the greenness of synthetic alternatives is one of the key topics of green chemistry. By coupling mass balance analysis and multi-criteria decision analysis, the paper seeks to assess the greenness of three commercial-scale production processes of a broad spectrum herbicide named glyphosate on the basis of seven assessment criteria and sixteen metrics. The seven criteria include mass intensity, efficiency of four core elements (i.e., carbon, nitrogen, phosphorous, and chlorine), energy consumption, nature of the industrial waste, cost of raw materials, and toxicity of materials. The multi-criteria decision method is applied to rank the greenness of glyphosates three synthetic alternatives in a comprehensive, aggregate manner. Our findings highlight the discrepancy between greenness-driven alternative and cost-driven alternative in fine chemical production. At present, the actual choice of glyphosate production process in China remains dominated by the economic criteria rather than a more comprehensive, balanced set of criteria spanning economic profitability, environmental soundness, and social responsibility. Nonetheless, the underlining research method is relevant to the choice of synthetic alternatives of other fine chemicals.

Network analysis of eight industrial symbiosis systems

Industrial symbiosis is the quintessential characteristic of an eco-industrial park. To divide parks into different types, previous studies mostly focused on qualitative judgments, and failed to use metrics to conduct quantitative research on the internal structural or functional characteristics of a park. To analyze a park’s structural attributes, a range of metrics from network analysis have been applied, but few researchers have compared two or more symbioses using multiple metrics. In this study, we used two metrics (density and network degree centralization) to compare the degrees of completeness and dependence of eight diverse but representative industrial symbiosis networks. Through the combination of the two metrics, we divided the networks into three types: weak completeness, and two forms of strong completeness, namely “anchor tenant” mutualism and “equality-oriented” mutualism. The results showed that the networks with a weak degree of completeness were sparse and had few connections among nodes; for “anchor tenant” mutualism, the degree of completeness was relatively high, but the affiliated members were too dependent on core members; and the members in “equality-oriented” mutualism had equal roles, with diverse and flexible symbiotic paths. These results revealed some of the systems’ internal structure and how different structures influenced the exchanges of materials, energy, and knowledge among members of a system, thereby providing insights into threats that may destabilize the network. Based on this analysis, we provide examples of the advantages and effectiveness of recent improvement projects in a typical Chinese eco-industrial park (Shandong Lubei).